Top Line: What is the optimal time to wait after standard neoadjuvant chemoradiation before proceeding with surgery for locally advanced rectal cancer?
The Study: The two big questions with the timing of surgery are whether waiting longer increases the observed response rate and whether that also increases the risk of complications. This multicenter cohort study from 6 large centers in Spain compared real-world time intervals between completing neoadjuvant therapy and surgery in 1506 patients with rectal cancer. All patients (100%) received radiation and most (88%) received long-course chemoradiation while the remaining 12% received short course RT. Nobody received TNT. While the study can’t account for why each patient had surgery at a given time interval, patients were divided into 3 categories based on those intervals: short (<8 weeks), intermediate (8-12 weeks), and long (>12 weeks). Overall, the pCR rate was 17.2%. Waiting >12 weeks versus waiting 8-12 weeks for surgery was not associated with a higher odds of pCR. However, there was a trend to a lower pCR rate in the short interval (<8 wk) group. Furthermore, a longer interval was associated with a >50% relative reduction in the risk observing a bad response on final pathology. On the other hand, a longer interval to surgery was associated with a higher risk of postoperative complications. The findings of this study are similar to those of a large pooled analysis of >3000 patients treated on 7 randomized trials, which found that 95% of pCR events occurred within a 10 week interval from neoadjuvant therapy to surgery.
TBL: In this multicenter cohort study from Spain, waiting longer than 12 weeks between standard neoadjuvant therapy and surgery for rectal cancer improved overall tumor regression, but it did not increase the chances of pCR compared to waiting 8-12 weeks. | Guzman, JAMA Surgery 2023
The Study: The two big questions with the timing of surgery are whether waiting longer increases the observed response rate and whether that also increases the risk of complications. This multicenter cohort study from 6 large centers in Spain compared real-world time intervals between completing neoadjuvant therapy and surgery in 1506 patients with rectal cancer. All patients (100%) received radiation and most (88%) received long-course chemoradiation while the remaining 12% received short course RT. Nobody received TNT. While the study can’t account for why each patient had surgery at a given time interval, patients were divided into 3 categories based on those intervals: short (<8 weeks), intermediate (8-12 weeks), and long (>12 weeks). Overall, the pCR rate was 17.2%. Waiting >12 weeks versus waiting 8-12 weeks for surgery was not associated with a higher odds of pCR. However, there was a trend to a lower pCR rate in the short interval (<8 wk) group. Furthermore, a longer interval was associated with a >50% relative reduction in the risk observing a bad response on final pathology. On the other hand, a longer interval to surgery was associated with a higher risk of postoperative complications. The findings of this study are similar to those of a large pooled analysis of >3000 patients treated on 7 randomized trials, which found that 95% of pCR events occurred within a 10 week interval from neoadjuvant therapy to surgery.
TBL: In this multicenter cohort study from Spain, waiting longer than 12 weeks between standard neoadjuvant therapy and surgery for rectal cancer improved overall tumor regression, but it did not increase the chances of pCR compared to waiting 8-12 weeks. | Guzman, JAMA Surgery 2023