Patrick J Loehrer

Indiana University Health, Bloomington, IN, USA

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Publications (40)224.87 Total impact

  • Article: The role of histology in predicting recurrence of type A thymomas: a clinicopathologic correlation of 23 cases.
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    ABSTRACT: Spindle cell thymomas (type A), as per the WHO definition, are benign tumors with an excellent prognosis. However, recent studies document aggressive behavior with local recurrences as well as extrathoracic metastases. More recently, Nonaka and Rosai have raised the question as to whether atypical features like cellular atypia, mitotic activity, necrosis, and vascular permeation could predict the adverse outcomes of these tumors. In an effort to address the 'atypia and outcome' issue of spindle cell thymomas, we analyzed our database of over 600 cases of thymic tumors to identify type A thymomas. The presence of histomorphological features like tumor size, nuclear shape and variability, mitotic rate, and presence/absence of necrosis were correlated with Masaoka stage, relapse/recurrence, and extrathoracic metastases. The study identified 23 patients of pure spindle cell thymomas (WHO type A) ranging in age from 40 to 88 years (median age, 54 years) and with male-to-female ratio of 1:0.9. Approximately 43% of the cases had recurrence or metastases during the followup period (average, 49 months). The presence of necrosis correlates with both relapse and extrathoracic metastases but not with the stage of diagnosis. However, none of the other clinical or histological features, including size, predominant nuclear shape, nuclear variability, and mitotic activity, were correlated with the outcome parameters, such as stage at diagnosis, presence or absence of relapse, and extrathoracic metastases. Histological atypia is fairly common in WHO type A thymomas. The presence of necrosis was associated with both locoregional and systemic disease. However, none of the other clinical or histological features correlated with aggressive behavior.Modern Pathology advance online publication, 12 April 2013; doi:10.1038/modpathol.2013.49.
    Modern Pathology 04/2013; · 4.79 Impact Factor
  • Article: Establishment and characterization of a novel cell line derived from human thymoma AB tumor.
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    ABSTRACT: Thymomas are low-grade epithelial tumors of the anterior mediastinum. The complexity of the disease and the lack of in vitro and in vivo models hamper the development of better therapeutics. In this study, we report a novel cell line, designated as IU-TAB-1, which was established from a patient with stage II thymoma (World Health Organization-type AB). The IU-TAB-1 cell line was established in vitro and characterized using histological and immunohistochemical staining, fluorescence-activated cell sorting, cytogenetic analyses and functional assays including in vitro and a NOD/SCID xenograft model. A whole-genome gene expression analysis (Illumina) was performed on the IU-TAB-1 cell line and 34 thymomas to determine the clinical relevance of the cell line. The IU-TAB-1 cell line was positive for epithelial markers (pan-cytokeratin and EpCAM/CD326) including thymic epithelial (TE) surface markers (such as CD29, CD9, CD54/ICAM-1, CD58 and CD24) and p63, and negative for B- and T-cell lineage markers. Gene expression profiling demonstrated overlapping and distinct genes between IU-TAB-1 and primary thymomas including the primary tumor (from which the cell line was derived). IU-TAB-1 cells are tumorigenic when implanted in immunodeficient mice with tumors reaching a volume of 1000 mm(3) at around 130 days. The established cell line represents a biologically relevant new tool to investigate the molecular pathology of thymic malignancies and to evaluate the efficacy of novel therapeutics both in vitro and in vivo.Laboratory Investigation advance online publication, 27 August 2012; doi:10.1038/labinvest.2012.115.
    Laboratory Investigation 08/2012; · 3.64 Impact Factor
  • Article: Phase II and gene expression analysis trial of neoadjuvant capecitabine plus irinotecan followed by capecitabine-based chemoradiotherapy for locally advanced rectal cancer: Hoosier Oncology Group GI03-53.
