How Does the Interval Between Completion of Adjuvant Chemotherapy and Initiation of Radiotherapy Impact Clinical Outcomes in Operable Breast Cancer Patients?

Abstract

Purpose The aim of this study was to evaluate the impact of time to radiotherapy (TTR) after completion of chemotherapy (CT), and TTR after surgery, in breast cancer (BC) patients. Patients and Methods Continuous breast cancer patients treated with surgery and CT followed by radiotherapy (RT) from 2009 through 2015 were retrospectively reviewed. Patients were categorized into four groups with respect to TTR after CT, i.e. <4, 4–8, 8–12, and >12 weeks, and TTR after surgery, i.e. <147, 147–180, 180–202, and >202 days. The Cox proportional hazards model was used to identify the independent effect of TTRs. Results Overall, 989 patients were enrolled. Patients with a TTR of >12 weeks after CT showed significantly worse breast cancer-specific survival (BCSS) and overall survival (OS) compared with those who had a TTR of <4 weeks (BCSS: hazard ratio [HR] 0.28, 95% confidence interval [CI] 0.1–0.76; OS: HR 0.33, 95% CI 0.13–0.88), 4–8 weeks (BCSS: HR 0.23, 95% CI 0.08–0.66; OS: HR 0.29, 95% CI 0.11–0.8), and 8–12 weeks (BCSS: HR 0.22, 95% CI 0.05–0.96; OS: HR 0.23, 95% CI 0.06–0.99). TTR after surgery showed no significant association with survival outcomes in the entire cohort, except in patients with hormone receptor (HR)-positive disease and those receiving mastectomy. In HR-positive tumors, a TTR after CT of >12 weeks remained an independent predictor for adverse BCSS and OS. Conclusion Initiation of RT beyond 12 weeks after CT might compromise survival outcomes. Efforts should be made to avoid delaying RT, especially after completion of CT and in patients with HR-positive tumors, positive lymph nodes, and those receiving mastectomy.

Influence of Adjuvant Radiotherapy Timing on Survival Outcomes in High-Risk Patients Receiving Neoadjuvant Treatments

“…In our study population, the majority of patients started RT within 12 weeks after the last cycle of adjuvant chemotherapy or within 16 weeks after surgery when no adjuvant chemotherapy is given, which is consistent with previous reports (21)(22)(23). In a recent retrospective study of the impact of TTR on survival, among 95 patients treated with NAC without adjuvant chemotherapy, Xie et al (21) reported that 25 (26.3%), 54 (56.8%), and 16 (16.8%) started RT at <8 weeks, 8-16 weeks, and > 16 weeks from surgery, respectively.…”

Predictors for Fear of Cancer Recurrence in Breast Cancer Patients Referred to Radiation Therapy During the COVID-19 Pandemic: A Multi-Center Cross-Section Survey

“…However, evidences for acceptable interval from end of adjuvant chemotherapy to RT were limited (35,36). A recent study of 989 operable BC patients reported that the time to RT after chemotherapy over 12 weeks negatively impact 5-year distant recurrence free survival and breast cancer specific survival (37). Long-term follow-up is needed to assess the prognosis of patients who experienced RT interruption or FIGURE 2 | The hierarchical multiple regression model of fear of cancer recurrence.…”

Timing of postmastectomy radiotherapy following adjuvant chemotherapy for high-risk breast cancer: A post hoc analysis of a randomised controlled clinical trial

“…Raphael et al [16] reported that a CRI of 6 weeks was associated with worse event-free survival in patients with stage I and II breast cancer who underwent BCS (HR 1.50; 95% CI: 1.00e2.22). Cao et al [17] reported that a CRI of >12 weeks was associated with worse breast cancer-specific survival and OS in patients with stage IeIII breast cancer who underwent either BCS or mastectomy. In comparison, most patients in the present study had more advanced disease (97% being stage III), and all the patients underwent mastectomy.…”