Pathologic characteristics of second breast cancers after breast conservation for ductal carcinoma in situ.
BACKGROUND
The number of women diagnosed with ductal carcinoma in situ (DCIS) is increasing. Although many eventually develop a second breast cancer (SBC), little is known about the characteristics of SBCs. The authors described the characteristics of SBC and examined associations between the pathologic features of SBC and index DCIS cases.


METHODS
Women were identified in the National Comprehensive Cancer Network Outcomes Database who were diagnosed with DCIS from 1997 to 2008 and underwent lumpectomy and who subsequently developed SBC (including DCIS or invasive disease that occurred in the ipsilateral or contralateral breast). The Fisher exact test and the Spearman test were used to examine associations between the pathologic characteristics of SBC and index DCIS cases.


RESULTS
Among 2636 women who underwent lumpectomy for DCIS, 150 (5.7%) experienced an SBC after a median of 55.5 months of follow-up. Of these 150 women, 105 (70%) received adjuvant radiotherapy, and 50 (33.3%) received tamoxifen for their index DCIS. SBCs were ipsilateral in 54.7% of women and invasive in 50.7% of women. Among the index DCIS cases, 60.6% were estrogen receptor (ER)-positive, and 54% were high grade, whereas 77.5% of SBCs were ER-positive, and 48.2% were high grade. Tumor grade (P = .003) and ER status (P = .02) were associated significantly between index DCIS and SBC, whereas tumor size was not (P = .87).


CONCLUSIONS
After breast conservation for DCIS, SBC in either breast exhibited pathologic characteristics similar to the index DCIS, suggesting that women with DCIS may be at risk for developing subsequent breast cancers of a similar phenotype.
Harvard Radiation Oncology Program, Harvard Medical School, Boston, Massachusetts, USA. narvold@partners.org
Nils D
ND
Arvold
Rinaa S
RS
Punglia
Melissa E
ME
Hughes
Wei
W
Jiang
Stephen B
SB
Edge
Sara H
SH
Javid
Christine
C
Laronga
Joyce C
JC
Niland
Richard L
RL
Theriault
Jane C
JC
Weeks
Yu-Ning
YN
Wong
Sandra J
SJ
Lee
Michael J
MJ
Hassett
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D016609:Neoplasms, Second Primary / Q000473:pathology* / Q000601:surgery; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries