248P - Impact of unilateral mastectomy with or without immediate breast reconstruction on vertebral alignment

Background

Many patients concern the body imbalance after mastectomy and it is often cited as justification for immediate-breast reconstruction (IBR). However, few studies have investigated the impact of mastectomy or IBR on scoliosis, and analyzed only a small number of patients. We investigated whether mastectomy impacts spine alignment compared to IBR with a large cohort.

Methods

We retrospectively reviewed the patients who underwent breast cancer surgery between 2004 and 2018 at a single institution. Using the deep learning-based algorithm (DeepNoid Inc.), we collected Cobb's angle from chest posteroanterior x-rays at three time points: pre-operation, postoperative one-year, and five-years. Patients who underwent bilateral surgery, delayed-reconstruction, or LD-flap were excluded.

Results

Totally 6246 patients were included: 3442 (55.1%), 1911 (30.6%), and 893 (14.3%) patients underwent breast-conservation surgery (BCS), mastectomy without IBR, and IBR, respectively. At postoperative five-years, the mastectomy group showed the significantly greater change in Cobb's angle compared to both the BCS (p<0.001) and IBR (p=0.004) groups, while there was no significant difference between the BCS and IBR groups (p=0.347). After adjusting for other clinicopathologic variables, operation methods, adjuvant hormone treatments, and the direction of cancer remained significant factors affecting vertebral alignment. However, there was no relationship between the excised breast weights and Cobb's angle. Propensity score matching also showed that mastectomy group has greater change in angle compared to the other groups (vs. BCS, p=0.041; vs. IBR, p=0.047). Cobb’s angle was more evidence among patients under 50 years old (p=0.016) and who administered hormone treatment (p=0.009). Lastly, significantly more patients experienced lumbar pain after mastectomy (8.4%) than after BCS (6.7%) or IBR (4.1%) during the surveillance (p<0.001).

Conclusions

This is the largest study that showed the significant change in thoracic spine alignment after mastectomy compared to BCS and IBR. The results would provide the evidence on recommending breast reconstruction especially for young patients and educating post-mastectomy postural correction.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Seoul National University Hospital.

Disclosure

H. Lee; W. Han: Financial Interests, Personal, Stocks or ownership, Not relevant to this study: DCGen. All other authors have declared no conflicts of interest.