The effect of immediate breast reconstruction on adjuvant therapy delay, locoregional recurrence, and disease-free survival

Background An important risk inherent to both alloplastic and autologous immediate breast reconstruction (IBR) is the higher incidence of postoperative complications and delays to adjuvant therapy. The main objective of this retrospective cohort study was to identify risk factors for locoregional recurrence after breast cancer mastectomy and IBR. Methods A 6-year retrospective study of breast cancer patients treated with mastectomy only (MO) or mastectomy and IBR (MIBR) was conducted from January 2013 to May 2019. The outcomes of interest included delay in adjuvant chemoradiotherapy, postoperative complications, and locoregional recurrence. Cox regression survival was used to estimate the risk of locoregional recurrence and time to adjuvant therapy. Results Of 1832 patients reviewed, 720 (38%) were included. The cohort consisted of 443 (62%) MO and 277 (38%) MIBR [140 (51%) direct-to-implant (MIBRi1), 96(35%) tissue expander to implant (MIBRi2), and 41(15%) autologous flap (MIBRf)]. MIBR had more delays to adjuvant therapy compared to MO [113 (70%) vs. 72 (80%) months, p = 0.022]. Kaplan-Meier analysis showed that MIBRi2 had significantly shorter DFS compared to MO [MIBRi2: 39.2 (15.6) vs MO: 41.7 (19.6) months, log-rank p-value = 0.01]. Cox regression indicated that MIBRi2 was associated with a 3.26-higher risk of locoregional recurrence compared to MO [HR: 3.26; 95% CI: 1.56, 9.24]. Conclusions Cox regression showed MIBRi2 was significantly associated with increased risk of locoregional recurrence compared to MO. Neither delays nor postoperative complications were identified as significant risk factors for locoregional recurrence risk.