NEW YORKThe lack of fluid yield from cancer-containing breast ducts may pose a significant barrier to using ductal lavage as a cancer-detection tool in women with mammographic calcifications, Seema A. Khan, MD, reported at the 57th Annual Cancer Symposium of the Society of Surgical Oncology (abstract 29). In a study of 20 patients with mammographic calcifications, there were 10 cases of ductal carcinoma in situ (DCIS), of which only 3 (30%) yielded fluid. "This is not a technique that should be offered to women with the hope that we might detect occult cancer," said Dr. Khan, director, Bluhm Family Breast Cancer Early Detection and Prevention Program, Northwestern Memorial Hospital.
Ductal lavage once held great promise as a potential method for cytological diagnosis of occult malignancies in the breast. These latest findings, however, follow earlier data discounting the promise of ductal lavage for detecting larger tumors, in a study also conducted by Dr. Khan and colleagues in 40 women with invasive cancers and DCIS (J Natl Cancer Instit, in press).
While the results are not encouraging, Dr. Khan said she was not yet ready to write off the potential for using this technology to diagnose breast cancer, since both of the studies were small.
In their previous study, Dr. Khan and her colleagues investigated the premise that ductal lavage could be used to detect known cancers in 40 women undergoing mastectomy. Results showed a specificity that was encouraging, according to Dr. Khan, but a "relatively poor" sensitivity ranging from 16% to 33%.
In that study, which included patients with large, palpable cancers (mean size of the invasive component, 3.2 cm), cancer detection was greater for earlier lesions. "The likelihood of detecting cancer using ductal lavage is far greater if there is significant DCIS, since the technique detects intraductal neoplasia," Dr. Khan explained.
Thus, the study presented at the Society of Surgical Oncology meeting looked at the "other end of the spectrum": women with microcalcifications (BIRADS 4 or 5) detected on screening. The 20 women in the study were scheduled to have ductal lavage prior to planned biopsy.
The lavage catheter was left in the duct, and radiographic contrast was instilled to the duct through the same catheter to confirm that the duct lavaged overlapped the area of calcification. If the duct did not overlap and there were additional fluid-yielding ducts, those additional ducts were lavaged to the extent possible. However, there were some constraints "related to patient willingness to undergo this procedure repeatedly, as well as timing and scheduling in the radiology suite," Dr. Khan reported.