Fertility Concerns May Affect Endocrine Therapy Decisions in Young Patients with Breast Cancer

A recent study found that among a substantial proportion of premenopausal women with breast cancer, endocrine therapy decisions and fertility concerns are interwoven.

Young women with breast cancer may be more likely to make endocrine therapy (ET) decisions based on their fertility concerns, highlighting a need for family planning to be addressed as a priority by care teams during cancer treatments.

This was demonstrated in a recent study published in Cancer, updating previous analyses reporting on the potential effect of fertility concerns on ET decisions among young women with hormone receptor-positive early breast cancer.

“We previously reported that at diagnosis, more than half of women enrolled in a prospective cohort of young breast cancer survivors were concerned about future fertility, and 29% stated that these concerns affected treatment decisions,” the study authors wrote.

When making treatment decisions, it is common for women to be concerned about family planning due to the fact that certain cancer treatments can impair fertility, they noted. It is typically recommended that most premenopausal women undergo a minimum of five years of ET, with the potential for additional benefits if treatment is extended to 10 years.

Adherence to ET (taking the right amount of medication at the right time) is low, the authors noted. Previous studies have shown that women younger than 40 at the time of diagnosis are less likely than older women to take ET as indicated, 50% more likely to discontinue therapy and 40% more likely to be nonadherent. More than half of young women on adjuvant ET have reported nonadherent behaviors such as forgotten pills.

“There has been research showing that probably the two main reasons for that are concerns regarding fertility – you can't get pregnant while you're on these treatments – and side effects, which is something that's common to all our patients regardless of age,” said Dr. Tal Sella, medical oncologist at Dana-Farber Cancer Institute and lead study author, in an interview with CURE®. “But fertility is something that's more specific to our younger patients.”

The researchers surveyed 643 women with estrogen/progesterone receptor-positive breast cancer who were eligible for inclusion in the study. The women were enrolled from 13 different sites across the US and Canada between 2006 and 2016, were age 40 or younger and were diagnosed with stage 0 to 5 breast cancer within six months before enrollment. They collected data on tumor stage, subtype, treatment, sociodemographic information, financial comfort levels, medical/treatment history, medications, fertility concerns and ET decision-making.

One-third of the study population indicated that fertility decisions affected their ET decisions within two years of diagnosis. Younger women, non-White/non-Hispanic women, non-married women, women who had never given birth and women who had a pretreatment fertility discussion with a health care provider were more likely to indicate that fertility concerns affected their ET decisions.

Of the participants, 6% did not initiate ET within two years of diagnosis and 20% were non-persistent (did not continue treatment for the prescribed duration) and reported discontinuation for at least one time period.

Among the women with fertility concerns, 7% did not initiate ET and 33% were nonpersistent. Of the women in either of these percentage groups, 56% reported a pregnancy. Of the women who did not report a pregnancy, eight reported at least one pregnancy attempt. Among women who achieved or attempted pregnancy, 27% resumed ET.

One-third of the women who were non-persistent stopped ET at least temporarily within two years of their diagnosis (33% of the concerned group and 34% of the non-concerned group).

“These striking findings highlight the dilemma facing many young women with hormone receptor–positive breast cancer and their loved ones: whether to optimize adjuvant breast cancer treatment or fulfill near-term family planning desires,” the study authors wrote.

Although nonadherence in the general population of women with breast cancer is typically driven by factors such as side effects, perceived lack of efficacy and financial constraints, younger women are at increased risk due to fertility concerns. Women who already have children before treatment show less interest/action in fertility preservation and may be underinformed by their providers about possible strategies, which could point to why women that have one or no children reported more of an effect of fertility concern on ET decisions, the authors added.

“One of the things that this study highlights and a lot of newer research now is also showing, is that these concerns really need to be discussed in an ongoing fashion,” said Sella. “Not just around diagnosis, but also in the years afterwards. Our patients don't always come to us with these concerns, or they think that they shouldn't.”

The authors concluded that the findings should encourage continued efforts to identify strategies to support young survivors and effectively address their family planning needs.

“Doctors also aren't good enough in revisiting this subject and asking a woman if her decisions regarding family planning have changed,” said Sella. “Maybe around her diagnosis, she did not want children and was very focused on the diagnosis. But then over the years, as time goes by, and this diagnosis becomes a piece of her history, suddenly things can change and maybe interests change and people's focus changes. And so it's really important to revisit the subject of fertility and family planning over time for both sides, for patients and for providers.”

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