Older Women With DCIS Have Low Risk of Invasive Breast Cancer, May Not Benefit From Treatment
Women ages 70 and older who were diagnosed with low- or intermediate-grade ductal carcinoma in situ (DCIS) and didn’t receive treatment had a very low risk of developing invasive cancer in the same breast, according to a study.
The research was published in the January 2022 issue of the journal Annals of Surgical Oncology.
DCIS is non-invasive, stage 0 breast cancer that starts in the milk ducts. In situ means in its original place. The condition is non-invasive because it hasn’t spread beyond the milk ducts into other healthy tissue. DCIS isn’t life-threatening, but people diagnosed with the condition have a higher-than-average risk of developing invasive breast cancer later in life.
According to the American Cancer Society, about 20% of new breast cancers are DCIS.
Because all DCIS is stage 0, your doctor uses the condition’s grade to decide which treatment options are best. The grade describes how much the DCIS cells look like healthy breast cells.
There are three grades of DCIS:
Low-grade or grade I cells look only a little bit different from healthy breast cells and grow slowly. Low-grade DCIS is less likely to come back (recur) than moderate- or high-grade DCIS.
Moderate-grade or grade II (also called intermediate-grade) cells look more different from healthy breast cells than low-grade cells and grow faster. Moderate-grade DCIS is more likely to come back than low-grade DCIS, but less likely to come back than high-grade DCIS.
High-grade or grade III cells look much different from healthy breast cells and tend to grow fastest. High-grade DCIS has a higher risk of coming back than low- or moderate-grade DCIS. High-grade also may be described as comedo or comedo necrosis, which means there are areas of dead cancer cells inside the DCIS.
Standard treatments for DCIS are:
lumpectomy followed by radiation therapy
lumpectomy alone, if the DCIS is very small and low-grade
mastectomy, if the DCIS is large or there are multiple areas
hormonal therapy, if the DCIS is hormone receptor-positive
Still, earlier studies have suggested that standard treatment for DCIS may not improve survival, raising concerns that women are being overtreated.
About the study
In this study, the researchers wanted to offer doctors more information about the risk of invasive breast cancer after a DCIS diagnosis based on the condition’s grade and treatment type.
They looked at information in the Surveillance, Epidemiology, and End Results (SEER) database for information on women ages 18 and older who were diagnosed with low- or intermediate-grade, hormone receptor-positive DCIS between 1992 and 2017. The SEER database is a large registry of cancer cases from sources throughout the United States maintained by the National Cancer Institute of the National Institutes of Health.
The study included 21,760 women:
22.4% were younger than 50
55.1% were ages 50 to 69
22.5% were ages 70 or older
30.2% were diagnosed with low-grade DCIS
67.8% were diagnosed with intermediate-grade DCIS
2.8% (604 women) received no treatment for DCIS
36.8% (8,005 women) were treated with lumpectomy only
60.4% (13,151 women) were treated with lumpectomy plus radiation
The researchers looked at how many women in each age group developed invasive breast cancer if they had no treatment for DCIS:
7.26% of women younger than 50 were diagnosed with invasive breast cancer
5.15% of women ages 50 to 69 were diagnosed with invasive breast cancer
2.4% of women ages 70 or older were diagnosed with invasive breast cancer
For women younger than 50 and women ages 50 to 69, lumpectomy alone or lumpectomy plus radiation treatment for DCIS was linked to a lower risk of invasive breast cancer versus receiving no treatment at all. This difference was statistically significant, which means it was likely due to the difference in treatment and not just because of chance.
For women ages 70 and older, there was no statistically significant difference in the risk of invasive breast cancer in any of the groups, whether the women received no DCIS treatment, lumpectomy alone, or lumpectomy plus radiation.
The researchers said they weren’t able to take into account whether any of the women received hormonal therapy.
“Given that [DCIS] guideline-concordant treatment [with lumpectomy] or [lumpectomy plus radiation] among elderly women may lead to operative complications, impaired quality of life, and substantial healthcare costs, consideration should be given towards the study of active surveillance as an alternative approach to the management of low-risk DCIS,” the researchers wrote.
What this means for you
This study strongly suggests that treating DCIS with lumpectomy or lumpectomy plus radiation in women who are 69 or younger reduces their risk of being diagnosed with invasive cancer in the same breast.
But the study also found that treating low- or intermediate-grade DCIS made no difference in the risk of invasive breast cancer — which was very low — in women who are 70 or older. Still, it’s not clear if treating high-grade DCIS would make a difference in the risk of invasive breast cancer in women ages 70 and older.
There are several ongoing studies comparing women who are carefully monitored for DCIS but receive no treatment versus women who receive lumpectomy or lumpectomy plus radiation for DCIS. But it will be several years before these results are published.
If you’ve been diagnosed with DCIS, it makes sense to talk to your doctor about the condition’s grade and ask about the benefits and risks of any recommended treatments.
Together, you and your doctor can make the best decisions for your unique situation.
Learn more about Ductal Carcinoma In Situ (DCIS).
Written by: Jamie DePolo, senior editor
— Last updated on July 14, 2022, 4:27 PM