Subsequent Invasive Breast Cancer Research Articles

Prognostic value of histopathological DCIS features in a large-scale international interrater reliability study

PurposeFor optimal management of ductal carcinoma in situ (DCIS), reproducible histopathological assessment is essential to distinguish low-risk from high-risk DCIS. Therefore, we analyzed interrater reliability of histopathological DCIS features and assessed their associations with subsequent ipsilateral invasive breast cancer (iIBC) risk.MethodsUsing a case-cohort design, reliability was assessed in a population-based, nationwide cohort of 2767 women with screen-detected DCIS diagnosed between 1993 and 2004, treated by breast-conserving surgery with/without radiotherapy (BCS ± RT) using Krippendorff’s alpha (KA) and Gwet’s AC2 (GAC2). Thirty-eight raters scored histopathological DCIS features including grade (2-tiered and 3-tiered), growth pattern, mitotic activity, periductal fibrosis, and lymphocytic infiltrate in 342 women. Using majority opinion-based scores for each feature, their association with subsequent iIBC risk was assessed using Cox regression.ResultsInterrater reliability of grade using various classifications was fair to moderate, and only substantial for grade 1 versus 2 + 3 when using GAC2 (0.78). Reliability for growth pattern (KA 0.44, GAC2 0.78), calcifications (KA 0.49, GAC2 0.70) and necrosis (KA 0.47, GAC2 0.70) was moderate using KA and substantial using GAC2; for (type of) periductal fibrosis and lymphocytic infiltrate fair to moderate estimates were found and for mitotic activity reliability was substantial using GAC2 (0.70). Only in patients treated with BCS-RT, high mitotic activity was associated with a higher iIBC risk in univariable analysis (Hazard Ratio (HR) 2.53, 95% Confidence Interval (95% CI) 1.05–6.11); grade 3 versus 1 + 2 (HR 2.64, 95% CI 1.35–5.14) and a cribriform/solid versus flat epithelial atypia/clinging/(micro)papillary growth pattern (HR 3.70, 95% CI 1.34–10.23) were independently associated with a higher iIBC risk.ConclusionsUsing majority opinion-based scores, DCIS grade, growth pattern, and mitotic activity are associated with iIBC risk in patients treated with BCS-RT, but interrater variability is substantial. Semi-quantitative grading, incorporating and separately evaluating nuclear pleomorphism, growth pattern, and mitotic activity, may improve the reliability and prognostic value of these features.

Abstract C108: Race and risk of subsequent aggressive breast cancer in women with ductal carcinoma in situ

Abstract Background: Ductal carcinoma in situ (DCIS) is a heterogeneous group of preinvasive neoplastic lesions in the breast. Black women with DCIS are more likely than White counterparts to subsequently develop invasive cancer in either breast. We examined the association between race and the risk of developing aggressive invasive breast cancer, characterized with hormone receptor (HR) negativity (both estrogen receptor and progesterone receptor negative) or intermediate-to-high risk Oncotype scores (≥18) in HR-positive subtypes, in women with DCIS. Methods: Using the Surveillance, Epidemiology, and End Results (SEER) data, we identified 133,705 women with DCIS diagnosed between 1990 and 2015, and 12.9% were black. Cox proportional hazards regression was used to estimate relative risks (RRs) of subtypes of subsequent invasive breast cancer in either breast and metastatic breast cancer. Results: During a median follow-up of 90 months, 6889 women developed invasive breast cancer and 6384 had HR status available. The risks of HR-defined (Pheterogeneity=0.0004) and Oncotype score-defined (Pheterogeneity=0.046) invasive breast cancer subtypes after initial DCIS significantly varied by race. The RR of HR-negative invasive breast cancer was 1.86 (95% CI 1.57-2.20) and the RR of subsequent invasive subtypes with intermediate-to-high Oncotype scores was 1.29 (95% CI 1.00-1.67) in Black women with DCIS, which was independent of age, pathologic features and treatment. In women who had data on HR status in both primary DCIS and subsequent invasive breast cancer, the HR discordant rate was higher in Black patients than in White patients (21.2% versus 18.9%, P=0.003), which was largely driven by HR loss (15.4% versus 9.5%). Black race was more strongly associated with HR loss (RR=1.92, 95% CI 1.41-2.61, Pheterogeneity=0.03) than HR concordance (RR=1.24, 95% CI 1.09-1.41) and HR gain (RR=1.04, 95% CI 0.67-1.62). Conclusions: Black women with DCIS had higher risks of developing aggressive invasive breast cancer compared with White counterparts, which may contribute to their worse survival. Future studies examining biologic differences in the progression of DCIS for Black patients are warranted. Citation Format: Ying Liu, Graham Colditz. Race and risk of subsequent aggressive breast cancer in women with ductal carcinoma in situ [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C108.

Real-world patterns of treatment and recurrence by frailty status among older women with HR-positive, HER2-negative early breast cancer.

535 Background: Frail health status impacts clinical decision making for older cancer patients and their families, and frailty is independently associated with increased risks of mortality. Our objective was to describe differences in treatment and rates of recurrence by frailty status among older women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer. Methods: We performed a large, population-based retrospective cohort study of women aged 65 years and older diagnosed with first primary stage I-III HR+/HER2-breast cancer using the Surveillance, Epidemiology, and End Results Medicare-linked database between 2007 and 2015. Using administrative health claims, we ascertained information on breast cancer treatment and utilized validated claims-based algorithms to determine frailty status (robust, pre-frail, and frail) and identify subsequent invasive breast cancer recurrences. Relative hazards of recurrence were determined using Fine and Gray competing risks regression models with estimated subdistribution hazard ratios (SHR) and robust 95% confidence intervals (CI). Results: From an overall cohort of 46,027 women, most women (56%) were classified as robust at breast cancer diagnosis, whereas 37% and 7% were identified as pre-frail and frail, respectively. Compared to robust patients, frail patients were more likely to have stage III disease (10% vs. 7%) and receive mastectomy (27% vs. 18%), and less likely to receive radiation (35% vs. 57%) or chemotherapy (5% vs. 9%). Five-year cumulative incidences of recurrence were 15%, 18% and 22% among robust, pre-frail, and frail women, respectively. In multivariable competing risks models adjusted for age, race, stage, and treatment, frail (SHR 1.28, 95%CI 1.17-1.41) and pre-frail (SHR 1.15, 95%CI 1.09-1.21) women had a significantly increased risk of breast cancer recurrence. Conclusions: Independent of differences in treatment, frailty was associated with increased breast cancer recurrence risk in this population-based cohort of older women. However, the vast majority of older women living with HR+/HER2- early breast cancer were not identified as frail. These study results suggest that age alone is not an adequate indicator of physical resilience and underscores the need to consider additional factors when assessing the benefits and risks of treatments for the prevention of recurrence among HR+/HER2- early breast cancer patients.

