SAN ANTONIO – Contralateral prophylactic mastectomy – in comparison to unilateral mastectomy – was associated with a significantly increased rate of major postoperative surgical complications in a 470-patient study.
Physicians therefore must provide appropriate information about these risks to patients who are considering the contralateral procedure, according to lead investigator Allison C. Stover, M.P.H. Major complications often require numerous unplanned procedures, which increase patient burden and treatment costs.
To assess the impact of the contralateral procedure on surgical outcomes, Ms. Stover of the University of California, San Francisco, and her colleagues identified patients who underwent unilateral or bilateral mastectomy with immediate reconstruction at her institution between 2005 and 2010. A minimum of 1 year of follow-up data was available for each study participant. Patients with bilateral cancer or bilateral prophylactic surgery were excluded from the analysis.
The investigators grouped the patients by unilateral or contralateral mastectomy status. They also prospectively captured complications, including infection with use of oral or intravenous antibiotics; implant exposure, loss, or removal; seroma; hematoma; delayed wound healing; necrosis; readmission; and return to the operating room.
Among the 470 patients (665 breasts) who met the study criteria, the mean follow-up time was 22 months. There were no differences between the groups in tumor grade, stage, follow-up time, smoking history, or radiation, either prior to or post surgery, Ms. Stover said in a poster presentation at the San Antonio Breast Cancer Symposium.
Significant between-group differences were observed in age and the number of skin-sparing mastectomies, she said, noting that the contralateral group was younger than the unilateral group (mean age 46.04 years vs. 50.55 years, respectively), and had a larger proportion of skin-sparing mastectomies.
The rate of any major complication was 1.5 times higher in the contralateral group compared with the unilateral group, Ms. Stover stated. "There were significant between-group differences in the number of severe infections requiring IV antibiotics and return to the operating room, as well as the overall rate of any major complication," she said.
A comparison of the complication rate by index vs. prophylactic breast within the contralateral group showed a significantly higher rate of implant loss in the index breast, but no significant differences in any other measure, Ms. Stover noted.
Because many contralateral cases are not at sufficiently high risk for a second breast cancer to meet clinical criteria for prophylactic surgery, the increased complication rate should be taken into consideration when counseling women who are contemplating contralateral mastectomy, Ms. Stover said, adding that they should also be incorporated into guidelines and clinical recommendations.
The poster discussant, Dr. Ismail Jatoi of the University of Texas Health Sciences Center in San Antonio, pointed out that the study’s mean follow-up of 22 months may be insufficient to adequately compare the complication rates. "There are long-term implications that may increase the value [of the contralateral procedure]. For example, patients who undergo the procedure no longer undergo mammograms and thus are not subject to false-positive reports and the subsequent associated testing. They may have lower morbidity over time," he said. "The long-term impact may be less dire than the short-term impact."
It is also possible that the results could be attributed to a "multiplicity of testing," Dr. Jatoi said. "When you test for a lot of bad outcomes, you’re likely to find one."
Despite these concerns, "there clearly are some risks, which point to the need for proper, thorough informed consent," said Dr. Jatoi. "The possible increased complication risks are definitely points to be made when we provide informed consent."
Ms. Stover and Dr. Jatoi reported that they had no relevant financial conflicts.