Answer:
Hughes et al reviewed all series reported in the medical literature of patients who had DCIS and were treated by breast conservation surgery with and without radiation therapy. Local excision without radiation had a recurrence rate of approximately 19%, half of which were invasive. Local excision with radiation yielded a 9% local recurrence rate, half of which were invasive. The NSABP-17 prospective trial showed 16% recurrence rate without radiation, 8% invasive. With radiation, the recurrence rate was 7%, with 3% invasive.
Slavin, Love and Goldwyn (1994) investigated whether reconstruction with myocutaneous flap affected diagnosis and treatment of locoregional recurrence. Recurrent tumor was observed in 11% (17/161), all invasive. All developed within the native skin and subcutaneous tissue adjacent to the mastectomy and flap reconstruction site. There was no delay in diagnosis or concealment of the recurrence (uncontrolled study). Petit at al (1994) compared risk of distant metastasis, recurrence and death in patients reconstructed with silicone gel implants vs. matched control in which there was no reconstruction. No significant differences were found.