Comment on "adjuvant therapy in pancreatic cancer: a critical appraisal"

Radiotherapy in the adjuvant management of pancreatic adenocarcinoma: is it helpful?

Curative-intent management for pancreatic adenocarcinoma requires gross total resection. Only 15-20% of patients are eligible for resection and of these only approximately 20% are long-term survivors. Adjuvant and neoadjuvant approaches have been, and are being, sought to improve upon surgical results. Radiotherapy has a role in the adjuvant management of many gastrointestinal malignancies and historically has also had a role in the adjuvant management of pancreatic adenocarcinoma. However, the role of radiotherapy in the management of pancreatic adenocarcinoma has been called into question. This review examines this controversy and the underlying issues and considers current efforts towards resolving them, as well as some likely future developments.

Failure to adhere to protocol specified radiation therapy guidelines was associated with decreased survival in RTOG 9704--a phase III trial of adjuvant chemotherapy and chemoradiotherapy for patients with resected adenocarcinoma of the pancreas

PURPOSE

In Radiation Therapy Oncology Group 9704, as previously published, patients with resected pancreatic adenocarcinoma received continuous infusion 5-FU and concurrent radiotherapy (5FU-RT). 5FU-RT treatment was preceded and followed by randomly assigned chemotherapy, either 5-FU or gemcitabine. This analysis explored whether failure to adhere to specified RT guidelines influenced survival and/or toxicity.

METHODS AND MATERIALS

RT requirements were protocol specified. Adherence was scored as per protocol (PP) or less than per protocol (<PP). Scoring occurred after therapy but before trial analysis and without knowledge of individual patient treatment outcomes. Scoring was done for all tumor locations and for the subset of pancreatic head location.

RESULTS

RT was scored for 416 patients: 216 PP and 200 <PP. For all pancreatic sites (head, body/tail) median survival (MS) for PP vs. <PP was 1.74 vs. 1.46 years (log-rank p = 0.0077). In multivariate analysis, PP vs. <PP score correlated more strongly with MS than assigned treatment arm (p = 0.014, p = NS, respectively); for patients with pancreatic head tumors, both PP score and gemcitabine treatment correlated with improved MS (p = 0.016, p = 0.043, respectively). For all tumor locations, PP score was associated with decreased risk of failure (p = 0.016) and, for gemcitabine patients, a trend toward reduced Grade 4/5 nonhematologic toxicity (p = 0.065).

CONCLUSIONS

This is the first Phase III, multicenter, adjuvant protocol for pancreatic adenocarcinoma to evaluate the impact of adherence to specified RT protocol guidelines on protocol outcomes. Failure to adhere to specified RT guidelines was associated with reduced survival and, for patients receiving gemcitabine, trend toward increased nonhematologic toxicity.