Review Finds Research Lacking On The Safety Of Pregnancy After Breast Cancer Treatment

April 01, 1997

New York, April 1, 1997 -- Researchers at Memorial Sloan-Kettering Cancer Center have found a lack of conclusive evidence to support previously published studies confirming the safety of pregnancy following breast-cancer treatment. After conducting a critical review of the literature, investigators found limited information regarding the safety of pregnancy and other childbearing issues of concern to young breast-cancer survivors.

"Multiple biases and the small number of patients studied earlier render the conclusions premature, necessitating further research," explained Dr. Jeanne Petrek, a breast surgeon at Memorial Sloan-Kettering Cancer Center. She co- authored the paper, which was published in the April 1st issue of the journal Cancer.

"We are not saying that it's unsafe to become pregnant after surviving breast cancer," Dr. Petrek stresses. "What we are saying is that the existing studies examining this issue are inconclusive and that more research is needed."

The researchers point out that the previous studies were retrospective, containing data gathered from hospital records where subsequent pregnancy was not recorded. Therefore, the reported data were dependent on the memory of the treating physician. This method predisposed the studies to a "recollection bias," which may account for the good outcomes reported.

In addition, the researchers also evaluated studies that reported better medical outcomes for breast-cancer patients who became pregnant after treatment than for matched controls who did not. However, the reviewers contend that these results may be flawed because the dates of disease recurrence were not taken into account. Therefore, the overall health of both groups is not accounted for accurately, rendering the comparison unreliable.

In light of laboratory data that have demonstrated the influence of estrogens on the promotion of breast cancer, the investigators say that further research is needed to determine if tumor growth is accelerated in pregnant women. "Tumor growth could occur because the total estrogen levels are vastly higher during pregnancy than at any other time in an adult woman's life, and the proportion of the estrogens are different," Dr. Petrek explains. "We simply do not know what effect this will have on the breast-cancer survivor."

Other Childbearing Issues Also Need Study
The researchers also emphasize the need to address other reproductive health concerns facing young breast-cancer survivors. These include treatment side effects, such as the risk of infertility and premature menopause, and alternatives such as in vitro fertilization, adoption, and surrogacy. "For the younger woman with breast cancer, these issues are of paramount importance," says Dr. Antonella Surbone, an Associate Attending Physician at Memorial Sloan- Kettering Cancer Center and co-author of the paper. "Clinicians must thoroughly discuss the risks associated with treatment and other childbearing issues and alternatives with their patients both before and after treatment."

This summer, Memorial Sloan-Kettering Cancer Center will launch the first prospective trial to study a host of complex childbearing issues facing young breast-cancer survivors. Especially designed questionnaires will be used to collect data on menstruation, pregnancy, the effect of chemotherapy on the reproductive system, and the quality-of-life issues facing women who become infertile after high-dose regimens of chemotherapy.

"Only a carefully designed prospective study will resolve the uncertainties surrounding the many issues of reproduction in women who have been treated for breast cancer," adds Dr. Surbone.

Memorial Sloan-Kettering is the world's oldest and largest private institution devoted to prevention, patient care, research and education in cancer. Throughout it's long and distinguished history, Memorial Sloan-Kettering has played a leadership role in defining the standard of care for persons with cancer. In 1996, Memorial Sloan-Kettering was named the nation's best cancer center by U.S. News and World Report for the fourth year in a row.
-end-


Memorial Sloan Kettering Cancer Center

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.