Women's study finds breast cancer drug side effects worse than known

Kathleen Blanchard's picture
Breast cancer drugs

(EmaxHealth) For the first time researchers have asked women why stop taking their breast cancer drugs, risking the chances that the disease will recur. Northwestern University researchers found 36 percent of women stop taking the drugs because the side effects are worse than previously known.

Lynne Wagner, an associate professor in medical social sciences at Northwestern University Feinberg School of Medicine and a clinical psychologist at Robert H. Lurie Comprehensive Cancer Center of Northwestern University says no one knew how bad the side effects were for women. Doctors might underestimate side effects of the breast cancer drugs because women don’t tell them.

Medications that stop breast cancer from recurring, known as aromatase inhibitors can cause joint pain, weight gain and moodiness.

Tamoxifen, which is also used, but not an aromatase inhibitor, can cause vaginal dryness, joint pain and cramping in the legs, according to the National Cancer Institute.

Aromatase inhibitors block the enzyme aromatase that converts another hormone – androgen – into estrogen. Tamoxifen is a SERM – Selective Estrogen Receptor Modulator, meaning it works against the effects of estrogen so breast cancer that is estrogen receptor positive won’t grow.

Two-thirds are breast cancer are estrogen sensitive.


In their study, the researchers found women stop the drugs primarily due to joint pain. Other side effects reported by the women were decreased libido, bloating and weight gain, irritability, mood swings, nausea and breast sensitivity.

Wagner says physicians "… give patients a drug they hope will help them, so they have a motivation to underrate the negative effects. Patients don't want to be complainers and don't want their doctor to discontinue treatment. So no one knew how bad it really was for patients."

She says the study is a "wake-up call" to help women so they can tolerate the drugs. She suggests counseling can help women understand how important the medications are for preventing breast cancer from returning.

The finding, presented Dec. 9 at the 34th Annual San Antonio Breast Cancer Symposium, found women who had surgery alone for breast cancer treatment were more likely to stay on the drugs.

Those who had chemotherapy or radiation and were still feeling bad when aromatase inhibitors were started were more likely to stop taking the drugs.

A recent study, reported by EmaxHealth, conducted by Dr. Maryam Lustberg, an assistant professor at the Ohio State College of Medicine showed omega-3 fatty acids might lessen joint pain and other symptoms from the medications. Lustberg is working on helping women find a solution, in conjunction with Tonya Orchard, a doctoral student in nutrition and neuroscientist Dr. Courtney DeVries.

Image credit: Wikimedia Commons


Please, click to subscribe to our Youtube Channel to be notified about upcoming health and food tips.