Abstract: The invention is generally directed to a diagnostic method for predicting the benefit of the response of a subject diagnosed with cancer to a platinum compound-based adjuvant chemotherapy, preferably to a cisplatin-based chemotherapy which implements the determination of the PARP expression level in the biological sample containing tumor cells, and, preferably, together with the MSH2 and/or ERCC1 expression level, more preferably together with the MSH2 and ERCC1 expression levels.