Japanese diabetic patients with Werner syndrome exhibit high incidence of cancer

Abstract

To the Editor Diabetes is associated with the occurrence and progression of malignant tumors [1, 2]. Werner syndrome (WS), an autosomal recessive disorder classified as a progeroid syndrome, occurs because of mutation of the WRN gene encoding a RecQ-type DNA helicase. Because WS patients often have diabetes and malignant tumors, we initiated a nation-wide epidemiological survey in Japan to clarify the current relationship between the prevalence of diabetes and malignant tumors in them. We sent 6921 survey sheets to hospitals with[200 beds. This survey confirmed 336 new WS patients; detailed clinical data were obtained for 163 patients with diabetes, malignant tumors, or both [3]. These patients were categorized as diabetic (n = 102) and non-diabetic (n = 61). The correlation between diabetes and epithelial tumors (cancers) or non-epithelial tumors was examined using the chi-square test. The proportions of patients grouped according to age were 1.2, 9.8, 23.3, 62.6, and 1.8 % for patients in their 20s, 30s, 40s, 50s, and 60s, respectively. The prevalence of cancers and non-epithelial tumors was 11.7 and 19.0 %, respectively. No significant difference was observed in the morbidity rates of non-epithelial tumors in diabetic or non-diabetic patients (21.6 vs. 21.3 %, p = 0.485). However, diabetic patients showed significantly higher cancer prevalence than non-diabetic patients (16.6 vs. 4.9 %, p = 0.013). The types of malignant tumors in these patients and their prevalence rates are shown in Table 1. The prevalence of non-epithelial tumors and cancers is similar in WS patients [4]; non-epithelial tumors are seldom observed in the general population. Insulin resistance is related to the high cancer prevalence in diabetic patients [5]. Diabetes in WS patients is usually caused by high insulin resistance [6], which may contribute to cancer development. WS patients usually die in their 40s [4]. However, in our study, more than 60 % WS patients were in their 50s, which confirmed that the average life expectancy of Japanese WS patients has increased by 5–10 years. Because cancer incidence has increased with age, aging may be a risk factor for cancer development, especially in diabetic WS patients. Thus, our results demonstrate that diabetic WS patients show high cancer prevalence. It is therefore important to monitor the development of not only non-epithelial tumors but also cancers in these patients, especially when WS is complicated with diabetes. Communicated by Renato Lauro.