BOSTON -- Oncologists at Boston's Dana-Farber Cancer Institute have found that women with the most common type of non-invasive breast cancer often overestimate the risk that the cancer will spread, and the risk that they will have a recurrence or deadly outcome.

One in five breast cancers is located in a women's milk ducts, a form known as ductal carcinoma in situ, or DCIS.

"Although DCIS typically is very treatable disease, many women diagnosed with DCIS develop inaccurate risk perceptions," said Ann Partridge, MD, MPH, the study's lead author and a breast oncologist at Dana-Farber. "This exaggerated sense of risk needs to be addressed, as it may cause women to make poor treatment choices and adversely affect their emotional well-being and subsequent health behaviors."

Researchers questioned more than 750 women with DCIS about their perceived risk of recurrence, death, or likelihood the cancer would spread to another body part.

Fifty-five percent believed they had a "moderate likelihood" of recurrence within five years. In reality, the chances are much lower.

Twenty-eight percent of women thought it was at least moderately likely the cancer would spread to another body part. The actual risk, say Dana-Farber doctors, is less than 1 percent.

Partridge told NewsCenter 5 she would recommend health care providers and patients recognize the confusion and do their best to convey the risk clearly and accurately. She said doctors should refer women with high anxiety for additional care.

The impact of the misconception is substantial anxiety and depression among women with DCIS, which doctors say could be avoided.

The findings will be published online by the Journal of the National Cancer Institute on Tuesday and later in a print edition.