Everyone is aware of breast cancer, but not everyone knows much about the various kinds of breast cancer. DCIS, or ductal carcinoma in situ, is a non-invasive type of breast cancer which may or may not become invasive breast cancer. This week on “Take Care,” we focus on DCIS with Dr. Tari A. King.
Dr. Tari A. King is Chief of Breast Surgery at the Dana Farber/Brigham and Women’s Cancer Center and the associate division chief for breast surgery at Brigham and Women’s Hospital.
According to King, DCIS is the earliest form of breast cancer in which the cancerous cells are still contained within the milk duct of the breast and they have no ability to live outside the milk duct; they’re dependent on the milk duct for their blood supply and therefore their survival.
In clinical practice, DCIS is classified as stage 0 breast cancer.
“I refer to it as stage 0 breast cancer when I discuss the diagnosis with patients,” says King.
DCIS is also sometimes referred to as precancerous or premalignant because it does not have the ability to metastasize to other parts of the body.
“DCIS is most frequently diagnosed on mammographic screening,” King says.
DCIS is only recognized by patients as a palpable mass 5-10 percent of the time.
There has been a dramatic increase in the diagnosis of DCIS within the past two decades because of increased use of mammographic screening.
DCIS is grouped into different categories based on factors including appearance of cells, growth patterns of cells and whether it is or isn’t sensitive to estrogen.
“We do believe that all breast cancers begin inside the milk duct in an in situ form. An overwhelming majority of the time when we operate on a woman with invasive breast cancer our pathologists are also able to identify DCIS in the milk duct surrounding that invasive breast cancer,” says King.
According to King it is uncommon to have DCIS in both breasts and this occurs less than 5 percent of the time.
“We don’t recommend routine MRI evaluation for women diagnosed with DCIS because the likelihood of her having anything going on in her other breast is incredibly low,” King says.
Data suggests that if 100 women with DCIS went without treatment, roughly 50-60 percent of them, depending on the study that you read, would ever develop invasive breast cancer.
“The problem is that we don’t know which 50 or 60 percent will and which 50 or 60 percent won’t,” says King.
King recommends that women diagnosed with DCIS who are deciding whether or not to pursue treatment seek a second opinion.
“The more information that patients have when they’re making their decision, then the more informed and the more confident they can feel about the decision they’ve made,” King says.
