Abstract Background: Biopsy diagnosis of benign breast disease (BBD) based on the most severe lesion in a sample predicts future breast cancer risk and has implications for screening and management. Lobules are the functional unit of the breast and the structures from which BBD arises. We developed and preliminarily validated an automated computational pathology algorithm to discriminate normal from BBD breast lobules as a step toward automated comprehensive characterization of benign biopsies. Methods: 152 BBD biopsies (27 training, 125 validation) from the Mayo Clinic were examined using scanned digital images of H&E stained sections. For each image, a pathologist annotated up to 10 representative lobules as normal or BBD using standard pathology criteria. A deep learning algorithm to quantify lobular features was developed using 129 lobules from 27 subjects. Nine features were identified that discriminate normal vs BBD lobules, expressing lobule size, acini size and number, acinar lumen size, proportion of lobular stroma, and capillaries. Here, we validate their performance to discriminate normal vs BBD lobules in a set of 1250 lobules from 125 subjects using area under the ROC curve (AUC) analysis. Random forest analysis was used for multivariable modeling; model performance was assessed with a tenfold cross-validation approach. Results: Median subject age was 52 years. Among the 125 validation subjects, BBD findings were nonproliferative in 39%, proliferative in 45%, and atypical hyperplasia in 16%. Sections included 552 (44%) normal lobules and 698 BBD (56%) lobules, with representation of both lobule types on each section. In univariate analyses, four individual features showed good discrimination between normal vs. BBD lobules, yielding the following AUCs: lobule size= 0.74, mean acini size= 0.75, epithelial area= 0.75, and number of acini with large lumens= 0.76. Lobule size and epithelial area were highly correlated (Spearman rank correlation r = 0.95), but both of these features showed lower correlation with mean acini size and number of acini with large lumens (each r < 0.5). With random forest modeling, number of acini with large lumens was the strongest discriminating feature, followed by mean acini size, lobule size, and epithelial area. With ten-fold cross validation of the multivariable random forest model, the overall AUC was 0.82 (95% CI: 0.79-0.85). Conclusion: Our validation showed that automated quantitative computational pathology assessment of breast lobules can discriminate normal versus BBD on a per lobule basis. This finding supports the feasibility of developing automated algorithms to classify every lesion in breast biopsies, expanding beyond visual assessment. Further studies using deep learning may reveal novel pathology features for classifying BBD biopsies with the potential to strengthen estimation of breast cancer risk. Citation Format: Amy C. Degnim, Thomas de Bel, Mark E. Sherman, Derek C. Radisky, Stacey J. Winham, Tanya L. Hoskin, Melody L. Stallings Mann, Marlene Frost, Robert A. Vierkant, Brendan T. Broderick, Ethan P. Heinzen, Rushin Brahmbhatt, Muhammad Arshad, Celine M. Vachon, Jodi M. Carter, Lori A. Denison, Daniel W. Visscher, Jeroen van der Laak. Discrimination of benign breast disease from normal lobules using an automated computational pathology algorithm [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2113.
Abstract B018: A tribal-academic multi-theory-driven messaging intervention to increase mammography participation is well-received by community women
Cancer Epidemiology, Biomarkers & Prevention | September 1, 2020 | Volume: 29 | Issue: 6_Supplement_2 | Pages: B018-B018
Abstract Purpose:: “No Squeeze Can Defeat Me: Mammograms for Life!” (locally, “My Life Matters: Mammograms for Life!”) was funded 2016-2019 by the Minnesota State Department of Health. It implemented a low-cost, low-tech intervention that used theory-based messaging to increase tribal women’s participation in annual mammograms and their adherence to local screening guidelines. Messaging was grounded in elements of theoretical models of health behavior that our previous research showed significantly differentiated adherent women from non-adherent women. Procedures: An 8-member tribal Community Advisory Project Board, including a 3-person Project Implementation Team, guided and carried out the intervention. The team developed and distributed 48 unique posters and placed 4-5 new posters every 6-8 weeks in 82 locations across four reservation communities. A convenience sample of women evaluated the posters. Posters had varied messages that were shaped by at least one influential element and theoretical model (e.g., Perceived Benefit from the Health Beliefs Model). 