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    ABSTRACT: We designed this study in locally advanced rectal cancer to determine the pathological response, toxicity, and disease-free survival (DFS) with induction capecitabine plus irinotecan followed by capecitabine-based chemoradiotherapy (CRT) and analyze the gene expression of enzymes involved in the metabolism of capecitabine and irinotecan for associations with response and toxicity. Patients with T3/T4 or node positive rectal cancer were treated with capecitabine 1,000 mg/m(2) twice daily (BID) days 1-14, and irinotecan 200 mg/m(2) on day 1 every 21 days for 2 cycles, followed by capecitabine 825 mg/m(2) BID days 1-5 per week with concurrent radiotherapy 50.4 Gy in 28 fractions. Surgical resection occurred a median of 7.4 weeks after CRT. Gene expression levels or sequencing were used to analyze carboxylesterase-converting enzymes (CES1, CES2), thymidylate synthase (TS), thymidine phosphorylase (TP), dehydropyrimidine dehydrogenase (DPD), topoisomerase I (TOPO I), and uridine-diphosphate (UDP) glucuronosyl transferase 1A1 in pre- and post-treatment tumor and normal tissue samples. Twenty-two patients were enrolled, and 18 completed neoadjuvant therapy and underwent R0 resection. Two patients with UGT1A1 7/7 had grade 3 and 4 neutropenic fever and sepsis. Pathological complete response (pCR) occurred in 6 of 18 patients (33 %) and 10 (56 %) had tumor and/or nodal downstaging. The 3-year DFS was 75.5 % (95 % CI, 39.7-91.8 %). Locoregional control rate was 100 %. We observed higher TP gene expression in pCR patients, but no correlations with toxicity. This neoadjuvant regimen was safe and demonstrated significant antitumor activity. High TP tumor gene expression was associated with obtaining pCR.
    Cancer Chemotherapy and Pharmacology 05/2012; 70(1):25-32. · 2.83 Impact Factor
  • Article: Thymic carcinoma: outcomes after surgical resection.
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    ABSTRACT: Thymic carcinoma is a rare malignancy with little information regarding outcomes after therapy with curative intent. We undertook a retrospective analysis of all patients who underwent resection of thymic carcinoma at 2 hospitals. From 1990 to 2011, 16 patients (9 men, 7 women) underwent surgical resection of thymic carcinoma at a mean age of 52 years. Patient demographics, extent of surgical resection, and outcomes were compiled. The distribution of Masaoka stages at presentation was I in 3 (19%), II in 4 (25%), III in 8 (50%), and IV in 1 (6%). Neoadjuvant chemotherapy was administered to 6 patients (38%) whose tumors were deemed to be more locally invasive. Surgical resection included en bloc extrapleural pneumonectomy in 1, lobectomy in 2, and superior vena cava resection and reconstruction in 4. There were no perioperative deaths. Complete resection was achieved in 14 (88%), and of these patients, only 1 experienced local recurrence. At last follow-up, 10 patients were alive and well, 1 patient was alive with disease, and 5 patients had died. Mean survival was 4.2 years. Although considered to have greater malignant potential, long-term survival can be achieved in patients with thymic carcinoma who are amenable to surgical therapy. With increased use of computed tomography imaging, patients with early-stage disease are being identified more frequently, and complete surgical resection appears to have favorable cure rates in these patients. Select patients with locally advanced disease can experience long-term survival with a multimodality approach.
    The Annals of thoracic surgery 03/2012; 93(5):1668-72; discussion 1672-3. · 3.74 Impact Factor
  • Article: The oncology pharmacy in cancer care delivery in a resource-constrained setting in western Kenya.
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    ABSTRACT: The movement to deliver cancer care in resource-limited settings is gaining momentum, with particular emphasis on the creation of cost-effective, rational algorithms utilizing affordable chemotherapeutics to treat curable disease. The delivery of cancer care in resource-replete settings is a concerted effort by a team of multidisciplinary care providers. The oncology pharmacy, which is now considered integral to cancer care in resourced medical practice, developed over the last several decades in an effort to limit healthcare provider exposure to workplace hazards and to limit risk to patients. In developing cancer care services in resource-constrained settings, creation of oncology pharmacies can help to both mitigate the risks to practitioners and patients, and also limit the costs of cancer care and the environmental impact of chemotherapeutics. This article describes the experience and lessons learned in establishing a chemotherapy pharmacy in western Kenya.
    Journal of Oncology Pharmacy Practice 01/2012;
  • Article: Molecular analysis of thymoma.
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    ABSTRACT: Histologic classification of thymomas has significant limitations with respect to both subtype definitions and consistency. In order to better understand the biology of the disease processes, we performed whole genome gene expression analysis. RNA was extracted from fresh frozen tumors from 34 patients with thymomas and followup data was available. Using the Illumina BeadStudio® platform and Human Ref-8 Beadchip, gene expression data was analyzed with Partek Genomics Suite®, and Ingenuity Pathways Analysis (IPA). Unsupervised clustering of gene expression data, representing one of the largest series in literature, resulted in identification of four molecular clusters of tumors (C1-C4), which correlated with histology (P = 0.002). However, neither histology nor clusters correlated with clinical outcomes. Correlation of gene expression data with clinical data showed that a number of genes were associated with either advanced stage at diagnosis or development of recurrence or metastases. The top pathways associated with metastases were amino acid metabolisms, biosynthesis of steroids and glycosphingolipids, cell cycle checkpoint proteins and Notch signaling. The differential expression of some of the top genes related to both metastases and stage was confirmed by RT-PCR in all cases of metastases and matched nonmetastatic cases. A number of potential candidates for therapeutics were also identified.
