Ductal Lavage May Not Detect Noninvasive Breast Cancer

 

 

Behind the Cancer Headlines®

October 21, 2003

 

 

A recently developed minimally invasive technique to sample breast cells has low sensitivity to detect noninvasive breast cancer, according to a new study. The finding comes from one of the first studies to evaluate the efficacy of ductal lavage (DL) in detecting high-risk breast tumors. The study appears in the journal Cancer.

 

Ductal carcinoma in situ (DCIS) is the most common noninvasive breast cancer. Its incidence has increased significantly over the last 20 years to over 50,000 new cases in 2002, a rise attributed to higher rates of screening mammography. Lobular carcinoma in situ (LCIS) is a pre-cancerous condition that is regarded as high-risk for subsequent invasive cancer.

 

DL is a relatively new innovative technique to collect breast epithelial cells by gently washing the mammary ducts. Prior studies have shown that DL yields more satisfactory samples of ductal epithelial cells than nipple fluid aspiration. Moreover, DL allows for mapping of the nipple. However, the sensitivity of DL in the detection of high-risk mammary intraepithelial lesions (MIL) including DCIS and LCIS has not been previously investigated.

 

Researchers led by Edi Brogi and Leslie Montgomery of Memorial Sloan-Kettering Cancer Institute in New York City evaluated DL in patients undergoing mastectomy. DL was performed in the affected breast of twenty-two patients with invasive carcinoma and in four with DCIS, as well as in four patients undergoing prophylactic removal of the breast (two with LCIS, two without MIL) because of contralateral carcinoma. The investigators correlated the findings in DL samples with those seen in the corresponding mastectomy specimens.

 

The authors found that of the 29 suitable samples obtained by DL from patients with MIL, none was clearly interpreted as malignant on independent examination by three cytopathologists. Four DL samples showed marked atypia; 10 samples showed mild atypia; and 15 were categorized as benign. In some cases, injection of dye in the ducts lavaged permitted identification of the ducts sampled and more specific cytomorphologic correlation. The reason for the low sensitivity of DL in the setting of adjacent invasive carcinoma may be that the ducts are no longer unobstructed once the cancer has become invasive. Additional studies are in progress to assess the sensitivity of DL as earlier stages of the disease.

 

The authors conclude, "DL has low sensitivity for carcinoma in situ in breasts also containing invasive carcinoma. Use of DL remains investigational and close follow-up should be obtained for all patients undergoing DL, including those with benign diagnosis."

 

They add, "Optimal utilization of DL samples may . . . evolve to combine cytologic evaluation with non-morphology based techniques . . . DL remains an extremely innovative method of sampling the breast epithelium and will undoubtedly play an important role in the study of breast carcinogenesis."

 

 

SOURCE:

 

Cancer, November 15, 2003