144P - Clinical implication of DNA damage response gene in patients with stage II or III gastric cancer

Background

This study was conducted to evaluate the relation of DNA damage repair (DDR) to clinical outcomes in gastric cancer patients with stage II or III treated gastrectomy.

Methods

From January 2005 to December 2017, 217 patients with stage II or III gastric cancer were analyzed for disease free survival (DFS) and overall survival according to DDR gene status. Immunohistochemical assessment of MLH1, MSH2, ARID1A, PARP-1, BRCA1 and ATM was performed in biologic samples.

Results

Among the 217 patients, the most commonly mutated DDR gene was MSH2 (n = 208, 95.9%), followed by BRCA1 (n = 191, 88.0%), MLH1 (n = 184, 84.8%), ARID1A (n = 170, 78.3%), ATM (n = 146, 67.3%) and PARP-1 (n=120, 55.3%). The high expression levels of PARP-1 group had a significantly longer 5-year OS rate as compared to low expression level of PARP-1 group (62.7% vs. 48.1%, HR 0.649, 95% CI 0.433-0.974, P = 0.035). In the multivariate OS analysis, TNM stage (HR = 5.202, P < 0.001), high expression PARP-1 (HR = 0.583, P = 0.011) and adjuvant chemotherapy (HR = 0.382, P <0.001) were only significantly prognostic factor.

Conclusions

A subgroup of patients with gastric cancer may benefit from targeted therapy. High PARP-1 expression may be a good prognostic factor for gastric cancer particularly, stage II or III gastric cancer post-surgery.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.