Ludmila Katherine Martin

The Ohio State University, Columbus, OH, United States

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Publications (10)38.7 Total impact

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    ABSTRACT: The objective of this study was to evaluate whether building upon multidrug chemotherapy regimens represents a viable strategy in pancreatic cancer clinical trial design. We performed a pooled analysis of all single-arm phase II studies in which a specific targeted agent (the anti-vascular endothelial growth factor monoclonal antibody bevacizumab) was added to gemcitabine-based cytotoxic doublets. The primary end point was overall survival (OS). Secondary end points included objective response rate, CA-19-9 biomarker response rate, and adverse event frequencies. Kaplan-Meier methods estimated time-to-event end points, whereas the Cox proportional hazard model estimated univariate hazard ratios of death. For the 300 patients included in the pooled analysis, median OS was 9.1 months (95% confidence interval, 8.3-10.2). Differences in OS were observed according to patients' baseline performance status (median OS, 10.4 vs 8.6 months for Eastern Cooperative Oncology Group 0 vs 1, respectively). Moreover, bevacizumab-related adverse events were not observed at increased frequency with gemcitabine-based doublets compared with historic data. Recognizing the limitations of cross-study comparisons, these results compare favorably to those from Cancer and Leukemia Group B 80303, a phase III trial testing bevacizumab in combination with gemcitabine alone. This is the largest data set available to demonstrate the feasibility of building upon more intensive chemotherapy backbones in clinical trials of novel targeted agents in pancreatic cancer.
    Pancreas 04/2014; 43(3):343-9. · 2.95 Impact Factor
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    ABSTRACT: Glioblastoma (GBM) is the most common and aggressive histologic subtype of brain cancer with poor outcomes and limited treatment options. Here we report the selective overexpression of the protein arginine methyltransferase PRMT5 as a novel candidate theranostic target in this disease. PRMT5 silences the transcription of regulatory genes by catalyzing symmetric di-methylation of arginine residues on histone tails. PRMT5 overexpression in patient-derived primary tumors and cell lines correlated with cell line growth rate and inversely with overall patient survival. Genetic attenuation of PRMT5 led to cell cycle arrest, apoptosis and loss of cell migratory activity. Cell death was p53-independent but caspase-dependent and enhanced with temozolomide, a chemotherapeutic agent used as a present standard of care. Global gene profiling and chromatin immunoprecipitation identified the tumor suppressor ST7 as a key gene silenced by PRMT5. Diminished ST7 expression was associated with reduced patient survival. PRMT5 attenuation limited PRMT5 recruitment to the ST7 promoter, led to restored expression of ST7 and cell growth inhibition. Lastly, PRMT5 attenuation enhanced GBM cell survival in a mouse xenograft model of aggressive GBM. Together, our findings defined PRMT5 as a candidate prognostic factor and therapeutic target in GBM, offering a preclinical justification for targeting PRMT5-driven oncogenic pathways in this deadly disease.
    Cancer Research 01/2014; · 9.28 Impact Factor
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    ABSTRACT: Pancreas cancer is highly lethal even at early stages. Adjuvant therapy with chemotherapy (CT) or chemoradiation (CRT) is standard following surgery to delay recurrence and improve survival. There is no consensus on the added value of radiotherapy (RT). We conducted a retrospective analysis of clinical outcomes in pancreas cancer patients treated with CT or CRT following surgery. Patients with resected pancreas adenocarcinoma were identified in our institutional database. Relevant clinicopathologic and demographic data were collected. Patients were grouped according to adjuvant treatment: group A: no treatment; group B: CT; group C: CRT. The primary endpoint of overall survival was compared between groups B vs. C. Univariate and multivariate analyses of potential prognostic factors were conducted including all patients. A total of 146 evaluable patients were included (group A: n = 33; group B: n = 45; group C: n = 68). Demographics and pathologic characteristics were comparable. There was no significant survival benefit for CRT compared with CT (mOS 16.8 months vs. 21.5 months, respectively, p = 0.76). Local recurrence rates were similar in all three groups. Univariate analyses identified absence of lymph node involvement (hazards ratio [HR] 1.43, p = 0.0082) and administration of adjuvant therapy (HR 0.496, p = 0.0008) as significant predictors for improved survival. Multivariate analyses suggested that patients without nodal involvement derived the most benefit from adjuvant treatment. The addition of RT to CT did not improve survival over CT. Lymph node involvement predicts inferior clinical outcome.
    Annals of Surgical Oncology 09/2013; · 4.12 Impact Factor
  • Ludmila Katherine Martin, Tanios Bekaii-Saab
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    ABSTRACT: Neoadjuvant chemoradiation (CRT) is standard treatment for stage II-III rectal cancer. Fluoropyrimidine-based CRT prolongs disease-free survival over adjuvant CRT and improves local control over both adjuvant CRT and neoadjuvant radiotherapy alone, but does not prolong overall survival. New approaches to neoadjuvant therapy may improve outcome in this disease. Oxaliplatin, a standard component of chemotherapy for the treatment of both resected and metastatic colon cancer, is a potent radiosensitizer with synergistic radiosensitizing activity in combination with 5-FU in preclinical studies. Early clinical trials showed promising activity with the addition oxaliplatin to 5-FU-based CRT in stage II-III rectal cancer; however, early data from phase III trials seem to be disappointing. This article reviews the existing literature and explores the potential role of oxaliplatin as part of neoadjuvant CRT for rectal cancer.
