The clinicopathologic and prognostic significance of CD44+/CD24−/low and CD44−/CD24+ tumor cells in invasive breast carcinomas

SummaryCells with distinct phenotypes and stem cell–like properties have been reported to exist in breast cancer. The aim of the present study was to investigate the clinicopathologic and prognostic significance of the CD44+/CD24−/low and CD44−/CD24+ tumor phenotypes' prevalence. Double immunohistochemistry was applied on a series of 155 paraffin-embedded breast tissue specimens to detect CD44 and CD24. Evaluation of the phenotypes was performed by image analysis. The prevalence of CD44+/CD24−/low and CD44−/CD24+ tumor cells was 58.7% and 82.6%, respectively. The dominance of the CD44+/CD24−/low tumor cells was inversely associated with lymph node metastasis (P = .019) and tended to inversely associate with the stage of the disease (P = .068). Moreover, the prevalence of CD44+/CD24−/low was found to exert no significant impact on patients' prognosis although it displayed a tendency toward an increase in disease-free survival (P = .074). On the other hand, the prevalence of CD44−/CD24+ tumor cells was found to have no clinicopathologic significance. However, it was found to exert an unfavorable impact on both relapse-free (P = .009) and overall survival (P = .046) of the patients with breast carcinomas of intermediate differentiation (grade 2). In breast tissue, CD44+/CD24−/low tumor cells seem to be associated with lack of lymph node metastasis and a tendency toward an increase of the relapse-free survival of the patients. On the contrary, tumor cells with the phenotype CD44−/CD24+ seem to identify patients with worse disease-free and overall survival within the group of intermediate-grade differentiation patients whose prognosis is difficult to assess.