Breast cancer and stopping hormone therapy: risks and side effects

Breast cancer: taking hormones and side effects

When do side effects of hormone therapy begin?

Hormone therapy is one of the possible treatments for breast cancer. Changing hormone levels or blocking hormones can slow the progression of cancer cells. Side effects may occur. They vary in intensity depending on the patient. They can appear quickly, a few days after starting treatment, or late, a few months or even years after starting it.

What are the side effects of hormone therapy (bone pain, fatigue, sleep, etc.) in men or women?

THE Common side effects of hormone therapy are :

• Symptoms of menopause (hot flashes, sweating);
• Digestive disorders: constipation or diarrhea;
• Weight gain ;
• Fatigue, leading to difficulty performing daily tasks or sleeping;
• Thinning of hair and hair;
• Increased cholesterol levels;
• Nausea;
• Joint and muscle pain;
• Musculoskeletal pain (muscles and bones);
• Sexual disorders.

When do the effects of hormone therapy wear off?

Most of the effects of hormone therapy go away on their own. Most of these side effects can also be treated or reduced. Some of them are delayed while others can persist over time.

After starting hormone therapy for breast cancer, joint or muscle pain sometimes occurs. If this is the case, do not hesitate to talk to your doctor or a member of your medical team. There are medications available to relieve this pain, such as acetaminophen.

What treatment can replace hormone therapy?

Hormone therapy is only indicated in cases of breast cancer for which the hormone receptors are positive. Indeed, if the cancer cells have receptors (estrogen, progesterone), the hormones can nourish these cells and help them grow. Hormone therapy blocks this phenomenon. Hormone therapy is often an adjuvant treatment, complementary to surgery or radiotherapy. The care team decides on the best treatment, with the patient’s consent.

Early cessation of hormone therapy: what are the risks?

80% of breast cancers are hormone-sensitive, meaning that the cancer cells have hormone receptors. In this case, patients, after curative treatment by surgery, chemotherapy or radiotherapy, must follow five to ten years of hormone therapy treatment. Oral, injectable or surgical, it consists, as explained by the National Cancer Institute (INCa), of “preventing the stimulating action of female hormones on cancer cells”. A heavy and long treatment that many women do not follow through to the end, which leads to negative repercussions: in a study published on June 22 in the Journal of Clinical Oncology, French medical researchers demonstrate for the first time that young women who stop their hormone therapy prematurely have greater risk of disease relapse but also of the appearance of metastases.

Hormone treatment: one in six women does not follow the medical prescription (tamoxifen)

To reach this conclusion, teams from Gustave Roussy, Inserm and the University of Paris-Saclay looked at the cases of 1,177 pre-menopausal women treated for localized breast cancer, who had agreed to take hormone therapy (in this case, tamoxifen). These patients were part of the national CANTO cohort (for CANcer TOxicities), formed to study the toxicities associated with cancer treatments. therapeutic non-adherencedefined as a patient not following their treatment correctly, was measured using declarative questionnaires on the taking of tamoxifen and a blood biological test of the drug, one year after the prescription.

“The results of the blood test of Tamoxifen after one year of treatment showed that:one in six women (16%) do not follow the medical prescription after only one year of treatmentwhich is higher than what was previously described”, explains Dr. Barbara Pistilli, oncologist at Gustave Roussy and co-author of the study, in a press release.

Stopping medication: risk of relapse

With a real loss of luck: at three years, the risk of relapse, locally and distantly (appearance of metastases), increases by 131%. “It is multiplied by 2.31 when women do not take their hormone therapy in the first year, which is considerable.says Dr. Pistilli. At three years, 95% of women who followed the treatment had not relapsed, while only 89.5% of those who adhered less well did so. “According to the new measurements that we are currently carrying out, the gap seems to be widening even further both in terms of the risk of relapse and in terms of mortality after five to ten years of non-followed hormone therapy treatment.”, adds Dr. Inès Vaz-Luis, director of the study.

Several factors of non-adherence to treatment found

Furthermore, half of the women who did not follow the medical prescription did not mention it in the questionnaire, where the question was nevertheless asked.We see a significant disconnect between what these women dare to tell us and reality. We need to understand why, in order to offer them better-adapted help and a more personalized approach. It is important to change the way we treat these patients to improve their adherence to treatment.”

Why do women stop hormone therapy?

Among the main factors of non-adherence to treatment found: adverse effects such as fatigue or muscle and joint pain, the presence of other diseases, the fact of not having received chemotherapy but also the fact of not living as a couple.The interpretation of these results is more complex than it seems, Dr. Pistilli is keen to point out. Having been treated with chemotherapy causes fatigue and this seems to be a barrier to taking hormone treatment regularly. Paradoxically, not having received chemotherapy – indicated to reduce the risk of recurrence – also seems to reduce adherence to treatment..”

Better understanding of these factors will help doctors to “develop suitable solutions and tools to help [les patientes] to continue [le traitement] in order to offer them a better quality of life after cancer, while protecting them as much as possible from a relapse”, concludes Dr. Vaz-Luis.