Abstract PD3-04: Classic lobular carcinoma in situ in the Netherlands: A population-based analysis

Abstract Background: Lobular carcinoma in situ (LCIS) is a non-invasive proliferation of epithelial cells of the terminal-duct lobular unit. Although LCIS is non-invasive itself, studies in the past showed that patients with LCIS have a 4-12 times higher risk of developing invasive breast cancer than the general population. Therefore, the optimal management of LCIS is still subject of debate. Despite lack of information about LCIS in the Dutch population, the Dutch guidelines recommend active surveillance for classic LCIS. This study aims to describe incidence and management of classic LCIS over time in the Netherlands, and to understand its behavior in terms of survival and the risk of developing subsequent ductal carcinoma in situ (DCIS) or invasive breast cancer. Methods: All female patients diagnosed with classic LCIS between 1989-2017 in the Netherlands were identified from the nationwide population-based Netherlands Cancer Registry. Patients previously diagnosed with DCIS or invasive breast cancer were excluded. Standardized incidence ratios (SIR) were calculated to estimate the risk of subsequent DCIS and invasive breast cancer, using data on population size from Statistics Netherlands (CBS). Multivariable Cox proportional hazards regression was performed to estimate hazard ratios (HR) of overall mortality and risk of subsequent invasive breast cancer for different patient-, tumor- and treatment-related characteristics. Competing risks were taken into account. Relative survival was estimated using the Ederer II method, with expected mortality of the general population (matched by age, gender, calendar year) as a reference. Results: We included 1,890 patients. The median age at diagnosis was 51 years (range 24-91 years). The incidence of classic LCIS increased from 186 patients between 1989-1993 to 497 patients between 2014-2017. Of all patients, 50.5% were treated with breast-conserving surgery, 10.2% were treated with mastectomy, 12.6% were treated with an unknown type of surgery and 26.7% did not receive surgery. While in 1989 all patients were surgically treated, only 41% were surgically treated in 2017. Radiotherapy was administered in 3.1% and endocrine therapy in 0.2% of the patients. Median follow-up to death, and subsequent DCIS or invasive breast cancer was 8.5 years (range 0-29 years) and 6.9 years (range 0-27 years). Unadjusted 10- and 20-year overall survival rates were 91% (95%CI:90-93%) and 76% (95%CI:73-79%). Unadjusted 10- and 20-year relative survival rates were 99% (95%CI:97-100%) and 95% (95%CI:91-99%). In total, 270 patients was diagnosed with subsequent invasive breast cancer and 48 were diagnosed with DCIS. Of these, 60% were ipsilateral and 40% were contralateral. The SIRs for DCIS and invasive breast cancer were 4.4 (95%CI:3.2-5.8) and 24.4 (95%CI:21.6-27.5) as compared to the general population, respectively. The SIR was higher for younger patients than for older patients, and the SIR of ipsilateral invasive breast cancer was higher in case no surgical management was performed. In multivariable analysis, increasing age was the most important predictor for overall mortality, while no surgical management was related to a higher incidence of subsequent invasive breast cancer. Conclusion: LCIS incidence has increased over time, while surgical management has decreased. This study shows that the mortality risk is very low compared to the general population. In contrast, the incidence of invasive breast cancer, over a median follow-up of 6.9 years (range 0-27 years), is over 24 times more common in LCIS patients than in the general population. These results suggest that LCIS patients have a good prognosis, even when a subsequent invasive breast cancer is diagnosed. However, the high incidence of second tumors suggest that we carefully monitor these patients. Citation Format: Marissa Corine van Maaren, Agustin Ortega Avila, Jos Bart, Pieter J Westenend, Sabine Siesling. Classic lobular carcinoma in situ in the Netherlands: A population-based analysis [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD3-04.

Abstract P2-08-26: Cardiovascular events and mortality in a population-based cohort treated for ductal carcinoma in situ

