Contribution of the seric cytokeartin fragment 21.1 (cyf 21.1) as a tumor marker in a population of algerien women with breast cancer undergoing chemotherapy.

In Algeria, breast cancer accounts for 37.8% of new cancer cases in women. It is an epithelial cell tumor in most cases. CA15-3 (carbohydrate antigen) is the marker of choice for therapeutic monitoring, although ASCO (the American Society of Clinical Oncology) does not recommend its routine use, preferring CYFRA21.1 (cytokeratin19 fragment) to assess response to treatment. The aim of this study was to estimate the degree of correlation between these two biological markers as a function of tumour histological type and the presence or absence of metastases. In a prospective descriptive study, sera from 110 breast cancer patients (mean age 49 ± 7.23 years) were measured using the electrochemiluminescence (ECL) technique to assess CYFRA 21.1 and CA 15.3 levels. Comparison of CA15.3 and CYFRA21.1 levels between patients and controls (79 controls) showed a highly significant association (p<0.0001) between these two markers and breast cancer. The significant correlation between CA15.3 and CYFRA21.1 (r=0.245; P< 0.0001) suggests that reliance on CYF 21.1 for monitoring breast cancer patients undergoing chemotherapy is possible. The results show a good correlation between the two markers, especially for the two histological types luminal a and luminal b+HER2 (r=0.602 ; p<0.0001, r=0.505 ;p< 0.0001 respectively). This study also assessed the correlation between CA15.3 and CYFRA21.1 levels in patients with and without metastases. A significant correlation was also found between CA15.3 and CYFRA 21.1 in the presence of metastases (r=0.472, p<0.0001). A multi-marker approach could provide a more comprehensive assessment of tumor burden and response to treatment.