An analysis of ERCC1, hENT1, RRM1, and RRM2 expression in resected pancreas adenocarcinoma: Implications for adjuvant treatment.

Abstract

206 Background: Tumor overexpression of excision repair cross complementing gene 1 (ERCC1) was recently shown to be associated with decreased survival in patients with pancreas adenocarcinoma (PAC). Ribonucleotide reductase 1 and 2 (RRM) and human equilibrative nucleotide transporter 1 (hENT1) are integral to DNA synthesis and cellular transport and are implicated as poor prognostic factors in other malignancies. Their role in PAC is not well defined. Methods: A prospective database (n=220) was used to randomly select 95 pts who underwent pancreaticoduodenectomy for PAC between 1/00-10/08. IHC analysis was performed on tumor samples for RRM1 and 2, hENT1, and ERCC1. Main outcomes were recurrence-free (RFS) and overall survival (OS). Results: Median age was 63 yrs; median FU, RFS, and OS was 49, 10.6 and 15.5 mo. Median tumor size was 3cm, 26% had a positive margin, 34% were poorly differentiated, 61% had positive lymph nodes (LN), 88% had perineural invasion (PNI), and 45% had lymphovascular invasion (LVI). High expression of RRM1, RRM2, hENT1, and ERCC1 was present in 40%, 17%, 85%, and 16% of patients, respectively. High RRM2 was associated with reduced RFS (6.9 vs 16.0 mo; p<0.0001) and decreased OS (9.1 vs 18.4 mo; p<0.0001). High ERCC1 was associated with reduced RFS (6.1 vs 15 mo; p=0.04) and decreased OS (8.9 vs 18.1 mo; p=0.03). RRM1 and hENT1 were not associated with survival. After accounting for known adverse factors, high RRM2 and ERCC1 persisted as negative prognostic factors for RFS and OS (Table). A subset analysis of those who received adjuvant therapy (n=74) revealed the same negative effect of high RRM2 and ERCC1 on RFS and OS. Conclusions: High RRM2 and ERCC1 tumor expression are associated with reduced RFS and OS after resection of pancreas cancer. These biomarkers may help personalize adjuvant therapy. [Table: see text]