Unraveling controversy noninvasive breast cancer

The most common type of noninvasive breast cancer called ductal carcinoma in situ (DCIS). Traditionally, DCIS is diagnosed when the cancer cells look under the microscope lie just leads chest system, but has not invaded surrounding tissues.

The standard treatment for DCIS is to remove the affected tissue, not sure remaining cancer cells in the breast ("clear margins"). That could be a mastectomy surgery or lumpectomy, which may be followed by radiotherapy.

DCIS carries an excellent prognosis. That is why this type of non-invasive cancer is also called "Phase 0" breast cancer.

Reconsider the best treatment for DCIS
Last month, JAMA Oncology published a study suggesting that the standard treatment may be too aggressive. Maybe some women with DCIS would do just fine without lumpectomy or mastectomy. As expected, which generated much controversy and confusion.

The researchers studied more than 108,000 women who were diagnosed with ductal carcinoma in situ at any time for a period of 20 years. They found that women who had a lumpectomy followed by radiation therapy had a lower risk of cancer returning in the breast affected. But the addition of radiation did not affect the final rate of breast cancer deaths. Either perform a mastectomy instead of a lumpectomy.

This type of research is known as an observational study. Observational studies can show potential links between treatments and outcomes. They do not prove that a therapy is actually better.Because this was an observational study, there are many questions about what could have affected the results of the study. These include why it was chosen each specific treatment for each patient, accurate diagnosis of DCIS, if each transaction had actually "healthy margins" and quality follow-up care, including regular mammograms to look for the possible return of cancer.

Furthermore, this study did not document patients, if any, also received hormonal therapy such as tamoxifen or aromatase inhibitors. These treatments can help prevent recurrence. For these reasons, it is difficult to interpret these data in the study, and more difficult to use this information to decide how to treat a woman with ductal carcinoma in situ.

What this study tells us is that all DCIS is the same. In this study, 500 patients died of breast cancer without invasive breast cancer. This suggests that for a very small proportion of women, or distant metastases occurred despite treatment of DCIS - a disturbing finding.

In addition, mortality rates were higher in women diagnosed with ductal carcinoma in situ before the age of 35, and for black women compared to non-Hispanic white women. This suggests that these women may need a more aggressive intervention.

The good news: The study also confirmed that, overall, the mortality associated with DCIS is extremely low. Less than 1% of patients in this study of 20 years died of breast cancer.

Does the media have sent the wrong message about the findings? 
Some media coverage of this study tended to give the impression that the DCIS does not need to be treated. In fact, all patients in the study received some form of treatment. That the said study is that no specific treatments against researchers compared each other (with or without radiation lumpectomy or mastectomy) was very different from each other with respect to the ultimate survival.Ongoing studies are trying to determine whether "watchful waiting" may be reasonable for some women - namely, by monitoring low-risk patients (eg, those with tumors in cancers of small or low intermediate grade) to determine whether and when treatment is necessary. However, we still have these results.

For some women, DCIS is a "precursor" to invasive breast cancer, but in many others, can not progress. However, at this time, we do not understand these cancers pretty well, and we can not accurately predict the biological behavior of these abnormal cells to a particular woman. More research is needed to determine the specific optimal treatment for every woman diagnosed ductal carcinoma in situ.

Ultimately, decisions about diagnosis and treatment of ductal carcinoma in situ must be made by a woman and her doctor should consider certain risk factors (age, race, etc.), as well as personal preferences wife on the face of the limits of current scientific knowledge. I hope that the results of research and future courses allow doctors to quickly better target these difficult decisions. Fortunately, the bottom line for DCIS is that no matter what treatment is continued, the results are excellent for most patients. 
By: Sara Fazio, MD, FACP.