Visscher, Daniel W.

Abstract Background: Terminal duct lobular units (TDLUs) are the anatomical source of most breast cancers. TDLU involution, manifested as atrophy and loss of TDLUs, is associated with reduced breast cancer risk. We hypothesize that breast cancer susceptibility loci are associated with TDLU involution. Accordingly, we evaluated relationships between 25 established breast cancer susceptibility markers and their association with TDLU involution in the Susan G. Komen for the Cure® Tissue Bank (KTB). Methods: Subjects were women ages 18-84 (N=680), who had no personal history of any cancer, were not currently taking menopausal hormones, completed a risk factor questionnaire, provided an Oragene® saliva sample, and donated a 10-guage needle tissue core from the upper outer breast quadrant for research. We genotyped 25 known single nucleotide polymorphisms (SNPs) associated with breast cancer risk using TaqMan® assays. Pathologists masked to risk data classified three features inversely related to TDLU involution using one histological section of breast tissue/subject: number of TDLUs per section (TDLU density), TDLU diameters and number of acini per TDLU. SNPS were compared to metrics of TDLU involution categorized in tertiles: TDLU density (0-1, 2-8, 9+), mean TDLU diameter (53-291, 292-415, 416-1143 microns), and mean number of acini per TDLU (2-10, 11-20, 21+). We estimated age-adjusted per-allele odds ratios (ORs) and 95% confidence intervals (CIs) using ordinal logistic regression models with TDLU measures as the outcome and SNPs as the explanatory variables. Associations with TDLU density were based on up to 680 women with genotype data, while associations with diameter and acini measures were based on up to 469 women with observed TDLUs. Results: The rs3803662 (TOX3/TNRC9) SNP risk allele showed an association with increased TDLU density, larger TDLUs, and more acini in TDLUs (TDLU density per-allele OR=1.29 95%CI=1.04-1.60; TDLU diameter OR=1.32 95%CI=1.00-1.74; and TDLU acini OR=1.34 95%CI=1.02-1.77), consistent with previous observations of significant associations seen for this SNP with mammographic density (a well-established risk factor for breast cancer), breast cancer risk, and survival of breast cancer. In addition, we observed associations for four other SNPs with TDLU density (rs311499, rs10483813, rs2981582, rs3817198), for one other SNP with mean TDLU diameter (rs11249433), and for three other SNPs with mean TDLU acini number (rs704010, rs10941679, rs11249433). Conclusion: These data suggest that breast cancer susceptibility SNPs may be associated with TDLU involution levels, and could represent a mechanism by which they influence breast cancer risk. These findings warrant replication in other studies and provide support for the concept that levels of TDLU involution represent an intermediate marker of breast cancer risk. Citation Format: Jonine D. Figueroa, Gretchen L. Gierach, Ruth Pfeiffer, Stephen Chanock, Louise Brinton, Deesha A. Patel, Daniel Visscher, Carolyn Mies, Stephen Hewitt, Susan Clare, Anna Maria Storniolo, Mark Sherman. Associations between breast cancer susceptibility markers and terminal duct lobular unit involution in normal breast tissues among women from the Susan G. Komen for the Cure® Tissue Bank. [abstract]. In: Proceedings of the AACR Special Conference on Post-GWAS Horizons in Molecular Epidemiology: Digging Deeper into the Environment; 2012 Nov 11-14; Hollywood, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(11 Suppl):Abstract nr 58.

