Dr. David L. Sherr at Weill Cornell Medical College and fellow researchers in New York, note that single-center trials with short follow-up have indicated that neoadjuvant radiation therapy improves resectability and decreases rates of distant metastases. However, studies from large population cohorts focusing on resectable disease at diagnosis are limited, and potential survival benefits of neoadjuvant radiation therapy are unknown.
The researchers’ current analysis, reported in the International Journal of Radiation Oncology, Biology and Physics for November 15, includes 3885 cases of surgically resected stage I and II pancreatic cancer treated between 1994 and 2003. Seventy patients (2%) had received neoadjuvant radiation therapy, 1478 (38%) had adjuvant radiation therapy, and 2337 (60%) had surgery alone.
Median survival time was 23 months for the neoadjuvant therapy group, 17 months for the adjuvant therapy group, and 12 months with no radiation therapy.
In analyses controlling for age, sex, stage, grade, and year of diagnosis, neoadjuvant radiation therapy was associated with significantly higher rates of survival compared with other treatments (hazard ratio for death 0.55, p = 0.001). Compared with adjuvant radiation therapy, neoadjuvant radiation therapy still held a survival advantage (HR 0.63, p = 0.03).
“There is no evidence to suggest that the effect of neoadjuvant radiation therapy was limited to particular demographic or staging groups,” Dr. Sherr’s team reports.
Despite the robustness of their findings, the authors point out that relevant factors, such as patient performance status, comorbidities, and chemotherapy, were not accounted for in the SEER database.
“Thus,” they conclude, “future studies are clearly warranted to validate our findings.”
Int J Radiation Oncology Biol Phys 2008;72:1128-1133.