Abstract Background: Ductal carcinoma in situ (DCIS) patients are mostly diagnosed through cancer screening programs, suggesting that this population may have a healthy screenee effect of being more health-conscious, have lower comorbidity and belong to a higher socio-economic class. In this population-based cohort, we assessed the likelihood of cardiovascular events and mortality in DCIS patients, comparing with a control group of non-DCIS patients. Methods: Using the Korean National Health Insurance Service database, 13,740 women who were diagnosed of DCIS between 2007 and 2013 were analyzed. Control group matched by age was selected three times the number of DCIS cases (n=41,200). Follow-up for comorbidities and survival was performed up to 2016. Cox proportional hazard regression analysis was used to evaluate the association between DCIS and myocardial infarction (MI) risk, cerebrovascular stroke risk and mortality rate. The DCIS group was divided into pure DCIS patients and DCIS patients with subsequent invasive breast cancer for analysis. Results: Compared to the control group, patients with DCIS history were more likely to have hypertension, diabetes mellitus, dyslipidemia and the Charlson’s Comorbidity Index score was significantly higher. Patients with DCIS history also had higher income and were more likely to live in urban districts. Despite of higher comorbidity rate, pure DCIS patients had a trend of lower MI risk (HR 0.710; 95% CI 0.448 - 1.125) and significantly lower stroke risk (HR 0.708; 95% CI 0.492 - 1.019). Whereas, DCIS patients with subsequent invasive breast cancer had a significantly lower MI risk (HR 0.582; 95% CI, 0.371 - 0.913) and trend of lower stroke risk (HR 0.815; 95% CI 0.610 - 1.108). Mortality rate was similar between control group and pure DCIS patients, but was higher in DCIS patients with subsequent invasive breast cancer (HR 1.629; 95% CI 1.339 - 1.983). The trend of lower risk for cardiovascular events was sustained when adjusting for age, income and comorbidities (hypertension, diabetes mellitus and dyslipidemia). Conclusion: DCIS patients had a lower risk for MI and stroke compared to the control group despite of higher rate of comorbidities, which may reflect socioeconomic differences. DCIS patients with subsequent invasive breast cancer had higher mortality rate, whereas pure DCIS patients had similar survival rate compared to the control group. Citation Format: Tae-Kyung Yoo, Byung Joo Chae, Kyung Do Han, DaHye Kim, Juneyoung Ahn, Woo-Chan Park, Se Jeong Oh. Cardiovascular events and mortality in a population-based cohort treated for ductal carcinoma in situ [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-26.

Abstract P6-10-20: Ductal carcinoma in situ (DCIS) of the breast: miRNA deregulation correlates with the Oncotype DX risk score

Abstract Background: Ductal carcinoma in situ (DCIS) is considered a non-obligate precursor of invasive breast cancer (IBC). It is estimated that 5-14% of women diagnosed with DCIS experience an ipsilateral IBC. Current clinical criteria do not discriminate well between women with DCIS who will and those who will not develop ipsilateral IBC or a DCIS recurrence. The Oncotype DX DCIS assay (12 genes) was derived from a multigene expression array (Oncotype DX, 21 genes), and includes 5 proliferation genes, PGR, GSTM1, and 5 reference genes. This assay has been shown to predict risk of subsequent ipsilateral IBC and DCIS, and is used by clinicians to evaluate both the risk of local recurrence and need for radiation therapy. Since abnormal expression of microRNAs (miRNAs) is thought to contribute to the development of IBC, and that very few studies have evaluated miRNA expression deregulation in DCIS lesions, we sought to determine if specific miRNA expression changes may help identify DCIS lesions with different Oncotype DX DCIS scores. Methods: For this study, we selected archived specimens from 52 women diagnosed with DCIS between 2012 and 2018, whose DCIS lesions were tested with the Oncotype DX DCIS assay (low (n=35), intermediate (n=11), high (n=6) risk scores). Total RNA was extracted by macrodissection of the DCIS lesions. MiRNA expression differences between DCIS lesions were evaluated using small-RNA next-generation sequencing. Quantitative PCR validations were performed using Taqman miRNA assays on the top 15 differentially expressed miRNAs Results: Small-RNA expression data obtained by next-generation sequencing of 43 DCIS RNA specimens identified miRNAs differentially expressed between the risk score groups. Fifteen differentially expressed miRNAs were selected for their association based on Oncotype DX DCIS score differences (miR-142-3p, miR-142-5p, miR-744, miR-155, miR-30c, miR-150, miR-146a, miR-190b, miR-135b, miR-193b) or on age of the patients (miR-19b, miR-19a, miR-135a, miR-132). QPCR validation of these 15 miRNAs, using RNA from 30 DCIS lesions with known Oncotypes DX DCIS scores, of which 21 were samples that had been sequenced (low (n=8), intermediate (n=9), and high (n=4)), and 9 were not sequenced (low (n=7), intermediate (n=1), high (n=1)) and identified 5 miRNAs (miR-135a (p=<0.05), miR-190b (p=0.043), miR-205 (p=<0.001), miR-30c (p=<0.01), miR-744 (p=<0.038)) that emerged for their association with the score groups. These 5 miRNAs provided a good discrimination tool between low and intermediate-high score samples. A composite score including these 5 miRNAs showed a highly significant association with the Oncotype DX DCIS Score (p=<0.001). Conclusions: Our analyses identified a subset of 5 miRNAs that is significantly associated with the Oncotype DX DCIS score of DCIS lesions. Interestingly, three of these miRNAs (miR-205, miR-744 and miR-135b) have been reported to regulate proliferation pathways, while the other two (miR-30c, and miR-190b) have been associated with estrogen expression pathways in breast cancer cells. Importantly, increased expression of miR-30c in IBC has been associated with benefit from endocrine therapy while increased expression of miR-205 has been associated with benefit from tyrosine kinase inhibitors in IBC, as well. Mir-205 has also been reported as a radiosensitizer in breast cancer cells. Altogether, our data suggest that evaluation of miRNA expression levels may add predictive and prognostic value to the diagnosis of DCIS. Citation Format: Olivier Loudig, Iddo Ben-Dov, Christina Liu, Miglena Komforti, Susan Fineberg. Ductal carcinoma in situ (DCIS) of the breast: miRNA deregulation correlates with the Oncotype DX risk score [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-10-20.

Associations of race and ethnicity with risk of developing invasive breast cancer after lobular carcinoma in situ

BackgroundLobular carcinoma in situ (LCIS) of the breast is a risk factor of developing invasive breast cancer. We evaluated the racial differences in the risks of subsequent invasive breast cancer following LCIS.MethodsWe utilized data from the Surveillance, Epidemiology, and End Results registries to identify 18,835 women diagnosed with LCIS from 1990 to 2015. Cox proportional hazards regression was used to estimate race/ethnicity-associated hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of subsequent invasive breast cancer.ResultsDuring a median follow-up of 90 months, 1567 patients developed invasive breast cancer. The 10-year incidence was 7.9% for Asians, 8.2% for Hispanics, 9.3% for whites, and 11.2% for blacks (P = 0.046). Compared to white women, black women had significantly elevated risks of subsequent invasive breast cancer (HR 1.33; 95% CI 1.11, 1.59), and invasive cancer in the ipsilateral breast (HR 1.37; 95% CI 1.08, 1.72) and in the contralateral breast (HR 1.33; 95% CI 1.00, 1.76). Black women had significantly higher risks of invasive subtypes negative for both estrogen receptor and progesterone receptor (HR 1.86; 95% CI 1.14, 3.03) and invasive subtypes positive for one or both of receptors (HR 1.30; 95% CI 1.07, 1.59). The risk of subsequent invasive breast cancer was comparable in Asian women and Hispanic women compared with white women.ConclusionsBlack women had a significantly higher risk of developing invasive breast cancer, including both hormone receptor-positive and hormone receptor-negative subtypes, after LCIS compared with white counterparts. It provides an opportunity to address health disparities.

