[Chemoradiation therapy for stage IV pancreatic cancer]

Pancreatic cancer is a malignant tumor with a poor prognosis. It frequently presents with locally advanced and distant metastasis at the time of diagnosis. Favorable results were obtained by performing intraoperative radiation therapy (IORT) and chemotherapy (administration of GEM) for the treatment of inoperable pancreatic cancer. A study was conducted on its efficacy as an adjuvant therapy for inoperable and advanced pancreatic cancer.

Between May 1998 and December 2002, 40 patients with stage IV pancreatic cancer were treated at our institution. The study comprised background factors, adjuvant therapy and survival rate.

According to the treatment modality, the study population was classified into four groups: group A, consisting of 3 patients with localized unresectable tumors who had been treated with IORT: group B, 5 patients who underwent curative resection of primary tumor combined with IORT: group C, 6 patients who were administered GEM combined with IORT: group D, 26 patients not falling into groups A, B or C. The mean survival for group A, B, C and D was 10.3 months, 6.7 months, 16.8 months and 9.4 months, respectively. The 1-year survival rates were 0%, 0%, 80.0% and 19.3%, respectively. The mean survival and the 1-year survival rate were significantly better in group C than in the other groups. In group C, the tumor decreased in size, invasion of large vessels and pancreatic posterior evolution was suppressed, and 4 patients survived for 17 months or more.

Prolongation of the survival period was shown by concomitant IORT and administration of GEM for inoperable advanced pancreatic cancer. Thus, attempting to combine chemotherapy with IORT and giving additional consideration to the administration method was shown to provide adjuvant therapy that can be expected to be effective against stage IV inoperable pancreatic cancer.