84% of displayed posters contained images of adherent tribal women. Pairwise associations of survey variables were examined using Fisher’s exact tests. Results: 229 women evaluated posters (32% under the age of 40, 64% between 40-70 years, 4% older than 70). Approximately 80% of women age 40 and older reported having at least one mammogram in their lifetime. 71% of all women said they learned something new. 96% of women said messages were personally important and 99% thought them important for other women. Of women finding the messages personally important, 99% were greater than age 40 compared to 90% who were less than age 40 (p=0.002). In those reporting they learned something new, 98% were greater than age 40 compared to 91% who were less than 40 (p=0.05). 97% of women said they would continue reading the messages when new ones were posted, underscoring the interest raised by the intervention. 164 women reported recognizing women featured on a poster. Of these, 77% said that recognition made the poster more interesting; only 2 said it made the poster less interesting. When asked if they would be more or less willing to get a mammogram if they knew others got one every year, 63% of women said they would get one regardless, 34% would be more willing, less than 1% would be less willing, and 3% said they would not get a mammogram regardless. Conclusions: Overall, women very positively regarded the posters. The sample was diverse by age, with almost one-third not yet age-eligible for screening. Across all ages and screening histories, a great majority of women agreed: 1) the posters were personally important and important for others; 2) were interested in seeing additional posters; and 3) appreciated seeing photos of adherent women on them. With 34% of viewers being more inclined to get mammograms upon knowing of others who had them, increases in monthly mammograms may be expected. Citation Format: Ann Nicometo, Robert A. Vierkant, Wesley O. Petersen. A tribal-academic multi-theory-driven messaging intervention to increase mammography participation is well-received by community women [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B018.
Clinicopathological characteristics of subsequent breast cancers in patients with benign breast disease
Journal of Clinical Oncology | August 25, 2020 | Volume: 27 | Issue: 15_suppl | Pages: 1061-1061
1061 Background: Benign breast disease (BBD) is a significant risk factor for breast cancer (BC); however little is known about the aggressiveness of the BCs these patients develop. Shared features between select atypias and low-grade DCIS have led some to speculate that a history of BBD portends the development of well-differentiated BCs. Methods: The Mayo BBD cohort includes 9,376 women who had benign breast biopsies from 1967–1991. Data on BC events were obtained from medical records and questionnaires. Tissue from the BCs was reviewed by a single breast pathologist (DWV). Results: Our cohort included 6,244 patients with nonproliferative disease (NP), 2,801 women with proliferative disease without atypia (PDWA), and 331 with atypical hyperplasias (AH). With a median of 18 years of follow-up, 799 patients with BBD have developed breast cancer, 416 initially had NP, 313 had PDWA, and 70 AH. BC tissue was available for 703 of the women. The cancers were invasive ductal in 76.1% (n = 535), invasive lobular in 9.4% (n = 66), and DCIS alone in 14.5% (n = 102) patients. Grade is currently available for 500 women, and is well differentiated in 29.4% (n = 150), moderately differentiated in 42.7% (n = 218) and poorly differentiated in 27.8% (n = 142). In 537 cases the malignant tissue had a concurrent benign component consisting of NP in 24% (n = 129), PDWA in 25.1% (n = 135), and AH in 50.8% (n = 273). In regards to tumor size, 69.6% had T1 tumors, 24.9% T2 tumors, and 5.5% T3 disease. Metastasis to lymph nodes occurred in 25% of patients. Median time to BC was 12.3 years and did not differ across the different benign entities. Breast cancer developed within 5 years from the initial BBD in 163 women (20%). In this group, tumor size was greater (p = 0.02), and there were more poorly differentiated tumors (p = 0.006) than in those who later developed BC. Conclusions: In the BCs that have developed in our BBD cohort, we do not see a preponderance of well-differentiated, good-risk BCs. Patients diagnosed within 5 years of BBD appear to have BCs with more aggressive features. No significant financial relationships to disclose.
