Endocrine Therapy: Getting to the Heart of the Matter

Looks like visiting a cardiologist after stopping aromatase inhibitors for breast cancer was a good idea after all.

The letrozole (aromatase inhibitor) that I’d been taking has been associated with cardiovascular effects, and since I was feeling progressively worse from the medication, I wanted to make sure that everything checked out okay.

With the improvement in surivorship comes an increase in the diseases that come about from cancer treatments. The longer people live, the more long-term effects take their toll.

It seems like the American Heart Association (AHA) agrees with my concerns. An April 26, 2021 statement by the AHA underscored the complicated picture of cancer treatments, in this case hormonal therapies for breast and prostate cancer. As stated in the article by Okwuosa et al. (2021) published in Circulation: Genomic and Precision Medicine, “As patients with hormone-dependent cancers continue to live longer, CVD [cardiovascular disease] has emerged as a leading cause of mortality and morbidity among survivors of these cancers.”

Ironically, breast and prostate cancers are some of the most common cancers in women and men, in addition to having some of the most effective treatments. The number is of breast and prostate cancer survivors is growing. Part of the success of treatment is expressly due to the development of hormonal therapies for long-term (5-10 year) use. At the same time, the increase in CVD problems is a result of this success, because as cancer survivors age they experience greater amounts of age-related cardiovascular events than do non-cancer surivors.

So, what do you do when the treatment that’s increasing your chances of beating cancer may also be increasing your chances of a cardiovascular event? Isn’t that one of the many problems with cancer? If your treatment works well, then that opens the door to having it work “too enthusiastically”, possibly with long-lasting negative effects.

It still comes down to healthy behaviors.

The AHA statement paper cited here stresses the importance of communicating with your oncological team about CVD risk factors and possibly requesting a referral to a cardiologist, having appropriate tests conducted (ECG/EKG, echocardiogram), and–in my opinion the most important thing the survivors themselves can do–modify lifestyle (diet, exercise, smoking cessation, etc.) to maximize your chances of a cardiovascular event-free survivorship.

While it may be frustrating to think of entering into an “out of the frying pan, into the fire” scenario with a potential leapfrog from cancer to CVD, nothing is written in stone. You can make an effort to protect yourself and avoid being a statistic. Focusing on healthy living will benefit you in many ways and is guaranteed to improve your life, no matter what your risks.

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Link to the AHA statement:
Okwuosa et al. (2021) Impact of Hormonal Therapies for Treatment of Hormone-Dependent Cancers (Breast and Prostate) on the Cardiovascular System: Effects and Modifications: A Scientific Statement From the American Heart Association. Circ Genom Precis Med,
DOI: 10.1161/HCG.0000000000000082

Link to a reader-friendly version:
People Taking Hormonal Therapy for Breast Cancer Have Higher Risk of Heart Disease, Monitoring Recommended, https://www.breastcancer.org/research-news/higher-risk-of-heart-disease-for-diagnosed-people-taking-hormonal-therapy

Pre- vs. Postmenopausal Breast Cancer Risk: There’s a Difference, But Does It Matter?

You’ve probably seen those plastic breast self-exam cards you hang on your showerhead as a reminder to feel for lumps on a monthly basis. I have one myself, and would read it over and over when I was trying to decide whether my lump was worrisome, reviewing the “reduce your risk” tips the card offered.

However, there are two points that I wasn’t aware of at the time that I was diagnosed: (1) we know little about causal factors, as most studies that examine risk are only correlational; and (2) there’s a difference between being premenopausal vs. postmenopausal when talking about breast cancer.

Okay, there’s a third one too: (3) risk factors don’t mean squat when I’m talking about my personal diagnosis.

First, a well-known fact: postmenopausal women make up the majority (approximately 2/3) of these cancer cases, so it’s not surprising that the focus is on them.

I, however, was premenopausal when I felt the lump in my left breast.

Imagine my surprise, then, when I learned that while being overweight or obese is a significant risk factor for postmenopausal women, being overweight as a premenopausal woman seems to offer protection against the disease. Whereas I thought I didn’t have any risk factors for breast cancer, as suggested by that plastic card in my shower, perhaps I did.

There’s not much talk about that protective element of weight for premenopausal women. You would be hard-pressed to find a popular website that mentions it. And no doctor would encourage a premenopausal woman to carry extra weight on the off chance that it might lower her risk of breast cancer; it’s too much of a liability for other health issues, including other cancers.

This explains why, if you’ve gone to a gathering of newly-diagnosed breast cancer patients, you’ll see some younger, remarkably fit women looking a little dazed and wondering what they’re doing there.

