Contrary to its reputation, DCIS emerges as complex, maybe lethal

Ductal carcinoma in situ often takes on an innocent guise in the mainstream media. It may be referred to as "precancerous" or "mostly harmless." Some say this common malignancy is overdiagnosed and overtreated.

In this month's cover story, a more complex picture emerges. Pathology experts say that DCIS is similar to invasive cancer in terms of its makeup and heterogeneous nature.

Furthermore, Dr. Laszlo Tabar, a leader in mammography education, has identified some cancers now classified as DCIS that actually behave like invasive cancer, possibly through a process called neoductgenesis.

For Tabar, misunderstandings about what DCIS is and is capable of becoming start with faulty terminology and outdated anatomical models. Newer pathology techniques showed several years ago that DCIS is often found not in the collecting ducts, but in the terminal ductal lobular units, which include the lobules and the terminal ducts.

The origin of in situ disease has implications for its likelihood of become invasive, according to pathologists.

It proved somewhat difficult to get leading radiologists to comment for this story. Most were more comfortable directing me to breast pathology experts such as Dr. Michael Lagios, conveniently based in Diagnostic Imaging's hometown, San Francisco.

Both Tabar and Lagios stress the importance of correlating mammographic findings with actual pathology findings. Ideally, the two specialists should become au fait with one another's terminology.

At a multidisciplinary seminar held in June, Tabar demonstrated the cooperative approach with pathologist Dr. Lee Tucker of the Carilion Breast Center in Roanoke, VA. The two experts believe that collaboration with modern pathology techniques can result in more accurate diagnosis and assessment of disease, with obvious benefits to patients in terms of more appropriate treatment.

Such an entwined working relationship is uncommon today but holds potential in the future, as more centers embrace specialized, interdisciplinary models for breast cancer management.