Background/Aim: Concurrent chemoradiotherapy with high-dose cisplatin (CDDP-RT) is the standard therapy for advanced head and neck cancer; however, due to CDDPinduced renal impairment, dose reduction or discontinuation is frequently required. Therefore, the identification of risk factors for renal impairment is of importance to improve the efficacy and safety of CDDP-RT. Patients and Methods: We retrospectively investigated risk factors for renal impairment in advanced head and neck cancer patients receiving CDDP-RT. Renal impairment was defined as a >25% decrease from baseline in estimated glomerular filtration rate within 14 days after CDDP administration in the first cycle. Results: Of the 82 patients analyzed in this study, 21 (26%) patients developed renal impairment. Multivariate logistic regression analysis showed that concomitant use of a calcium channel blocker or lower hemoglobin levels significantly contributed to the increased risk of CDDP-induced renal impairment (odds ratio=3.60, 95% confidence interval=1. 04-12.40; odds ratio=0.71, 95% confidence interval=0.50-0.99, respectively), while concomitant use of proton pump inhibitors was a factor associated with a decreased risk of CDDP-induced renal impairment (odds ratio=0.20, 95% confidence interval=0.04-0.
86). Conclusion: Renal function of patients receiving calcium channel blocker or patients with lower hemoglobin levels should be monitored cautiously when receiving CDDP-RT.Concurrent chemoradiotherapy with high dose-cisplatin (CDDP-RT) is considered to be the standard therapy for advanced head and neck cancer (1-4). The standard CDDP-RT regimen for head and neck cancer consists of three cycles of CDDP at 100 mg/m 2 every 3 weeks and RT (70 Gy for curative treatment and 60-66 Gy for postoperative adjuvant chemotherapy), CDDP is used at higher doses than in regimens for other cancer types, requiring more attention for CDDP-induced toxicity. Despite the many clinical effects of this CDDP-RT therapy, renal impairment results in dose reduction or discontinuation of CDDP. In clinical practice, the completion rate of the CDDP-RT regimen in Japan is lower than that in the West (5-7). Some groups have considered that a reduced dose CDDP-RT regimen is needed because of intolerance in clinical practice (8-10). Therefore, identifying risk factors for renal impairment is of importance to improve the efficacy and safety of CDDP-RT.Acute kidney injury is observed in approximately 30% of CDDP-administered cases (11, 12), and CDDP is known to cause chronic kidney disease because of further progression of renal injury. CDDP is transported to the renal tubules via renal transporters, resulting in renal impairment (13). Previous studies including various cancer types and regimens have shown that female sex, age, hypoalbuminemia, smoking, cardiovascular disease, diabetes, or diagnosis of cancer stage 4 are risk factors for the development of CDDPinduced renal impairment in cancer patients (14, 15). In addition, previous studies on 5-fluorouracil and CDDP therapy have...