The role of carcinoembryonic antigen in predicting colorectal cancer in resource poor setting of Kwazulu-Natal, South Africa.

Abstract

Background: Colorectal cancer (CRC) is the fourth most common malignancy in South Africa. Currently the most reliable screening tool, colonoscopy, is not readily accessible in resource-deprived settings of KwaZulu-Natal. The aim of this study was to determine whether serum CEA levels in patients symptomatic for lower GI pathology correlates with the histological presence and severity of primary colorectal cancer in a large referral centre within KwaZulu-Natal. Perhaps CEA may have a larger role as a marker for CRC development in these resource deprived communities. Patients and Methods: This study was a retrospective analysis of prospectively collected clinical data of 380 patients with colorectal cancer attending a tertiary referral centre in KwaZulu-Natal. Patients were of various age groups, various population groups and both genders. Serum levels of CEA were analysed and stratified into < 5 μg/l and ≥ 5 μg/l. Data were analyzed using descriptive statistics and findings were compared with those from the existing literature. Results: CEA levels were studied in 380 consecutive patients with known pre-treatment CEA levels. The mean CEA level of the study population was 170.0 ± 623.3 μg/l. The number of participants with a CEA level < 5μg/l was 151 (39.74%) whilst the majority 229 (60.26%) had a CEA level ≥ 5 μg/l. There was no significant correlation between CEA levels and gender (p=0.8) or age (p=0.6). CEA levels were highest in the Black African race group. Pairwise comparison demonstrated a statistically significant difference between the Black and Indian population groups (p=0.02). The current study demonstrates an upregulation of CEA as the stage of CRC progresses (p<0.0001). Conclusion: There was no significant difference in CEA levels across age and gender. A positive correlation was noted between CEA level and stage of CRC. CEA levels were highest in the black race group. Low sensitivity of CEA as a screening test for CRC was confirmed.