Counseling points
OBG Management: How do you counsel patients about the adverse effects of preventive medications, and how can they be managed?
Dr. Pederson: Patients’ fears about adverse effects are often worse than the adverse effects themselves. Women will fester over, Should I take it? Should I take it possibly for years? And then they take the medication and they tell me, “I don’t even notice that I’m taking it, and I know I’m being proactive.” The majority of patients who take these medications don’t have a lot of significant adverse effects.
Severe hot flashes can be managed in a number of ways, primarily and most effectively with certain antidepressants. Oxybutynin use is another good way to manage vasomotor symptoms. Sometimes we use local vaginal estrogen if a patient has vaginal dryness. In general, however, I would say at least 80% of my patients who take preventive medications do not require management of adverse side effects, that they are tolerable.
I counsel women this way, “Don’t think of this as a 5-year course of medication. Think of it as a 90-day trial, and let’s see how you do. If you hate it, then we don’t do it.” They often are pleasantly surprised that the medication is much easier to tolerate than they thought it would be.
OBG Management: What role does lifestyle modification play in conjunction with chemoprevention?
Dr. Pederson: It would be neat if a trial would directly compare lifestyle interventions with medications, because probably lifestyle change is as effective as medication is—but we don’t know that and probably will never have that data. We do know that alcohol consumption, every drink per day, increases risk by 10%. We know that obesity is responsible for 30% of breast cancers in this country, and that hormone replacement probably is overrated as a significant risk factor. Updated data from the Women’s Health Initiative study suggest that hormone replacement may actually reduce both breast cancer and cardiovascular risk in women in their 50s, but that’s in average-risk women and not in high-risk women, so we can’t generalize. We do recommend lifestyle measures including weight loss, exercise, and limiting alcohol consumption for all of our patients and certainly for our high-risk patients.
The only 2 things a woman can do to reduce the risk of triple negative breast cancer are to achieve and maintain ideal body weight and to breastfeed. The medications that I have mentioned don’t reduce the risk of triple negative breast cancer. Staying thin and breastfeeding do. It’s a problem in this country because at least 35% of all women and 58% of Black women are obese in America, and Black women tend to be prone to triple-negative breast cancer. That’s a real public health issue that we need to address. If we were going to focus on one thing, it would be focusing on obesity in terms of risk reduction.
Final thoughts
OBG Management: Would you like to add any other points about chemoprevention?
Dr. Pederson: I would like to direct attention to the American Heart Association scientific statement published at the end of 2020 that reported that hormone replacement in average-risk women reduced both cardiovascular events and overall mortality in women in their 50s by 30%.5 While that’s not directly related to what we are talking about, we need to weigh the pros and cons of estrogen versus estrogen blockade in women in terms of breast cancer risk management discussions. Part of shared decision making now needs to include cardiovascular risk factors and how estrogen is going to play into that.
In women with atypical hyperplasia or LCIS, they may benefit from the preventive medications we discussed. But in women with family history or in women with genetic mutations who have not had benign atypical biopsies, they may choose to consider estrogen during their 50s and perhaps take tamoxifen either beforehand or raloxifene afterward.
We need to look at patients holistically and consider all their risk factors together. We can’t look at one dimension alone.
OBG Management: Thank you for sharing your insights, Dr. Pederson. ●