Decrease of creatinine clearance rate with aging in patients with head and neck cancer in Japan

We aimed to clarify the reason for the lower dosage of cis-platinum (CDDP) in patients with head and neck cancer in Japan compared with that in other countries, by evaluating renal function. We studied 375 patients with head and neck cancer who had been hospitalized from January 1998 to October 2005, to evaluate and treat the disease. The creatinine clearance rate (Ccr) was calculated at least three times before beginning the treatments, and the average Ccr was estimated to evaluate the renal function. The Ccr decreased with aging, and the percentages of patients with Ccr lower than 65 ml/min per 1.73 m(2) were 27.1% of patients in their fifties, 36.8% in their sixties, 62.3% in their seventies, and 87.5% in their eighties. There was no correlation between renal function and the Japanese lifestyle (i.e., diet. water consumption). The renal function of Japanese decreases rapidly with aging, whereas that of Americans is maintained for longer periods. The poor renal function of Japanese is one of the causes of the need to reduce the dosage of or avoid the administration of CDDP in cancer patients.