Pathological response following long-course neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Histopathology. 2005 Aug;47(2):141-6. doi: 10.1111/j.1365-2559.2005.02176.x.


Aims: To standardize the pathological analysis of total mesorectal excision specimens of rectal cancer following neoadjuvant chemoradiotherapy for locally advanced disease (T3/T4), including tumour regression.

Methods and results: Standardized dissection and reporting was used for 60 patients who underwent total mesorectal excision following long-course chemoradiotherapy. Tumour regression was scored by two pathologists (K.S., D.G.) using both an established 5-point tumour regression grade (TRG), and a novel 3-point grade. Both scores were evaluated for interobserver variability. A complete or near-complete pathological response (3-point TRG 1) was found in 10 patients (17%). Using the 5-point TRG, there was good agreement between both pathologists (kappa = 0.64). Using the 3-point grade, agreement was excellent (kappa = 0.84). No disease recurrence has been reported in patients with a complete, or near complete pathological response (3-point TRG 1), after a mean follow-up of 22 months.

Conclusion: Tumour regression grade is a useful method of scoring tumour response to chemoradiotherapy in rectal cancer. TRG 1 and 2 can be regarded as a complete pathological response (ypT0). A modified 3-point grade has the advantage of better reproducibility, with similar prognostic significance.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Neoadjuvant Therapy
  • Neoplasm Staging / methods*
  • Prognosis
  • Rectal Neoplasms / pathology*
  • Rectal Neoplasms / surgery
  • Rectal Neoplasms / therapy
  • Reproducibility of Results
  • Treatment Outcome