Clinical predictors of rectal cancer response after neo-adjuvant (Chemo)Radiotherapy in Australia and New Zealand: Analysis of the Bi-National Colorectal Cancer Audit (BCCA)

• Published in: European journal of surgical oncology Vol. 49; no. 11; p. 107070
• Main Authors: Liu, Jianliang, Lee, Justin Y.T., Bedrikovetski, Sergei, Traeger, Luke, Moore, James W., Perry, Joanne L., Kroon, Hidde M., Sammour, Tarik
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2023
• Subjects: Australia - epidemiology; Chemoradiotherapy; Humans; Neoadjuvant Therapy; Neoplasm Staging; New Zealand - epidemiology; Rectal cancer; Rectal Neoplasms - pathology; Rectal Neoplasms - therapy; Response; Retrospective Studies; Treatment Outcome; Tumour regression grade; New Zealand; Australia; Response; Neoadjuvant therapy; Tumour regression grade; Rectal cancer; Chemoradiotherapy
• ISSN: 0748-7983; 1532-2157
• DOI: 10.1016/j.ejso.2023.107070

Pathological complete response (pCR) is observed in 11–26% of locally advanced rectal cancers undergoing neoadjuvant chemoradiotherapy (nCRT). This study aims to determine pCR rates and clinicopathological predictors in the Australian and New Zealand (ANZ) cohort. The Bi-National Colorectal Cancer Audit (BCCA) was interrogated for all rectal cancer patients who underwent nCRT prior to surgical resection between 2007 and 2020. Patients were divided in two groups: pCR (AJCC tumour regression grade 0) and partial/no response (pPR, regression grade 1,2 or 3). In total, 3230 patients were included. Rates of pCR and pPR were 704 (21.8%) and 2526 (78.2%), respectively. Long-course nCRT (p < 0.0001), lower clinical tumour stage (cT; p < 0.0001), and nodal stage (cN; p = 0.003) were associated with pCR on univariate analysis. On multivariable analysis, cN0 stage and long-course nCRT remained independent factors for a pCR. Awareness of these predictors provides valuable information when counseling patients regarding prognosis and treatment options.