[The current clinical status of kidney cancers in patients with the VHL disease in Japan: a nationwide epidemiological survey].

Purpose: To understand the current clinical features of kidney cancers in patients with von Hippel-Lindau (VHL) disease in Japan.

Subject And Result: We performed a nationwide epidemiological survey of patients with VHL disease using the epidemiology program for incurable disease by the Ministry of Health, Labour and Welfare. The content of the survey included age of onset of VHL disease, sex, residential area, treatment modalities, kidney function, ECOG performance status, and prognosis. Here, we report the results of kidney cancer. The incidence rate of kidney cancer in VHL disease in Japan is 50.3% (206/409). Males and females are equally affected. The mean age of onset is 37.8 + 0.92 years. The median age of onset is 35 years. The ages of onset are distributed between 15 and 75 years. The mostly affected age of onset is between 20 and 50 years. The incidence rate of patients with metastasis is 11.1% (23/206). The most common site for metastasis is the lung (60%, 14/23). Due to multiple numbers of tumors at initial diagnosis and the metachronous development of tumors, patients received treatment on multiple occasions (mean 1.6 times), including partial nephrectomy (46%), total nephrectomy (31%) or radiofrequency ablation (14%) up to 6 times. The multiple treatments resulted in deterioration of the kidney function, causing chronic dialyses in 7 cases (3%). The ECOG performance status was scored as more than 1 in 42% of patients. The ten-year survival rate in VHL patients with kidney cancer was 94%, which is relatively high compared with that survival rates in sporadic kidney cancers.

Conclusion: The current study indicates that the age of onset of kidney cancers in VHL disease is relatively young, and kidney cancers have features of metachronous development. The clinical features of kidney cancer developed in VHL disease among Japanese population are very similar with those in European countries. Multiple treatments result in deterioration of the kidney function.