    PLoS ONE 01/2012; 7(8):e42669. · 4.09 Impact Factor
  • Article: Phase II Trial of Erlotinib and Docetaxel in Advanced and Refractory Hepatocellular and Biliary Cancers: Hoosier Oncology Group GI06-101.
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    ABSTRACT: Background Patients with advanced hepatocellular (HCC) and biliary tract carcinomas (BTC) have poor prognosis. While the EGFR pathway is overactive in HCC and BTC, single agent anti-EGFR therapies confer modest activity. Preclinical data showed synergistic antiproliferative and proapoptotic effects between anti-EGFR therapies and taxanes. We conducted a phase I study of erlotinib and docetaxel in solid tumors, and noted good tolerability and sustained complete (5 years +) and partial responses in patients with HCC and BTC. This trial evaluated the efficacy of erlotinib with docetaxel in refractory hepatobiliary cancers. Methods Eligible patients were allowed to have two prior systemic therapies. Docetaxel 30 mg/m(2) i.v. was administered on days 1, 8, 15, and erlotinib 150 mg was dosed orally on days 2-7, 9-14, 16-28 of each 28-day cycle. The primary endpoint was 16 weeks progression-free survival (PFS), and secondary endpoints included response, stable disease, and overall survival. Tumor samples were analyzed for KRAS gene mutations and E-cadherin expression by immunohistochemistry (IHC). Patients with BTC and HCC were accrued and assessed in separate strata for the efficacy endpoints, but for the two-stage initial design of the study, combined PFS was considered. A Simon optimal two-stage design tested the hypothesis that the 16-week PFS is < 15% (clinically inactive) versus the alternative of ≥ 30% (warranting further study). Results Twenty-five patients, 14 with HCC and 11 with BTC, were enrolled. Common toxicities were rash (76%), diarrhea (56%), and fatigue (52%), mostly grade 1 or 2. No objective responses were seen. Seven BTC (64%) and 6 HCC patients (46%) had stable disease as best response, with a median duration of 16.1 weeks (95% CI 3.7-56.3) for BTC, and 17.6 weeks (95% CI 8.1-49.8) for HCC. The 16-week PFS was 64% for BTC (95% CI 29.7-84.5), and 38% for HCC (95% CI 14.1-62.8). Median overall survival was 5.7 and 6.7 months for BTC and HCC patients, respectively. BTC patients with grade ≥ 2 rash had higher median PFS (6.2 vs 2.2 months) and OS (14.2 vs 4.2 months). HCC patients with negative/low E-cadherin expression had higher median PFS (6.7 vs 2.1 months) and OS (14.5 vs 4 months). Conclusions Erlotinib with docetaxel met the 16-week PFS ≥ 30% endpoint, but overall survival was comparable to that seen with single-agent erlotinib. With the limitation of small numbers of patients, grade ≥ 2 rash (in BTC), and negative/low E-cadherin expression (HCC) were associated with higher PFS and OS. Discussion Refractory biliary tract and hepatocellular cancers are difficult to treat, and no chemotherapy or biologically targeted therapies have impacted survival. Based on preclinical synergism and prior phase I data, we conducted a multi-institutional study sequentially combining the EGFR-targeted agent erlotinib with docetaxel. Results from this study show that the primary endpoint, 16-week PFS of ≥ 30%, was met for the combined group of BTC and HCC patients (as originally planned in the study design), as well as in each disease category: 63.6% for BTC and 38.5% for HCC patients. Nevertheless, no patients attained an objective response and the median survival of 5.7 months for BTC, and 6.7 months for HCC patients (while heavily pretreated), is comparable to that seen with single-agent EGFR-targeted therapies. Safety analysis shows that this regimen was generally well tolerated, and most adverse events were grade 1 or 2. Few patients had reversible grade 3 transaminase elevation (8%), and severe anorexia, fatigue, and rash were uncommon. As expected, patients with grade ≥ 2 rash experienced higher PFS and OS, but this was noted only among the BTC group, likely because too few HCC patients had grade ≥ 2 rash. KRAS is an important predictive marker for anti-EGFR therapies for lung and colorectal cancers, but for HCC or the heterogeneous group of BTC (with 10-50% KRAS mutations) no significant correlations have been established. We were not able to identify a correlation between KRAS and benefit from erlotinib-based therapy, as all but one HCC patient had KRAS wild type gene status. Preclinical data in multiple tumor types showed that E-cadherin, a signature marker for an "epithelial" tumor phenotype when overexpressed, predicts EGFR pathway activation and determines sensitivity to EGFR-targeted agents. E-cadherin is often seen as a poor prognostic marker when downregulated, as noted during cancer progression. Not all studies demonstrate beneficial effects from E-cadherin overexpression, possibly due to histological expression variability or tumor type specificity for this biomarker. Six BTC and 8 HCC patients had evaluable tumor samples for E-cadherin analysis. While the numbers were small and conclusions should be viewed with caution, negative/low E-cadherin expression was associated with improved PFS and OS for hepatobiliary cancers (most significant in HCC) in this refractory patient population where we expected lower expression levels. In conclusion, the combination of erlotinib with docetaxel provided a 16-week PFS of ≥ 30% but showed no appreciable differences in overall survival from historical data with single-agent erlotinib. While EGFR represents an important target in this group of malignancies, it is clear that hepatobiliary cancers are heterogeneous, thus a meaningful improvement in survival most likely will require careful treatment selection based on patient tumor's molecular and genetic profiling.
