The CD200‐tolerance Signaling Molecule Associated with Pregnancy Success is Present In Patients with Early‐stage Breast Cancer but Does not Favor Nodal Metastasis

PROBLEM: The CD200-tolerance signaling molecule prevents pregnancy failure and is also expressed by a wide variety of malignant tumors. The effect of CD200 mRNA expression on progression of human tumors has been variable. METHOD OF STUDY: A cross-sectional study was performed to examine the correlation between CD200 protein expression in the primary tumors from postoperative Stage I-IIIA human breast cancer and the likelihood of regional lymph node metastasis. RESULTS: Fifty-eight percentage of patients had strong CD200(+) tumor staining (71% of Stage I and 53% Stage II-IIIA). Strong staining was associated with large T2-3 primary tumors compared to T1 tumors (64 versus 50%) and T2-3 N(+) versus T1 N(-) tumors (70 versus 63%), but this was not statistically significant. Nodal metastases were not more frequent in patients with strong CD200(+) staining (57% compared to 58% for weak/negative staining cases), and the metastatic tumor cells in regional lymph nodes were often CD200(-) when the primary tumor was CD200(+). CONCLUSION: CD200 expression by early-stage human breast cancer cells in primary tumors did not correlate with increased regional lymph node metastasis.