Time to surgery after neoadjuvant chemotherapy in breast cancer and its impact on survival in a middle-income country.

Abstract

e12640 Background: The time to surgery after neoadjuvant chemotherapy (NACT) in breast cancer and its impact on survival has not been sufficiently evaluated in low- or middle-income countries. The objective of this study was to analyze the impact on overall survival in a cancer hospital in Guayaquil, Ecuador. Methods: This is a retrospective study carried out at the SOLCA Guayaquil Hospital in Ecuador from January 2009 to December 2011. The inclusion criteria were women ≥18 years old, diagnosed with invasive breast cancer in stages II and III, who were treated with NACT followed by surgery. The data were collected from clinical records; those with incomplete data were excluded, and the variables age, stage, lymphovascular invasion (LVI), and pathological response were included. Survival was grouped into <8 and ≥8 weeks for the comparative analysis. Survival time was calculated from diagnosis by biopsy until death; A p-value of ˂0.05 was taken as significant; The Kaplan-Meier estimate was used for overall survival, then the groups were compared by Log Rank, and the influence of the covariates was estimated in the Cox regression model. The data were analyzed in an SPSS v29 statistical program. Results: 200 patients were identified, 195 of whom had all the information for the analysis. The median time between the end of NACT and surgery was 7.57 weeks (range, 2.43-29.14 weeks). In the < 8 and ≥ 8 weeks group, there were 111 and 84 patients, respectively. The clinical characteristics are described in the Table. The median overall survival in the entire cohort was 8.32 years (CI: 6.68-9.96), and for the < 8 and ≥ 8 weeks groups, it was 10.0 and 6.56 years, respectively, with a Log-Rank of 0.031. The follow-up (median) of the entire cohort was 7.54 years (range 0.63 – 10.99 years). The multivariate Cox regression showed that LVI, HR: 2.35 p<0.001; clinical stage III (II vs III), HR: 2.47 p<0.001; residual disease (pathological complete response vs residual disease), HR: 2.70 p=0.012; age ≤ 50 years (≤ 50 years vs > 50 years), HR: 1.69 p=0.011; were factors that statistically contributed to worse survival, however, the time between the end of NACT and surgery < 8 and ≥ 8 weeks (p = 0.07) had no statistical impact on survival. Nonetheless, a numerical trend towards better survival was noted in the < 8 week group. Conclusions: The delay in time to surgery after NACT had a negative trend in survival, although it was not statistically significant, which may be due to the small sample size. [Table: see text]