Interferon-based adjuvant chemoradiation therapy after pancreaticoduodenectomy for pancreatic adenocarcinoma

Patients with cancer who undergo pancreaticoduodenectomy (PD) followed by radiation and 5-fluorouracil (5-FU) therapy have experienced median overall survival from 18 to 24 months and an actuarial 2-year overall survival from 34% to 48%. We previously reported an 84% 2-year survival using a novel adjuvant chemoradiation protocol that included alpha interferon. This report describes the continued observations regarding this methodology with longer follow-up and more than twice the number of patients as the original report.

From July 1995 to May 2002, 43 patients with adenocarcinomas in the pancreatic head underwent PD at our institution. The mean age was 62 years (range 29 to 77) and 60% were men. Final pathologic findings were stage I (2%), II (12%), III (72%), and IVa (14%) while 84% had positive lymph nodes (average number of nodes positive was 3.2 nodes, (range 0 to 13). Tumor extended through the capsule of the surgical specimen in 70%. These patients then received our investigational protocol consisting of external-beam irradiation at a dose of 4,500 to 5,400 cGy (25 fractions over 5 weeks) and three-drug chemotherapy: continuous infusion 5-FU (200 mg/m(2) daily, days 1 to 35), weekly intravenous bolus cisplatin (30 mg/m(2) daily, days 1,8,15,22,29), and subcutaneous alpha, interferon (3 x 10(6) units, days 1 to 35). This chemoradiation was followed by continuous infusion 5-FU (200 mg/m(2) daily, weeks 9 to 14 and 17 to 22). Chemoradiation was generally initiated between 6 and 8 weeks after surgery.

All patients completed radiation therapy. There were no deaths due to chemoradiation but 42% were hospitalized during chemoradiation, virtually all due to gastrointestinal toxicity. With a mean follow-up time of 31.9 months, 67% of the patients are alive. Therefore, the median survivorship has not been reached. Actuarial overall survival for the 1-, 2-, and 5-year periods was 95% (confidence interval [CI] = 91% to 98%), 64% (CI = 56% to 72%), and 55% (CI = 46% to 65%), respectively.

This follow-up report further suggests overall survival may be improved for patients with adenocarcinoma in the pancreatic head using an adjuvant interferon-based chemoradiation protocol. These results are obtained despite a high incidence of node involvement and advanced tumor stage. From this limited patient series, the actuarial 2-year and 5-year overall survival rates suggest a potential for improved long-term survival. Further study of this regimen in a multiinstitutional setting is needed.