Abstract Background: Ovarian carcinoma is composed of five major histologic types, which associate with outcome and predict therapeutic response. Our aim was to evaluate histologic type assessments across the centers participating in the Ovarian Tumor Tissue Analysis (OTTA) consortium using an immunohistochemical (IHC) prediction model. Methods: Tissue microarrays (TMA) and clinical data were available for 524 pathologically confirmed ovarian carcinomas. Centralized IHC was conducted for ARID1A, CDKN2A, DKK1, HNF1B, MDM2, PGR, TP53, TFF3, VIM, and WT1, and three histologic type assessments were compared: the original pathologic type, an IHC-based calculated type (termed TB_COSPv2), and a WT1-assisted TMA core review. Results: The concordance between TB_COSPv2 type and original type was 73%. Applying WT1-assisted core review, the remaining 27% discordant cases subdivided into unclassifiable (6%), TB_COSPv2 error (6%), and original type error (15%). The largest discordant subgroup was classified as endometrioid carcinoma by original type and as high-grade serous carcinoma (HGSC) by TB_COSPv2. When TB_COSPv2 classification was used, the difference in overall survival of endometrioid carcinoma compared with HGSC became significant [RR 0.60; 95% confidence interval (CI), 0.37–0.93; P = 0.021], consistent with previous reports. In addition, 71 cases with unclear original type could be histologically classified by TB_COSPv2. Conclusions: Research cohorts, particularly those across different centers within consortia, show significant variability in original histologic type diagnosis. Our IHC-based reclassification produced more homogeneous types with respect to outcome than original type. Impact: Biomarker-based classification of ovarian carcinomas is feasible, improves comparability of results across research studies, and can reclassify cases which lack reliable original pathology. Cancer Epidemiol Biomarkers Prev; 22(10); 1677–86. ©2013 AACR.

Abstract Benign breast disease (BBD) is an established risk factor for breast cancer among Caucasian women but less is known about BBD in African American women. As African American women suffer from disproportionate mortality due to breast cancer, special focus on pathologic characteristics that may influence disease risk is warranted. Benign breast biopsies from African American women were identified by the University Pathology Group (Detroit, MI). African American women of ages 20 to 84 years, who underwent a breast biopsy from 1997 to 2000, were eligible for the study. Subsequent breast cancers were identified through a linkage with the Detroit Surveillance Epidemiology and End Results (SEER) program. The first biopsy was reviewed by the pathologist, and lesions were classified following Dupont and Page criteria along with involution and other histologic features. Logistic regression was used to estimate the risk of developing a subsequent breast cancer with the histologic characteristics of BBD. A total of 1,406 BBD biopsies from African American women were included in this study with a median follow-up of 10.1 years. The majority (68%) showed nonproliferative disease, 29% had proliferative disease without atypia, and 3% had proliferative disease with atypia. Subsequent incident breast cancers occurred in 55 women (3.9%). Women whose biopsies showed proliferative disease with atypia were more than three-fold more likely to develop breast cancer as compared with women who had nonproliferative disease [relative risk (RR) 3.29, 95% confidence interval (CI) 1.21–8.93]. Better characterization of the risk of breast cancer among women with BBD, considering both ethnicity and detailed molecular findings, can lead to better surveillance, earlier diagnosis, and potentially improved survival. Cancer Prev Res; 5(12); 1375–80. ©2012 AACR.

Abstract High throughput sequencing technologies open up a new dimension in cancer genomics by enabling the characterization of cancer genomes at base-pair resolution. To date, the majority of large-scale genomics projects rely on fresh-frozen biospecimens in their studies, which are difficult to obtain and often lack long-term clinical data. Unlike fresh-frozen samples, archived formalin-fixed paraffin-embedded (FFPE) tissues are more readily accessible, and are often associated with known clinical outcomes and more complete clinical annotations. However, sequencing library preparation methods need to be further optimized with regard to applicability to FFPE samples. To test whether next-generation sequencing technologies could overcome previously reported artifacts associated with formalin fixation and report accurate sequencing results, we compared whole-genome and targeted enrichment DNA sequencing data obtained from five FFPE tumor samples for which matching frozen tissues were available. We successfully generated sequencing libraries using 1 µg of genomic DNA as input material and a modified TruSeq™ sample preparation protocol. We designed a custom enrichment pool targeting exons from 215 cancer-related genes and utilized this pool to pull-down and sequence approximately 1.3 Mb region of the genome with an average 400x coverage depth to test if deep sequencing would improve validation of tumor-specific somatic mutations. We used the Illumina sequence analysis pipeline and the Windows-based second generation DNA sequencing software NextGENe® to analyze the data and identify sequence variations that are different from the human reference genome. CNV detection was overall higher among FFPE samples compared with fresh-frozen samples, demonstrating that tissue processing impacts sequencing data quality. We obtained good concordance in variant calls between matched FFPE and fresh-frozen samples. Discordant variant calls were mainly due to low depth of coverage in the regions where variant calls were made. Improvements to DNA sequencing methods for archived samples will significantly enhance cancer research and will result in more reliable prediction of individual cancer therapies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3179. doi:1538-7445.AM2012-3179

