The clinicopathological spectrum and treatment outcomes in metastatic colorectal cancer in the KwaZulu-Natal province of South Africa.

Abstract

Background: In high-income countries (HICs) 17-20% of colorectal cancer (CRC) patients have metastatic CRC (mCRC) at the time of diagnosis, of which 10-25% are or become resectable, and a further 4-11% of patients will develop metachronous metastases. The study aimed to establish the prevalence and pattern of metastatic CRC to document treatment outcomes in KwaZulu-Natal (KZN), and to compare results to international norms.

Methods: The study population comprised patients with mCRC presenting between 2000 and 2019. Demographics, primary tumour site, spectrum of metastatic disease and resection rate were assessed.

Results: MCRC occurred in 33% of the CRC patient population. Eight hundred and thirty-six patients had metastatic disease, comprising Africans (325, 38.8%), Indians (312, 37.3%), Coloureds (37, 4.4%) and Whites (161, 19.2%). Six hundred and fifty-four patients (79%) had synchronous metastases and 182 patients had metachronous metastases (21%). Single organ metastases occurred in 596 patients (71.2%) (M1A) and multiple organ metastasis occurred in 240 patients (28.7%) (M1B). Metastases occurred in the liver (613), lung (240) and peritoneum (85). Fifty-two patients (6.2%) underwent resection of their metastases.

Conclusion: The prevalence of stage IV CRC in our setting is at the upper limit of international norms. mCRC occurred in 33%, with similar proportions in all races. Resection rate for metastases is low.