Breast-Feeding Appears Safe in Breast Cancer Survivors

October 20, 2010

October 20, 2010 (Milan, Italy) — Many women are discouraged from breast-feeding after treatment for breast cancer, but new data suggest that it is feasible. Even though the sample size was small, there is no evidence to suggest that breast-feeding affects prognosis.

There are many advantages to breast-feeding, both for the mother and infant, said study author Hatem Azim, MD, from the Jules Bordet Institute in Brussels, Belgium, who presented the findings here at the 35th European Society for Medical Oncology Congress.

There is no evidence to suggest that breast-feeding is detrimental after breast cancer treatment, yet women are advised not to attempt it, he explained during a press briefing.

"The main reason that women in our survey didn't breast-feed was medical counseling against it," Dr. Azim said. "This was the message that was delivered by us, by oncologists. We say that we prefer that you don't breast-feed, but this is based on a perception rather than on concrete information that breast-feeding is detrimental."

He emphasized that even though the numbers in this study are low, breast cancer survivors who breast-fed their newborns were not found to be at a higher risk for disease recurrence.

"This information should be taken into consideration when counseling women in clinics who are considering getting pregnant and breast-feeding their newborns," he added.

Return to Normal Life

Fortunato Ciardiello, MD, PhD, who moderated the briefing, said that this is a "very important observation, and a very positive message."

"Breast-feeding signifies a return to normal life, which is very important to the patient," said Dr. Ciardiello, who is a professor of medical oncology at Seconda Università di Napoli, in Naples, Italy.

Dr. Azim and colleagues previously conducted a meta-analysis that confirmed the safety of pregnancy in breast cancer survivors. The results of that analysis, which were presented at the 2010 European Breast Cancer Conference (Abstract 504), showed that the hazard ratios in all 14 studies in the review favored pregnancy for overall survival.

The result of the meta-analysis was that pregnancy after treatment for breast cancer appeared to be safe and was not contraindicated, he explained. "However, [that] analysis did not answer some questions — namely, the feasibility and safety of breast-feeding."

The reason for conducting this survey was to take it a step further, and to evaluate the effect of breast-feeding on cancer recurrence among breast cancer survivors.

Limited Success

Dr. Azim and colleagues used the database of the European Institute of Oncology to identify women 40 years of age and younger who had been diagnosed with breast cancer from 1988 to 2006. They put together a questionnaire and conducted a survey of patients who had completed a pregnancy after treatment for breast cancer to evaluate lactation behavior and its effect on disease outcome.

A total of 32 women were identified, and 20 agreed to participate in the survey. Of this group, 15 women had been treated with breast-conserving surgery; the remaining participants had undergone mastectomy. Only half (n = 10) of the women had initiated breast-feeding.

The patients were followed for a median of 4 years after delivery. During that time, 2 relapses occurred: 1 in the group that did breast-feed, and 1 in the group that did not.

Of the 10 women who breast-fed, only 6 were successful at doing so over the long term (median, 11 months; range, 7 to 17 months). The other 4 women stopped breast-feeding within 1 month. Of the 15 women who had undergone breast-conserving surgery and radiotherapy, 14 reported hypoplasia of the irradiated breast during pregnancy.

Seven women attempted to breast-feed from the treated breast but found that their milk production was significantly reduced and that the infant had difficulty latching on. Only 2 women were able to breast-feed from both breasts, but only for a period of 2 weeks.

"We found that the affected breast did not enlarge normally during pregnancy, and the baby had problems latching on to the affected breast," explained Dr. Azim. "Based on previous studies and our own data, the quality of milk from the treated breast is very compromised. But normal feeding is possible on the contralateral breast."

Breast-Conserving Surgery and Counseling

The authors observed that there were 2 primary factors associated with successful long-term breast-feeding in this study. The first was the type of surgical intervention that the patient had undergone. Although all of the participants nursed from only the contralateral breast, women who had undergone breast-conserving surgery were more likely to successfully breast-feed than those who had undergone mastectomy.

The other major factor in breast-feeding success was postdelivery lactation counseling. All 6 women who experienced long-term success had undergone breast-conserving surgery and had received lactation counseling at the time of delivery.

In general, Dr. Azim reiterated that using 1 breast for feeding is feasible. "It may require professional counseling on how to satisfy the needs of the baby with 1 breast, but it is feasible and possible."

Dr. Azim acknowledged that their findings are limited because of the small sample size, but that it is not really possible to conduct a randomized study, and that this is a very small and uncommon population of breast cancer survivors.

"This may compromise the quality of research, but . . . there are absolutely no data that show it has a negative effect," he said. "I would not promote breast-feeding as a protective mechanism, but at least we can say that it appears to be safe."

Dr. Ciardiello noted that "we have data that show that a normal life for cancer survivors is best, so we don't need a randomized trial to show that."

"This is the message: If the woman is cured of breast cancer, she should go back to a normal life, and breast-feeding is normal life," he said.

The researchers have disclosed no relevant financial relationships.

35th European Society for Medical Oncology (ESMO) Congress: Abstract 251P. Presented October 10, 2010.


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