Abstract Little is known about the effects of many recognized breast cancer risk factors on the normal breast. We hypothesize that risk factors affect the number and morphometry of terminal ductal lobular units (TDLUs), the microanatomical structure from which most breast cancers arise. To assess this hypothesis, we evaluated relationships between breast cancer risk factors and TDLU number, TDLU diameter, and acini per TDLU in breast tissue donated by healthy volunteers. Subjects included 786 healthy women ages 18-84 years without a personal history of any cancer, who provided a risk factor questionnaire and donated a 10-guage needle core from the upper outer breast quadrant. A pathologist, masked to subject data, assessed TDLU number per section, TDLU diameter and acini per TDLU using digitized images of hematoxylin and eosin stained sections of tissue. Seventy-two randomly selected images were examined by two additional pathologists. We generated ordered categorical variables for the number of TDLUs per section (0-1, 2-8, 9+), median TDLU diameter (53-262, 263-377, 378-1375 microns) and median number of acini per TDLU (2-10, 11-20, 21+). We computed Spearman correlations between measures, and intraobserver and interobserver agreement. Associations between breast cancer risk factors and TDLU measures were assessed by estimating odds ratios (OR) and 95% confidence intervals (CI) using ordinal logistic regression models, adjusted for age. TDLU diameter and acini count were highly correlated (rho =0.71); TDLU number per section was less strongly related to the diameter (rho= 0.18) and acini measures (rho=0.20). Inter and intraobserver agreement for TDLU measures were highly correlated (rho range 0.68-0.98). All TDLU measurements were significantly lower among women age 50 years and older compared with younger women. Compared with Caucasians, African American women had more TDLUs per section (ORadj=2.03, 95% CI= 1.06-3.89). Greater numbers of TDLUs were also related to having a family history of two or more relatives with breast cancer compared with none (ORadj=2.01, 95% CI=0.91-4.46); and for parous compared with nulliparous women (ORadj=1.61, 95% CI=1.16-2.25). In contrast, parity was associated with reduced median number of acini per TDLU (ORadj=0.60, 95% CI = 0.40-0.90) and median diameter (ORadj=0.64, 95% CI = 0.42-0.96) compared with nulliparity. Our data suggest that TDLUs are more frequent among women with a positive family history of breast cancer or African Americans. Parity, an established protective factor for breast cancer risk, was related to increased numbers of TDLUs, but fewer acini per TDLU, suggesting that TDLUs may increase with pregnancy and then involute. Our data, along with published results linking TDLU involution with a reduction in breast cancer risk, suggest TDLU morphometry may reflect early biologic changes marking breast cancer susceptibility. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4465. doi:1538-7445.AM2012-4465

Rac1b mediates the matrix metalloproteinase–induced epithelial-mesenchymal transition in lung adenocarcinoma and is a potential therapeutic target in early-stage lung cancer.

