Local control, surgical outcomes, and post-operative complications in management of locally advanced rectal cancer with sequential neoadjuvant short-course radiation therapy and chemotherapy
Faculty and Abstracts
Purpose: Total neoadjuvant therapy (TNT), defined as the administration of chemotherapy and radiation therapy prior to surgical resection, has emerged as an innovative treatment approach for locally advanced rectal cancer. The sequence of short-course radiation therapy (SCRT) and consolidation chemotherapy has been shown to be an effective and well-tolerated TNT regimen in the recently published RAPIDO trial. However, there are concerns raised with regards to a poorer surgical outcome due to a prolonged duration between radiation and surgery, with implications for local control.
Methodology: We retrospectively reviewed the local control rates in patients with LARC treated with upfront SCRT followed by chemotherapy at our institution. We also examined surgical outcomes and post-operative complications among patients who proceeded to surgical resection upon completion of their neoadjuvant therapy.
Results: In our cohort of 119 patients, the 2-year local control rate was 93.4%. Presence of high-risk features (i.e. T4a or T4b disease, involved circumferential resection margin as assessed by MRI, extramural vascular invasion, and/or extramesorectal/lateral lymphadenopathy) was associated with inferior local control- 90.4% vs 97.6%- although this difference was not statistically significant. Among our cohort of 83 patients who proceeded to surgery after completion of neoadjuvant therapy, a complete/near-complete mesorectal specimen was achieved in 90% of patients and this outcome was not associated with the time interval from completion of radiation to surgery. Post-operative complications were low at 18% for Clavien-Dindo grade 3 or higher events, and the 30-day readmission rate was 16%.
Conclusions: Upfront short-course radiation therapy and consolidation chemotherapy represents an effective TNT course. Lengthened time from radiation to surgery does not decrease surgical specimen quality nor increase postoperative complications. Further follow-up is needed for assessment of long-term local control rates.
