Objective:
To investigate the association between medically assisted reproduction (MAR) and the risk of hormone-related cancers in women.
Approach:
- Study Design: A retrospective cohort study using an emulated target trial design based on linked Australian national registries and administrative datasets.
- Population: Included 1,748,927 women aged 18 to 55 years from 1991 to 2018, with 396,661 undergoing MAR.
- Treatment Exposure: Included assisted reproductive technology (ART), intrauterine insemination or ovarian stimulation (IUI/OS), and ovulation induction with clomiphene citrate.
- Outcomes: Main outcomes were incident hormone-related invasive cancers, including breast, ovarian, uterine, thyroid, colorectal, and melanoma.
Key Findings:
- Higher observed rates of hormone-related cancers were noted in women who underwent MAR, with hazard ratios ranging from 1.09 to 1.64, but these associations may be influenced by underlying infertility-related conditions and increased medical surveillance.
- The estimated excess risk amounted to fewer than 20 additional cancers per 100,000 treated women annually compared to matched groups.
- Increased risks were observed in the first years following MAR, decreasing over time, often reaching little or no excess risk after approximately 10 years.
- Underlying infertility-related conditions may account for several observed associations with cancers.
- Increased medical surveillance and earlier cancer detection may contribute to the observed associations.
Interpretation:
The findings indicate that the observed associations with hormone-related cancer following MAR may reflect underlying patient characteristics and increased medical surveillance rather than treatment effects.
Limitations:
- The observational design prevents establishing causality.
- Important confounders such as the underlying cause of infertility, smoking, family history of cancer, and other patient characteristics were unavailable.
- Findings may not be generalizable beyond Australia's subsidized MAR system.
Conclusion:
The study indicates that any excess risk of hormone-related cancer following MAR may be influenced by the health and sociodemographic profile of women receiving MAR and increased surveillance during treatment.
Sources:
This content is an AI-generated, fully rewritten summary based on a published scholarly article. It does not reproduce the original text and is not a substitute for the original publication. Readers are encouraged to consult the source for full context, data, and methodology.
