Future chemoradiation strategies in pancreatic cancer.
ABSTRACT Although not universally accepted, 5-fluorouracil (5-FU)-based chemoradiation is considered a standard treatment for patients with localized pancreatic cancer. Randomized trials have indicated that chemoradiation improves median survival of both locally advanced and resected pancreatic cancer. While the use of adjuvant chemoradiation in pancreatic cancer has been called into question since the publication of the European Study Group for Pancreatic Cancer (ESPAC)-1 trial, this study has not changed standard practice in the United States. All randomized trials investigating adjuvant chemoradiation have reported significant local as well as distant disease control limitations, making the study of novel chemoradiation and adjuvant chemotherapy important. Selected centers are investigating neoadjuvant chemoradiation in radiographically resectable patients. Advantages of neoadjuvant chemoradiation compared to postoperative therapy include increased local control, increased access to therapy, addressing the systemic disease recurrence risk without delay, and optimal patient selection for pancreaticoduodenectomy through exclusion of patients with rapidly progressive metastatic disease. In the years since it was approved for use in pancreatic cancer, gemcitabine has stood the test of time as a systemic agent but has not been widely adopted as a radiosensitzer in pancreatic cancer. Single-arm clinical trials that initially explored gemcitabine as a radiosensitzer in locally advanced pancreatic cancer demonstrated the potential for significant toxicity without dramatic improvements in efficacy. Recent strategies for improving the efficacy of chemoradiation include improved chemoradiation sensitization through the concurrent incorporation of molecular targeted agents, and the use of new radiation technology such as intensity-modulated radiotherapy (IMRT) and stereotactic radiotherapy. Herein, we discuss the relative merits of strategies that seek to improve outcome through these novel means and present recent data from novel strategies that will provide the background for future trials.
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ABSTRACT: BACKGROUND AND PURPOSE: Hypofractionated radiotherapy (RT) of pancreatic adenocarcinoma is limited by the tolerance of adjacent normal tissues. A better understanding of the influence of dosimetric variables on the rate of toxicity after RT must be considered an important goal. METHODS AND MATERIALS: Sixty-one patients with histologically proven locally advanced disease (LAPD) were analyzed. The therapeutic strategy consisted of induction chemotherapy (ChT) followed by concurrent chemoradiotherapy (CRT). In 39 out of 61 patients the target volume was based on a four-dimensional CT (4D-CT) procedure. Delivered dose was 44.25Gy in 15 fractions to PTV2, which consisted of pancreatic tumor and regional lymph nodes considered radiologically involved; 23 out of 61 patients received a simultaneous integrated boost (SIB) to a tumor sub-volume infiltrating the great abdominal vessels (PTV1) with dose in the range of 48-58Gy. RT was delivered with Helical Tomotherapy. Dose-volume histograms (DVHs) of target volumes and organs at risk (OARs) were collected for analysis. The predictive value of clinical/dosimetric parameters was tested by univariate/multivariate analyses. RESULTS: The crude incidence of acute gastrointestinal (GI) grade 2 toxicity was 33%. The 12-month actuarial rate of "anatomical" (gastro-duodenal mucosa damage) toxicity was 13% (95% CI: 4-22%). On univariate analysis, several stomach and duodenum DVH endpoints are predictive of toxicity after moderately hypofractionated radiotherapy. Multivariate analysis confirmed that baseline performance status and the stomach V20[%] were strong independent predictors of acute GI grade ⩾2 toxicity. The high-dose region of duodenum DVH (V45[%]; V40[%]) was strongly correlated with grade ⩾2 "anatomical" toxicity; the best V40[%] and V45[%] cut-off values were 16% and 2.6% respectively. CONCLUSION: Regarding dosimetric indices, stomach V20[%] correlates with a higher rate of acute toxicity; more severe acute and late anatomical toxicities are related to the high dose region of duodenum DVH.Radiotherapy and Oncology 05/2013; · 4.52 Impact Factor
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ABSTRACT: A major challenge with pancreatic cancer management is in the discrimination of clearly resectable tumors from those that would likely be accompanied by a positive resection margin if upfront surgery was attempted. The standard of care for clearly resectable pancreatic cancer remains surgery followed by adjuvant therapy, but there is considerable controversy over whether such therapeutic adjuvant strategies should include radiotherapy. Furthermore, in a malignancy with such high rates of distant metastasis, investigators are now exploring the feasibility and outcomes of delivering therapy in the neoadjuvant setting, both for clearly resectable as well as borderline resectable tumors. In this review, we explore the current standard of care of upfront surgery for clearly resectable cancers followed by adjuvant therapy, focusing on the role of radiotherapy. We highlight the difficulties in interpreting a literature fraught with inconsistencies in how resectable vs borderline resectable cancers are defined and treated. Finally, we explore the role of neoadjuvant strategies in the modern era.Seminars in radiation oncology 01/2014; 24(2):113–125. · 4.32 Impact Factor
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ABSTRACT: The aim of this study was to compare short-term surgical results in pancreatic cancer patients who underwent surgical resection after neo-adjuvant chemoradiation therapy (NACRT) using S-1. The study population comprised 77 patients with pancreatic cancer between 2006 and 2010. Out of 34 patients who underwent staging laparoscopy between 2008 and 2010, 31 patients without occult distant organ metastasis underwent chemoradiation and of whom 30 underwent pancreatectomy (NACRT group). Of the other 43 patients, 36 underwent surgical resection in 2006-2008, followed by adjuvant therapy (adjuvant group). The primary endpoint was frequency of pathological curative resection (R0). The new regimen of NACRT was feasible and safe. Twenty-eight of 30 (93%) patients in the NACRT group had R0 resection, which was significantly higher than in the adjuvant group (21 of 36 patients, 58%, p = 0.005). The number and extent of metastatic lymph nodes in the NACRT group (1 (0-25), N0/1; 18 of 38) was significantly lower than in the adjuvant group (2 (0-19), N0/1; 23 of 30), p = 0.0363). The frequency of intractable ascites in the NACRT group (eight of 30) was significantly higher than in the adjuvant group (two of 36, p = 0.035). Neo-adjuvant chemoradiation therapy using S-1 followed by pancreatectomy can improve the rate of pathologically curative resection and reduces the number and extent of lymph node metastasis.Journal of Gastrointestinal Surgery 12/2011; 16(4):784-92. · 2.36 Impact Factor