Is There a Role for Postmastectomy Radiation Therapy in Ductal CarcinomaIn Situ?

Abstract

Background. DCIS treated by mastectomy ensures high local control rates. There is limited data on risk for relapse and lack of clear indication for adjuvant radiation therapy (RT). We report a retrospective review on a population of DCIS patients treated with mastectomy. The objective was to identify the overall incidence of relapse, risk factors for local recurrence, and accordingly for whom adjuvant postmastectomy RT may be considered. Methods. This is an IRB-approved retrospective study on a prospective breast cancer database. From 1997 to 2007, we identified 969 patients with diagnoses of DCIS, among them 211 breasts in 207 patients were treated with mastectomy and comprise the study group. Results. With a median followup of 55 months (4.6 years) the 10-year relapse-free survival is 97%. Two of 211 breasts (0.9%) treated with mastectomy developed a local-regional recurrence. Both the relapses were among patients defined as having <1 mm final mastectomy margin. Conclusions. The rare local relapse after mastectomy limits our ability to reliably identify risk factors for relapse. The consideration for postmastectomy RT should be based on an individualized risk evaluating surgical technique used, presence of BRCA mutation, grade and extent of tumor, and proximity of lesion to the margin of resection.

Determinants of optimal mastectomy skin flap thickness

“…Kim and colleagues reported on ten such instances and discovered that the presence of residual normal breast tissue was a common feature. Chadha et al carried out a retrospective review of 207 patients treated by mastectomy for DCIS between 1997 and 2007. Only two (1·0 per cent) developed a local recurrence and both patients had a final mastectomy margin of less than 1 mm.…”

Incidence and Consequence of Close Margins in Patients with Ductal Carcinoma-In Situ Treated with Mastectomy: Is Further Therapy Warranted?

“…Both LRRs occurred in patients with margins <1 mm, and there were no LRRs among patients with margins ≥1 mm. 16 …”

“…6–10 Several studies have evaluated potential predictors of LRR after mastectomy for DCIS in an attempt to improve the already low rates of LRR. 11–16 One of these potential predictors is margin status. There is a large body of literature regarding the relationship between margin status and risk of LRR in patients with DCIS who undergo breast-conserving therapy.…”

Incidence and Consequence of Close Margins in Patients with Ductal Carcinoma-In Situ Treated with Mastectomy: Is Further Therapy Warranted?

“…Both LRRs occurred in patients with margins \1 mm, and there were no LRRs among patients with margins C1 mm. 16 In 2012, Owen et al from British Columbia reported on 637 patients treated with mastectomy for DCIS with a median follow-up time of 12 years. This represents the second largest published series of patients with DCIS treated with mastectomy.…”

“…[6][7][8][9][10] Several studies have evaluated potential predictors of LRR after mastectomy for DCIS in an attempt to improve the already low rates of LRR. [11][12][13][14][15][16] One of these potential predictors is margin status. There is a large body of literature regarding the relationship between margin status and risk of LRR in patients with DCIS who undergo breastconserving therapy.…”