R1 resection in pancreatic cancer has significant impact on long-term outcome in standardized pathology modified for routine use
Rau BM et al. – The 51% rate of R1 resections in ductal pancreatic carcinoma indicates a high quality standard of pathologic evaluation. The vast majority of R1 margins are located at the retroperitoneal dissection surface. Standardization of histopathologic analysis has a clinically relevant impact on survival after oncologic resection of pancreatic cancer and can be achieved by less extensive protocols.Methods
- Authors performed 265 pancreatic resections from September 2003 to September 2010.
- Among 128 patients with malignant neoplasms, histology revealed ductal pancreatic adenocarcinoma in 97, ampullary cancer in 10, and distal bile duct cancer in 21 patients.
- Resected specimens were analyzed according to this improved standardized pathology protocol introduced in 2000.
- Follow–up data on overall and cancer–related survival, presence and site of tumor recurrence, and chemotherapy were obtained from 120 patients.
- Pancreatic resection comprised a pylorus–preserving or classical pancreaticoduodenectomy in 112, a distal pancreatectomy in 8, and a total pancreatectomy in 7 patients.
- In the overall series, 56 (44%) were classified R1 resections and 68 (43%) R0 resections, 3 patients with R2 resections were excluded, leaving 125 patients for analysis.
- In pancreatic adenocarcinoma, the rate of R1 was 51% (48/94).
- R1 resection involved most frequently the circumferential margin in 86% (48/125) of the total group and in 92% (44/48) in pancreatic cancer.
- Follow–up was performed after a median of 17 months (range, 1–85) postoperatively.
- Cancer–related death rate in R0 and R1–resected patients was 60% and 83% (P < .02) in all cancers (n = 117) and 66% and 80% in patients with pancreatic adenocarcinoma (n = 88).
- Median tumor–related survival in R0 and R1 resections was 22 (range, 4–85) vs 14 months (range, 2–48) in all cancers (P < .002), and 19 (range, 4–85) vs 14 months (range, 2–48) in pancreatic adenocarcinoma (P < .04).
- Kaplan–Meier survival analysis revealed a survival benefit after R0 resection in both all cancers (P = .002) and pancreatic adenocarcinoma (P < .02).
- The pattern of tumor recurrence had a greater rate of regional metastases in the R1 group (P < .05).