Quantitative molecular diagnosis of axillary drainage fluid for prediction of locoregional failure in patients with one to three positive axillary nodes after mastectomy without adjuvant radiotherapy

Abstract

A quantitative multiple-marker reverse transcriptase (RT)-polymerase chain reaction (PCR) assay for sensitive detection of cancer cells in axillary drainage fluid was developed to examine whether the presence of cancer cells in axillary drainage fluid can be used as a predictor of locoregional recurrence (LRR) in patients with breast cancer who had T1/2 primary tumors and one to three positive axillary lymph nodes treated with modified radical mastectomy without adjuvant radiotherapy. Axillary drainage fluid was collected from 126 patients with invasive ductal carcinoma of the breast who were treated with modified radical mastectomy and were found to have one to three positive axillary nodes. Cancer cells in axillary drainage fluid were detected by RT-PCR assay using primers specific for carcinoembryonic antigen (CEA) and cytokeratin-19 (CK-19) together with numerous clinicopathologic and treatment-related factors and were analyzed for their impact on LRR. A total of 38 patients suffered LRR during follow-up and the multimarker RT-PCR assays for CEA and CK-19 in the axillary drainage fluid both were positive in 34 patients (27.0%), of which 29 patients had LRR. In univariate analysis, the 5-year LRR-free survival showed higher rates in patients with PCR-negative findings in axillary drainage fluid (p<0.0001), age>or=40 years old (p<0.0001), tumor size<2.5 cm (p<0.0001), negative lymph-vascular space invasion (p=0.026), and T1 status (<0.0001); in multivariate analysis, PCR-positive findings together with age and tumor size were found to be independent predictors of LRR (all p<0.05). Multiplex RT-PCR assay for CEA and CK-19 was highly sensitive for detection and might be useful for prediction of LRR in such subgroup breast cancer patients.