    The Oncologist 01/2012; 17(1):13-e26. · 3.91 Impact Factor
  • Article: Gemcitabine alone versus gemcitabine plus radiotherapy in patients with locally advanced pancreatic cancer: an Eastern Cooperative Oncology Group trial.
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    ABSTRACT: The purpose of this trial was to evaluate the role of radiation therapy with concurrent gemcitabine (GEM) compared with GEM alone in patients with localized unresectable pancreatic cancer. Patients with localized unresectable adenocarcinoma of the pancreas were randomly assigned to receive GEM alone (at 1,000 mg/m(2)/wk for weeks 1 to 6, followed by 1 week rest, then for 3 of 4 weeks) or GEM (600 mg/m(2)/wk for weeks 1 to 5, then 4 weeks later 1,000 mg/m(2) for 3 of 4 weeks) plus radiotherapy (starting on day 1, 1.8 Gy/Fx for total of 50.4 Gy). Measurement of quality of life using the Functional Assessment of Cancer Therapy-Hepatobiliary questionnaire was also performed. Of 74 patients entered on trial and randomly assigned to receive GEM alone (arm A; n = 37) or GEM plus radiation (arm B; n = 34), patients in arm B had greater incidence of grades 4 and 5 toxicities (41% v 9%), but grades 3 and 4 toxicities combined were similar (77% in A v 79% in B). No statistical differences were seen in quality of life measurements at 6, 15 to 16, and 36 weeks. The primary end point was survival, which was 9.2 months (95% CI, 7.9 to 11.4 months) and 11.1 months (95% CI, 7.6 to 15.5 months) for arms A and B, respectively (one-sided P = .017 by stratified log-rank test). This trial demonstrates improved overall survival with the addition of radiation therapy to GEM in patients with localized unresectable pancreatic cancer, with acceptable toxicity.
    Journal of Clinical Oncology 11/2011; 29(31):4105-12. · 18.37 Impact Factor
  • Article: Phase II study of belinostat in patients with recurrent or refractory advanced thymic epithelial tumors.
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    ABSTRACT: Thymic epithelial tumors are rare malignancies, and there is no standard treatment for patients with advanced disease in whom chemotherapy has failed. Antitumor activity of histone deacetylase (HDAC) inhibitors in this disease has been documented, including one patient with thymoma treated with the pan-HDAC inhibitor belinostat. Patients with advanced thymic epithelial malignancies in whom at least one line of platinum-containing chemotherapy had failed were eligible for this study. Other eligibility criteria included adequate organ function and good performance status. Belinostat was administered intravenously at 1 g/m(2) on days 1 to 5 of a 21-day cycle until disease progression or development of intolerance. The primary objective was response rate in patients with thymoma. Of the 41 patients enrolled, 25 had thymoma, and 16 had thymic carcinoma; patients had a median of two previous systemic regimens (range, one to 10 regimens). Treatment was well tolerated, with nausea, vomiting, and fatigue being the most frequent adverse effects. Two patients achieved partial response (both had thymoma; response rate, 8%; 95% CI, 2.2% to 25%), 25 had stable disease, and 13 had progressive disease; there were no responses among patients with thymic carcinoma. Median times to progression and survival were 5.8 and 19.1 months, respectively. Survival of patients with thymoma was significantly longer than that of patients with thymic carcinoma (median not reached v 12.4 months; P = .001). Protein acetylation, regulatory T-cell numbers, and circulating angiogenic factors did not predict outcome. Belinostat has modest antitumor activity in this group of heavily pretreated thymic malignancies. However, the duration of response and disease stabilization is intriguing, and additional testing of belinostat in this disease is warranted.