Genomic landscape of ductal carcinoma in situ and association with progression.

The detection rate of breast ductal carcinoma in situ (DCIS) has increased significantly, raising the concern that DCIS is overdiagnosed and overtreated. Therefore, there is an unmet clinical need to better predict the risk of progression among DCIS patients. Our hypothesis is that by combining molecular signatures with clinicopathologic features, we can elucidate the biology of breast cancer progression, and risk-stratify patients with DCIS. Targeted exon sequencing with a custom panel of 223 genes/regions was performed for 125 DCIS cases. Among them, 60 were from cases having concurrent or subsequent invasive breast cancer (IBC) (DCIS + IBC group), and 65 from cases with no IBC development over a median follow-up of 13years (DCIS-only group). Copy number alterations in chromosome 1q32, 8q24, and 11q13 were analyzed using fluorescence in situ hybridization (FISH). Multivariable logistic regression models were fit to the outcome of DCIS progression to IBC as functions of demographic and clinical features. We observed recurrent variants of known IBC-related mutations, and the most commonly mutated genes in DCIS were PIK3CA (34.4%) and TP53 (18.4%). There was an inverse association between PIK3CA kinase domain mutations and progression (Odds Ratio [OR] 10.2, p < 0.05). Copy number variations in 1q32 and 8q24 were associated with progression (OR 9.3 and 46, respectively; both p < 0.05). PIK3CA kinase domain mutations and the absence of copy number gains in DCIS are protective against progression to IBC. These results may guide efforts to distinguish low-risk from high-risk DCIS.

Abstract 751: Ductal carcinoma in situ of the breast: Cancer precursor or not

Abstract Background. Ductal carcinoma in situ (DCIS) is a potential precursor of invasive breast cancer (IBC). However, the natural course of a particular DCIS lesion is unknown, because almost all women with DCIS are treated. Furthermore, most studies are biased because these comprise DCIS adjacent to IBC, also known as synchronous DCIS and IBC, indicating that such DCIS lesions already have the capacity to progress to IBC. It is still unknown which proportion and type of subsequent ipsilateral IBCs (iIBC) are related to the initial primary “pure” DCIS lesion. Therefore, we performed an extensive molecular characterization of DCIS and matched subsequent iIBC, to better understand the natural course of DCIS. Patients and methods. We used a unique series of 78 women diagnosed with DCIS and treated by breast conserving surgery (BCS) alone, which subsequently developed iIBC. Mean time to iIBC event was 6.3 years (range 0.5-17.0). These 78 women are a representative sample of a case-control series, nested in a nation-wide, population-based cohort including all patients diagnosed with DCIS between 1989 and 2005 in the Netherlands (Visser, et al Clin Can Res 2018). Data on tumor location (ICD-10) was available for all lesions. DNA and RNA was simultaneously extracted for 78 DCIS lesions and 78 matched subsequent iIBC (DNA &amp;gt;20ng; RNA &amp;gt;100ng), and RNA sequencing (RNAseq) and low coverage whole genome sequencing (CNVseq) was performed. Panel sequencing (PanelSeq), using a custom panel of 53 breast cancer driver genes, was performed with the remaining DNA of 42 DCIS and iIBC matched pairs. We determined if the iIBC lesion and DCIS lesion were related, by comparing tumor location and genomic features. Results. Based on tumor location and histological grade, &amp;gt;95% of the subsequent iIBC reflected outgrowth of residual disease. Based on RNAseq data, 77% of all DCIS and IBC lesions classified into the same PAM50 subtypes. The CNVseq data showed that the DCIS lesions contained copy number aberrations on typical breast cancer-associated loci, such as 1q gain, 8q gain, 16q loss, 20q gain. However, when we compared DCIS with their matched iIBC, we observed in 41% of the cases very distinct copy number profiles, indicating either outgrow of a different tumor (minority) subclone or a second primary tumor. Analysis of PanelSeq mutation data supported this clonal or independent origin of the subsequent iIBC. Conclusion. To our knowledge, our study is the first to investigate if subsequent iIBC is likely to originate from the initial primary “pure” DCIS in a large series with long-term follow-up. Surprisingly, our CNVseq and PanelSeq results indicate that more than one third of the subsequent iIBCs after BCS alone treated primary DCIS are likely to be second primary tumors or represent selective outgrowth of a minority DCIS subclone. Citation Format: Lindy Visser, Marlous Hoogstraat, Tycho Bismeijer, Lotte Elshof, Koen van de Vijver, Emilie Groen, Mathilde Almekinders, Joyce Sanders, Carolien Bierman, Dennis Peters, Ingrid Hofland, Frank Nieboer, Michiel de Maaker, Petra Kristel, Lennart Mulder, Annegien Broeks, Michael Schaapveld, Marjanka Schmidt, Lodewyk Wessels, Esther Lips, Jelle Wesseling, On behalf of the PRECISION team. Ductal carcinoma in situ of the breast: Cancer precursor or not [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 751.

Race and risk of subsequent aggressive breast cancer following ductal carcinoma in situ.

