Long-term survival of women with basal-like ductal carcinoma in situ of the breast: a population-based cohort study.
BACKGROUND
Microarray gene-profiling of invasive breast cancer has identified different subtypes including luminal A, luminal B, HER2-overexpressing and basal-like groups. Basal-like invasive breast cancer is associated with a worse prognosis. However, the prognosis of basal-like ductal carcinoma in situ (DCIS) is still unknown. Our aim was to study the prognosis of basal-like DCIS in a large population-based cohort.


METHODS
All 458 women with a primary DCIS diagnosed between 1986 and 2004, in Uppland and Västmanland, Sweden were included. TMA blocks were constructed. To classify the DCIS tumors, we used immunohistochemical (IHC) markers (estrogen-, progesterone-, HER2, cytokeratin 5/6 and epidermal growth factor receptor) as a surrogate for the gene expression profiling. The association with prognosis was examined for basal-like DCIS and other subtypes using Kaplan-Meier survival analyses and Cox proportional hazards regression models.


RESULTS
IHC data were complete for 392 women. Thirty-two were basal-like (8.2%), 351 were luminal or HER2-positive (89.5%) and 9 unclassified (2.3%). Seventy-six women had a local recurrence of which 34 were invasive. Another 3 women had general metastases as first event. Basal-like DCIS showed a higher risk of local recurrence and invasive recurrence 1.8 (Confidence interval (CI) 95%, 0.8-4.2) and 1.9 (0.7-5.1), respectively. However, the difference was not statistically significant. Also, no statistically significant increased risk was seen for triple-negative or high grade DCIS.


CONCLUSIONS
Basal-like DCIS showed about a doubled, however not statistically significant risk for local recurrence and developing invasive cancer compared with the other molecular subtypes. Molecular subtyping was a better prognostic parameter than histopathological grade.
Department of Surgical Science, Uppsala University, Uppsala, SE-75105, Sweden. wenjing.zhou@surgsci.uu.se
Wenjing
W
Zhou
Karin
K
Jirström
Christine
C
Johansson
Rose-Marie
RM
Amini
Carl
C
Blomqvist
Olorunsola
O
Agbaje
Fredrik
F
Wärnberg
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000737:chemistry / Q000235:genetics / Q000401:mortality* / Q000556:secondary / Q000628:therapy; D016009:Chi-Square Distribution; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D017741:Survivors / Q000706:statistics & numerical data*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D046888:Tissue Array Analysis; D016896:Treatment Outcome
D014408:Biomarkers, Tumor