Small carcinoma of the pancreas. Factors of prognostic relevance.

Abstract

Tumor size seems to be one of the primary prognostic factors that influence outcome in pancreatic cancer patients. This finding is reflected in both the Japanese and the International Union against Cancer (UICC) staging systems, in which T categories have a major influence on stage grouping. To investigate whether small tumor size is a prognostic indicator in patients with pancreatic carcinoma, we evaluated (in a prospective study) patients with a small pancreatic cancer, categorized as T1a (<2 cm) or T1b (<4 cm) tumors according to the UICC (1997). Of 670 treated patients with pan-creatic malignancies, 26 (3.8%) had a small pancreatic tumor (20 T1b; 6 T1a), Twenty-one patients were treated by pylorus-preserving duodenopancreatectomy, 4 patients re-ceived a left pancreatic resection, and 1 patient underwent a total pancreatectomy. All procedures included extensive soft tissue clearance. Local growth pattern was analyzed according to the Japan Pancreas Society (JPS) criteria for pancreatic cancer, i.e., lymph node involvement - N1 (limited to group 1 nodes) was found in 6/26 patients. Serosal infiltration - S1 (single area) was found in 6/26 and S2 (multiple areas) in 6/26; S3 (infiltration to adjacent organs) was found in 1/26. Retroperitoneal infiltration - Rp1 (adjacent to the pancreas) was found in 7/26 and Rp2 (not limited to adjacent tissues, but no other organs involved) was found in 3/26. Venous involvement (Pv2) was found in 1/26. The 5- and 10-year survival rate for the 26 patients was 46%. Interestingly, the T1a tumor patients had a significantly lower 5 year survival rate than the T1b patients (32% vs 58%; P < 0.05). Of prognostic relevance was lymph node metastasis, and retroperitoneal and serosal involvement and these patients had a significantly lower 5-year survival rate than those without such involvement regardless of tumor size (P < 0. 01). An overall 5-year survival rate of 46% is exceptionally good. Unfortunately, among pancreatic cancer patients those with a small carcinoma represent a highly selected group, representing less than 5% in our series. Interestingly tumor size is of less prognostic relevance than lymph node, retroperitoneal, and serosal involvement. Radical resection with extensive soft tissue clearance therefore seems essential to achieve such a high survival rate.