Vascular calcification and response to neoadjuvant therapy in locally advanced rectal cancer: an exploratory study

Katrina A Knight,Campbell S D Roxburgh,Donald C Mcmillan,James H Park,John T Jenkins,Paul G Horgan,Ioanna Drami

doi:10.1007/s00432-021-03570-1

Abstract

PurposePatients with locally advanced rectal cancer (LARC) may experience a clinical complete response (cCR) to neoadjuvant chemoradiotherapy (NACRT) and opt for non-operative management. Pathological factors that relate to NACRT response have been well described. Host factors associated with response, however, are poorly defined. Calcification of the aortoiliac (AC) vessels supplying the rectum may influence treatment response.MethodsPatients with LARC having NACRT prior to curative surgery at Glasgow Royal Infirmary (GRI) and St Mark’s hospital (SMH) between 2008 and 2016 were identified. AC was scored on pre-treatment CT imaging. NACRT response was assessed using pathologic complete response (pCR) rates, tumour regression grades (TRGs), the NeoAdjuvant Rectal score and T-/N-downstaging. Associations were assessed using Chi-squared, Mantel–Haenszel and Fisher’s exact tests.ResultsOf 231 patients from GRI, 79 (34%) underwent NACRT for LARC. Most were male (58%), aged over 65 (51%) with mid- to upper rectal tumours (56%) and clinical T3/4 (95%), node-positive (77%) disease. pCR occurred in 10 patients (13%). Trends were noted between higher clinical T stage and poor response by Royal College of Pathologist’s TRG (p = 0.021) and tumour height > 5 cm and poor response by Mandard TRG (0.068). In the SMH cohort, 49 of 333 (15%) patients underwent NACRT; 8 (16%) developed a pCR. AC was not associated with NACRT response in either cohort.ConclusionsAC was not associated with NACRT response in this cohort. Larger contemporary cohorts are required to better assess host determinants of NACRT response and develop predictive models to improve patient selection.

Highlights

The management of rectal cancer has evolved significantly
total mesorectal excision (TME) following neoadjuvant chemoradiotherapy (NACRT) remains the standard of care for patients with locally advanced rectal cancer (LARC) who have an incomplete response or who opt for operative management (Gollins et al 2017)
This study aimed to explore the relationship between host factors including the degree of AC present on pre-treatment imaging and response to NACRT in patients with LARC

Summary

Introduction

The management of rectal cancer has evolved significantly. The introduction of total mesorectal excision (TME) in the 1980s contributed to a substantial decline in local recurrence rates (Heald and Ryall 1986). In 15–20% of patients, a pathologic complete response (pCR) occurs where no viable tumour is found on histological examination of the resection specimen (Maas et al 2010). On this basis, the concept of non-operative management was described (Habr-Gama et al 2004). TME following NACRT remains the standard of care for patients with locally advanced rectal cancer (LARC) who have an incomplete response or who opt for operative management (Gollins et al 2017)

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