Volume-corrected mitotic index in human pancreatic cancer. Relation to histologic grade, clinical stage, and prognosis.

A retrospective study was performed on 59 pancreatic cancer patients diagnosed during 1970-1988. The mean follow-up time of all individual patients was 6.9 months (range, 0-37 months). Histologic grade, clinical stage (UICC), and volume-corrected mitotic index (M/V index) were correlated to the survival of patients. Histologic grade (p = 0.167) and clinical stage (p = 0.066) were not related to overall survival with statistical significance. The M/V index was significantly associated with overall survival (p = 0.004). M/V index (p = 0.004), clinical stage (p = 0.029), and histologic grade (p = 0.126) predicted survival at 1 year after diagnosis. M/V index divided grade-II tumors into two prognostically different groups (p = 0.050). Seven of 59 patients who survived more than 12 months had an M/V index less than 2, and patients who survived less than 6 months had significantly higher M/V index values (chi-square = 528.3, p less than 0.001). The metastasizing potential of pancreatic cancer and lymph node involvement was also associated with the M/V index. Histologic grade and M/V index were positively correlated (chi-square = 38.6, p less than 0.001, r = 0.702). On the basis of our results, it seems that the M/V index is better than histologic grade or clinical stage in predicting survival of pancreatic cancer patients. This result suggests the potential use of the M/V index in selecting patients for different modes of therapy.