Background & Aims: Effective screening of colorectal cancer (CRC) in early stage could reduce advancement of CRC and therefore mortality. Effective screening is either stool dependent tests or colon dependent examination. The aim of the study was comparative evaluation of chromo colonoscopy and Colon Cancer-Specific Antigen-2 test for early detection of colorectal cancer in Egyptian patients.
Methods: This case control study was carried out on 55 patients classified into 3 groups: group I of twenty patients with Precancerous lesions detected by colonoscopy. Group II: consisted of twenty patients diagnosed with colorectal cancer. Group III: consisted of fifteen persons (who underwent colonoscopy for other indications) as a control group. All subjects were subjected to measure occult blood in stool, measurement of Colon Cancer-Specific Antigen-2 level in serum and tissue and chromo colonoscopy using Indigo Carmine stain.
Results: There was a statistically significant increase in CCSA2 in serum in group II compared to other 2 groups. Cutoff >11.3 CCSA2 in serum had a sensitivity 65%, specificity 85%, PPV 81.2%, NPV 70.8% and accuracy 70.3% in differentiation of group II with cancer colon from group I with premalignant colonic lesions. A cutoff > 9.1 CCSA2 in serum had a sensitivity 95%, specificity 46.67 %, PPV 70.4%, NPV 87.5% and accuracy 73.5% in differentiating group II with cancer colon from normal controls (group III)
Conclusion: CCSA-2 level in serum was significantly higher in cancer colon. Chromoendoscopy has a role in detection of polyps, both neoplastic and non-neoplastic.