Abstract B094: Impact of a multi-theory-driven community-based intervention to increase mammographic screening in a Midwest American Indian tribe
Cancer Epidemiology, Biomarkers & Prevention | August 11, 2020 | Volume: 29 | Issue: 6_Supplement_1 | Pages: B094-B094
Abstract Purpose: The “No Squeeze Can Defeat Me: Mammograms for Life!” study is locally known as “My Life Matters: Mammograms for Life!” and is funded by the Minnesota Department of Health. The intervention's purpose with one Midwest tribe is to increase American Indian women's regular participation in yearly mammographic screening beginning at age 40. At study initiation, mid-year 2016, adherence with annual screening guidelines stood at 36% for women 40 and older. Using previous work that significantly differentiated nonadherent women from adherent women, we are working with tribal health and the Indian Health Service partners to utilize differentiating theoretical models and elements of those models in an attempt to increase screening and adherence through poster messaging. Posters incorporated six elements of the Health Beliefs Model, two components of the Social Norms and Social Support Models, and three features of the Theory of Planned Behavior model. Multiple elements or features of each model are employed in the poster messaging. Procedures: No Squeeze works through a Community Advisory Project Board (CAPB) and a Project Implementation Team (PIT) consisting of tribal health, Indian Health Service, and community members of varied ages, screening status, and cancer history status. CAPB members take the lead on all decisions regarding messaging, message placement, frequency of new message placements, messaging evaluation and radiology performance figures. The PIT is responsible for executing CAPB decisions. Mayo Clinic is responsible for development of poster messages and data analysis. Evaluation of the intervention considers changes in screening participation and no-show (unfilled scheduled appointments) rates and collection and analysis of community women's evaluations of posted messages. The intermediate analysis takes into account comparable months from July-June of 2016/17 and 2017/18. Analysis is primarily descriptive. Where appropriate, chi-square statistics are calculated. Results: In the first half of each of the two years of the intervention (2017 and 2018), the average number of mammograms increased by 8 and 10, respectively, over an average of 36 at baseline (2016). In the same period, monthly no-show mammogram appointment rates decreased from an average of 47% to 39%. Community women's poster evaluations indicate that messages are likely to contribute to increased mammogram screening (p = <0.004). Among notable evaluation findings: Women of all ages like the posters and will continue to read them. They find the messages personally important and important to other women of the tribe. Use of community women's images in the posters adds interest in the posters and has a positive effect on women's future screening (p = 0.0002). Conclusions: To date, poster messaging appears to be associated with increased screening, decreased no-show rates and community receptiveness. Further study will be necessary to determine whether it can be employed with other tribes. Citation Format: Wesley Petersen, Ann Nicometo, Robert A. Vierkant. Impact of a multi-theory-driven community-based intervention to increase mammographic screening in a Midwest American Indian tribe [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 B094.
Breast Cancer Risk and Use of Nonsteroidal Anti-inflammatory Agents After a Benign Breast Biopsy
Cancer Prevention Research | July 27, 2020 | Volume: 13 | Issue: 11 | Pages: 967-976
Abstract Over one million women in the United States receive biopsy diagnoses of benign breast disease (BBD) each year, which confer a 1.5–4.0-fold increase in breast cancer risk. Studies in the general population suggest that nonsteroidal anti-inflammatory agents (NSAID) lower breast cancer risk; however, associations among women with BBD are unknown. We assessed whether NSAID use among women diagnosed with BBD is associated with lower breast cancer risk. Participants included 3,080 women (mean age = 50.3 ± 13.5 years) in the Mayo BBD surgical biopsy cohort diagnosed between January 1, 1992 and December 31, 2001 who completed breast cancer risk factor questionnaires that assessed NSAID use, and whose biopsies underwent detailed pathology review, masked to outcome. Women were followed from date of BBD biopsy to breast cancer diagnosis (main outcome) or censoring (death, prophylactic mastectomy, reduction mammoplasty, lobular carcinoma in situ or last contact). Median follow-up time was 16.4 ± 6.0 years. Incident breast cancer was diagnosed among 312 women over a median follow-up of 9.9 years. Regular non-aspirin NSAID use was associated with lower breast cancer risk [HR = 0.63; 95% confidence interval (CI) = 0.46–0.85; P = 0.002] with trends of lower risk (highest tertiles of use vs. nonuse) for greater number of years used [HR = 0.55; 95% CI = 0.31–0.97; Ptrend = 0.003), days used per month (HR = 0.51; 95% CI = 0.33–0.80; Ptrend = 0.001) and lifetime number of doses taken (HR = 0.53; 95% CI = 0.31–0.89; Ptrend = 0.003). We conclude that nonaspirin NSAID use is associated with statistically significant lower breast cancer risk after a BBD biopsy, including a dose–response effect, suggesting a potential role for NSAIDs in breast cancer prevention among patients with BBD.
