To examine the histopathologic effect of neoadjuvant therapy and its impact on survival in patients with carcinoma of the pancreas, we retrospectively reviewed the records of 116 patients who underwent resections for pancreatic cancer from 1987 to 2000. Median follow-up of surviving patients was 19 mo(range 4-150 mo). Preoperative chemotherapy was administered in 61 patients (53%) and consisted of 5-fluorouracil/mitomycin C in 35 patients and gemcitabine in 26 patients, given concurrently with external beam radiation (5040 cGy). All resections were performed with curative intent (98 Whipples, 11 total, 6 distal, and 1 central pancreatectomy). Histopathologic examination included an estimation of the amount of fibrosis present in the tumor specimen (expressed as the percentage of fibrosis identified relative to the amount of neoplastic cells present). The mean fibrosis level for the series was 56% (range 5% to 100%). The administration of neoadjuvant therapy resulted in greater fibrosis (73%) than no preoperative treatment (38%) (p = 0.0001). Higher mean fibrosis levels were observed in patients with negative lymph nodes (p = 0.0006) and negative margins (p = 0.05). Factors associated with improved survival(log rank test) included: negative margins (p = 0.001), negative lymph nodes (p = 0.03), and use of neoadjuvant therapy (p = 0.03). Median survival in the neoadjuvant group was 23 mo vs 16 mo without preoperative therapy (p = 0.03). In conclusion, the use of neoadjuvant therapy resulted in a greater degree of fibrosis in the specimen. Patients with negative margins and negative lymph nodes had a greater amount of fibrosis present, and these were significant predictors of improved outcome. Although retrospective,this series suggests an improvement in survival in patients treated with neoadjuvant therapy.