Radiotherapy after local excision decreased breast cancer recurrence
Adjuvant radiotherapy after local excision for ductal carcinoma in situ reduced the incidence of in situ and invasive local recurrence, according to study results.
“Although reduction was seen in all subgroups, it did not affect OS,” the researchers wrote. “However, patients with invasive local recurrence had a significantly worse survival compared with patients without local recurrence, and thus, invasive local recurrence should be prevented.”
Researchers set out to assess the long-term risk for developing local recurrence and the impact it may have on survival after local treatment for ductal carcinoma in situ.
The analysis included 1,010 women treated between 1986 and 1996. Of them, 503 underwent local excision and no further treatment. Researchers assigned the other 507 women to receive radiotherapy after local excision.
Median follow-up was 15.8 years.
The use of radiotherapy reduced risk for any local recurrence by 48% (HR=0.52; 95% CI, 0.40-0.68). The 15-year local recurrence-free rate was 82% among patients who underwent radiotherapy compared with 69% among those who did not. The 15-year invasive local recurrence-free rate was 90% among patients who underwent radiotherapy and 84% among those who did not (HR=0.61; 95% CI, 0.42-0.87).
Women with invasive local recurrence demonstrated significantly worse breast cancer-specific survival (HR=17.66; 95% CI, 8.86-35.18) and OS (HR=5.17; 95% CI, 3.09-8.66) compared with women who did not experience local recurrence.
The overall salvage mastectomy rate after local recurrence was lower in women who underwent radiotherapy after local excision (13% vs. 19%).
“Although women who developed an invasive recurrence had worse survival, the long-term prognosis was good and independent of the given treatment,” the researchers wrote. “On the basis of the results of this trial, a subgroup of patients in whom radiotherapy can be withheld could not be identified.”
Disclosure: The researchers report no relevant financial disclosures.