Population-based targeted sequencing of 54 candidate genes identifies
PALB2
as a susceptibility gene for high-grade serous ovarian cancer
Journal of Medical Genetics | June 16, 2020 | Volume: 58 | Issue: 5 | Pages: 305-313
Purpose The known epithelial ovarian cancer (EOC) susceptibility genes account for less than 50% of the heritable risk of ovarian cancer suggesting that other susceptibility genes exist. The aim of this study was to evaluate the contribution to ovarian cancer susceptibility of rare deleterious germline variants in a set of candidate genes. Methods We sequenced the coding region of 54 candidate genes in 6385 invasive EOC cases and 6115 controls of broad European ancestry. Genes with an increased frequency of putative deleterious variants in cases versus controls were further examined in an independent set of 14 135 EOC cases and 28 655 controls from the Ovarian Cancer Association Consortium and the UK Biobank. For each gene, we estimated the EOC risks and evaluated associations between germline variant status and clinical characteristics. Results The ORs associated for high-grade serous ovarian cancer were 3.01 for PALB2 (95% CI 1.59 to 5.68; p=0.00068), 1.99 for POLK (95% CI 1.15 to 3.43; p=0.014) and 4.07 for SLX4 (95% CI 1.34 to 12.4; p=0.013). Deleterious mutations in FBXO10 were associated with a reduced risk of disease (OR 0.27, 95% CI 0.07 to 1.00, p=0.049). However, based on the Bayes false discovery probability, only the association for PALB2 in high-grade serous ovarian cancer is likely to represent a true positive. Conclusions We have found strong evidence that carriers of PALB2 deleterious mutations are at increased risk of high-grade serous ovarian cancer. Whether the magnitude of risk is sufficiently high to warrant the inclusion of PALB2 in cancer gene panels for ovarian cancer risk testing is unclear; much larger sample sizes will be needed to provide sufficiently precise estimates for clinical counselling.
N-terminal pro-brain natriuretic peptide levels after receipt of anthracycline for breast cancer.
Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: e24103-e24103
e24103 Background: Many of the 200,000 patients diagnosed with breast cancer (BC) annually in the United States receive anthracycline-based therapy, increasing their risk of future congestive heart failure. N-terminal brain natriuretic peptide (NT-proBNP) has been used as a biomarker of asymptomatic cardiac dysfunction in the general population and is of interest to identify patients who might benefit from echocardiography during survivorship. This study aimed to assess how age, baseline comorbidities, and time since BC diagnosis impact NT-proBNP levels after anthracycline-based chemotherapy. Methods: This retrospective study, using samples collected in our ongoing prospective Mayo Clinic Breast Disease Registry, included 20 survivors of non-metastatic BC patients per year for each of the first 5 years after anthracycline-based chemotherapy (n=100 total). NT-pro-BNP levels were assessed using a Roche immunoassay. Cardiac risk factors were obtained by chart review. Multivariable linear regression models assessed associations between NT-proBNP values and these independent variables: baseline cardiac risk factors (including hypertension, hyperlipidemia, obesity, diabetes mellitus, and smoking), tumor ER status (surrogate for possible endocrine therapy), time between diagnosis and serum collection, T and N status, use of trastuzumab, and age. Results: The mean age at the time of BC diagnosis was 52.2 (SD 9.8). 13% of tumors were human epidermal growth factor receptor (HER2)-positive and 71% were estrogen receptor (ER) positive. NT-proBNP was elevated in 34%. Mean NT-BNP level was higher (p=0.047) for those in years 4-5 (158 pg/mL) compared to those in years 1-3 (106 pg/mL) (See Table.) Models revealed years from diagnosis to serum draw (p=0.026), older age (p=0.006), more cardiac risk factors (p=0.064), and N2-3 (p=0.001) were associated with elevated NT-pro-BNP level. Use of trastuzumab, ER status, and tumor size were not associated with NT-proBNP. Conclusions: NT-proBNP is elevated in 1/3 of survivors who received anthracycline therapy for BC. As expected, cardiac risk factors and advancing age are associated with higher NT-proBNP. NT-proBNP values >300 were only found in patients who were 4-5 years after diagnosis. Additional research will be needed to further define the diagnostic and prognostic merit of NT-proBNP in survivors after receipt of anthracycline therapy. [Table: see text]