    Journal of Clinical Oncology 05/2011; 29(15):2052-9. · 18.37 Impact Factor
  • Article: Phase II study of carboplatin and paclitaxel in advanced thymoma and thymic carcinoma.
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    ABSTRACT: The purpose of this study was to evaluate the impact of carboplatin and paclitaxel in patients with advanced previously untreated thymoma and thymic carcinoma. We conducted a prospective multicenter study in patients with unresectable thymoma (n = 21) or thymic carcinoma (n = 23). Patients were treated with carboplatin (area under the curve, 6) plus paclitaxel (225 mg/m(2)) every 3 weeks for a maximum of six cycles. The primary end point of this trial was to evaluate the objective response rate. From February 2001 through January 2008, 46 patients were enrolled. Thirteen patients had grade 4 or greater toxicity, mostly neutropenia. Using RECIST (Response Evaluation Criteria in Solid Tumors) 1.0 criteria, three complete responses (CRs) and six partial responses (PRs; objective response rate [ORR], 42.9%; 90% CI, 24.5% to 62.8%) were observed in the thymoma cohort; 10 patients had stable disease. For patients with thymic carcinoma, no CRs and five PRs (ORR, 21.7%; 90% CI, 9.0% to 40.4%) were observed; 12 patients had stable disease. Progression-free survival (PFS) was 16.7 (95% CI, 7.2 to 19.8) and 5.0 (95% CI, 3.0 to 8.3) months for thymoma and thymic carcinoma cohorts, respectively. To date, only seven patients (33.3%) with thymoma have died, compared with 16 patients (69.6%) with thymic carcinoma. Median survival time was 20.0 months (95% CI, 5.0 to 43.6 months) for patients with thymic carcinoma, but it has not been reached for patients with thymoma. Carboplatin plus paclitaxel has moderate clinical activity for patients with thymic malignancies, but this seems less than expected with anthracycline-based therapy. Patients with thymic carcinoma have poorer PFS and overall survival than patients with thymoma.
    Journal of Clinical Oncology 05/2011; 29(15):2060-5. · 18.37 Impact Factor
  • Source
    Article: The role of chemotherapy in advanced thymoma.
    Jordan Schmitt, Patrick J Loehrer
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    ABSTRACT: Thymoma and thymic carcinomas are rare malignancies. Most thymomas and about one-third of thymic carcinomas can be cured with local therapy. The remainder of will be candidates for systemic therapy. Numerous retrospective trials confirm objective responses to a variety of single-agent and combination chemotherapeutic regimens. No prospective randomized comparison of regimens has been performed because of the rarity of the disease. This paper reviewed the literature of chemotherapy in advanced thymic malignancies. Existing data suggest that anthracycline plus cisplatin regimens seem to demonstrate higher response rates and perhaps longer median survival times compared with nonanthracycline-containing regimens. Thymic malignancies are sensitive to a broad spectrum of systemic agents. Thymic carcinoma has a distinct clinical presentation and worse therapeutic outcomes than thymoma. Despite reproducible high response rates in thymoma, durable complete remissions are rare. Thus, novel new therapeutic targets need to be identified and appropriate agents developed to have further impact on this disease.
    Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 10/2010; 5(10 Suppl 4):S357-60. · 4.55 Impact Factor
  • Article: WHO types A and AB thymomas: not always benign
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    ABSTRACT: The 2004 WHO classification of thymic tumors recognizes five major subtypes of thymomas and thymic carcinoma. Subtypes A and AB thymomas are purported to be benign neoplasms, although prior studies have suggested a potential for malignant behavior. The purpose of this study was to assess the clinical behavior of A and AB thymomas identified from a large institutional pathologic database. A retrospective slide review of 500 thymic epithelial tumors identified 71 (~14%) cases of types A and AB thymomas. Clinical history and follow-up information were obtained through retrospective chart review. There were 38 and 33 cases of types A and AB thymomas, respectively. Complete follow-up data were available in 37 (52%) cases. Eighteen (49%) patients (type A, n=9 and type AB, n=9) had evidence of recurrent/metastatic disease at an average of 62 months (range from 6 to 244 months) after initial diagnosis. Survival curves for patients with types A and AB thymomas, with and without recurrences, show a statistically significant difference (P=0.001 and 0.005, respectively). Analysis of this large cohort confirms the potential for subtypes A and AB thymomas to show malignant behavior. Long-term clinical monitoring, therefore, appears to be justified in these cases. This study also shows the poor correlation between the WHO classification and tumor behaviorKeywords: type A; type AB; thymoma; WHO
    Modern Pathology 09/2010; 23(12):1641-1649. · 4.79 Impact Factor
  • Article: A phase II study of gemcitabine in combination with radiation therapy in patients with localized, unresectable, pancreatic cancer: a Hoosier Oncology Group study.
