Long-term survival of women with basal-like ductal carcinoma in situ of the breast: a population-based cohort study

Abstract

BackgroundMicroarray 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.MethodsAll 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.ResultsIHC 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.ConclusionsBasal-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.

Characteristics and behaviour of screen-detected ductal carcinoma in situ of the breast: comparison with symptomatic patients

“…Of our cohort of DCIS, 33.7 % were identified to be basal-like. This differs from the reported rates of basal-like DCIS from studies by Livasy et al [48] at 8.0 %, Zhou et al [46] at 8.2 %, and Clark et al [45] at 4.2 %. This difference may be due to the higher sensitivity of 34bE12, which targets 4 cytokeratins (CK1, 5, 10, and 14).…”

“…The rate of triple-negative DCIS in our study was noted to be at 7.1 %, which does not differ greatly from the findings of Clark et al [45] and Zhou et al [46], whose documented rates of triple-negative DCIS were 7.5 and 7.8 %, respectively. We observed a higher proportion of triple-negative DCIS subtype in the symptomatic group compared to the screen-detected group.…”

Racial disparities in risk of second breast tumors after ductal carcinoma in situ

“…Using immunohistochemical markers (ER, PR, HER2, and Ki67), Sharaf Aldeen et al [25] classified 94 DCIS cases into five subtypes and found a similar distribution of molecular subtypes between black and white women. In addition, the basal-like DCIS defined by ER, PR, HER2, CK5/6, and EGFR displayed a comparable risk of IBTs to the other molecular subtypes [26]. Future efforts should focus on the clinical relevance of these findings and novel molecular markers that mediate poorer DCIS outcomes in black women.…”

Breast Cancer Subtypes and Previously Established Genetic Risk Factors: A Bayesian Approach

“…While this could bias effect estimates of SNPs associated with disease aggressiveness or progression, shared risk profiles (3, 90, 91) and subtype distributions (1, 3, 92) suggest this bias would be small.…”