High nodal positivity rates even in good clinical responders after chemoradiation of rectal cancer: is organ preservation feasible?

Colorectal Dis. 2016 Oct;18(10):976-982. doi: 10.1111/codi.13114.

Abstract

Aim: Local excision (LE) is emerging as a treatment option for rectal cancer responding well to chemoradiation. However, it does not address the mesorectal nodal burden. We aimed to identify the factors influencing nodal positivity and subsequently defined a low-risk group by including only patients at low risk.

Method: A single-centre, retrospective database analysis was carried out of patients with radically resected rectal cancer after neoadjuvant chemoradiation.

Results: This study included 524 patients with predominantly low rectal tumours. Nodal positivity among ypT0, T1 and T2 groups was 14.7%, 28% and 30%, respectively. Multivariate analysis with stepwise logistic regression identified the following low-risk features: age ≥ 40 years, nonsignet ring cell carcinoma (SRCC) histology and pathological complete response (pCR). Sixty-nine patients fulfilling all three criteria were analysed and the nodal positivity was found to be 10.1%, which implies that, if these patients had been selected for LE, one in 10 would have had positive mesorectal nodes.

Conclusion: Even in patients with low-risk criteria (pCR, non-SRCC histology and age ≥ 40 years), the residual positive nodal disease burden is 10%. Whether this high incidence of residual nodal disease translates into a similar risk of locoregional recurrence if an organ-preservation strategy is adopted is unclear.

Keywords: Neoadjuvant chemoradiation; local excision; nodal response; organ preservation protocol; rectal cancer.

Publication types

  • Evaluation Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Chemoradiotherapy
  • Colectomy / methods*
  • Combined Modality Therapy
  • Databases, Factual
  • Feasibility Studies
  • Female
  • Humans
  • Lymph Nodes / pathology*
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Neoadjuvant Therapy / methods
  • Neoplasm Staging
  • Organ Sparing Treatments / methods*
  • Rectal Neoplasms / pathology*
  • Rectal Neoplasms / therapy*
  • Retrospective Studies
  • Tumor Burden
  • Young Adult