Chemoradiotherapy response in recurrent rectal cancer

Abstract

The efficacy of response to preoperative chemoradiotherapy (CRT) in recurrent versus primary rectal cancer has not been investigated. We compared radiological downsizing between primary and recurrent rectal cancers following CRT and determined the optimal size reduction threshold for response validated by survival outcomes. The proportional change in tumor length for primary and recurrent rectal cancers following CRT was compared using the independent sample t-test. Overall survival (OS) was calculated using the Kaplan–Meier product limit method and differences between survival for tumor size reduction thresholds of 30% (response evaluation criteria in solid tumors [RECIST]), 40%, and 50% after CRT in primary and recurrent rectal cancer groups. A total of 385 patients undergoing CRT were analyzed, 99 with recurrent rectal cancer and 286 with primary rectal cancer. The mean proportional reduction in maximum craniocaudal length was significantly higher for primary rectal tumors (33%) compared with recurrent rectal cancer (11%) (P < 0.01). There was no difference in OS for either primary or recurrent rectal cancer when ≤30% or ≤40% definitions were used. However, for both primary and recurrent tumors, significant differences in median 3-year OS were observed when a RECIST cut-off of 50% was used. OS was 99% versus 77% in primary and 100% versus 42% in recurrent rectal cancer (P = 0.002 and P = 0.03, respectively). Only patients that demonstrated >50% size reduction showed a survival benefit. Recurrent rectal cancer appears radioresistant compared with primary tumors for tumor size after CRT. Further investigation into improving/intensifying chemotherapy and radiotherapy for locally recurrent rectal cancer is justified.

Treatment of Locally Recurrent Rectal Carcinoma in Previously (Chemo)Irradiated Patients

“…7,25 Preoperative tumor volume reduction, which can be caused by preoperative radiotherapy, increased the likelihood of complete resections, 15 and volume reduction of >50% shows a survival benefit. 24 also, several studies have shown that complete surgical resections provide a significant survival advantage compared with incomplete resections. [11][12][13]15,17,19,21,[26][27][28][29][30][31][32] in the included studies, most recurrences were treated with chemoradiation instead of radiotherapy alone.…”

“…[33][34][35][36] a recent study demonstrated good responses and improved survival in patients who were treated with reirradiation with concurrent Ctx in lRRC patients compared with radiotherapy only. 24 So, although the evidence is weak, chemoradiation seems to be the preferred treatment option to reirradiate patients with lRRC.…”

Efficacy and safety evaluation of laparoscopic D3 lymphadenectomy combined with pelvic autonomic nerve preservation for rectal cancer

“…Rectal cancer is a very common gastrointestinal cancer with a high malignancy rate and unknown etiology (1) . Even worse, rectal cancer is a leading cause of cancer-related deaths worldwide and may occur in younger people (2) .…”

Stereotactic body radiotherapy (SBRT) reirradiation for pelvic recurrence from colorectal cancer

“…On the other hand, the rates of postoperative complications had been reported to be up to 68% . Chemotherapy (CT) and further external beam radiation therapy (EBRT) may only provide palliative benefit . Conventional EBRT reirradiation can be risky as dose limiting normal tissues in pelvis such as the bowel or the bladder have often been treated to tolerance and further radiation may prove unsafe .…”