From the Division of Plastic Surgery, Department of Surgery, Federal University of São Paulo; the Departments of Plastic Surgery, Cardiothoracic Surgery, Pathology, Bioengineering, and Medicine, University of Pittsburgh; the McGowan Institute of Regenerative Medicine; and the University of Pittsburgh Cancer Center.
Plast Reconstr Surg. 2019 Jan;143(1):103-112. doi: 10.1097/PRS.0000000000005085.
Clinical outcomes suggest that postoncologic reconstruction with fat grafting yields cumulative incidence curves of recurrence comparable to those of other breast reconstruction procedures; however, results from experimental research studies suggest that adipose stem cells can stimulate cancer growth. In this study, a novel animal model of residual cancer was developed in mouse mammary pads to test whether lipofilling impacts the probability of locoregional recurrence of breast cancer after breast conserving surgery.
Mammary fat pads of female NOD-SCID gamma mice were each injected with MCF-7 cells in Matrigel. Tumors were allowed to engraft for 2 weeks, after which time either sterile saline (n = 20) or human fat graft (n = 20) was injected adjacent to tumor sites. After 8 weeks, tumors were assessed for volume measurement, histologic grade, Ki67 positivity, and metastatic spread.
Animals receiving lipofilling after tumor cell engraftment had lower tumor volume and mass (p = 0.046 and p = 0.038, respectively). Macroscopic invasion was higher in the saline group. Histologic grade was not significantly different in the two groups (p = 0.17). Ki67 proliferation index was lower in tumors surrounded by fat graft (p = 0.01). No metastatic lesion was identified in any animal.
Adipose transfer for breast reconstruction performed in the setting of residual breast tumor in a clinically relevant animal model did not increase tumor size, proliferation, histologic grade, or metastatic spread. This study supports the oncologic safety of lipofilling as part of the surgical platform for breast reconstruction after cancer therapy.
临床结果表明，肿瘤切除后采用脂肪移植进行重建的累积复发率与其他乳房重建手术相当；然而，实验研究结果表明脂肪干细胞可能会刺激癌症生长。在这项研究中，我们在小鼠乳腺垫中建立了一种新的残留癌动物模型，以测试脂肪填充是否会影响保乳手术后乳腺癌局部区域复发的概率。
将 MCF-7 细胞在 Matrigel 中注射到雌性 NOD-SCID gamma 小鼠的乳腺脂肪垫中。肿瘤允许植入 2 周，之后在肿瘤部位附近注射无菌生理盐水（n = 20）或人脂肪移植（n = 20）。8 周后，评估肿瘤体积测量、组织学分级、Ki67 阳性和转移扩散情况。
在肿瘤细胞植入后接受脂肪填充的动物的肿瘤体积和质量较低（p = 0.046 和 p = 0.038）。生理盐水组的宏观侵袭率较高。两组的组织学分级无显著差异（p = 0.17）。脂肪移植周围的肿瘤 Ki67 增殖指数较低（p = 0.01）。任何动物均未发现转移病灶。
在临床相关动物模型中，在残留乳腺肿瘤的情况下进行乳房重建的脂肪转移并没有增加肿瘤大小、增殖、组织学分级或转移扩散。这项研究支持脂肪填充作为癌症治疗后乳房重建手术平台的肿瘤安全性。
