Neoadjuvant chemotherapy without radiation therapy for rectal cancer with negative prognosis

AIM: to assess the effectiveness of neo-CT in the FOLFOX6 regimen in patients with mid-and upper rectal cancer (RC) associated with poor prognosis. PATIENTS AND METHODS: fifty-two patients were included into study. All had neo-CT with subsequent surgical treatment between 2017 and 2021. Of them 94.2% had stage I I I and 5.8% had stage II. An extramural vascular invasion was detected by MRI in 33 (63.5%) patients. The distance between the tumor and the mesorectal fascia was ≤ 2 mm in 17%. All patients had 4 cycles of neo-CT in FOLFOX6 regimen followed by surgery. RESULTS: the compliance (≥ 4 cycles of neo-CT) was 82.7% (n = 43). The overall toxicity rate was 35.6%. Sphincter-saving surgery was performed in 51 (98.1%) patients. Postoperative morbidity was 25.0%. Final pathology revealed stage I I I in 29 (55.8%) patients, stage 0 — stage I I — in 22 (42.3%). In accordance with the degree of patho-morphosis (CAP, 2019), 12 (23.1%) patients showed a partial response. In one patient (1.9%) no signs of residual tumor were detected. Down staging of the Tstage compared with M RI data before neo-CT was noted in 23 (44.2%) patients, N stage — in 29 (55.8%). With a mean follow-up of 31 (3-54) months, local recurrences were detected in 5 (9.6%) patients, and distant metastases in 4 (7.7%). The cumulative 3-year recurrence rate was 11.3 ± 4.8%. The three-year overall and recurrence-free survival rate was 88.2 ± 5.8% and 76.4 ± 7.4%, respectively. CONCLUSION: the multimodal approach for RC with adverse prognostic factors using neo-CT in the FOLFOX6 regimen is well tolerated by patients, has a small toxicity and postoperative morbidity as well. It is necessary to develop new pathology criteria for tumor response to neo-CT. © 2022, Association of Coloproctologists of Russia. All rights reserved.