Lipofilling of the Breast Does Not Increase the Risk of Recurrence of Breast Cancer

A Matched Controlled Study

Steven J. Kronowitz, M.D.; Cosman Camilo; Mandujano, M.D.; Jun Liu, M.D., Ph.D.; Henry M. Kuerer, M.D., Ph.D.; Benjamin Smith, M.D.; Patrick Garvey, M.D.; Reshma Jagsi, M.D.; Limin Hsu, M.A.; Summer Hanson, M.D.; Vicente Valero, M.D.

Disclosures

Plast Reconstr Surg. 2016;137(2):385-393. 

In This Article

Patients and Methods

Patient Identification

The Institutional Review Board of The University of Texas M. D. Anderson Cancer Center approved this retrospective analysis. The patients for analysis were identified in two stages. First, the database of prospectively collected data maintained by the M. D. Anderson Department of Plastic Surgery was searched for all patients who underwent segmental or total mastectomy for breast cancer or breast cancer risk reduction followed by breast reconstruction with lipofilling as an adjunct or primary procedure. For the patients identified as a result of this search, the dates of segmental or total mastectomy ranged from June of 1981 through April of 2013, and the dates of lipofilling ranged from January of 2001 through February of 2014. The patients identified from this initial search were divided into two groups: patients who underwent mastectomy for breast cancer treatment (i.e., cases) and patients who underwent mastectomy for reduction of breast cancer risk (i.e., cancer-free breasts), of which BRCA mutation information was available for 233 patients. Thirty-three patients were BRCA1/BRCA2 mutation carriers.

In the second stage of patient identification, the database of prospectively collected data maintained by the M. D. Anderson Department of Breast Medical Oncology was searched to identify patients with breast cancer who underwent mastectomy and breast reconstruction during the period from June of 1981 through April of 2013 but did not undergo lipofilling (i.e., controls).

Study Design

To assess the effect of lipofilling on the risk of locoregional recurrence of breast cancer, we compared outcomes in the breasts reconstructed with (i.e., cases) and without (i.e., controls) lipofilling after mastectomy for breast cancer. Breasts reconstructed with lipofilling after mastectomy for breast cancer risk reduction or benign disease were analyzed to achieve our secondary objective of determining whether patients who underwent lipofilling after risk-reducing mastectomy had an increased risk of primary breast cancer.

Statistical Analysis

Descriptive statistics, such as means and standard deviations, were used to summarize age and follow-up time. Frequencies and proportions were used to summarize the categorical characteristics. Demographic and clinical information was compared by using Fisher's exact test and the Wilcoxon rank sum test. The recurrence-free survival time was defined as the interval from the date of mastectomy to the date of first locoregional recurrence or the date of last follow-up if no locoregional recurrence was observed. Patients without locoregional recurrence were censored in the analyses. The probability of locoregional recurrence was estimated by the Kaplan-Meier product-limit method. Because lipofilling was often performed at various time intervals after the oncologic surgery, we used time-dependent Cox proportional hazards regression models to assess the effect of lipofilling on locoregional recurrence. We also used the multivariable Cox proportional hazards regression models to adjust the potential confounding factors. All the tests were two-sided. The p value was calculated by comparing breast cancer patients who received lipofilling to breast cancer patients who did not receive lipofilling. A value of p < 0.05 was considered significant. The analyses were performed using SAS 9.3 (SAS Institute, Inc., Cary, N.C.) and R (The R Foundation for Statistical Computing, Vienna, Austria).

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