Werth et al reported that Hispanic women were more likely to choose a long-acting reversible contraceptive (LARC) method compared with non-Hispanic women and had a high rate of continuation and satisfaction of this method. LARC included levonorgestrel intrauterine system, subdermal implant, and copper intrauterine device. The Contraceptive CHOICE Project promoted the use of LARC methods. In this study, a levonorgestrel intrauterine system was inserted in 3549 women, and a progestogen implant was inserted in 1390 women, for a total of 7403 women.

However, in this study these women were not informed on the potential risks of levonorgestrel on the breast; progestagen as contraception seems to play an important role in the development of breast cancers in vitro and in vivo.

Indeed, in the study of Soini et al, levonorgestrel-releasing intrauterine system use was associated with a higher incidence of breast cancer compared with the general population.

Ruan et al showed that levonorgestrel increased the proliferation in MCF-7 breast cancer cells by overexpressing the progesterone receptor.

Furthermore, women with familial history of breast cancer and carriers of BCRA1 or BCRA2 mutations were not screened and not excluded from hormonal LARC methods.

The continuation of levonorgestrel intrauterine system is not recommended for women with a history of breast cancer. Unfortunately, there was no information concerning cancer history of women who were included in this study. Indeed, the recurrence of breast cancer is increased in women who continue to use the levonorgestrel intrauterine system.

We understand that oral contraceptives do not prevent abortions and unwanted pregnancies sufficiently; however, the enthusiasm around hormonal LARC methods should be moderated by the new studies on the increased risks of breast cancer. The screening of risks factors for breast tumors should be reinforced before these methods are prescribed.

Short-, median-, and long-term follow-up examination and evaluation of side-effects on the breast are necessary when the levonorgestrel contraceptive system is inserted.