Laurie Barclay, MD

Medscape Medical News 2004. © 2004 Medscape

Dec. 23, 2004 — Breast implants used for reconstruction after mastectomy for breast cancer do not appear to adversely affect survival, according to the results of an analysis of surveillance, epidemiology, and end results data published in the January issue of Breast Cancer Research and posted online Dec. 23.

"Few studies have examined the effect of breast implants after mastectomy on long-term survival in breast cancer patients, despite growing public health concern over potential long-term adverse health effects," write Gem M. Le, from the Northern California Cancer Center in Fremont, and colleagues.

The investigators collected and analyzed data from 4,968 women enrolled between 1983 and 1989 in the Surveillance, Epidemiology and End Results Breast Implants Surveillance Study, carried out in Iowa, the San Francisco area, and the Seattle area. In this population-based, retrospective cohort study, women younger than 65 years, when diagnosed with early or unstaged first primary breast cancer, were treated with mastectomy and followed for a median of 12.4 years.

Postmastectomy breast implants were used in 20% of women, and silicone gel–filled implants were the most common type. Compared with patients not receiving implants, those with implants were younger and more likely to have in situ disease.

After adjustment for age and year of diagnosis, race and ethnicity, stage, tumor grade, histology, and radiation therapy, risk of breast cancer mortality was lower in patients with implants than in those without implants (hazard ratio [HR], 0.54; 95% confidence interval [CI], 0.43 - 0.67), as was risk of non–breast cancer mortality (HR, 0.59; 95% CI, 0.41 - 0.85). Breast cancer mortality was 12.4% in women with an implant compared with 19.7% in women without an implant. The type of implant used did not appear to affect long-term survival.

Compared with women without implants, women with breast implants had a significant excess proportion of deaths due to suicide.

"Certainly, further research is needed to explain this survival differential in women with breast implants and those without, by examining potentially explanatory factors such as socioeconomic status, comorbidity, smoking, or other lifestyle factors," the authors write. "One explanation for our finding of reduced mortality in patients with breast implants may relate to self-selection rather than to a causal role of implants."

The authors note that surgeons may not recommend breast implants to women with health conditions such as obesity or a recent history of smoking that may increase postoperative complications. In this study, the possibility of self-selection based on smoking is supported by the higher proportions of deaths from respiratory cancers and chronic obstructive pulmonary diseases in women without breast implants.

Other methodological concerns include loss to follow-up in 231 patients (5.3%) included in the survival analysis, potential bias related to differences between nonresponders and responders, and uncontrolled confounding by social class, medical care, and psychological factors related to implant use and survival.

"Because women with breast implants may be more closely followed in their medical care, they may have recurrences diagnosed and treated earlier; thus they may experience better survival than women without implants," the authors write. "Furthermore, psychological factors underlying a woman's decision to obtain breast implants, including body image concerns and self-esteem, may play a role in lifestyle behaviors relevant to survival, although the extent to which they directly impact survival is unclear."

Data for the SEER Breast Implant Surveillance Study were collected by the Northern California Cancer Center, Seattle-Puget Sound Cancer Registry, and Iowa Cancer Registry, with support of the National Cancer Institute, National Institutes of Health. The authors report no potential financial conflicts of interest.

Breast Cancer Res. 2005;7:R184-R193

Reviewed by Gary D. Vogin, MD

http://www.medscape.com/viewarticle/496579_print