DCIS (ductal carcinoma in situ) is the most common form of non-invasive breast cancer and is considered stage 0 cancer. DCIS usually is treated by surgically removing the cancer -- lumpectomy in most cases. After surgery, hormonal therapy medicine may be recommended if the DCIS is hormone-receptor-positive (most are). Radiation therapy also is recommended for many women.
A study has found that women diagnosed with DCIS who were treated with lumpectomy (also called breast-conserving surgery) at Memorial Sloan Kettering Cancer Center in New York City from 1999 to 2010 had a 40% lower risk of recurrence than women who had lumpectomy for DCIS between 1978 and 1998 at the same center.
The study was published in the October 2015 issue of the Annals of Surgical Oncology. Read the abstract of “Decreasing Recurrence Rates for Ductal Carcinoma In Situ: Analysis of 2996 Women Treated with Breast-Conserving Surgery Over 30 Years.”
The researchers looked at information on 2,996 women in a database of DCIS patients who were treated at Memorial Sloan Kettering.
Overall, 363 (12%) recurrences happened among the 2,996 women.
Among the women who didn’t have a recurrence, half were followed for more than 6 years (some up to 30 years) and half were followed for shorter periods of time. More than 730 of the women were followed for 10 years or longer.
The researchers used statistical analysis to adjust the information for a number of factors, including:
- how the DCIS was diagnosed (by screening or by a clinical exam)
- family history
- cancer grade
- the status of the surgical margins (positive vs. negative)
- whether the women had radiation or not
- whether the women had hormonal therapy or not
Even after controlling for all those variables, among women who did not receive radiation after lumpectomy, 5-year recurrence rates were:
- 13.6% in 1978-1998
- 6.6% in 1999-2010
This 40% difference was statistically significant, which means that it was likely because of when the women were treated and not just due to chance.
"Since radiation is given only to reduce local recurrence rates and has never been shown to improve survival, a woman treated currently with [lumpectomy] without radiation can expect about a 40% lower recurrence rate than in the earlier decades," said Kimberly Van Zee, M.D., M.S., of the Memorial Sloan Kettering Cancer Center, who was one of the study’s authors.
Among women who received radiation after lumpectomy to remove DCIS, the risk of recurrence was 60% lower overall.
"Using multivariable analysis, we showed that after adjusting for all of these factors, there was still a lower risk of recurrence in later years that was limited to those not receiving radiation. This suggests that the decline in recurrence is not the result of changes in radiation efficacy, but may be due to improvements in mammographic quality or in the pathological analysis leading to more complete excision," Van Zee said in an interview.
The results of this study are very encouraging and suggest that advances in detection, management, and treatment are making a difference for women diagnosed with DCIS.
If you’ve been diagnosed with DCIS, your doctor will recommend a treatment plan after surgery tailored to your specific recurrence risk for DCIS or invasive breast cancer. Your doctor also will take into account your preferences. Your treatment plan may include radiation therapy, hormonal therapy, both, or neither. Together, you can decide on a treatment plan that makes the most sense for you and your unique situation.
For more information, visit the Breastcancer.org DCIS pages.