Ductal intraepithelial neoplasia: postsurgical outcome for 1,267 women cared for in one single institution over 10 years.
BACKGROUND
Diagnosis of breast ductal intraepithelial neoplasia (DIN) has increased over the last decades, but proper postsurgical treatment remains controversial. We analyzed risk factors and treatment outcome in a large series of women treated at one institution.


METHODS
Women undergoing surgery for DIN at the European Institute of Oncology between 1996 and 2005, with follow-up until December 2006, were included.


RESULTS
We evaluated the postsurgical treatment outcome of 974 and 293 patients who underwent breast-conserving surgery (BCS) or mastectomy, respectively. The 5-year cumulative incidence of breast cancer (BC) events was 11.8%, with a significant trend according to age (from 43% in women <36 years to 8% in women >65 years). Among the 727 BCS patients with DIN2-DIN3 histology, 414 (57%) received radiotherapy (RT), and they were both younger and with worse prognostic factors than the 313 patients who did not receive it. In these groups, the adjusted hazard ratio (HR) for RT versus non-RT was 0.40 (95% confidence interval [CI], 0.26-0.63). Among the 691 BCS patients with estrogen receptor (ER)(+) disease, 329 (48%) received low-dose tamoxifen (either 5 mg/day or 20 mg once a week) and they were younger than the 362 who did not receive it. In these groups, the adjusted HR for tamoxifen versus no tamoxifen was 0.68 (95% CI, 0.43-1.07), and the HR was 0.55 (95% CI, 0.32-0.97) after excluding human epidermal growth factor receptor (HER)2/neu-overexpressing DIN.


CONCLUSIONS
BC events were more frequent in young patients. RT was associated with a lower incidence of BC events. Low-dose tamoxifen was associated with a lower incidence of BC events in patients with ER(+) disease when HER-2 was not overexpressed. Further prospective studies should confirm our observations.
Guerrieri-Gonzaga
Aliana
A
Division of Cancer Prevention and Genetics, European Institute of Oncology, Milan, Italy.
Botteri
Edoardo
E
Rotmensz
Nicole
N
Bassi
Fabio
F
Intra
Mattia
M
Serrano
Davide
D
Renne
Giuseppe
G
Luini
Alberto
A
Cazzaniga
Massimiliano
M
Goldhirsch
Aaron
A
Colleoni
Marco
M
Viale
Giuseppe
G
Ivaldi
Giovanni
G
Bagnardi
Vincenzo
V
Lazzeroni
Matteo
M
Decensi
Andrea
A
Veronesi
Umberto
U
Bonanni
Bernardo
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D002278:Carcinoma in Situ / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D015331:Cohort Studies; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult