Should ductal carcinoma-in-situ (DCIS) be removed from the ASTRO consensus panel cautionary group for off-protocol use of accelerated partial breast irradiation (APBI)? A pooled analysis of outcomes for 300 patients with DCIS treated with APBI.
OBJECTIVE
To analyze outcomes in patients with ductal carcinoma-in-situ (DCIS) treated with accelerated partial breast irradiation (APBI) within a pooled set of patients.


METHODS
A total of 300 women with DCIS underwent APBI between April 1993 and November 2010 as part of American Society of Breast Surgeons MammoSite Registry Trial (n = 192) or at William Beaumont Hospital (n = 108). Patients with pure DCIS <3 cm (n = 125) were assigned to the cautionary risk group per American Society of Radiation Oncology consensus panel guidelines for off-protocol use of APBI and analyzed compared to a pooled invasive suitable (n = 653) risk group and pooled invasive suitable/cautionary (n = 1,298) risk group.


RESULTS
The rate of ipsilateral breast tumor recurrence (IBTR) for all 300 DCIS patients was 2.6 % at 5 years with no regional recurrences, while cause-specific survival was 99.5 % and overall survival (OS) was 96.4 %. When comparing the cautionary DCIS group to the invasive suitable/cautionary group, no difference in IBTR was noted (2.6 vs. 3.1 %, P = 0.90) with significant improvements in distant metastases (0 vs. 2.5 %, P = 0.05), disease-free survival (98.5 vs. 94.4 %, P = 0.05), and OS (95.7 vs. 90.8 %, P = 0.03) noted for DCIS patients. When comparing cautionary DCIS patients to invasive suitable patients, no difference in IBTR were noted (2.6 vs. 2.4 %, P = 0.76), while improved OS for DCIS patients was noted (95.7 vs. 90.9 %, P = 0.02).


CONCLUSIONS
This analysis of the largest cohort of patients with DCIS treated with APBI supports previously reported excellent outcomes; as a result of small numbers of events, further data are necessary to confirm these findings.
Michigan Healthcare Professionals/21st Century Oncology, Farmington Hills, MI, USA. fvicini@pol.net
Frank
F
Vicini
Chirag
C
Shah
J
J
Ben Wilkinson
Martin
M
Keisch
Peter
P
Beitsch
Maureen
M
Lyden
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008875:Middle Aged; D001918:Brachytherapy / Q000401:mortality; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000401:mortality / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000401:mortality / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005500:Follow-Up Studies; D015412:Mastectomy, Segmental / Q000401:mortality; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate; D003245:Consensus Statements as Topic