Clinical significance of bone marrow micrometastasis detected by nested RT-PCR for cytokeratin-19 in breast cancer patients.

Abstract

Abstract Abstract #4032 Purpose: Breast cancers frequently undergo distant metastasis during the early phase, on which the survival of patients is greatly dependent. It has been suggested that the occurrence of micrometastasis relates with other prognostic features of breast cancer, such as lymph node metastasis and the presence of vascular invasion. The aim of this study was to examine the presence of cytokeratin-19 mRNA in bone marrow aspirates obtained from breast cancer patients, and their possible correlation with distant disease free survival.
 Method: Between 1999 and 2003, bone marrow samples were obtained from 254 breast cancer patients during primary surgery. We separated the mononuclear fraction from the samples and carried out nested reverse transcriptase polymerase reaction (RT-PCR) for the detection of cytokeratin-19 mRNA using two different pairs of primers. The clinical and pathological data and the results of the bone marrow cytokeratin-19 nested RT- PCR were reviewed and analyzed together with clinical results on distant recurrence and survival. We also studied the possible correlations between CK-19 and the tumor size, nodal involvement, stage, and distant metastasis. The median follow up time was 57 months. The median age of patients was 46 years old.
 Results: 66(26%) of the 254 samples were cytokeratin-19 positive. And four stage VI patients and two patients lost during follow up period were excluded. 16 cases (24%) of in the cytokeratin-19 positive group showed a recurrent disease in distant organs. Whereas, 23(12.5%) out of 182 cytokeratin-19 negative patients had distant recurrences. Therefore CK-19 positive group have more distant recurrence than CK-19 negative group (p=0.024). And we found that CK-19 positive group have lower disease free survival rate than CK-19 negative group (p=0.017). However, there was no statistically significant difference in overall survival (p=0.083). The stage, nodal status, and estrogen receptor were independent of bone marrow micrometastasis.
 Conclusion: Bone marrow micrometastasis, detected by nested RT-PCR for cytokeratin-19, could be a useful predictive marker for the distant metastasis of breast cancer. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4032.