Interferon-based adjuvant chemoradiation therapy improves survival after pancreaticoduodenectomy for pancreatic adenocarcinoma.

BACKGROUND

Based on a 2-year survival of 43%, the Gastrointestinal Tumor Study Group (GITSG) recommended adjuvant 5-FU-based chemoradiation for resected patients with adenocarcinoma of the pancreatic head. Here we report improved survival over the GITSG protocol with a novel adjuvant chemoradiotherapy based on interferon-alpha (IFNalpha).

METHODS

From July 1993 to September 1998, 33 patients with adenocarcinoma of the pancreatic head underwent pancreaticoduodenectomy (PD) and subsequently went on to adjuvant therapy (GITSG-type, n = 16) or IFNalpha-based (n = 17) typically given between 6 and 8 weeks after surgery. The latter protocol consisted of external-beam irradiation at a dose of 4,500 to 5,400 cGy (25 fractions per 5 weeks) and simultaneous three-drug chemotherapy consisting of (1) continuous infusion 5-FU (200 mg/m2 per day); (2) weekly intravenous bolus cisplatin (30 mg/m2 per day); and (3) IFNalpha (3 million units subcutaneously every other day) during the 5 weeks of radiation. This was then followed by two 6-week courses of continuous infusion 5-FU (200 mg/m2 per day, given weeks 9 to 14 and 17 to 22). Risk factors for recurrence and survival were compared for the two groups.

RESULTS

A more advanced tumor stage was observed in the IFNalpha-treated patients (positive nodes and American Joint Committee on Cancer [AJCC] stage III = 76%) than the GITSG group (positive nodes and stage III = 44%, P = 0.052). The 2-year overall survival was superior in the IFNalpha cohort (84%) versus the GITSG group (54%). With a mean follow-up of 26 months in both cohorts, actuarial survival curves significantly favored the IFNalpha group (P = 0.04).

CONCLUSIONS

With a limited number of patients, this phase II type trial suggests better survival in the interferon group as compared with the GITSG group even though the interferon group was associated with a more extensive tumor stage. The 2-year survival rate in the interferon group is the best published to date for resected pancreatic cancer. The interferon/cisplatin/5-FU-based adjuvant chemoradiation protocol appears to be a promising treatment for patients who have undergone PD for adenocarcinoma of the pancreatic head.