Women with a ductal carcinoma in situ (DCIS) diagnosis were over three times more likely to die from breast cancer versus those in the general population, a retrospective study found.
In over 140,000 women who underwent surgery after being diagnosed with DCIS, 1,540 died from invasive breast cancer compared with an expected 458 for cancer-free women (standardized mortality ratio [SMR] 3.36, 95% CI 3.20-3.53), reported Steven Narod, MD, and colleagues from the Women’s College Research Institute in Toronto.
And this risk persisted beyond 15 years after diagnosis, according to the findings in JAMA Network Open.
“The SMR was lower among women who received lumpectomy plus radiation compared with women who received lumpectomy alone,” the authors wrote. “The rate of breast cancer death was nearly 12-fold higher among women diagnosed with DCIS before age 40 years and 7-fold higher in Black women diagnosed with DCIS compared with the general population.”
For patients treated with lumpectomy, SMRs were 3.42 without radiation therapy (95% CI 3.07-3.80) and 2.81 with radiation (95% CI 2.55-3.04). Among patients who did not receive radiation therapy, SMRs were 4.12 in those who underwent a single mastectomy (95% CI 3.59-4.67) and 4.14 with a double mastectomy (95% CI 2.83-5.59).
As the authors noted, SMRs varied widely according to age, ranging from a low of 2.65 for women ages 60-69 at the time of their DCIS diagnosis (95% CI 2.39-2.92) to a high of 11.95 for those under 40 years of age (95% CI 9.66-14.39).
SMRs varied widely in women according to race/ethnicity as well:
East Asian (SMR 1.89, 95% CI 1.36-2.49)
Southeast Asian (SMR 2.40, 95% CI 1.65-3.31)
White (SMR 3.03, 95% CI 2.86-3.21)
Black (SMR 7.56, 95% CI 6.76-8.42)
“This study is not designed to generate information on clinical managements of DCIS,” Narod’s group cautioned. “The lifetime risk of death following DCIS is approximately 3%, and this level of risk is too low to recommend chemotherapy.”
However, they pointed out that some patients — Black women and those under 40 — had mortality rates that approached 10%. “[A]t this level, chemotherapy might be considered,” the authors wrote. “Ideally, we would be able to identify the few women with DCIS with metastatic potential from the outset and offer them systemic therapy.”
Stephanie Bernik, MD, of the Icahn School of Medicine at Mount Sinai in New York City, expressed caution over the findings that mastectomy patients had the highest recurrence risk, as this might have been driven by women with more extensive disease or close margins.
Read the full article here: https://www.medpagetoday.com/hematologyoncology/breastcancer/88648
