Abstract
Gemcitabine has high activity against nasopharyngeal carcinoma (NPC). The level of ribonucleotide reductase subunit M1 (RRM1) expression is closely related to the efficacy of gemcitabine on non-small cell lung cancer and pancreatic cancer. However, the expression of RRM1 and its association with sensitivity to gemcitabine-based chemotherapy in advanced NPC is not known. In this study, we retrospectively collected 48 formalin-fixed, paraffin-embedded NPC tissues to evaluate the expression of RRM1 using immunohistochemistry. All patients were diagnosed and treated with gemcitabine-based chemotherapy at Sun Yat-sen University Cancer Center. RRM1 expression was positive in 17(35%) patients. RRM1 expression was not associated with sex, age, performance status, WHO histological type, number of distant metastases, previous treatment, or cycles of gemcitabine-based chemotherapy(P> 0.05). The progression-free survival of the RRM1-positive group was shorter than that of the RRM1-negative group (5 months vs. 7 months, P = 0.036), and the response rate of the RRM1-positive group was somewhat lower than that of the RRM1-negative group (51.6% vs. 35.3%, P = 0.278). There was no significant difference in median survival between the RRM1-positive and RRM1-negative groups (22 months vs. 19 months, P = 0.540). Our results show that RRM1-negative expression is related with longer progression-free survival in advanced NPC patients treated with gemcitabine-based regimens.