Variations in the type of adjuvant chemotherapy among Stage III colon cancer patients in England

Abstract Purpose : Treatment with any adjuvant chemotherapy for Stage III colon cancer has been shown to differ between groups. Few studies, however, explore variations in the type of adjuvant chemotherapy received, none of which from the UK. The aim of this study is to explore variation in the type of chemotherapy received by Stage III colon cancer patients. Methods : Data from the national cancer registry was linked to the Systemic Anti-Cancer Therapy database, which provides detailed information on treatment of malignant diseases from all NHS England chemotherapy providers. Demographic and clinical characteristics were compared between those who received monotherapy (fluoropyrimidine) or combination chemotherapy (fluoropyrimidine and oxaliplatin) among Stage III colon cancer patients. Results : Of 8,750 patients who received adjuvant chemotherapy, 22.3% (n=2,359) received monotherapy and 60.4% (n=6,391) received combination therapy. The odds of receiving combination therapy decreased with age. Those from the most deprived group had half the odds (OR: 0.5, CI: 0.42,0.59, p<0.001) of receiving combination therapy compared to the least deprived group. Women were 14% less likely to get combined therapy (OR: 0.86, CI: 0.77,0.95, p=0.005). Those with the largest tumour size (T4) and those with more than 3 lymph nodes involved (N2) had 30% (OR: 1.30; CI: 1.07,1.59; p=0.008) and 50% (OR: 1.50; 1.34,1.69; p<0.001) higher odds of receiving combination therapy compared to T1 or T2 and N1, respectively. Conclusion : There is variation in the type of chemotherapy received for stage III colon cancer patients by sociodemographic factors, despite clear clinical guidelines.