The association of menopausal hormone therapy with the incidence of urinary tract cancer: a national population-based study

Abstract

This study evaluates the relationship between menopausal hormone therapy (MHT) and the risk of urologic cancer in women. It was conducted for South Korea’s national population based on the National Health Insurance Service Database between January 2002 and January 2019. The types of MHT in this study included tibolone, combined oestrogen plus progestin by the manufacturer (CEPM) or physician (CEPP), and oral and topical oestrogen. Furthermore, select patient characteristics and reproductive factors were reviewed. We performed a Cox proportional hazard analysis to clarify the risk of urologic cancer associated with MHT. According to MHT types, 104,089 were treated with tibolone, 65,597 with CEPM, 29,357 with oral oestrogen, 3,913 with CEPP, and 1,174 with topical oestrogen. Among women on MHT, the incidence of kidney cancer was significantly increased with oral oestrogen (hazard ratio [HR] 1.36, 95% confidence interval [CI]: 1.062–1.735) and topical oestrogen (HR 2.84, 95% CI: 1.270–6.344), whereas other formulations were not associated with kidney cancer. Meanwhile, tibolone significantly decreased the incidence of bladder cancer (HR 0.69, 95% CI: 0.548–0.858), whereas other formulations were not associated with bladder cancer. Our findings suggest that MHT in postmenopausal women affects the incidence of urologic cancers.