BackgroundGeneral populations of black women have a higher risk of developing breast cancer negative for both estrogen receptor (ER) and progesterone receptor (PR) in comparison with white counterparts. Racial differences remain unknown in the risk of developing aggressive invasive breast cancer (IBC) that is characterized by negativity for both ER and PR (ER–PR–) or higher 21‐gene recurrence scores after ductal carcinoma in situ (DCIS).MethodsThis study identified 163,892 women (10.5% black, 9.8% Asian, and 8.6% Hispanic) with incident DCIS between 1990 and 2015 from the Surveillance, Epidemiology, and End Results data sets. Cox proportional hazards regression was used to estimate hazards ratios (HRs) of subsequent IBC classified by the hormone receptor status and 21‐gene recurrence scores.ResultsDuring a median follow‐up of 90 months, 8333 women developed IBC. In comparison with white women, the adjusted HR of subsequent ER–PR– breast cancer was 1.86 (95% confidence interval [CI], 1.57‐2.20) for black women (absolute 10‐year difference, 2.2%) and 1.40 (95% CI, 1.14‐1.71) for Asian women (absolute 10‐year difference, 0.4%); this was stronger than the associations for ER+ and/or PR+ subtypes (P heterogeneity = .0004). The 21‐gene recurrence scores of subsequent early‐stage, ER+ IBCs varied by race/ethnicity (P heterogeneity = .057); black women were more likely than white women to have a recurrence score of 26 or higher (HR, 1.38; 95% CI, 1.00‐1.92). No significant difference was observed in the risks of subsequent IBC subtypes for Hispanic women.ConclusionsBlack and Asian women with DCIS had higher risks of developing biologically aggressive IBC than white counterparts. This should be considered in treatment decisions for black and Asian patients with DCIS.

Abstract PD8-09: Approximately 40% of invasive recurrences after treatment of ductal carcinoma in situ is likely to be a second primary tumor

Abstract Background. Ductal carcinoma in situ (DCIS) is a potential precursor of invasive breast cancer, because: DCIS often accompanies invasive breast cancer; its risk factors are similar to those of invasive breast cancer; and genetic markers found in DCIS are similar to the ones found in invasive breast cancer. However, clinical behavior of DCIS is still poorly understood, as there is only limited information on its long-term natural history. Altogether, this makes it difficult to understand the relatedness of DCIS and its subsequent ipsilateral invasive breast cancer (iIBC). Here, we set-up a comparison between primary DCIS and matched subsequent iIBC, by making use of pathological and molecular data. Patients and methods. For this study, we used a unique series of 155 DCIS cases which developed a subsequent iIBC during a median follow up period of 12.6 years. We assessed histological characteristics, tumor location, estrogen and progesterone receptor status, p16 expression, and HER2 and p53 overexpression. RNA sequencing and copy number sequencing was done on 78 DCIS lesions and 78 matched invasive breast cancer relapses. We determined if the iIBC lesion and DCIS lesion were related, with respect to tumor location, immunohistochemical (IHC) markers, and genomic features. Results. Based on tumor location and histological grade, &amp;gt;95% of the subsequent invasive breast cancers reflected outgrowth of residual disease. HER2 was the only IHC marker that showed a significant difference in expression between DCIS and matched iIBC: 40% of the HER2 positive DCIS was followed by a HER2 negative invasive recurrence. In addition, RNAseq data was used to classify DCIS and IBC lesions into PAM50 subtypes. 77% of the DCIS IBC pair belonged to the same subtype. The DCIS lesions showed copy number aberrations on typical breast cancer-associated loci. However, when we compared the DCIS with its matched iIBC, we saw in 41% of the cases very distinct copy number profiles, indicating either outgrow of a different tumor subclone or a second primary. Conclusion. This is the first time that a sound comparison could be made between primary DCIS and its subsequent invasive breast cancer with such a large patient group, integrating pathological and molecular data. Our results strongly suggest that many subsequent iIBCs after treatment of pure DCIS could be considered as second primary breast cancer lesions. To provide definite proof for this, in depth DNA sequencing and heterogeneity studies will be presented at SABCS 2018. Citation Format: Visser LL, Hoogstraat M, Elshof LE, van de Vijver K, Groen EJ, Almekinders MM, Bierman C, Nieboer F, de Maaker M, Kristel P, Mulder L, Schaapveld M, Schmidt MK, Lips E, Wesseling J. Approximately 40% of invasive recurrences after treatment of ductal carcinoma in situ is likely to be a second primary tumor [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-09.

Abstract P5-18-04: HER2 overexpression in ductal carcinoma in situ: A biomarker for risk stratification and therapeutic implication

