Post-Treatment Lifestyle Shapes Breast Cancer Outcomes

• Younger patients can breastfeed safely without increasing the risk of developing cancer or a new cancer in the opposite breast
• A telephone intervention can be effective in motivating overweight patients to exercise more, to lose weight

Three studies led by researchers at the Dana-Farber Cancer Institute have promising results for breast cancer patients. Two studies focus on breastfeeding after breast cancer diagnosis and treatment. Studies have found that it is safe and possible for young patients with genetic variants to breastfeed without increasing the risk of breast cancer or cancer in the other breast, and that it was safe and possible to breastfeed in hormone receptor-positive patients. HR+) breast cancer that developed after temporary interruption of endocrine therapy. A third study shows that a telephone training program can significantly increase physical activity in obese patients, which can improve their outcomes. Studies were presented at the European Society of Medical Oncology (ESMO) Congress 2024 in Barcelona, ​​Spain.

Breastfeeding after breast cancer is safe and possible for breast cancer survivors

The first study was a collaboration among researchers from 78 hospitals and cancer treatment centers around the world. It included 474 patients with inherited mutations in the cancer-causing genes BRCA1 or BRCA2 who became pregnant after being diagnosed with stage I-III invasive breast cancer at age 40 or more than.

The researchers divided the patients into two groups – those who breastfed after giving birth and those who did not – and followed their health over time. At seven years after delivery, there was no difference between the two groups in the occurrence of cancer in the first tumor site or in the opposite breast. Disease-free survival – how long patients live without cancer – and overall survival were also similar in the two groups.

A second study presents breastfeeding results from the POSITIVE trial that demonstrated the initial safety of temporary interruption of endocrine therapy in trying to conceive. The second important outcome was the effects on breastfeeding. The study included 518 patients aged 42 years or younger with HR+, stage I-III breast cancer. Of these patients, 317 gave birth alive while 196 chose to breastfeed. Breast-conserving surgery was the mainstay of breastfeeding.

Previous research led by Dana-Farber has shown that young breast cancer survivors who have breast-conserving therapy and go on to breastfeed may have problems breastfeeding from the treated breast and need relying on the other and unaffected breast to feed the baby.

“These studies provide the first evidence on the safety of breastfeeding after breast cancer in young patients with BRCA variants that can lead to breast cancer, as well as in patients who conceive after stopping treatment. endocrine,” says Ann Partridge, MD, MPH, founder and director of the Dana-Farber Young Breast Cancer Program, and principal investigator on the study. “Our findings emphasize the possibility of supporting the needs of mothers and babies without compromising the protection of pregnant women.”

Issued paper session: Supportive and silent care

• Breastfeeding in women with hormone-responsive breast cancer who conceived after temporary interruption of endocrine therapy: Results from the POSITIVE trial (1814O)
• Ann Partridge, MD, MPH, Dana-Farber, co-principal investigator

Issued paper session: Supportive and silent care

• Breastfeeding after breast cancer in young BRCA carriers: results of an international cohort study (1815O)
• Ann Partridge, MD, MPH, Dana-Farber, co-principal investigator

A training program for more exercise

The third study draws on data from the Cancer Weight Loss Trial (BWEL), which is examining the effectiveness of participating in a weight loss program after a breast cancer diagnosis. may reduce the risk of cancer recurrence in women with a body mass index (BMI) that is overweight or obese. The BWEL trial assigned 3,180 women with breast cancer to a group that received a telephone coaching program focused on reducing calories and increasing exercise combined with health education materials. beauty and health education materials only. The primary objective of the study is to determine whether a weight loss program reduces the risk of developing cancer and a secondary objective focuses on examining whether a weight loss program helps cancer survivors. of breasts to exercise more and eat a healthy diet.

The study, presented at ESMO, looks at changes in exercise in 541 BWEL study participants who took part in a study that assessed their exercise patterns over time. Half of the patients participated in a weight loss program and an educational program, and the other half received only the educational materials.

At the time of enrollment in the trial, patients in both groups were doing very little exercise—between zero minutes per week in the health education group and 10 minutes per week in the weight loss group. Six months after enrollment, women receiving the weight loss program increased their weekly physical activity by an average of 40 minutes and women in the study group did not. increase their exercise at all. In addition, women who participated in the weight loss program were more likely to exercise at least 150 minutes per week—a level of exercise associated with many health benefits—and there were it is easier to report not exercising at all, compared to women in the study. one group.

Across all study patients, those who participated in at least 150 minutes of moderate or vigorous exercise per week lost more weight than those who did not.

“Our results show that a telephone intervention to lose weight can motivate this group of patients to be more physically active,” says first author of the study, Jennifer Ligibel, MD, Director of the Center for Leonard P. Zakim of Integrative Therapy Health Dana-Farber. “We will continue to follow these patients to determine if changes in exercise influence the outcome of the cancer.”

Small talk session: Supportive and supportive care

• Effect of weight loss intervention (WLI) on exercise behavior in women with breast cancer: Results from the Breast Cancer Pain Trial (BWEL) (1817MO)
• Jennifer Ligibel, MD, Dana-Farber, contributing author