Adjuvant versus neoadjuvant chemoradiotherapy in distal rectal cancer: Comparison of two decades in a single center

Abstract

Objective: Standard surgery alone was not able to download local recurrence (LR) rate below 20% in rectum cancer treatment. Thus, many centers administered neoadjuvant radiotherapy (preopRTx) with or without concomitant chemotherapy for the prevention of LR. In this study, the results of 164 consecutive patients with mid- and distal rectum cancer, of whom received surgery and adjuvant chemoradiotherapy (Group-A) or neoadjuvant chemoradiotherapy (Group-NA) followed by surgery, are presented.

Material and Methods: The staging system used in this study is that of the American Joint Committee on Cancer (AJCC), also known as the TNM system. Eligible patients had to have; radiologically assessed stage I (only T2N0M0) to stage IIIC (T4bN1-2M0) tumor with pathologically confirmed R0 resection. The surgical method was Total Mesorectal Excision (TME). Radiotherapy was applied with daily 180cGy fractions for 28 consecutive days. Chemotherapy comprised of 5-FU (450mg/m2/d) and Leucovorin (20mg/m2/d) bolus at days 1 to 5 and 29 to 33.

Results: Nine patients (13%) in group-NA achieved pathologic complete response (pCR). In group-NA and group-A, locoregional recurrence (LR) rate was 6.7% and 30.8%, (p<0.001), the mean LR-free survival was 190.0±7.3 mo. and 148.0±11.7 mo. (p=0,002) and the mean overall survival (OS) was 119.2±15.3 mo. and 103.0±9.4 mo. (p=0.23), respectively. A significant difference with regard to LR has been obtained with a statistical power of 0.92. The secondary outcome measures (DFS and OS) have not been met.

Conclusion: Neoadjuvant chemoradiotherapy with TME is an efficient treatment protocol, particularly for the treatment of MRI-staged IIA to IIIC patients with 2/3 distal rectal adenocarcinomas. Given that a considerable proportion of patients with cT2N0M0 would develop pCR, this method of treatment can be considered for further studies.

At the time the present study started there was no Local Review Board.

Written informed consent was obtained from patients who participated in this study.

Externally peer-reviewed.

Concept - A.U., B.Z.; Design - A.U., B.Z., H.Y.; Supervision - B.Z., A.U.; Funding - A.U., F.C., A.A.; Materials - B.Z., Z.A., A.U., A.A., N.E.; Data Collection and/or Processing - B.Z., C.S., G.A., I.Z., A.D.; Analysis and/or Interpretation - B.Z., A.U., Z.A., H.Y., A.A.; Literature Review - A.U., B.Z., B.C., A.A.; Writer - B.Z., A.U.; Critical Review - H.Y., A.A., B.C., F.C., C.S.; Other - Z.A., A.D., I.Z., N.E.

No conflict of interest was declared by the authors.

The authors declared that this study has received no financial support.