Abstract Background: After initial treatment for ductal carcinoma in situ (DCIS), a subsequent clinically significant event (SCSE) such as another diagnosis of DCIS, atypia or invasive breast cancer (IBC), will likely lead to further surgical/medical therapy. Pathologically, DCIS is treated on the basis of estrogen (ER) and progesterone receptor (PR) status with hormonal therapy (HT), ie, tamoxifen (TMX) or aromatase inhibitor, regardless of human epidermal growth factor receptor (HER2) overexpression. Although HER2 is a well-established prognostic marker for IBC, the role of HER2 in DCIS is less appreciated. Recent studies have documented the prognostic value of p16, COX-2 and Ki67 as prognostic biomarkers for locoregional invasive recurrences due to abrogated response to cellular stress (ARCS). Notably, a high-risk population of DCIS patients lacking ER expression but over-expressing HER2, p16 and COX-2 has been recently identified. In the present study, we compared expression levels of HER2 and the 3 ARCS markers in a large cohort of DCIS patients treated with contemporary standard of care and with &amp;gt;5-year follow-up to assess their association with cancer progression and predictive value for developing a SCSE. Methods: Formalin-fixed paraffin-embedded tissue sections from 99 patients diagnosed with primary DCIS(1999-2013) were stained forER, PR and HER2 expression by immunohistochemistry (IHC).If equivocal, HER2 amplification was assessed by Silver In Situ Hybridization. An additional slide was stained forp16, Ki67 and COX-2 using a novel multiplex IHC strategy. Quantification of the 3 ARCS markers' expression in both epithelial and stromal compartments was carried out using a software (InformTM)-guided approach. For expression level comparison of the three markers between HER2+ and HER2- DCIS, Wilcoxon-Mann-Whitney test was used. Fisher's exact or Chi-square test was used for other data analysis. Results: Simultaneous increase in epithelial p16, COX-2 and Ki67 expression in DCIS lesions was associated with subsequent IBC progression. HER2+ DCIS was significantly associated with high grade (p=0.0014), comedo-necrosis subtype (p=0.0022) compared to HER2- lesions. Upregulation of stromal COX-2 and p16 was significantly (p=0.008) associated with progression to SCSE in HER2- DCIS. The majority (5/6, 83%) of HER2+ DCIS patients treated with HT developed a SCSE, while only 22% (6/27) of HER2- DCIS patients treated with HT developed a SCSE. COX-2 upregulation was significantly associated with resistance to HT in HER2+ DCIS patients. Conclusion: High expression of p16, COX-2 and Ki67 in DCIS lesions can serve as powerful predictive biomarkers for DCIS progression to IBC. Our preliminary data suggest that overexpression of stromal p16 and COX-2 may help predict SCSEs in HER2- DCIS. Additionally, assessment of HER2 expression in DCIS may allow identification of patients who would not benefit from traditional HT as HER2 overexpression may predict TMX resistance. Since our data suggest that TMX resistance in HER2+ DCIS may be linked to upregulation of COX-2, one may propose that COX-2 inhibitors in conjunction with TMX may minimize TMX resistance in HER2+ DCIS. These preliminary data will need to be reproduced in a larger cohort to solidify their significance. Citation Format: Yin J, Gascard P, Last B, Singh M, Tlsty T, Tjoe JA. HER2 overexpression in ductal carcinoma in situ: A biomarker for risk stratification and therapeutic implication [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-04.

Mortality of women with ductal carcinoma in situ of the breast: a population-based study from the Girona province, Spain (1994\u20132013)

PurposeWe aim to comprehensively describe the incidence and mortality trends of ductal carcinoma in situ (DCIS) in the Girona province, Spain (1994–2013) and to estimate the all-cause mortality excess risk of diagnosed women.MethodsAge-standardized rates of DCIS were estimated between 1994 and 2013. Standard mortality ratios (SMR) and absolute excess mortality were calculated overall and by tumor and patient characteristics. A sensitivity analysis was conducted excluding cases with a subsequent invasive breast cancer (sIBC).ResultsOf the 641 women included, 56 died (follow-up time: 8.4 person-years). Between 1994 and 2013, a significant increase in incidence and decrease in mortality was identified among women aged between 50 and 69 years old. Neoplasms and circulatory system disease were the most common causes of death. No excess risk of death was found overall, except for women aged < 50 years (SMR = 3.44, 95% CI 1.85; 6.40) and those with a sIBC (SMR = 2.51, 95% CI 1.26; 5.02), risk that lessened when cases with sIBC were excluded. Patients with sIBC also showed an excess risk (SMR = 2.29, 95% CI 1.03; 5.10).ConclusionsAmong women aged 50–69 years old, incidence of DCIS has significantly increased yet mortality has decreased. Overall, the all-cause mortality risk of women diagnosed with DCIS remains similar to that of the general population except for women diagnosed before age 50 and those with sIBC, who showed a significant increased risk. Differential management of these patients should be considered.

Abstract 4348: In depth molecular analysis of 183 primary DCIS lesions and 78 subsequent invasive breast cancers

Abstract Background. Ductal carcinoma in situ (DCIS) is a potential precursor of invasive breast cancer (IBC). As we are currently unable to predict which DCIS lesions will progress to IBC, almost all women with DCIS are treated with surgical treatment, adjuvant therapy, or both. Yet, most DCIS lesions will never progress, implying overtreatment in many women. To increase our knowledge of DCIS and improve DCIS risk stratification, we performed a molecular characterization of a large series of DCIS lesions with long-term follow-up. Patients and methods. We made use of a DCIS case-control series, nested in a nation-wide population-based cohort of Dutch women diagnosed with primary DCIS and treated with breast conserving surgery alone between 1989-2005. Mean follow-up time was 12.0 years. DNA and RNA were simultaneously extracted from FFPE laser-microdissected tissue fragments of 183 primary DCIS lesions (100 associated with subsequent invasive recurrences; and 83 which remained free of invasive recurrence during the same follow-up duration) and 78 matched subsequent ipsilateral IBCs. RNA sequencing (RNAseq) and low coverage DNA sequencing (CNVseq) were performed to identify differentially expressed and aberrated genes between DCIS with and without an invasive recurrence and to compare primary DCIS and its subsequent IBC. Results. After exclusion of samples with poor data quality, 158 DCIS lesions and 72 IBCs (88%) were included for CNVseq analysis and 155 DCIS lesions and 68 IBCs (85%) were included in the RNAseq analysis. CNVseq analysis identified copy number aberrations of known breast cancer-related genes. Amplification of FGFR1, CCND1, ZNF217, and ERBB2 was found in 16, 19, 22, and 44 DCIS samples, respectively. Furthermore, loss of CBFB, CDKN2A, CDKN2B, TP53, and MAP2K4 was found in 10, 11, 11, 11, and 14 DCIS samples, respectively. Deletion of CBFB, TP53, and CDH1 was more often detected in DCIS with subsequent IBC as compared of DCIS without invasive recurrence. When comparing DCIS and subsequent IBC, aberrations of breast cancer-related genes were mostly comparable. RNAseq analysis revealed genes, differentially expressed between DCIS with and without subsequent IBC, which were enriched in immune-related pathways. Conclusion. We performed the first large-scale analysis of primary DCIS lesions with and without subsequent invasive recurrences, with long-term follow-up. Our data show differences in aberrated genes between DCIS with and without subsequent IBC, whereas DCIS and subsequent IBC were more alike. Furthermore, our transcriptomic data suggest that immune-related pathways are involved in DCIS progression. More extensive data analysis will be presented at AACR 2018. The results of our unique study add to the current understanding of DCIS and allow optimized risk stratification of DCIS in the near future. Citation Format: Lindy Visser, Marlous Hoogstraat, Asli Kucukosmanogl, Frank Nieboer, Michiel de Maaker, Petra Kristel, Lennart Mulder, Lotte Elshof, Flora van Leeuwen, Emiel Rutgers, Marjanka K. Schmidt, Esther Lips, Jelle Wesseling. In depth molecular analysis of 183 primary DCIS lesions and 78 subsequent invasive breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4348.

