ENIGMA
CHEK2
gether Project: A Comprehensive Study Identifies Functionally Impaired
CHEK2
Germline Missense Variants Associated with Increased Breast Cancer Risk
Abstract Purpose: Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT). Experimental Design: We collected 460 CHEK2 missense VUS identified by the ENIGMA consortium in 15 countries. Their functional characterization was performed using CHEK2-complementation assays quantifying KAP1 phosphorylation and CHK2 autophosphorylation in human RPE1–CHEK2-knockout cells. Concordant results in both functional assays were used to categorize CHEK2 VUS from 12 ENIGMA case–control datasets, including 73,048 female patients with breast cancer and 88,658 ethnicity-matched controls. Results: A total of 430/460 VUS were successfully analyzed, of which 340 (79.1%) were concordant in both functional assays and categorized as functionally impaired (N = 102), functionally intermediate (N = 12), or functionally wild-type (WT)–like (N = 226). We then examined their association with breast cancer risk in the case–control analysis. The OR and 95% CI (confidence intervals) for carriers of functionally impaired, intermediate, and WT-like variants were 2.83 (95% CI, 2.35–3.41), 1.57 (95% CI, 1.41–1.75), and 1.19 (95% CI, 1.08–1.31), respectively. The meta-analysis of population-specific datasets showed similar results. Conclusions: We determined the functional consequences for the majority of CHEK2 missense VUS found in patients with breast cancer (3,660/4,436; 82.5%). Carriers of functionally impaired missense variants accounted for 0.5% of patients with breast cancer and were associated with a moderate risk similar to that of truncating CHEK2 variants. In contrast, 2.2% of all patients with breast cancer carried functionally wild-type/intermediate missense variants with no clinically relevant breast cancer risk in heterozygous carriers.
Abstract A19: Aspirin use and ovarian cancer risk by lymphocyte infiltration
Abstract Introduction: There is growing evidence to support a modest inverse association between daily aspirin use and ovarian cancer risk. We previously hypothesized that this association may differ by immune cell infiltration. In our prior study evaluating heterogeneity by tumor-associated macrophage (TAM) infiltration, aspirin use was associated with lower risk of ovarian cancer with high protumorigenic M2-type TAM infiltration, but not low M2-type TAM infiltration. The goal of the present study was to evaluate the hypothesis that the association between aspirin use and ovarian cancer risk also differs by infiltration with tumor-infiltrating lymphocytes (TILs). Methods: We included cases and matched controls from the Nurses’ Health Study (NHS), NHSII, and New England Case Control Study. Study participants self-reported aspirin use including regular use (≥1 x per week), duration of use, and number of tablets. A gynecologic pathologist (JLH), who was blinded to exposure status, reviewed hematoxylin and eosin stained tumor slides to quantify TILs for all cases (n=547). We used polytomous logistic regression, adjusted for ovarian cancer risk factors, to estimate odds ratios (OR) for aspirin use and ovarian cancer risk by TIL infiltration. Results: Overall, recent aspirin use was associated with lower risk of ovarian cancer compared with no regular aspirin use (OR=0.65, 95%CI=0.47-0.89). Recent aspirin use was associated with a lower risk of ovarian cancer exhibiting TIL infiltration (OR=0.38, 95%CI=0.26-0.56) but not with TIL-negative cancers (OR=1.00, 95%CI=0.71-1.41; p-heterogeneity <0.001). We observed similar results for aspirin duration and tablets. For duration, comparing ≥10 years of aspirin use to <1 year we observed a significantly lower risk of ovarian cancer with TILs (OR=0.47, 95%CI=0.41-0.71; p-trend=0.004), but a nonsignificant reduction for ovarian cancer without TILs (OR=0.86, 95%CI=0.59-1.26; p-trend=0.72; p-heterogeneity=0.03). Comparing ≥6 tablets to <1 tablet per week, there was evidence of a lower risk of ovarian cancer with TILs (OR=0.47, 95%CI=0.30-0.75; p-trend=0.001) but not without TILs (OR=1.02, 95%CI=0.70-1.48; p-trend=0.84; p-heterogeneity=0.003). Conclusions: Our results suggest that prediagnosis aspirin use may be an important modulator of immune cell infiltration in ovarian tumors, supporting an immunogenic mechanism for aspirin in ovarian carcinogenesis. Further work is under way to evaluate nonaspirin nonsteroidal anti-inflammatory drugs, and to consider which subsets of TAMs and TILs may be driving heterogeneity in the associations between anti-inflammatory drugs and ovarian cancer risk. Citation Format: Mollie E. Barnard, Britton Trabert, Jonathan L. Hecht, Ellen L. Goode, Naoko Sasamoto, Kathryn L. Terry, Shelley S. Tworoger. Aspirin use and ovarian cancer risk by lymphocyte infiltration [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A19.