Impact of chemoradiotherapy after disease control with chemotherapy in locally advanced pancreatic adenocarcinoma in GERCOR phase II and III studies

Purpose The management of locally advanced (LA) pancreatic cancer patients remains controversial. To select patients who could benefit from chemoradiotherapy (CRT), the therapeutic strategy used by the Groupe Cooperateur Multidisciplinaire en Oncologie (GERCOR) consisted of initial chemotherapy (CT) for at least 3 months. The decision to administer CRT or continue CT in nonprogressive patients was the investigator's choice. Patients and Methods Retrospective analysis of outcome in 181 patients with LA pancreatic cancer (76 women and 105 men; mean age, 61 years; range, 37 to 85 years) enrolled onto prospective phase II and III GERCOR studies was performed to compare the survival of patients who received CRT with that of patients who continued CT alone. Results Median progression-free survival (PFS) and overall survival (OS) times for the 181 patients were 6.3 and 11.4 months, respectively. Fifty-three patients (29.3%) had metastatic disease after 3 months of CT and were not eligible for CRT. Among the 128 remaining patients (70.3%) who had no disease progression and who were, therefore, eligible for CRT, 72 (56%) received CRT (group A), whereas 56 (44%) continued with CT (group B). The two groups were balanced for initial characteristics (performance status, sex, age, and type of CT), as well as for induction CT results. In groups A and B, the median PFS times were 10.8 and 7.4 months, respectively (P = .005), and the median OS times were 15.0 and 11.7 months, respectively ( P = .0009). Conclusion These results suggest that, after control of disease by initial CT, CRT could significantly improve survival in patients with LA pancreatic cancer compared with CT alone. A prospective phase III study is ongoing to evaluate this strategy.