Abstract P5-08-06: NSAID use and breast cancer risk in a retrospective cohort of women with benign breast disease
Cancer Research | March 26, 2020 | Volume: 80 | Issue: 4_Supplement | Pages: P5-08-06-P5-08-06
Abstract Background Prior epidemiologic studies have shown an inverse relationship of aspirin and NSAID use with breast cancer (BC) risk in the general population. Women with benign breast disease (BBD) are at an increased BC risk compared with women in the general population, and we have shown that BBD biopsies contain increased numbers of immune cells compared with normal breast tissues donated for research in the Komen Tissue Bank. We hypothesized that NSAID use among women with BBD is associated with reduced risk of BC. Methods We evaluated BC risk in relation to aspirin and NSAID use in a single institution retrospective cohort of 4,498 women who received a biopsy diagnosis of BBD between 1/1/1992 and 12/31/2001. Information on usual medication use, including average number of days used per month (0, 1-7, 8-28 and >28), was collected via questionnaires mailed after identification of participants. NSAIDs were categorized into three classes: 1) Aspirin, 2) Ibuprofen (plus other prostaglandin synthesis inhibitors), and 3) COX inhibitors. BC events were captured via medical record, questionnaires, and Tumor Registry records. Medication use was evaluated for associations with clinical and pathology features. Hazard ratios (HR) and 95% confidence intervals (CI) examining associations between medication use and BC risk were estimated using Cox regression analyses, with adjustment for age and BMI at biopsy, years between biopsy and questionnaire, and pathologic features related to BC risk (severity of BBD and degree of involution in background lobules). Tests for trend examining frequency of use were calculated from ordered values (lowest to highest) in Cox models with a one degree-of-freedom linear term. We assessed BC associations with any type of NSAID use, as well as the three subclasses. Results Information on NSAID use was available for 3,089 (69%) of the participants in the cohort; these women had a median age of 49 and did not differ in BC risk from women who did not provide data on NSAID use (p=0.46). Of the 3,089 respondents, 313 (10.1%) subsequently developed BC with median follow-up of 17 years. Age was significantly associated with use of all types of NSAIDs, with increasing use in older women. BMI at the time of biopsy, severity of BBD findings, and involution in background lobules were also associated with NSAID use; thus these factors and age were adjusted for in risk association analyses. Ever users of NSAIDs (any type) had a significantly lower risk of BC than never users (HR 0.76, CI 0.59-0.98, p=0.03), and increasing frequency of NSAID use was significantly associated with lower BC risk (HRs 0.81, 0.79, and 0.70 for regular use 1-7, 8-28, and >28 days/month), trend p=0.02. Analyses of drug classes revealed that ever use of ibuprofen (HR 0.61, CI 0.42-0.89, p=0.01) and ever use of COX inhibitors (HR 0.59, CI 0.39-0.89, p=0.01) were associated with decreased BC risk. COX inhibitors in particular showed a strong dose response effect with increasing use (HRs 0.97, 0.52, and 0.47 for regular use 1-7, 8-28, and >28 days/month), trend p<0.01. Use of aspirin was not associated with BC risk (HR 0.88, CI 0.64-1.21, p=0.44). Conclusions In this exploratory analysis, we found use of ibuprofen and other NSAIDs to be associated with decreased BC risk among women who had undergone a BBD biopsy. These findings suggest that anti-inflammatory approaches may have value in chemoprevention among women with BBD. Citation Format: Amy Degnim, Robert Vierkant, Stacey Winham, Marlene Frost, Daniel Visscher, Jodi Carter, Suneetha Kaggal, Julie Cunningham, Teresa Allers, Tanya Hoskin, Ethan Heinzen, Celine Vachon, Keith Knutson, Keith Knutson, Derek Radisky, Mark Sherman. NSAID use and breast cancer risk in a retrospective cohort of women with benign breast disease [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 P5-08-06.
