After being diagnosed and treated for DCIS, six factors seem to be linked to a higher risk of recurrence of invasive breast cancer, according to a study.
The factors are:
- DCIS found by a doctor during a physical exam
- being premenopausal
- positive margins (DCIS was found at the edge of the removed tissue)
- high-grade DCIS
- high levels of p16 protein, a protein that helps regulate cell growth
- being African American
The research was published online on April 25, 2019, by the journal Cancer Epidemiology, Biomarkers & Prevention. Read the abstract of "Predictors of an Invasive Breast Cancer Recurrence after DCIS: A Systematic Review and Meta-analyses."
What is DCIS?
DCIS — ductal carcinoma in situ — is non-invasive breast cancer. Ductal means that the cancer starts inside the milk ducts, carcinoma refers to any cancer that begins in the skin or other tissues (including breast tissue) that cover or line the internal organs, and in situ means "in its original place." DCIS is called non-invasive because it hasn’t spread beyond the milk duct into any normal surrounding breast tissue. DCIS isn’t life-threatening, but being diagnosed with DCIS increases your risk of developing invasive breast cancer later on.
Current DCIS treatment guidelines recommend surgery to remove the DCIS, often followed by radiation therapy and hormonal therapy, if the DCIS is hormone-receptor-positive (most are).
Still, the researchers who did this study said most cases of DCIS likely will not progress, so many women are overtreated.
"There is a large unmet need to distinguish harmless from potentially hazardous DCIS," said senior author of the study Jelle Wesseling, M.D., professor of breast pathology at the Netherlands Cancer Institute and Leiden University Medical Center, in a statement. "We hope our work will help reduce the burden of intensive treatment that thousands of women with low-risk DCIS undergo annually."
How the study was done
This study was a meta-analysis. A meta-analysis combines and analyzes the results of a number of earlier studies. In this case, the researchers analyzed the results of 17 studies published between 1970 and 2018 looking at the risk of invasive breast cancer coming back in the same breast after a diagnosis of DCIS.
The number of women in each study ranged from 52 to 37,692, and average follow-up time ranged from 3.2 years to 15.8 years.
The researchers found 26 factors that could be linked to invasive breast cancer recurrence after DCIS. Their analysis found that six of those factors were statistically significant, which means the factors were likely linked to a higher risk of invasive breast cancer recurrence rather than it being due to chance.
The researchers said that the reason each of the six factors was linked to a higher risk of invasive breast cancer recurrence could be biologically explained.
- Positive margins: If the DCIS has positive margins, it means that some cancer cells were left behind at the cancer site and could eventually lead to a recurrence.
- Being premenopausal: Premenopausal women are younger. Women who are diagnosed at a younger age are more likely to have worse outcomes after being diagnosed with DCIS or breast cancer.
- Being African American: Research has shown that black women are more likely to be diagnosed with more aggressive breast cancer than women of other races. This disparity is likely due to several factors, including genetics, the biology of the cancer, and differences in healthcare.
- DCIS found by a doctor’s exam is likely to be more aggressive than DCIS found by a regular screening mammogram. According to the researchers, DCIS found by an exam is more often hormone-receptor-negative and HER2-positive.
- High-grade DCIS also is likely to be more aggressive than low-grade DCIS.
- High p16 levels means that the cells are more likely to grow in an uncontrolled fashion.
The researchers recommended that these six factors be validated in other studies. They also recommended that the type of recurrence after a DCIS diagnosis and treatment be specified in new studies on DCIS.
"New studies need to capture information about whether the cancer recurrence was DCIS or a subsequent invasive cancer and whether these are true recurrences or new, primary lesions," Wesseling said.
What this means for you
This is one of the first studies to try to identify risk factors for an invasive breast cancer recurrence after a DCIS diagnosis. Although the factors have not been validated by other studies, it makes sense to talk to your doctor about whether you have any of these factors if you’ve been diagnosed with DCIS. It also makes sense to talk to your doctor about calculating your personal risk of invasive breast cancer using one of the assessment tools available.
If you have a higher-than-average risk of invasive disease, there are a number of lifestyle choices you can make, including:
- maintaining a healthy weight
- exercising regularly at the highest intensity possible
- limiting or avoiding alcohol
- limiting processed foods and foods high in sugar
- eating healthy, nutrient-dense food
- not smoking
There are other, more aggressive risk reduction steps you may want to take, including:
- a more aggressive screening plan starting at an earlier age
- hormonal therapy to block the effect of estrogen on breast tissue or reduce the amount of estrogen in the body
- removing the healthy breasts (prophylactic mastectomy)
Together, you and your doctor can figure out a risk-reduction plan for your unique situation.
For more information on DCIS and how it is treated, visit the Breastcancer.org Ductal Carcinoma In Situ pages.
Written by: Jamie DePolo, senior editor
Reviewed by: Brian Wojciechowski, M.D., medical adviser