The weight risk factor is often posed in the following way (from the Mayo Clinic site): “Overweight and obese women have a higher risk of being diagnosed with breast cancer compared to women who maintain a healthy weight, especially after menopause.” Well, that’s not wrong, but it doesn’t tell the entire story.

Harvard Health Online puts it differently, with a caveat: “Being overweight or obese has been linked to breast cancer risk, especially for women after menopause, but the relationship is complicated. It may be that risk is increased in women who gain weight in adulthood but not in those who’ve been overweight since childhood.” That seems even more confusing and less reassuring.

It’s true that everything about cancer is complicated. If it were straightforward, we would have found a cure by now. Furthermore, when it comes to guidelines to follow, people don’t want details, they want sound bites. But simplification cuts out information. For example, this CDC webpage about what you can do to lower your breast cancer risk posts recommendations geared for older women, including maintaining a “healthy weight”, but the photo that’s shown is clearly of two younger women.

Even a cursory glance at the research reveals what a difference menopausal status makes. In addition to extra weight seeming to have a protective effect in premenopausal women (Cold et al., 1998, Eur J Cancer; Lahmann et al., 2004, Int J Cancer), it’s also been determined that greater red meat consumption in adolescence is significantly associated with increased risk of breast cancer in premenopausal women (Farvid et al., 2015, Int J Cancer). Interestingly, higher quality diets have a more beneficial effect on the risk of postmenopausal women and seemingly no effect on premenopausal ones (Haridass et al., 2018, J Nutr). I would expect that a more exhaustive search would yield even greater differences.

Live as if your life depends on it.

So what does this tell us? This is less about the specific differences between pre- and postmenopausal breast cancer risk, and more that there simply is a difference. At this point in our knowledge, we are still putting together pieces of the cancer puzzle.

Additionally, many studies that offer preventative guidelines are based on other studies–they may be meta-analyses of previously collected data from a broad range of subjects. The data may be self-reported, which may result in recall error. And when you have a sample size of ~30,000 women, you’re talking about general risks for populations, not a specific risk for a specific, and very unique, individual: you.

All this sounds exasperating, but one concept holds true: no matter what your risks, the healthier you are before you’re diagnosed with cancer, the better your outcome compared to someone with less healthful habits, should you get the disease. Instead of obsessing about possible risk factors, give yourself the respect you deserve–put the effort into improving lifestyle habits to grant yourself the best chance for survival. In the end, that’s what matters.

A Final Word On Risk Factors

Okay, maybe this post’s title is a lie, since I keep bringing this topic up. But I admit that I need to stop whining about getting breast cancer when I didn’t have risk factors, so I’m officially giving myself one last time to vent. And then it’s time to let it go.

First, what is a risk factor? The NIH National Cancer Institute dictionary defines a risk factor as “something that increases the chance of developing a disease”. However, that does not mean that it’s necessarily a cause of that disease. And that’s where the potential confusion (and in my case, irritation) arises.

While breast cancer has a number of risk factors, none of them are 100%-for-sure causal in nature. Even having the BRCA gene does not guarantee that you’ll get breast cancer, although your risk is quite high.

So why does this matter? Turn this around and look at someone with breast cancer. Based on risk factors, you’d expect them to be overweight, sedentary, a smoker, a drinker, an unhealthy eater…and you might be completely wrong. Ascribing unhealthy behaviors to an individual just because they are a cancer patient is potentially stigmatizing (it suggests that they are responsible for bringing on their disease) and ignores the fact that we still don’t know why cancer develops. And what of all those making poor health choices who do not get cancer?

Engaging in the opposite behaviors — being a lean, active, non-smoker, non-drinker with a plant-based diet — likewise is not guaranteed to protect you from breast cancer. And yet, that’s exactly the feeling you get from reading all the recommendations, which leads to a potentially dangerous false sense of security.

Risk factor, schmisk factor! Putting in the effort to live as healthfully as possible is well worth it, no matter what.

Certainly, no matter what disease you have, the more healthy behaviors you engage in, the better your outcome. However, even being a paragon of healthy living is not the “get out of cancer jail free” card that we are led to believe it is. So get yourself checked out and don’t take your health for granted!

What brought all of this up? At a recent gathering, I had an interesting conversation with another former cancer patient who also happens to be a medical psychologist. She felt as frustrated as I did about the way cancer risk factors are presented, so I felt a vindication of sorts. We both agreed that it is critical to highlight the difference between cancer risk factors and causes. And of course, no matter what your perceived cancer risk, to live as healthfully as possible.

Now that I’ve gotten that off my chest, I will do my best to shut up and move on.