Abstract B39 Background The breast glandular epithelium is composed of lobules that undergo age-related involution that increases as women age and has been associated with lowered breast cancer risk. Mammographic density (MD) is an established risk factor for breast cancer that has been shown to decrease with age. This study examined the association of age-related lobular involution with mammographic breast density. Materials and Methods The study sample was selected from approximately 20,000 healthy women who were enrolled in a screening cohort at the Mayo Clinic (Mayo Mammography Health Study) from 2003 to 2006 and had a benign breast biopsy (BBD) within 2 years of the enrollment mammogram. A quantitative measure of mammographic density, percent density (PD) was estimated on the enrollment mammogram, in addition to its components dense and nondense area (NDA). All biopsies were reviewed by a breast pathologist for the type of benign breast disease (BBD) as well as lobular involution status. Involution was defined as the proportion of terminal ductal lobular units (TDLUs) in the background tissue on biopsy that showed at least 50% decrease in size and number of acini from normal lobules and was subjectively assessed as: No- 0% involution, Partial- 1 to 74%, or Complete- >75% involution. Mean density was estimated for the 3 categories of involution using generalized linear models and square root transformation. Confounders were assessed including age, parity, body mass index (BMI), type of BBD, menopausal status, age at first birth and family history Results A total of 317 women from the MMHS had BBD within 2 years of enrollment. Mean age at BBD diagnosis in this sample was 55 years. Age- and BMI- adjusted analyses suggested an inverse association of involution and percent density with adjusted mean PD values of 23.3 (95%CI [17.2, 30.3]) for no involution, 21.9 (95%CI [20.0, 23.9]) for partial involution, and 17.8 (95% CI [14.7, 21.3]) for complete involution (p for trend 0.05). This trend was driven primarily by the positive association of involution with nondense area with adjusted mean NDA values of 103.1cm2 (95% CI [86.1, 121.7]) for no involution, 104.9 cm2 (95% CI [99.4, 110.7]) for partial involution, and 126.2 cm2 (95% CI [115.0, 137.9]) for complete involution (p for trend 0.004). Discussion Our findings suggest that MD is inversely associated with involution of breast tissues, providing a plausible mechanism through which MD influences breast cancer risk. Citation Information: Cancer Prev Res 2008;1(7 Suppl):B39.

Purpose NCCTG (North Central Cancer Treatment Group) N9831 is the only randomized phase III trial evaluating trastuzumab added sequentially or used concurrently with chemotherapy in resected stages I to III invasive human epidermal growth factor receptor 2–positive breast cancer. Patients and Methods Patients received doxorubicin and cyclophosphamide every 3 weeks for four cycles, followed by paclitaxel weekly for 12 weeks (arm A), paclitaxel plus sequential trastuzumab weekly for 52 weeks (arm B), or paclitaxel plus concurrent trastuzumab for 12 weeks followed by trastuzumab for 40 weeks (arm C). The primary end point was disease-free survival (DFS). Results Comparison of arm A (n = 1,087) and arm B (n = 1,097), with 6-year median follow-up and 390 events, revealed 5-year DFS rates of 71.8% and 80.1%, respectively. DFS was significantly increased with trastuzumab added sequentially to paclitaxel (log-rank P < .001; arm B/arm A hazard ratio [HR], 0.69; 95% CI, 0.57 to 0.85). Comparison of arm B (n = 954) and arm C (n = 949), with 6-year median follow-up and 313 events, revealed 5-year DFS rates of 80.1% and 84.4%, respectively. There was an increase in DFS with concurrent trastuzumab and paclitaxel relative to sequential administration (arm C/arm B HR, 0.77; 99.9% CI, 0.53 to 1.11), but the P value (.02) did not cross the prespecified O'Brien-Fleming boundary (.00116) for the interim analysis. Conclusion DFS was significantly improved with 52 weeks of trastuzumab added to adjuvant chemotherapy. On the basis of a positive risk-benefit ratio, we recommend that trastuzumab be incorporated into a concurrent regimen with taxane chemotherapy as an important standard-of-care treatment alternative to a sequential regimen.

