Hormone replacement therapy after cervical cancer treatment: a Japanese claims-based cohort study

Background Hormone replacement therapy (HRT) plays a key role in maintaining quality of life in women with cancer treatment-induced estrogen deficiency. This study aimed to examine the real-world use of HRT among Japanese women with newly diagnosed cervical cancer who might experience iatrogenic estrogen deficiency. Methods Using the JMDC claims database (mainly employment-based insured persons and their dependents), we included women aged 18–54 years, diagnosed with cervical cancer from January 2006 to March 2024 and treated by surgery or radiotherapy. The primary outcome was HRT initiation within 6 months of primary treatment. Cumulative prescription over 72 months was estimated by the Kaplan–Meier method. Factors associated with HRT were assessed by multivariable logistic regression. Results Of 1,520 women (surgery 1,259; radiotherapy 261; median age 44 years), 334 (22.0%) initiated HRT within 6 months. HRT was more frequent after surgery than radiotherapy (23.4% vs 14.9%), and no woman aged 55–59 years initiated HRT. It fell steeply with age (from 35.3% at 18–34 years to 3.0% at 50–54 years) and rose across treatment eras (16.7% to 23.9%). Cumulative prescription was significantly higher after surgery and did not converge with radiotherapy over 72 months. In multivariable analysis, HRT initiation was associated with surgery (adjusted odds ratio [aOR] 2.52), younger age (aOR 0.91 per year), concurrent chemotherapy (aOR 2.05), and more recent treatment era. Among initiators, HRT began early (median 1.7 months), was predominantly transdermal and estrogen-only, but continued for a median of about two years. In the radiotherapy group, where the uterus is typically preserved, only 33% received combination estrogen-progestin therapy, a potential endometrial-protection concern. Conclusions HRT prescription was uncommon in this claims-based cohort of younger women treated for cervical cancer, and initiation was relatively short, suggesting a potential gap in survivorship care that warrants further investigation. Systematic assessment of ovarian status and structured counseling remain pragmatic targets for quality improvement.