Radiotherapy Does Not Improve Outcome in Borderline Resectable Pancreatic Cancer

For the significant percentage of patients with locally advanced pancreatic cancers with local vascular involvement that are deemed borderline resectable, outcomes with upfront surgery are poor. Preoperative chemotherapy with or without radiation therapy is considered for these patients, but there is no clear care standard.

Investigators now report results of a multicenter, randomized, phase 2 trial evaluating treatment for patients with locally advanced pancreatic cancer who met criteria for borderline resectable disease on central radiology review. Patients were assigned to 8 cycles of modified FOLFIRINOX or to 7 cycles of modified FOLFIRINOX followed by radiotherapy (33–40 Gy administered in 5 fractions by stereotactic body radiotherapy or 25 Gy administered in 5 fractions by hypofractionated image-guided radiation therapy), followed by attempted surgery. After surgery an additional 3 or 4 cycles of modified FOLFIRINOX was recommended.

Of 126 patients, half were female, median age was 64, and the median CA 19–9 level was 167 U/mL in the chemotherapy arm and 260 U/mL in the radiotherapy arm. Completion of accrual to each arm required that 12 or more of the first 30 patients achieve an R0 resection. This was achieved in the chemotherapy arm (17 patients) and accrual to 70 patients was completed, but was not achieved in the radiotherapy arm (10 patients) and enrollment was closed prematurely at 56 patients.

Pancreatectomy was performed in 49% of the chemotherapy arm and 35% of the radiotherapy arm, with R0 resection achieved in 88% and 74%, respectively. Pathologic complete response was observed in 2 patients, both treated with radiotherapy. At a median follow-up of 42.9 months, the primary endpoint of a minimum 18-month overall survival of 50% was exceeded in the chemotherapy arm (66.1%) but was not met in the radiotherapy arm (47.3%). Median overall survival with chemotherapy was 29.8 months.