Physical activity and risk of postmenopausal breast cancer defined by hormone receptor status and histology: A large prospective cohort study with 18 years of follow up
Journal of Clinical Oncology | March 9, 2020 | Volume: 24 | Issue: 18_suppl | Pages: 1002-1002
1002 Background: Physical activity is a modifiable breast cancer risk factor, perhaps mediating risk reduction through regulation of estrogen metabolism. Evidence regarding effect of physical activity is conflicting partly because breast cancer is a heterogenous constellation of different tumor subtypes with differing etiologies. No prospective study has examined the relationship between physical activity and breast cancer incidence based on ER/PR status or histological subtype. Objective: Examine effect of physical activity on breast cancer incidence based on ER/PR status and histological subtypes of breast cancer. Methods: The Iowa Women’s Health Study is a prospective cohort study of postmenopausal women (N=41,837). Physical activity was self-reported on baseline questionnaire, and three levels (high, medium and low) were defined. Breast cancer incidence, histologic subtype and ER/PR status, through 18 years of follow-up, were ascertained by linkage with the Iowa SEER Cancer Registry. Cox proportional hazards models were used to estimate multivariate relative risks (RRs) and 95% confidence intervals (CIs) of breast cancer, adjusting for other breast cancer risk factors. Results: During 554,819 person-years of follow-up, 2548 incident cases of breast cancer were observed. High physical activity was associated with decreased risk for breast cancer (RR 0.91, 95 % CI 0.81–1.01) compared to low activity. The protective effect was most marked in ER+/PR− (RR 0.66, CI 0.46–0.94), intermediate in ER−/PR− (RR 0.80, CI 0.56–1.15), weakest in ER+/PR+ (RR 0.94, CI 0.81–1.08), and elevated in ER-/PR+ (RR 1.42, CI 0.67–3.01) tumors. Higher physical activity was also associated with a decreased risk of invasive ductal/lobular carcinoma (RR 0.90, CI 0.80–1.02), but not with invasive breast cancer with a favorable histology (RR 1.19, CI 0.78–1.81). Conclusions: Higher physical activity was associated with a 10% decreased risk of breast cancer. Unexpectedly, risk reduction was most marked in PR- tumors, particularly ER+/PR-, and the more aggressive histologic forms. Further studies are needed to confirm these findings, and also evaluate other risk factors based on ER/PR status and histological subtypes. No significant financial relationships to disclose.
Bioinformatics and DNA-extraction strategies to reliably detect genetic variants from FFPE breast tissue samples
No container title available | October 12, 2019 | Volume: No volume available | Issue: No issue available | Pages: No page available
Abstract Background: Archived formalin fixed paraffin embedded (FFPE) samples are valuable clinical resources to examine clinically relevant morphology features and also to study genetic changes. However, DNA quality and quantity of FFPE samples are sub-optimal, and resulting NGS-based genetics variant detections are prone to false positives. Evaluations of wet-lab and bioinformatics approaches are needed to optimize variant detection from FFPE samples. Results: As a pilot study, we designed within-subject triplicate samples of DNA derived from paired FFPE and fresh frozen breast tissues to highlight FFPE-specific artifacts. For FFPE samples, we tested two FFPE DNA extraction methods to determine impact of wet-lab procedures on variant calling: QIAGEN QIAamp DNA Mini Kit ("QA"), and QIAGEN GeneRead DNA FFPE Kit ("QGR"). We also used negative-control (NA12891) and positive control samples (Horizon Discovery Reference Standard FFPE). All DNA sample libraries were prepared for NGS according to the QIAseq Human Breast Cancer Targeted DNA Panel protocol and sequenced on the HiSeq 4000. Variant calling and filtering were performed using QIAGEN Gene Globe Data Portal. Detailed variant concordance comparisons and mutational signature analysis were performed to investigate effects of FFPE samples compared to paired fresh frozen samples, along with different DNA extraction methods. In this study, we found that five times or more variants were called with FFPE samples, compared to their paired fresh-frozen tissue samples even after applying molecular barcoding error-correction and default bioinformatics filtering recommended by the vendor. We also found that QGR as an optimized FFPE-DNA extraction approach leads to much fewer discordant variants between paired fresh frozen and FFPE samples. Approximately 92 % of the uniquely called FFPE variants were of low allelic frequency range (<5%), and collectively shared a “C>T|G>A” mutational signature known to be representative of FFPE artifacts resulting from cytosine deamination. Based on control samples and FFPE-frozen replicates, we derived an effective filtering strategy with associated empirical false-discovery estimates. Conclusions: Through this study, we demonstrated feasibility of calling and filtering genetic variants from FFPE tissue samples using a combined strategy with molecular barcodes, optimized DNA extraction, and bioinformatics methods incorporating genomics context such as mutational signature and variant allelic frequency.