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    ABSTRACT: A Phase II study was conducted at Indiana University to evaluate the safety and efficacy of combined weekly Gemcitabine (GEM) with external beam radiotherapy (RT) in unresectable, locally advanced pancreatic cancer (LAPC). Eligible patients had biopsy-proven LAPC without evidence of metastatic disease. In part A of the treatment plan, patients received GEM 600 mg/m(2) IV weekly, with concurrent RT (50.4 Gy in 28 fractions, 1.8 Gy/d, 5 days per week). Part B of the treatment plan began approximately 4 weeks after completing part A: patients without disease progression received weekly GEM 1000 mg/m(2) on days 1, 8, and 15 of a 28-day cycle for 6 cycles or until disease progression. From April 2001 to June 2003, of 28 patients evaluated, 24 (86%) completed part A. About 22 patients had grade 3 toxicities, primarily hematologic (43%) and gastrointestinal (36%). Three patients (11%) had grade 4 toxicities (one each for hyperbilirubinemia, infection, and dyspnea). The median follow-up was 10 months (1-63 months) for all enrolled patients. Six patients (21%) had a radiologic partial response, 16 (57%) had stable disease, 5 (18%) had progressive disease, and 1 patient (4%) had an unevaluable response at last follow-up. Four patients (14%) underwent surgical resection (2 with R0 resection). Median time to progression was 6 months (0-36 months). Median survival time was 10.3 months (95% confidence interval, 7.9-14.6 months). The 1- and 2-year actuarial survival rates were 30% and 11%. At last analysis, all but 2 patients died. The activity and toxicity profile of combination GEM and RT indicates that this can be safely administered for patients with LAPC.
    American journal of clinical oncology 09/2010; 34(5):460-5. · 2.21 Impact Factor
  • Article: Epidermal growth factor receptor, C-kit, and Her2/neu immunostaining in advanced or recurrent thymic epithelial neoplasms staged according to the 2004 World Health Organization in patients treated with octreotide and prednisone: an Eastern Cooperative Oncology Group study.
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    ABSTRACT: Advanced or recurrent nonresectable thymic epithelial tumors show only a modest response to standard chemotherapy. A recent study using octreotide and prednisone in thymic tumors, Eastern Cooperative Oncology Group study E1C97, was conducted to verify the activity of octreotide for thymic tumors. The aim of this study was to determine whether epidermal growth factor receptor (EGFR) immunoreactivity correlated with outcomes and to identify new biologic markers for potential targeted therapy. Three markers, EGFR, C-kit, and Her2/neu, were selected for evaluation in patients with advanced thymic epithelial tumors treated on E1C97. Of the 42 patients entered onto E1C97, 34 patients (World Health Organization [WHO] categories: type A = 1, type AB = 1, type B1 = 10, type B2 = 11 type B3 = 8, and type C = 3) had sufficient tissue available for immunohistologic study. Each tumor was assessed to have 0, 1+, 2+, or 3+ immunoreactivity in the cytoplasm or membranes of the neoplastic cells for Her2/neu and EGFR and for the presence or absence of C-kit immunoreactivity. EGFR immunoreactivity of 2+ or 3+ was associated with more aggressive thymic tumors (WHO types B2 and B3). However, strong EGFR immunoreactivity was not consistently seen with thymic carcinoma. The presence of EGFR within cells was associated with a significantly improved progression-free survival (PFS) and a trend for overall survival (OS). Twelve patients demonstrated C-kit immunoreactivity; the lack of C-kit immunoreactivity was significantly associated with superior PFS but not OS. Her2/neu immunoreactivity was uniformly negative for all tumors evaluated. There was no association between response and biomarker status. High EGFR immunoreactivity is seen in more aggressive thymic neoplasms as classified according to the 2004 WHO, but regardless of classification, the presence of EGFR in tumor cells (1+, 2+, and 3+) is associated with improved performance free survival (PFS) and a trend for better OS. In contrast, the absence of C-kit immunoreactivity was associated with improved PFS. These data suggest that EGFR and C-kit may be prognostic, and further studies of these markers in subcategories of thymic malignancies is warranted.
    Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 06/2010; 5(6):885-92. · 4.55 Impact Factor
  • Article: Prognostic indicators after surgery for thymoma.
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    ABSTRACT: We undertook a 20-year retrospective institutional study to investigate prognostic indicators after surgery for thymoma. From 1989 to 2009, 83 patients underwent surgical resection of thymoma or thymic carcinoma at our institution. Twelve of these patients were determined to have either World Health Organization type C disease or Masaoka stage IV-B disease and were excluded from analysis. The remaining 71 patients were reviewed. The majority of patients in this series were female 64.7% (n=46) with an overall average age of 51.0 years. The distribution of Masaoka stages I, II, III, and IV-A was 40.8% (n=29), 19.7% (n=14), 18.3% (n=13), and 21.1% (n=15), respectively. Thirteen of the 28 (46.2%) patients who presented with stage III or IV-A disease received preoperative chemotherapy. After a mean follow-up of 66 months (range, 6 to 241 months), 54 (75.3%) patients are alive and well while six are alive with disease. Eleven (16.0%) patients have died, but only 3 (4.3%) of these patients died of thymoma. The overall disease-specific survival was 97% and 89% at 5 and 10 years. Of the variables analyzed, only age was predictive of overall survival (p=0.03). Masaoka stages I to III as compared with stage IV-A was significantly predictive of disease-free survival (p<0.01). Long-term disease-specific survival can be expected not only after surgery for early stage thymoma but also after surgery for advanced disease, including patients with pleural metastases. However, patients who undergo surgery for stage IV-A disease have reduced disease-free survival. Late mortality due to secondary cancers and associated immunologic disorders was more frequent than mortality from thymoma in this series.
    The Annals of thoracic surgery 04/2010; 89(4):1071-7; discussion 1077-9. · 3.74 Impact Factor
  • Article: Retrospective analysis of the efficacy of gemcitabine for previously treated AIDS-associated Kaposi's sarcoma in western Kenya.
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    ABSTRACT: Evaluation of outcomes in the use of single-agent gemcitabine for the treatment of AIDS-associated Kaposi's sarcoma (KS) in a western Kenyan cancer treatment program. Retrospective chart review of all patients with KS treated with single agent gemcitabine following failure of first-line Adriamycin, bleomycin, and vincristine (ABV). Baseline demographics were collected, and clinicians' assessments of response were utilized to fill out objective criteria for both response as well as symptom benefit assessment. Twenty-three patients with KS who had previously failed first-line therapy with ABV were evaluated. Following treatment, 22 of the 23 patients responded positively to treatment with stable disease or better. Of the 18 patients who had completed therapy, with a median follow-up of 5 months, 12 patients had no documented progression. Treatment options in the resource-constrained setting are limited, both by financial constraints as well as the need to avoid myelotoxicity, which is associated with high morbidity in this treatment setting. This work shows that gemcitabine has promising activity in KS, with both objective responses and clinical benefit observed in this care setting. Gemcitabine as a single agent merits further investigation for AIDS-associated KS.
    Oncology 03/2010; 78(1):5-11. · 2.27 Impact Factor
  • Article: Rituximab for the treatment of thymoma-associated and de novo myasthenia gravis: 3 cases and review.
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    ABSTRACT: Myasthenia gravis (MG) is an immune-mediated disorder associated with autoantibodies against postsynaptic nicotinic acetylcholine receptors at neuromuscular junctions. Rituximab, a monoclonal antibody specific for CD20, is used primarily to treat B-cell non-Hodgkin lymphoma. Although it has been used for treatment of a number of autoimmune diseases, there is limited experience in MG. Three patients with refractory MG (2 with concurrent thymoma) were given rituximab. Symptoms stabilized and reductions in immunosuppressive medications were tolerated for extended periods, without adverse effects or infectious complications. These observations support the concept that rituximab may be helpful for the treatment of MG. Remissions in patients with or without thymoma are achievable with rituximab given in combination with commonly used modalities. Furthermore, rituximab is not necessarily contraindicated for the treatment of MG in patients being treated for thymoma. Controlled studies are called for to define its role in the treatment of refractory MG.
    Journal of clinical neuromuscular disease 07/2009; 10(4):170-7.
  • Article: Postoperative radiotherapy after surgical resection of thymoma: differing roles in localized and regional disease.
