Daniel W. Cramer

Patterns of Associations with Epidemiologic Factors by High-Grade Serous Ovarian Cancer Gene Expression Subtypes

Abstract Background: Ovarian high-grade serous carcinomas (HGSC) comprise four distinct molecular subtypes based on mRNA expression patterns, with differential survival. Understanding risk factor associations is important to elucidate the etiology of HGSC. We investigated associations between different epidemiologic risk factors and HGSC molecular subtypes. Methods: We pooled data from 11 case–control studies with epidemiologic and tumor gene expression data from custom NanoString CodeSets developed through a collaboration within the Ovarian Tumor Tissue Analysis consortium. The PrOTYPE-validated NanoString-based 55-gene classifier was used to assign HGSC gene expression subtypes. We examined associations between epidemiologic factors and HGSC subtypes in 2,070 cases and 16,633 controls using multivariable-adjusted polytomous regression models. Results: Among the 2,070 HGSC cases, 556 (27%) were classified as C1.MES, 340 (16%) as C5.PRO, 538 (26%) as C2.IMM, and 636 (31%) as C4.DIF. The key factors, including oral contraceptive use, parity, breastfeeding, and family history of ovarian cancer, were similarly associated with all subtypes. Heterogeneity was observed for several factors. Former smoking [OR = 1.25; 95% confidence interval (CI) = 1.03, 1.51] and genital powder use (OR = 1.42; 95% CI = 1.08, 1.86) were uniquely associated with C2.IMM. History of endometriosis was associated with C5.PRO (OR = 1.46; 95% CI = 0.98, 2.16) and C4.DIF (OR = 1.27; 95% CI = 0.94, 1.71) only. Family history of breast cancer (OR = 1.44; 95% CI = 1.16, 1.78) and current smoking (OR = 1.40; 95% CI = 1.11, 1.76) were associated with C4.DIF only. Conclusions: This study observed heterogeneous associations of epidemiologic and modifiable factors with HGSC molecular subtypes. Impact: The different patterns of associations may provide key information about the etiology of the four subtypes.

Differential blood count as triage tool in evaluation of pelvic masses

Triaging patients with presumptive ovarian cancer to the appropriate specialist may improve survival. Therefore, there is increasing interest in complementary diagnostic markers to the standard serum CA125. In patients with pelvic masses, we examined the ability of epidemiologic variables and preoperative differential blood counts to improve detection of ovarian cancer over CA125 alone. From pathology reports, patients were classified as having: epithelial ovarian cancer (n=743), including fallopian tube and primary peritoneal cancer, non-epithelial ovarian cancers (n=46), non-ovarian cancers (n=122), or benign disease (1,129). From women with epithelial ovarian cancer, we excluded those who received prior neoadjuvant chemotherapy (n=19). Women were also excluded if they did not have a serum CA125 or complete blood count measured within 180 days prior to surgery (n=1099) or did not have both tests within 90 days of each other (n=13). Categorizing patients by menopausal status, we calculated Pearson correlations between differential counts or ratios and CA125, and used t tests to identity univariate predictors of malignancy and stepwise logistic regression and likelihood ratio tests to create models best distinguishing epithelial ovarian cancer from benign disease. 337 women with epithelial ovarian cancer and 365 with benign disease were included in the analysis. Compared with cancers, women with benign disease had lower average: age, 52.5 versus 58.4 years (p<0.0001); serum CA125, 20 versus 239 U/mL (p<0.0001), neutrophil-to-lymphocyte ratio, 2.4 versus 3.5 (p<0.0001); and platelet-to-lymphocyte ratio, 158 versus 222 (p<0.0001); but greater average body mass index, 28.5 versus 26.8 kg/m Epidemiologic variables and differential counts or ratios better distinguished between benign and malignant disease when compared with serum CA125 alone using separate models for pre- and postmenopausal women.

Ovarian Cancer Ascites Inhibits Transcriptional Activation of NK Cells Partly through CA125

Abstract Malignant ascites is a common clinical problem in ovarian cancer. NK cells are present in the ascites, but their antitumor activity is inhibited. The underlying mechanisms of the inhibition have yet to be fully elucidated. Using an Fcγ receptor–mediated NK cell activation assay, we show that ascites from ovarian cancer patients potently inhibits NK cell activation. Part of the inhibitory activity is mediated by CA125, a mucin 16 fragment shed from ovarian cancer tumors. Moreover, transcriptional analyses by RNA sequencing reveal upregulation of genes involved in multiple metabolic pathways but downregulation of genes involved in cytotoxicity and signaling pathways in NK cells purified from ovarian cancer patient ascites. Transcription of genes involved in cytotoxicity pathways are also downregulated in NK cells from healthy donors after in vitro treatment with ascites or with a CA125-enriched protein fraction. These results show that ascites and CA125 inhibit antitumor activity of NK cells at transcriptional levels by suppressing expression of genes involved in NK cell activation and cytotoxicity. Our findings shed light on the molecular mechanisms by which ascites inhibits the activity of NK cells and suggest possible approaches to reactivate NK cells for ovarian cancer immunotherapy.