Abstract p16, a nuclear protein encoded by the p16INK4a gene, is a regulator of cell-cycle regulation. Previous studies have shown that expression of p16 in tissue biopsies of patients with ductal carcinoma in situ (DCIS) is associated with increased risk of breast cancer, particularly when considered in combination with other markers such as Ki-67 and COX-2. Here, we evaluated how expression of p16 in breast tissue biopsies of women with atypical hyperplasia (AH), a putative precursor lesion to DCIS, is associated with subsequent development of cancer. p16 expression was assessed by immunohistochemistry in archival sections from 233 women with AH diagnosed at the Mayo Clinic. p16 expression in the atypical lesions was scored by percentage of positive cells and intensity of staining. We also studied coexpression of p16, with Ki-67 and COX-2, biomarkers of progression in AH. Risk factor and follow-up data were obtained via study questionnaire and medical records. Forty-seven patients (20%) developed breast cancer with a median follow-up of 14.5 years. Staining of p16 was increased in older patients relative to younger patients (P = 0.0025). Although risk of developing breast cancer was not associated with increased p16 expression, joint overexpression of Ki-67 and COX-2 was found to convey stronger risk of breast cancer in the first 10 years after diagnosis as compared with one negative marker (P &lt; 0.01). However, the addition of p16 levels did not strengthen this association. p16 overexpression, either alone or in combination with COX-2 and Ki-67, does not significantly stratify breast cancer risk in women with AH. Cancer Prev Res; 4(12); 1953–60. ©2011 AACR.

Abstract Background: Epithelial proliferation in benign breast disease (BBD) is a well-established biomarker of breast cancer risk, and BBD tissues can be used as a platform to assess other biomarkers for breast cancer risk. Lobular involution (the degree of age-related atrophy in lobules) is a new biomarker, with greater degrees of involution associated with lower breast cancer risk. Successful application of tissue biomarkers of risk to breast tissues from normal women would be valuable for risk prediction in the general population. We hypothesized that normal breast tissue samples would differ from BBD tissues in these histologic features of breast cancer risk, with less epithelial proliferation but a similar degree of involution compared to BBD tissues. Methods: Core biopsy samples from the Mayo Benign Breast Disease Cohort Study were compared to core biopsy samples of normal breast tissue obtained from the Susan G. Komen for the Cure Tissue Bank at IU Simon Cancer Center (KTB), a unique resource of breast tissue from donor women without any known breast abnormalities. All core biopsies were assessed histologically by a single breast pathologist for degree of epithelial proliferation (classified as non-proliferative, proliferative without atypia, or atypical hyperplasia) and extent of lobular involution (classified as none, 1-24%, 25-74%, or &gt;75% of lobules). Data were analyzed using chi-square tests and logistic regression. Results: Overall, 318 Mayo BBD and 303 normal (KTB) core breast biopsy samples were evaluated. As anticipated, significantly less epithelial proliferation was present in normal samples compared to BBD samples. Proliferative disease occurred in 9/303 (3%) of normals versus 79/318 (25%) of BBD, and atypical hyperplasia was seen in 2/303 (0.7%) of normal samples versus 24/318 (8%) of BBD core biopsies, p &lt; 0.0001. This difference remained significant after adjusting for age (which was greater overall in the BBD samples). Complete involution was more frequent in normal compared to BBD tissues, although the difference did not reach statistical significance. The age-adjusted odds ratio of complete involution in normal versus BBD tissues was 1.46 (95% CI 0.98-2.17, p = 0.06), suggesting a possible delay or failure of involution in women with BBD. Conclusions: Histologic features of normal breast tissues are different from those of BBD tissues, with less epithelial proliferation and more lobular involution, consistent with a lower risk of breast cancer expected for women with normal breast tissue compared to those with benign breast disease. Normal breast tissues are a valuable and distinct resource that should be considered for biomarker validation studies. Citation Information: Cancer Prev Res 2010;3(12 Suppl):B23.