PO-070 Identification of risk factors for subsequent invasive breast cancer after primary DCIS by transcriptomic profiling

IntroductionDuctal carcinoma in situ (DCIS) is a pre-invasive breast lesion, frequently detected by breast cancer screening, with thousands of new cases each year. While DCIS is not life threatening, it does increase a women’s risk of developing invasive breast cancer; this in turn can lead to breast-cancer specific mortality. Therefore, almost all DCIS lesions are treated to prevent progression to invasive disease. However, many DCIS lesion will never develop into invasive breast cancer if left untreated, indicating that many women are overtreated. In this study, we performed RNA sequencing (RNAseq) on a large set of primary DCIS lesions, comparing lesions with a subsequent invasive breast cancer recurrence (IBCR) to those without, to identify factors distinguishing harmless from potentially hazardous DCIS.Material and methodsWe made use of a DCIS case-control series, nested in a nation-wide population-based cohort of Dutch women diagnosed with primary DCIS and treated with breast conserving surgery alone (standard clinical practice) between 1989–2005. Mean follow up time was 12.0 years. RNA was extracted from FFPE laser-microdissected tissue fragments of 183 primary DCIS lesions: 100 associated with subsequent IBCR and 83 which remained free of invasive recurrence. RNAseq was performed to identify differentially expressed genes between DCIS with and without IBCR. Subsequently, gene set enrichment analysis (GSEA) was performed. Finally, findings were correlated with patients’ clinical and histopathological characteristics.Results and discussionsDCIS lesions were categorised into PAM50 intrinsic subtypes: Luminal A 25%, Luminal B 38%, Her2 22%, Basal 10%, Normal 5%. Within each PAM50 subtype, 1 to 64 genes were statistically significant (p<0.05) differentially expressed between DCIS lesions with and without IBCR. GSEA revealed these genes were enriched in immune-related pathways. In Luminal A DCIS the pathways interferon alpha response and interferon gamma response and were associated with subsequent IBCR. Correlation of these findings with clinical and histopathological characteristics is ongoing.ConclusionTo our knowledge, we performed the first large-scale transcriptome analysis of primary DCIS lesions with and without subsequent IBCR and long-term follow-up. Our data suggest that immune-related pathways are involved in DCIS progression. The results of our study add to the current understanding of DCIS and to risk stratification of DCIS in the near future.

Validation of the IBIS breast cancer risk evaluator for women with lobular carcinoma in-situ

BackgroundManagement advice for women with lobular carcinoma in situ (LCIS) is hampered by the lack of accurate personalised risk estimates for subsequent invasive breast cancer (BC). Prospective validation of the only tool that estimates individual BC risk for a woman with LCIS, the International Breast Cancer Intervention Study Risk Evaluation Tool (IBIS-RET), is lacking.MethodsUsing population-based cancer registry data for 732 women with LCIS, the calibration and discrimination accuracy of IBIS-RET Version 7.2 were assessed.ResultsThe mean observed 10-year risk of invasive BC was 14.1% (95% CI:11.3%-17.5%). IBIS-RET overestimated invasive BC risk (p = 0.0003) and demonstrated poor discriminatory accuracy (AUC 0.54, 95% CI: 0.48 – 0.62).ConclusionsClinicians should understand that IBIS-RET Version 7.2 may overestimate 10-year invasive BC risk for Australian women with LCIS. The newer IBIS-RET Version 8.0, released September 2017, includes mammographic density and may perform better, but validation is needed.

Somatic mutations in benign breast disease tissue and risk of subsequent invasive breast cancer

BackgroundInsights into the molecular pathogenesis of breast cancer might come from molecular analysis of tissue from early stages of the disease.MethodsWe conducted a case–control study nested in a cohort of women who had biopsy-confirmed benign breast disease (BBD) diagnosed between 1971 and 2006 at Kaiser Permanente Northwest and who were followed to mid-2015 to ascertain subsequent invasive breast cancer (IBC); cases (n = 218) were women with BBD who developed subsequent IBC and controls, individually matched (1:1) to cases, were women with BBD who did not develop IBC in the same follow-up interval as that for the corresponding case. Targeted sequence capture and sequencing were performed for 83 genes of importance in breast cancer.ResultsThere were no significant case–control differences in mutation burden overall, for non-silent mutations, for individual genes, or with respect either to the nature of the gene mutations or to mutational enrichment at the pathway level. For seven subjects with DNA from the BBD and ipsilateral IBC, virtually no mutations were shared.ConclusionsThis study, the first to use a targeted multi-gene sequencing approach on early breast cancer precursor lesions to investigate the genomic basis of the disease, showed that somatic mutations detected in BBD tissue were not associated with breast cancer risk.

MicroRNA expression in benign breast tissue and risk of subsequent invasive breast cancer.

