The gentamicin-collagen implant and the risk of distant metastases of rectal cancer following short-course radiotherapy and curative resection: the long-term outcomes of a randomized study

Int J Colorectal Dis. 2018 Aug;33(8):1087-1096. doi: 10.1007/s00384-018-3045-3. Epub 2018 Apr 15.

Abstract

Purpose: A previous randomized study conducted by our group showed that application of gentamicin-collagen implant (GCI) into the pelvic cavity after total mesorectal excision (TME) reduced the incidence of distant metastases. Therefore, we decided to conduct a confirmatory study.

Methods: Patients with rectal cancer were included in the study if they met the following criteria: adenocarcinoma of the rectum, preoperative short-term radiotherapy (5 × 5 Gy), and WHO performance score 0-1.

Results: One hundred seventy-six patients were randomly assigned either to an experimental group in which GCI was applied (n = 81) or to a control group without GCI (n = 81). Median follow-up was 80 months. Cumulative incidence of distant metastases at 5 years was higher in the control group compared to the experimental group: 23.5 vs 8.6% (HR 2.4 [95% CI 1.1-5.5], P = 0.005). Overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) did not differ between the experimental group and the control group: HR 0.95 [95% CI 0.55-1.70], P = 0.864; HR 0.85 [95% CI 0.50-1.45], P = 0.548, and HR 0.5 [95%CI 0.22-1.22], P = 0.093, respectively. The predefined by the protocol subgroup analysis for yp stage III disease showed better DFS in the experimental group compared to the control group; HR 0.47 [95%CI 0.23-0.97], P = 0.042).

Conclusions: The results confirmed our previous finding that GCI applied in the pelvis significantly reduced the rate of distant metastases in patients after radical rectal cancer resection.

Keywords: Gentamicin-collagen implant; Metastases; Preoperative radiotherapy; Rectal cancer.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adenocarcinoma / drug therapy*
  • Adenocarcinoma / pathology
  • Aged
  • Anti-Bacterial Agents / administration & dosage*
  • Collagen
  • Disease-Free Survival
  • Female
  • Gentamicins / administration & dosage*
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Metastasis / prevention & control*
  • Neoplasm Recurrence, Local
  • Neoplasm Staging
  • Rectal Neoplasms / drug therapy*
  • Rectal Neoplasms / pathology
  • Rectum

Substances

  • Anti-Bacterial Agents
  • Gentamicins
  • Collagen