We would like to thank Dr. Alireza Hamidian Jahromi for his thoughtful comments regarding our recently published study: “Determining the Oncologic Safety of Autologous Fat Grafting as a Reconstructive Modality: An Institutional Review of Breast Cancer Recurrence Rates and Surgical Outcomes.”1 As Dr. Jahromi pointed out in his letter, there are indeed inherent differences between our autologous fat grafting group and non–autologous fat grafting control group, which are discussed in our article and for which a multivariate regression analysis was performed.
First, regarding patient demographics, patients in our therapeutic autologous fat grafting group were significantly younger than those in our non–autologous fat grafting control group. Although age has been identified as an independent risk factor for breast cancer recurrence, our multivariate analysis does not identify age as an independent risk factor for breast cancer recurrence in our data set. However, our planned long-term follow-up analysis will further evaluate this question.
Second, regarding breast cancer pathology, BRCA status, Oncotype score, and estrogen/progesterone/human epidermal growth factor receptor status were similar between the two groups. Although it is true that a prophylactic mastectomy in a non-BRCA patient differs from a prophylactic mastectomy in a BRCA patient, BRCA status was not an independent predictor for breast cancer recurrence after mastectomy. In addition, there was no statistically significant difference in BRCA status between the two groups.
Dr. Jahromi’s point regarding a higher rate of ductal carcinoma in situ and lower cancer stage in the autologous fat grafting group is valid, as is the fact that surgical procedures were not entirely comparable between the two groups. This is highlighted in our Discussion section, where we state that this inherent difference between the two groups may play a role in the shorter time to cancer recurrence we observed in the non–autologous fat grafting control group. However, as mentioned, our regression analysis determined that more advanced pathologic stage was not associated with increased breast cancer recurrence rates in these two study groups. Therefore, although differences do exist in age, tumor pathology, and treatment modalities between our two groups, we performed a regression analysis to specifically evaluate our data set for any factors affecting our overall recurrence rates to support the conclusions of our study.
Lastly, concerns do exist regarding the ability of autologous fat grafting to interfere with breast cancer detection and early recurrence, a point we considered in our study. As mentioned in our Discussion, the delay in detection of cancer recurrence in patients who underwent autologous fat grafting could possibly represent a delay in tumor detection secondary to interference with tumor detection. It would follow that cancer recurrence would be detected later as more advanced disease in the autologous fat grafting group; however, this was not observed in our study. In addition, there was no increase in rates of distant metastasis in our autologous fat grafting group, with a distant metastasis rate of 1.9 percent compared with 3 percent in our control group.
We do agree that our longer follow-up study will further evaluate these findings and is necessary to support our initial findings. Most certainly, the oncologic safety of autologous fat grafting is a clinically relevant topic, which necessitates further investigation with longer term, prospective follow-up. We greatly appreciate these important points and considerations raised by Dr. Hamidian Jahromi.
None of the authors has commercial associations or financial disclosures to report that create a conflict of interest with information presented in this communication.
Oriana Cohen, M.D.Nolan Karp, M.D.Mihye Choi, M.D.Hansjörg Wyss Department of Plastic SurgeryNew York University Langone Medical CenterNew York, N.Y.
1. Cohen O, Lam G, Karp N, Choi M. Determining the oncologic safety of autologous fat grafting as a reconstructive modality: An institutional review of breast cancer recurrence rates and surgical outcomes. Plast Reconstr Surg. 2017;140:382e392e.