Colorectal adenocarcinoma (CRA) was rated the third leading cause of cancer-related deaths in 2020. A search for new methods for the early diagnosis of CRA remains an urgent task for modern oncology.

OBJECTIVE

To assess the effectiveness of the electrochemical biosensors for determining alkaline phosphatase activity as a marker of functional atypism in biopsy specimens with colorectal adenocarcinoma.

MATERIAL AND METHODS

Fragments of colorectal adenocarcinoma and healthy colon mucosa from 78 patients undergoing a diagnostic colonoscopy were examined by the electrochemical method. After the study, the biopsies were stored in phosphate buffer (48 patients) and buffered formalin (30 patients); after 2 hours, the histological and immunohistochemical examinations were performed.

RESULTS

In the biopsies from 70 patients, the average current was 49.2 (95% CI 41.3—88.9) nA and 33.1 (95% CI 9.5—44.2) nA in «fresh» and formalin-fixed biopsies, respectively. The average current obtained from healthy mucosa was 119.7 (95% CI 96.8—167.1) nA and 59.6 (95% CI 48.3—71) nA in «fresh» and formalin-fixed biopsies, respectively. Immunohistochemistry showed that the adenocarcinoma biopsies had no expression of alkaline phosphatase; then, healthy mucosa biopsies had high membrane expression of alkaline phosphatase. Material from 8 patients had heterogeneous results of electrochemical and histological studies.

CONCLUSIONS

The electrochemical biosensors can be used for a quick, direct assessment of the alkaline phosphatase content in biopsy specimens of colorectal adenocarcinoma. It may be considered an additional method for assessing the functional atypism of tumor cells.