Ductal lavage cytology in patients with ductal carcinoma in situ (DCIS).

Abstract

89 Background: Ductal lavage (DL) is a procedure used to obtain epithelial cells from a breast duct for cytologic evaluation. Previous studies have investigated DL as a potential screening procedure for women at high-risk for cancer. The data, however, does not support a significant correlation between lavage cytology and the presence of invasive carcinoma. It is postulated that an invasive cancer causes destruction of the involved ducts which prevents direct sampling of the malignant intraductal cells. Because ductal carcinoma in-situ (DCIS) does not disrupt the breast ductal structure, DL may yield a more representative cytologic sample in patients with DCIS. Methods: Ductal lavage was performed in the affected breast of 32 women undergoing mastectomy with preoperative diagnosis of DCIS. The lavage procedure was done in the operating room after induction of general anesthesia by cannulating a duct yielding fluid on the nipple and instilling saline which was then aspirated and sent for cytologic evaluation. A cytopathologist classified each sample as insufficient cellular quantity, benign, mild atypia, marked atypia, or malignant. Results: A successful lavage was obtained from 22 (69%) of 32 women undergoing DL in the operating room. Of these 22 cytology samples; 4(18%) had an insufficient cellular quantity, 4 (18%) had mild atypia, 6 (27%) had marked atypia, and 8 (36%) had malignant cells. Twenty one of these 22 women had DCIS in the surgical mastectomy specimen. Seven (32%) patients were found to have invasive ductal cancer in addition to DCIS on final pathology. Conclusions: Our results show that DL reveals markedly atypical or malignant cytology in 64% of patients with DCIS who underwent a successful lavage procedure. As an office procedure, DL may have the ability to obtain viable ductal carcinoma cells repeatedly over time in the same patient. Thus, DL may have an important role in patients with DCIS who are involved in window trial studies investigating response to medical treatments prior to surgical intervention. Further studies to evaluate the reproducibility of the ductal lavage results in patients with DCIS are needed to confirm these findings.