A recently published study on breast cancer might leave women more puzzled about the disease than ever before. The study was on DCIS or ductal cancer in situ, a condition that according to many experts shouldn’t get categorized as cancer. Sometimes this condition is referred to as stage 0 breast cancer.

Although DCIS is a recognized breasts cancer risk factor, doctors are still not sure whether there’s any need of treating it.

The findings of the new study present us with some additional information on DCIS but fail to deliver enough clarity. According to the study, around 3% of women suffering from DCIS have finally died of breast cancer. What’s even more perplexing is that it appears that these women died irrespective of the fact whether they underwent treatment for breast cancer or not.

Researchers conducting the study analyzed cases of over 100,000 DCIS affected women. The health records of these women were monitored through a period of 20 years. Here, it must be mentioned that as the researchers only checked the medical records of the women, they didn’t have enough information about each case’s individual details.

During these 20 years, a total of 517 women died of breast cancer. The researchers found that women getting diagnosed with DCIS at the age of 35 and black women had maximum chances of eventually dying of breast cancer. According to the study, women getting diagnosed with DCIS before reaching 35 were 17 times more likely to die of breast cancer than normal women.

Must Read: New study on DCIS diagnosis raises several questions on breast cancer

How much risk a woman has of dying of breast cancer, also depended significantly on the size of the tumor and how aggressive it appeared. However, confusingly 50% of the women who had a tumor and received radiation and appeared to have recovered died of the disease later. The recurring breast cancer possibly didn’t show up any symptom until reaching an advanced stage.

How was that possible? According to University of California’s breast surgeon Dr. Deanna Atlai, invasive cancers don’t always give birth to lumps. According to Dr. Atlai, all these cancers need are a few cells for burrowing through the patient’s tissues and organs. This indicates that in some cases DCIS is actually breast cancer and cannot be tagged just as a precancerous lesion.

The entire study was published in the journal JAMA Oncology.