    Journal of the National Comprehensive Cancer Network: JNCCN 03/2013; 11(3):298-307. · 5.11 Impact Factor
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    ABSTRACT: Purpose Prolonged exposure of cancer cells to triapine, an inhibitor of ribonucleotide reductase, followed by gemcitabine enhances gemcitabine activity in vitro. Fixed-dose-rate gemcitabine (FDR-G) has improved efficacy compared to standard-dose. We conducted a phase I trial to determine the maximum tolerated dose (MTD), safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of prolonged triapine infusion followed by FDR-G. Experimental Design Triapine was given as a 24-hour infusion, immediately followed by FDR-G (1000 mg/m(2) over 100-minute). Initially, this combination was administered days 1 and 8 of a 21-day cycle (Arm A, triapine starting dose 120 mg); but because of myelosuppression, it was changed to days 1 and 15 of a 28-day cycle (Arm B, starting dose of triapine 75 mg). Triapine steady-state concentrations (Css) and circulating ribonucleotide reductase M2-subunit (RRM2) were measured. Results Thirty-six patients were enrolled. The MTD was determined to be triapine 90 mg (24-hour infusion) immediately followed by gemcitabine 1000 mg/m(2) (100-minute infusion), every 2 weeks of a 4-week cycle. DLTs included grade 4 thrombocytopenia, leukopenia and neutropenia. The treatment was well tolerated with fatigue, nausea/vomiting, fever, transaminitis, and cytopenias being the most common toxicities. Among 30 evaluable patients, 1 had a partial response and 15 had stable disease. Triapine PK was similar, although more variable, compared to previous studies using doses normalized to body-surface-area. Steady decline in circulating levels of RRM2 may correlate with outcome. Conclusions This combination was well tolerated and showed evidence of preliminary activity in this heavily pretreated patient population, including prior gemcitabine failure.
    Investigational New Drugs 07/2012; · 3.50 Impact Factor
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    ABSTRACT: Triapine, a novel inhibitor of the M2 subunit of ribonucleotide reductase (RR), is a potent radiosensitizer. This phase 1 study, sponsored by the National Cancer Institute Cancer Therapy Evaluation Program, assessed the safety and tolerability of triapine in combination with radiation (RT) in patients with locally advanced pancreas cancer (LAPCA). We evaluated 3 dosage levels of triapine (24 mg/m(2), 48 mg/m(2), 72 mg/m(2)) administered with 50.4 Gy of RT in 28 fractions. Patients with LAPCA received triapine thrice weekly, every other week during the course of RT. Dose-limiting toxicity (DLT) was assessed during RT and for 4 weeks after its completion. Dynamic contrast-enhanced magnetic resonance imaging and serum RR levels were evaluated as potential predictors for early response. Twelve patients were treated. Four patients (1 nonevaluable) were enrolled at dosage level 1 (DL1), 3 patients at DL2, and 5 patients (2 nonevaluable) at DL3. No DLTs were observed, and the maximum tolerated dose was not reached. Two patients (17%) achieved partial response, and 6 patients (50%) had stable disease. One patient underwent R0 resection after therapy. Ninety-two percent of patients (100% at DL3) experienced freedom from local tumor progression. In 75% of patients who eventually experienced progression, metastases developed without local progression. RR levels did not seem to predict outcome. In 4 patients with available data, dynamic contrast-enhanced magnetic resonance imaging may predict early response or resistance to therapy. The combination of triapine at 72 mg/m(2) 3 times weekly every other week and standard RT is tolerable with interesting activity in patients with LAPCA.
    International journal of radiation oncology, biology, physics 07/2012; 84(4):e475-81. · 4.59 Impact Factor
  • Ludmila Katherine Martin, Lai Wei, Elizabeth Trolli, Tanios Bekaii-Saab
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    ABSTRACT: CA19-9 is the most specific biomarker for pancreas cancer. We investigated the prognostic significance of normal (≤37 U/mL) versus elevated (>37 U/mL) CA19-9 levels in patients with resected and advanced pancreas cancer. Relevant data were obtained from patients treated for early-stage or advanced pancreatic adenocarcinoma at our institution. Log-rank tests were used to evaluate relationship between CA19-9 and clinical outcomes of interest for both early- and advanced-stage patients. A total of 123 patients were included (Group A: N = 30 stage I/II; Group B: N = 93 stage III/IV). In group A, elevated preoperative CA19-9 was significantly associated with lymph node involvement (p = 0.031), tumor ≥3 cm (p = 0.011), and lack of tumor differentiation (p = 0.048). Failure of postoperative CA19-9 to normalize predicted significantly worse DFS (p = 0.021). For group B, elevated baseline CA19-9 was associated with shorter OS on chemotherapy (p = 0.0008) and decline in CA19-9 >25 % with treatment was a significant predictor of improved OS (p = 0.0099). Higher than normal CA19-9 level is an adverse prognostic factor in both early and advanced settings and may prove to be useful in the selection of patients for more aggressive therapy in future trials. CA19-9 level decrease of >25 % predicts improved survival in advanced disease on chemotherapy.
