Ethnicity and rectal cancer management in New Zealand

Research shows survival disparities between Maori and non-Maori colon cancer patients, with comorbidity and cancer care being major contributing factors. We studied rectal cancer management and survival in a cohort of Maori and non-Maori patients with a newly diagnosed rectal cancer.

194 Maori and non-Maori patients diagnosed with rectal cancer between 2006 and 2008 were identified from the New Zealand Cancer Registry. Medical records were reviewed and patients compared on presentation, patient and tumour characteristics, and receipt and timing of treatment. Cox regression models were fitted to compare cancer-specific survival.

Compared to non-Maori patients, Maori patients were younger (mean age at diagnosis 63.5 and 69.2 for Maori and Non-Maori respectively; p<0.001) and had higher prevalence of comorbidity. Stage, grade and tumour size distributions were similar. Almost all stage I-III patients (97%) underwent definitive surgery, with no difference between Maori and non-Maori. Maori patients waited longer for referral to medical oncologists (40 days vs. 33 days; p=0.03). Results suggested Maori patients with stage IV disease may be less likely than non-Maori to be referred to palliative care (13% vs. 40%; p=0.07). The hazard ratio for cancer-specific death for Maori compared with non-Maori patients was 1.24 (95% CI 0.65-2.35).

The findings suggest both similarities and some differences in treatment and outcomes between Maori and non-Maori rectal cancer patients, but firm conclusions are limited by small sample size.