The role of carcinoembryonic antigen as an assessment tool for predicting disease severity among patients with colorectal cancer in resource-poor setting of Kwazulu-Natal, South Africa

Abstract

Introduction: the most reliable screening tool for colorectal cancer, colonoscopy, is not readily accessible in resource-deprived settings of KwaZulu-Natal. The aim of this study was to determine whether serum carcinoembryonic antigen (CEA) levels in patients symptomatic for lower gastrointestinal (GI) pathology correlates with the histological presence and severity of primary colorectal cancer in a large referral centre. Perhaps CEA may have a larger role as a marker for colorectal cancer (CRC) development in these resource deprived communities.

Methods: this study was a retrospective analysis of prospectively collected clinical data of 380 pretreatment patients with colorectal cancer attending a tertiary referral centre in KwaZulu-Natal. Data were analyzed using descriptive statistics and findings were compared with those from the existing literature.

Results: 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. Carcinoembryonic antigen levels were highest in the black race group. Low sensitivity of CEA as a screening test for CRC was confirmed.