Postmenopausal Hormone Therapy-Also Use Of Estradiol Plus Levonorgestrel-Intrauterine System Is Associated With An Increased Risk Of Primary Fallopian Tube Carcinoma

Data on the possible impact of postmenopausal hormone therapy (HT) on the incidence of rare primary fallopian tube carcinoma (PFTC) are scarce. Therefore, we conducted a nationwide case-control study analyzing the association between the use of different HTs and PFTC. All women aged 50 years or older with an incident PFTC (n=360) during 1995-2007 were identified from the Finnish Cancer Registry. For each case of PFTC, ten age- and place of residence-matched controls were selected from the Finnish National Population Register, which also provided information on parity. Data on HT purchases were received from the Prescription Register, and data on hysterectomies and sterilizations from the National Care Register. Controls with a salpingectomy before the PFTC diagnosis of the respective case were excluded. The PFTC risk in relation to different HTs was estimated with a conditional logistic regression model, adjusted for parity, age at last delivery, hysterectomy and sterilization. The use for five years or more of estradiol combined with levonorgestrel-releasing-intrauterine system (odds ratio 2.84, 95% confidence interval 1.10-7.38) and sequential estradiol-progestin therapy (EPT; 3.37; 2.23-5.08) were both linked with increases in the risk of PFTC, while the risk with use of estradiol-only therapy or continuous EPT was not statistically significantly increased. The OR for the use of tibolone for one year or more was 1.56 (0.55-4.41). The use of HT is related to an increased risk of PFTC, particularly when a progestin component is intrauterine or systemic progestin is given in sequential manner.What's New? Primary fallopian tube carcinoma (PFTC) is a rare disease of unknown etiology. Among the suspected risk factors is postmenopausal hormone therapy, regimens of which are linked to ovarian cancer, a disease closely related to PFTC. In this analysis of data from the Finnish Cancer Registry and Prescription Register, both sequential estradiol-progestin therapy and the combined use of estradiol and a levonorgestrel-releasing-intrauterine system were associated with increased PFTC risk among women age 50 or older. Risk rose significantly after the regimens had been used for five years or longer. The study supports the idea of hormonal involvement in PFTC.