IUDs and Breast Cancer Risks
Hormonal contraception is important for many aspects of women’s health. If a you have a family member with breast cancer the first question we get at Women’s Health Practice is it healthiest to continue the method? It’s important to speak to your provider and find out what nuances your case may have. IUD does carry small increased risk of breast cancer in some studies,
The guidelines from major organizations grade recommendations as very safe (grade 1) or absolute avoid. A family history of breast cancer is US MEC category 1 (no restriction) for the Mirena, Kyleena, Skyla, or Liletta Hormonal ( LNG-IUD) IUDs , and only a current personal breast cancer diagnosis makes it category 4 (must avoid). The 2025 Society of Family Planning/SGO recommendation likewise states that individuals at increased familial or hereditary risk, without a personal history, should be offered all contraceptive methods (GRADE 1B), and notes the CDC MEC places no restrictions in this group. Knowing your family members diagnosis and genetics may help you understand your particular contraceptive and hormonal needs going forward.
Nuances worth considering
– Baseline signal for LNG-IUS. Observational data consistently show a small increase in breast cancer risk with LNG-IUS: Danish nationwide HR ~1.4 with an excess of 14 cancers per 10,000 users, no clear duration-response. There is no reason to discontinue when you are in your 40s as age didn’t make a difference. Swedish cohort adjusted HR 1.13; Australian nested case-control OR 1.26. A meta-analysis found OR 1.16 overall, but 1.52 in women ≥50 versus 1.12 in those <50.
– Family history may modify the effect. The Swedish study found a significant additive interaction between LNG-IUD use and family history of cancer for breast cancer (19% relative excess risk from interaction, ~1.63 additional cases per 10,000 person-years); the authors advise close monitoring in women with a family history. A separate analysis reported RR 2.07 among LNG-IUS users with a breast cancer family history. These are observational with residual confounding, and the absolute increments remain small.
– Kyleena specifically. Kyleena is a 19.5 mg device — nearly all of the above data derive from the 52 mg LNG-IUS. There is insufficient evidence on the relative breast safety of lower-dose LNG IUDs, which cuts both ways but plausibly favors the lower-dose device given its lower systemic exposure. Notably, one large Swedish analysis found levonorgestrel-based methods, including the IUS, carried lower risk than desogestrel-containing products (~8 additional cases per 100,000 person-years).
– Offsetting benefits. LNG-IUD use is cancer protective in other ways. IUD use is associated with reduced endometrial, ovarian, and cervical cancer risk.
Practical plan
1. Continue the device now. Removal based on an undetailed family history is not supported and would leave you without contraception at an age when pregnancy still occurs.
2. Review a three-generation family history and apply criteria for genetic testing referral — age at the mother’s diagnosis, bilaterality, triple-negative status, male breast cancer, ovarian/pancreatic/prostate cancer, and Ashkenazi ancestry are the key triggers for increased risk. Obtain the mother’s pathology and, ideally, have the mother tested first.
3. Confirm mammographic screening is current (annual under most schedules); consider risk-model assessment (Tyrer-Cuzick/BOADICEA) which would be done by a genetic counselor, if the history is significant, which may prompt supplemental MRI.
4. Revisit the topic if new information comes to light, or as you get older or increase risk. Even then, MEC places no restriction absent a personal breast cancer history, though counseling shifts: pooled prospective data show ever-use of hormonal contraception associated with increased breast cancer risk in BRCA1 carriers (HR 1.29) but not BRCA2, and one 2026 cohort found prior LNG-IUD use associated with breast cancer in BRCA carriers (HR 1.69 overall; 2.00 in BRCA1). NCCN also notes LNG-IUD as an option for ovarian cancer risk reduction in this population.
5. Always do your best to reduce cancer risks, see other posts or come for consultation on that.
6. Reassess if you develop breast cancer — that converts the LNG-IUD to category 4 and mandates removal, with the copper IUD as the category 1 alternative.