    Medical Oncology 06/2012; · 2.14 Impact Factor
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    ABSTRACT: BACKGROUND: Mutations in the v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) are present in approximately 30% to 40% of colorectal adenocarcinomas. Wild-type (WT) KRAS mutation status is predictive of tumor response with epidermal growth factor receptor-directed therapies, but the results from studies evaluating the prognostic value of KRAS status in localized disease have been contradictory. The prognostic value of KRAS in metastatic disease, specifically according to whether patients have synchronous or metachronous disease at presentation, is less understood. METHODS: One-hundred ten consecutive patients with metastatic colorectal adenocarcinoma underwent testing for KRAS exon 2 mutations by polymerase chain reaction amplification and direct nucleotide sequencing. The clinical characteristics, treatments, and outcomes of these patients were then analyzed retrospectively, stratified according to whether patients presented with synchronous or metachronous metastasis and according to KRAS mutation status (WT or mutated). RESULTS: For the entire cohort, the median overall survival from the date of diagnosis of metastatic disease was 34.3 months (95% confidence interval, 28.3-49.4 months) for patients with WT KRAS (n = 70). The median overall survival for patients with mutated KRAS (n = 40) was 40.3 months (95% confidence interval, 27.9-51.1 months; log-rank P = .91). Kaplan-Meier survival analysis indicated that 3-year overall survival and 5-year overall survival were not statistically different. Within the subgroups of patients with synchronous and metachronous metastatic disease, no significant differences were observed in median overall survival, 3-year overall survival, or 5-year overall survival between the WT KRAS and mutated KRAS groups. CONCLUSIONS: In this study, KRAS mutation status did not influence overall survival in either synchronous or metachronous metastatic colorectal adenocarcinoma and, as such, had no prognostic role in this disease setting. Cancer 2012. © 2012 American Cancer Society.
    Cancer 06/2012; · 5.20 Impact Factor
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    ABSTRACT: Few patients with metastatic colorectal cancer (mCRC) are candidates for resection of their hepatic disease. Yttrium-90 ((90)Y) radioembolization has promise in the treatment of unresectable mCRC. We conducted a retrospective study to assess the efficacy in patients with refractory mCRC who underwent (90)Y radioembolization. Patients with unresectable mCRC with liver metastases treated at The Ohio State University were included in this analysis. Demographic data, carcinoembryonic antigen (CEA) values, observed toxicities, and information on prior therapies were collected. Response was assessed by RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 criteria. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Twenty-four patients (median age, 63 years) were included. Of the patients, 54% had extrahepatic disease; 67% had bilobar involvement. The patients had received a median of 3 prior therapies. No objective responses were observed. Five patients had a CEA response. Median PFS and OS were 3.9 months (95% CI, 2.4-4.8 months) and 8.9 months (95% CI, 4.2-16.7 months), respectively. Patients older than 65 years had improved PFS (4.6 vs. 2.4 months) and OS (14 vs. 5.5 months) vs. younger patients, likely due to receipt of (90)Y treatment earlier in their disease course. The presence of extrahepatic disease and the absence of CEA response appeared negatively predictive of efficacy. Toxicities were expected and manageable. (90)Y radioembolization is active in select patients with refractory mCRC and with liver metastases, and is safe and well tolerated in the elderly. In patients with extensive extrahepatic disease, (90)Y should be used in combination with chemotherapy. CEA may be a predictor of efficacy.
    Clinical Colorectal Cancer 01/2012; 11(3):195-9. · 1.80 Impact Factor
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    Ludmila Katherine Martin, Tanios Bekaii-Saab
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    ABSTRACT: Venous thromboembolism (VTE) is a frequent complication of gastrointestinal cancers that increases morbidity and may impact mortality. Low-molecular-weight heparins (LMWHs) and vitamin K antagonists (VKAs) are standard anticoagulation options for the ambulatory gastrointestinal cancer patient with VTE, but both of these agents are challenging to use for various reasons. Novel oral anticoagulants (NOAs) are new, orally available anticoagulants designed to be easier to administer with more reliable pharmacokinetics that eliminate the need for frequent monitoring of various laboratory parameters. This paper reviews the existing efficacy and safety data for the use of NOAs dabigatran etexilate, rivaroxaban, and apixaban and discusses the potential role of these agents in the management of gastrointestinal cancer-related VTE.
    Thrombosis. 01/2012; 2012:758385.