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    ABSTRACT: To analyze the Surveillance, Epidemiology and End Results (SEER) registry data to determine the impact of postoperative radiotherapy (PORT) for thymoma and thymic carcinoma (T/TC). Patients with surgically resected localized (LOC) or regional (REG) malignant T/TC with or without PORT were analyzed for overall survival (OS) and cause-specific survival (CSS) by querying the SEER database from 1973-2005. Patients dying within the first 3 months after surgery were excluded. Kaplan-Meier and multivariate analyses with Cox proportional hazards were performed. A total of 901 T/TC patients were identified (275 with LOC disease and 626 with REG disease). For all patients with LOC disease, PORT had no benefit and may adversely impact the 5-year CSS rate (91% vs. 98%, p = 0.03). For patients with REG disease, the 5-year OS rate was significantly improved by adding PORT (76% vs. 66% for surgery alone, p = 0.01), but the 5-year CSS rate was no better (91% vs. 86%, p = 0.12). No benefit was noted for PORT in REG disease after extirpative surgery (defined as radical or total thymectomy). On multivariate OS and CSS analysis, stage and age were independently correlated with survival. For multivariate CSS analysis, the outcome of PORT is significantly better for REG disease than for LOC disease (hazard ratio, 0.167; p = 0.001). Our results from SEER show that PORT for T/TC had no advantage in patients with LOC disease (Masaoka Stage I), but a possible OS benefit of PORT in patients with REG disease (Masaoka Stage II-III) was found, especially after non-extirpative surgery. The role of PORT in T/TC needs further evaluation.
    International journal of radiation oncology, biology, physics 06/2009; 76(2):440-5. · 4.59 Impact Factor
  • Article: Clinical management of thymoma patients.
    Erin M Casey, Patrick J Kiel, Patrick J Loehrer
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    ABSTRACT: Thymoma and thymic carcinomas are rare epithelial tumors that arise from the thymus gland. Current management depends on staging, with surgery being the mainstay of therapy for stages I and II disease. Combined modality therapy, including radiation and chemotherapy, is recommended for patients who have invasive and metastatic disease. Relapse has been documented decades after initial therapy with options for treating recurrent advanced stage disease. Prospective studies have been limited, and current studies aim to evaluate novel treatment options.
    Hematology/Oncology Clinics of North America 07/2008; 22(3):457-73. · 2.64 Impact Factor
  • Article: A Phase 1 dose-escalation trial of glufosfamide in combination with gemcitabine in solid tumors including pancreatic adenocarcinoma.
    [show abstract] [hide abstract]
    ABSTRACT: To evaluate safety and pharmacokinetics and to establish the maximum tolerated dose of glufosfamide when administered in combination with gemcitabine in advanced solid tumors. This Phase 1 dose-escalation study evaluated the combination of glufosfamide + gemcitabine in patients with advanced solid tumors. Cohorts of three to six patients were treated with glufosfamide doses from 1,500 to 4,500 mg/m(2) i.v. over 4 h on Day 1 and gemcitabine 1,000 mg/m(2) i.v. over 30 min on Days 1, 8 and 15 of every 28-day cycle. Detailed PK sampling was performed on days 1 and 8 of the first two cycles. Nineteen patients were enrolled. Two patients had dose-limiting toxicity: Grade 3 fatigue at 2,500 mg/m(2) and Grade 4 thrombocytopenia at 4,500 mg/m(2). Five patients completed six cycles and one patient remained on study for ten cycles. Two patients discontinued for adverse events. Grade 3/4 neutropenia and thrombocytopenia occurred in seven patients and five patients, respectively. The CrCL fell below 60 mL/min in two patients. There was one unconfirmed partial response and 10 of 19 (52.6%) patients had stable disease or better at 8 weeks and three patients had continuing stable disease at 24 weeks. Pharmacokinetic analyses suggest no interaction between glufosfamide and gemcitabine. Phase I data indicate that full dose glufosfamide (4,500 mg/m(2)) can be given safely in combination with gemcitabine. A Phase II study in patients with pancreatic adenocarcinoma is ongoing.
    Cancer Chemotherapy and Pharmacology 06/2008; 61(6):1019-26. · 2.83 Impact Factor

Institutions

  • 2012
    • Indiana University Health
      • Melvin and Bren Simon Cancer Center
      Bloomington, IN, USA
  • 2002–2012
    • Indiana University-Purdue University Indianapolis
      • • Department of Medicine
      • • Division of Hematology/Oncology
      Indianapolis, IN, USA
  • 2011
    • National Institutes of Health
      • Branch of Medical Oncology Branch and Affiliates
      Bethesda, MD, USA
  • 2010
    • Indiana University-Purdue University School of Medicine
      Indianapolis, IN, USA
  • 2003
    • Medical University of Ohio at Toledo
      Toledo, OH, USA