Impact of Surgery-Radiation Interval on Locoregional Outcome in Patients Receiving Neo-adjuvant Therapy and Mastectomy

Abstract

Delays in the initiation of radiation are increasingly common for medically underserved patients. We evaluated the impact of delay in initiation of postmastectomy radiation (PMRT) in breast cancer patients treated with neo-adjuvant therapy (NAT) in a cohort of medically underserved patients with multiple barriers to timely care. We retrospectively reviewed medical records of 248 consecutively treated patients. Clinical stage was 34.4% II, 65.6% III. The median interval from surgery to PMRT was 11.9 weeks; 22.2% started PMRT within 8 weeks of surgery, 52% within 12 weeks, and 67.3% within 16 weeks. The cumulative 5-year incidence of locoregional recurrence (LRR) was 5.8% (95% CI: 3.2-9.7). There was no significant difference in locoregional outcome among patients starting PMRT within 8 weeks versus >8 weeks (p = 0.634), ≤ 12 versus >12 weeks (p = 0.332), or ≤ 16 versus >16 weeks (p = 0.549) after surgery. Although timely initiation of PMRT remains a priority, the locoregional control benefit of PMRT appears to be maintained up to at least 16 weeks, and in those without early locoregional recurrence, PMRT should be offered despite such a delay.

Long-term survival effect of the interval between mastectomy and radiotherapy in locally advanced breast cancer

“…Our findings were similar to those of the aforementioned studies. 20 – 22 That is, the survival outcomes and patterns of treatment failure did not differ according to the interval between mastectomy and PMRT. The German Society for Radiooncology recommends that PMRT should be started 4–6 weeks after surgery or completion of the primary or adjuvant chemotherapy.…”

“…The rates of LRR at 8 years were 13%, 4%, and 12% in patients with surgery–PMRT intervals of ≤2, 2.1–6, and >6 months, respectively ( P = 0.51). 21 Desai et al 22 examined 248 patients and demonstrated no significant effect of the surgery–PMRT interval on LRR in patients who underwent neoadjuvant chemotherapy and mastectomy.…”

“…PMRT should still be administered to patients who have experienced a delay but have not developed LRR. 22 …”

The impact on clinical outcomes of post-operative radiation therapy delay after neoadjuvant chemotherapy in patients with breast cancer: A multicentric international study

“…After an evaluation of more than 1000 patients, we found no clear relationship between the time to start RT and oncological outcomes. Similarly with our findings, a retrospective study reported on 248 patients across different time-points who underwent RT, did not find significant differences in locoregional outcome among the three groups of patients [8 weeks vs. >8 weeks (p = 0.634, ≤12 vs > 12 weeks (p = 0.332), or ≤16 vs > 16 weeks (p = 0.549)], suppporting the theory that RT should be offered regardless of the time elapsed since the last treatment [ 27 ]. However, in our study, in the subgroup of luminal patients, the early start of RT was associated with improvement in DFS, LRRFS and DDFS.…”

“…Of note, it has been demonstrated that time to initiation post-operative chemotherapy significantly impact on survival rates [ 22 , 23 ]. Nevertheless, the clinical influence of delayed RT is uncertain, as previous reports generated conflicting results [ [24] , [25] , [26] , [27] ].…”