MOLECULAR METASTASES IN STAGE-I PANCREATIC-CANCER - IMPROVED SURVIVALWITH ADJUVANT CHEMORADIATION

Background. Reports of improved survival rates for patients with resec ted adenocarcinoma of the pancreas coincide with the adoption of adjuv ant chemoradiation protocols. The impact of nodal micrometastases demo nstrated ly molecular assays and adjuvant therapy on survival of patie nts with stage I pancreatic cancer has not been adequately assessed. M ethods. A retrospective analysis of postoperative chemoradiation on su rvival in 61 patients undergoing resection of pancreatic adenocarcinom as from 1984 to 1997 was performed. Archival tumors and regional nodes from 25 patients with stage I cancers were tested for a Kiras oncogen e mutation using polymerase chain reaction and analysis for restrictio n fragment length polymorphisms (PCR/RFLP). Results. Adjuvant chemorad iation was associated with improved survival for stage I (P < .01), bu t not stage III, disease. Seventeen (68%) of 25 patients with stage I disease tested had evidence of mutant Kiras in one or more regional no des. Survival did not differ for patients with molecular micrometastas es. Six of 17 (35%) patients with micrometastases received adjuvant ch emoradiation and had improved survival (P < .05). Conclusions. The maj ority of patients with stage I pancreatic cancer have PCR/RFLP evidenc e of lymph node micrometastases. Adjuvant chemoradiation improves surv ival in these patients by treating micrometastases not detected by his tology. Adjuvant chemoradiation should be used for patients with stage I pancreatic cancers.