Women who perform breast self-exams (BSE) may be more likely to detect a cancerous breast lump at an earlier stage than women who don’t do these exams. But the research on whether BSE actually leads to fewer breast cancer deaths has yielded contradictory results. Now, research published in the October 2, 2002 Journal of the National Cancer Institute suggests that BSE does not reduce breast cancer deaths. In fact, the study results suggest that women who perform BSE are more likely to unnecessarily undergo a breast biopsy—a procedure to remove and test a tissue sample from a breast lump.

About the Study

Researchers from the Fred Hutchinson Cancer Research Center in Seattle, Washington collaborated with Chinese researchers from the Shanghai Textile Industry Bureau (STIB) to study 266,064 Chinese women. All of the women were born between 1925 and 1958 and either worked at or retired from one of the 520 STIB textile factories in Shanghai. Women were enrolled in the study between October 1989 and October 1991 and were followed up until December 2000. Women with a history of breast cancer were excluded from this study.

At the start of the study, the women completed questionnaires about medical history and lifestyle habits. All of the women received primary health care through their STIB factories, which did not include screening mammograms. Although clinical breast exams were not included either, a small number of medical factory workers did perform them. Each factory was randomly assigned to either have BSE training for its female study participants (BSE group) or to provide no information on breast cancer screening (control group). In addition, the factory medical workers were instructed not to perform clinical breast exams unless a woman reported finding a lump.

The BSE training consisted of the following:

  • Initial instruction in BSE techniques
  • Individual instruction and practice on silicon breast models and on their own breasts
  • Reinforcement training at one and three years
  • BSE videos and more practice after one and two years
  • Individual practice under the supervision of the medical worker several times per year for five years
  • Other reminders to practice BSE, including letters, home visits, posters in the factories, etc.

Researchers monitored medical records and cancer registries for 12 years to determine who developed breast cancer and who died from the disease. They compared breast cancer death rates in the BSE group with those in the control group. In addition, they compared breast biopsy procedures between the two groups.

The Findings

Women in the BSE group were no less likely to die of breast cancer than women not taught BSE. However, women in the BSE group were more likely to detect breast lumps than women not taught BSE. While this did not improve their chances of surviving breast cancer, it did increase the likelihood that they would undergo a breast biopsy only to learn that the lump was not cancerous. These findings remained the same after adjustment for other breast cancer risk factors, such as age, contraceptive practices, alcohol, and smoking.

Although these results suggest that BSE is not effective for breast cancer screening, this study has its limitations. First, this study was conducted in the absence of mammography and clinical breast exams, so it doesn’t assess the effectiveness of BSE in conjunction with these other screening methods. Second, the women in the BSE group may not have actually performed the BSEs monthly as they were instructed. Third, information on family history of breast cancer does not seem to have been collected, so the role of this important risk factor remains unclear.

How Does This Affect You?

Do you need to perform regular breast self-exams to protect yourself from dying of breast cancer? Probably not. When the results of this study are combined with findings from other studies, there no longer seems to be compelling evidence that these exams reduce your risk of dying of breast cancer. And in fact, this study suggests BSE may increase your chances of undergoing unnecessary breast biopsies.

However, it’s still a good idea to be on the lookout for changes in your breasts (including lumps) and report these changes to your doctor. Drs. Russell Harris and Linda Kinsinger explain in their editorial on this study that the focus on BSE over recent decades has helped increase women’s awareness of breast cancer and breast health. While they say physicians no longer need to promote BSE to their female patients, they recommend that physicians continue to perform careful clinical breast exams.