MicroRNAs are endogenous, small non-coding RNAs that control gene expression by directing their target mRNAs for degradation and/or posttranscriptional repression. Abnormal expression of microRNAs is thought to contribute to the development and progression of cancer. A history of benign breast disease (BBD) is associated with increased risk of subsequent breast cancer. However, no large-scale study has examined the association between microRNA expression in BBD tissue and risk of subsequent invasive breast cancer (IBC). We conducted discovery and validation case-control studies nested in a cohort of 15,395 women diagnosed with BBD in a large health plan between 1971 and 2006 and followed to mid-2015. Cases were women with BBD who developed subsequent IBC; controls were matched 1:1 to cases on age, age at diagnosis of BBD, and duration of plan membership. The discovery stage (316 case-control pairs) entailed use of the Illumina MicroRNA Expression Profiling Assay (in duplicate) to identify breast cancer-associated microRNAs. MicroRNAs identified at this stage were ranked by the strength of the correlation between Illumina array and quantitative PCR results for 15 case-control pairs. The top ranked 14 microRNAs entered the validation stage (165 case-control pairs) which was conducted using quantitative PCR (in triplicate). In both stages, linear regression was used to evaluate the association between the mean expression level of each microRNA (response variable) and case-control status (independent variable); paired t-tests were also used in the validation stage. None of the 14 validation stage microRNAs was associated with breast cancer risk. The results of this study suggest that microRNA expression in benign breast tissue does not influence the risk of subsequent IBC.

Abstract 350: Pregnancy at early age is associated with a reduction of progesterone-responsive cells and epithelial Wnt signaling in human breast tissue

Abstract Background: Pregnancy at early age is the most significant modifiable factor which consistently decreases lifetime breast cancer risk. However, the underlying mechanisms haven’t been conclusively identified. Studies in mice suggest a reduction in progesterone-receptor (PR) sensitive epithelial cells as well as a downregulation of the Wnt signaling pathway as being one of the main mechanisms for the protective effect of early pregnancy. The aim of our study was to validate these findings in humans. Methods: We collected benign breast tissue of 123 women who had been stratified according to age at first pregnancy and the occurrence of subsequent breast cancer, and performed immunohistochemistry for PR, Wnt4 and the Wnt-target Versican. Results: The number of PR positive epithelial cells was significantly lower in the group of women with early pregnancy and no subsequent breast cancer compared to the group of nulliparous women with subsequent invasive breast cancer (p=0.017). In women with early pregnancy, expression of Versican and Wnt4 was significantly lower compared to nulliparous women (p=0.0064 and p=0.0156 respectively), and Versican expression was also significant lower compared to women with late pregnancy (p&amp;lt;0.0001). Discussion: Our results confirm prior observations in mice and suggest a role of downregulation of epithelial Wnt signaling in the protective effect of early pregnancy in humans. This results in a decreased proliferation of stem/progenitor cells; therefore, the Wnt signaling pathway may represent a potential target for breast cancer prevention in humans. Citation Format: Robert Mechera, Simone Münst, Silvio Däster, Salvatore Piscuoglio, Charlotte Ng, Fabienne Meier-Abt, Walter P. Weber, Savas D. Soysal. Pregnancy at early age is associated with a reduction of progesterone-responsive cells and epithelial Wnt signaling in human breast tissue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 350. doi:10.1158/1538-7445.AM2017-350

Abstract 4738: Risk of ipsilateral invasive breast cancer after DCIS: a comparison of primary DCIS and subsequent invasive disease by morphological and immunohistochemical analysis

Abstract INTRODUCTION. The wide spread adoption of population-based breast cancer screening has led to a substantial increase in diagnosis of ductal carcinoma in situ (DCIS). When detected, almost all DCIS is treated to prevent progression to invasive disease, even though the majority of DCIS will never progress. Yet, we are unable to discriminate harmless from potentially hazardous DCIS. Hence, there is an urgent need to find characteristics of DCIS and biomarkers that predict subsequent invasive tumor development. In this study, we compared primary DCIS lesions with their subsequent ipsilateral invasive breast cancer (iIBC), to explore how the initial DCIS lesion and its subsequent iIBC are related. PATIENTS AND METHODS. We used a population-based, nation-wide cohort consisting of 2,654 women who were treated for primary DCIS by breast conserving surgery (BCS) only. Within a median follow-up time of 10.7 years, 316 women developed a subsequent iIBC (12%). FFPE tissue blocks of both DCIS and subsequent iIBC could be collected for 158 of these 316 women. We assessed histology characteristics, tumor location, estrogen and progesterone receptor status, p16 expression, and HER2 and p53 overexpression. Additionally, DNA and RNA were simultaneously isolated from 100 DCIS and 100 matched subsequent iIBC specimens for extensive molecular profiling. RESULTS. More than 95% of the invasive recurrences were located at or near the site of the primary DCIS. Concordant histological grade was found in 94% of the matched pairs and identical immunohistochemical (IHC) marker expression in 58%. Of the 44 patients with HER2 positive DCIS, 36% developed HER2 negative iIBC. Furthermore, this change in HER2 status was also a main cause of a change in surrogate intrinsic subtype (based on ER, PR, HER2) between DCIS and iIBC, which was observed in 16% of the patients. These dissimilarities were not found when we compared invasive disease with synchronous DCIS (present in 83 of 158 patients). Molecular analyses is still ongoing. CONCLUSION. This is the first time that an unbiased comparison could be made between primary DCIS and its subsequent iIBC within such a large patient group, integrating clinical, histological and IHC data. Our results suggest that the majority of invasive breast cancers in our cohort reflect outgrowth of residual disease based on tumor location and histological grade. DCIS and iIBC are very similar when comparing histological grade, but frequently show differences on the IHC level. Remarkably, the dissimilarities in HER2 status and surrogate intrinsic subtype as seen in primary DCIS vs. iIBC are missing when comparing IBC with synchronous DCIS. As a next step, we will analyse the lesions on the molecular level, to verify these findings and to look for molecular characteristics of DCIS that could be associated with progression to invasive disease. Citation Format: Lindy L. Visser, Lotte L. Elshof, Koen van de Vijver, Emma J. Groen, Mathilde Almekinders, Marjanka K. Schmidt, Flora van Leeuwen, Emiel J. Rutgers, Michael Schaapveld, Esther H. Lips, Jelle Wesseling. Risk of ipsilateral invasive breast cancer after DCIS: a comparison of primary DCIS and subsequent invasive disease by morphological and immunohistochemical analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4738. doi:10.1158/1538-7445.AM2017-4738