Post-Surgical Hormonal Therapy ‘Critical’ to Avoiding Subsequent Breast Tumors

For women with ductal carcinoma in situ (DCIS), adhering to a hormonal therapy regimen “is critical to minimizing the occurrence of developing subsequent breast tumors,” researchers have found.

An analysis of population-based data from state cancer registries in California, New Jersey, New York and Texas on women at least 65 years old and who were newly diagnosed with DCIS and underwent surgery with or without radiation from 2006 to 2013, results of which were published in Cancer, found that while excellent adherence to hormonal therapy had no impact on death from breast cancer, the risk of developing a subsequent tumor was reduced by excellent adherence to hormonal therapy, researchers stated.

Patients with excellent adherence to therapy saw their risk of a subsequent tumor reduced by 10.54 percentage points if they had received breast-conserving surgery (BCS) alone, and by 6.24 percentage points if they received surgery with radiation therapy (RT), according to the study.

The authors also noted that “for excellent versus good adherence, the reduced risk among women who had BCS with and without RT was approximately 3 and 5 percentage points, respectively. A similar pattern emerged for the risk of IBC (invasive breast cancer) among women who achieved excellent versus good or low adherence, whereas good versus low adherence comparisons were not significant.”

Tara Rick, a physician assistant at the University of Minnesota specializing in cancer survivorship, spoke with CURE via email about these findings, which she said show that “good adherence to endocrine therapy is important for reducing the risk of recurrence in patients with ER+ (estrogen receptor-positive) DCIS who have had breast conserving therapy.”

Q: Did anything about these findings surprise you? If so, what and why?

A: I am glad to see studies looking at women 65+ years as half of our breast cancer population (is) in this age group and it is important to understand if there are unique outcomes in this group. In this particular study, the results were consistent with the population as a whole. 

Q: The study stresses the importance of adhering to hormonal therapy after surgery for patients with DCIS. What are some potential barriers to treatment adherence for this patient population?

A: In any patient population we need to weigh the risks and benefits of treatment. The major challenge of adhering to treatment are the side effects such as joint/muscle aches, vaginal dryness, hot flashes/night sweats (and) mood and sleep changes.

It depends on the individual's goals of care. Hormone therapy for DCIS doesn't affect survival but does reduce the risk of recurrence and it can affect quality of life. For example, if a patient in their 70s has a good quality of life and takes hormone therapy and their life is significantly impacted by treatment, perhaps they could have a conversation with their oncologist. By not taking the medication they are not increasing the risk of dying of breast cancer, but they have a higher risk of having a recurrence. Individuals accept living with risk differently, so this conversation looks different in different people.

Q: How, if at all, have attitudes towards hormonal therapy evolved over time?

A: In my opinion, over time we have shifted away from treatment decisions being made solely by the oncologist. Now there is more shared decision making where (an oncologist) will provide options with risks and benefits of treatment and have a discussion with the patient about their goals of care. This is called informed decision making and (as a) result a patient is more empowered in her care.

Q:What implications could these findings have regarding utilization of hormonal therapy for patients with other types of cancers?

A: The same principles apply to patients with invasive hormone-positive breast cancer in that informed decision making is important with considering side effects and goals of care. And there are different factors to take into account with risk (regard to) with invasive disease so it is very individualized.

Q: Is there anything else you would like the CURE audience to know about this topic?

A: Since a majority of breast cancers are hormonally driven, we need to do better providing supportive care for side effects from treatment to help with adherence to treatment and quality of life. 

For example, at our institution, we are currently studying cannabis and cannabinoids for aromatase inhibitor induced joint pains. Also, sexual side effects need to be addressed more routinely and providers need to be better educated on how to manage these side effects.

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