Pathologic and technical considerations in the treatment of ductal carcinoma in situ of the breast with lumpectomy and radiation therapy.
BACKGROUND
Lumpectomy and radiation therapy is considered a standard treatment option for ductal carcinoma in situ (DCIS) of the breast. The incidence of locally recurrent carcinoma using this therapeutic approach ranges from 6%-19%. Multiple studies have attempted to identify factors associated with the development of local recurrences in these patients. Despite extensive reports examining this issue, no factor(s) has consistently been correlated with outcome.


METHODS
This review examines the criteria that various authors have proposed as being associated with recurrence, including DCIS grade, size, histologic subtype, status of surgical margins, and technical factors to help clarify their roles in optimizing treatment outcome. The issue of the definition of the type of recurrence is also addressed.


RESULTS
Though multiple studies have examined the impact of grade, histologic subtype, necrosis, and DCIS size on outcome, no consistent results have been observed to suggest that these factors can be routinely used to guide therapy. The adequacy of excision appears to correlate with local control but is imprecisely defined by margin status alone. Based upon recent data, it appears that atypical ductal hyperplasia and cancerization of lobules in the context of coexistent DCIS, may need to be considered as part of the DCIS lesion that should be excised. This issue may account for some of the disparate results of different studies of DCIS. For statistical purposes, recent studies also suggest that only recurrences developing within or adjacent to the bed of the initial DCIS lesion should be considered when analyzing factors associated with outcome. Recurrences developing elsewhere in the breast may include new DCIS and invasive lesions that bear no biologic relationship with the initial DCIS lesion. Finally, since it is impossible to insure that all DCIS has been removed, it may be more appropriate to consider DCIS lesions as adequately or inadequately excised instead of completely or incompletely excised. Since DCIS is essentially a microscopic disease, pathologists should have a primary role in helping to define the adequacy of excision.


CONCLUSIONS
Additional studies with complete pathology review and longer follow-up are needed to reach a consensus on which prognostic factors are consistently associated with recurrence for patients with DCIS treated with lumpectomy and radiation therapy. At the present time, adequacy of excision appears to correlate with outcome. However, more precise and consistent methods need to be developed to assist in the determination of adequate DCIS extirpation.
Vicini
F A
FA
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI, USA. fvicini@beaumont.edu
Goldstein
N S
NS
Kestin
L L
LL
D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D002986:Clinical Trials as Topic; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D015996:Survival Rate; D016896:Treatment Outcome