Eloise Chapman-Davis

Iron Chelation Therapy Elicits Innate Immune Control of Metastatic Ovarian Cancer

Abstract Iron accumulation in tumors contributes to disease progression and chemoresistance. Although targeting this process can influence various hallmarks of cancer, the immunomodulatory effects of iron chelation in the tumor microenvironment are unknown. Here, we report that treatment with deferiprone, an FDA-approved iron chelator, unleashes innate immune responses that restrain ovarian cancer. Deferiprone reprogrammed ovarian cancer cells toward an immunostimulatory state characterized by the production of type-I IFN and overexpression of molecules that activate NK cells. Mechanistically, these effects were driven by innate sensing of mitochondrial DNA in the cytosol and concomitant activation of nuclear DNA damage responses triggered upon iron chelation. Deferiprone synergized with chemotherapy and prolonged the survival of mice with ovarian cancer by bolstering type-I IFN responses that drove NK cell-dependent control of metastatic disease. Hence, iron chelation may represent an alternative immunotherapeutic strategy for malignancies that are refractory to current T-cell–centric modalities. Significance: This study uncovers that targeting dysregulated iron accumulation in ovarian tumors represents a major therapeutic opportunity. Iron chelation therapy using an FDA-approved agent causes immunogenic stress responses in ovarian cancer cells that delay metastatic disease progression and enhance the effects of first-line chemotherapy. See related commentary by Bell and Zou, p. 1771

Racial and Ethnic Disparities in Genetic Testing at a Hereditary Breast and Ovarian Cancer Center

Prior studies suggest that referral to genetic counseling and completion of genetic testing vary by race/ethnicity; however, the data are limited. We sought to evaluate patterns of genetic testing and clinical outcomes across race/ethnicity at a hereditary breast and ovarian cancer center. The medical records for all patients undergoing genetic assessment at a hereditary breast and ovarian cancer center were reviewed and stratified by self-reported race/ethnicity (non-Hispanic White, Hispanic, non-Hispanic Black, and Asian). A total of 1666 patients met inclusion criteria (non-Hispanic Whites, 1367; Hispanics, 85, non-Hispanic Blacks, 101; Asians, 113). Demographics, patient characteristics, and referral patterns for patients who underwent genetic testing were analyzed using Kruskal-Wallis tests, chi-square test, or Fisher's exact tests, stratifying by self-reported race/ethnicity. Pathogenic mutations and variants of unknown significance (VUS) were reviewed. Outcomes of patients with genetic mutations and personal history of breast and/or gynecologic malignancies were compared. Non-Hispanic Whites were more likely to be referred due to family cancer history compared to all other ethnicities while Non-Hispanic Blacks, Hispanics, and Asians were more likely to be referred due to personal history of cancer (p < 0.001). Non-Hispanic Blacks and Hispanics were more likely to have advanced-stage cancer at the time of genetic testing (p < 0.02). Rates of mutations did not differ by race/ethnicity when Ashkenazi Jewish patients were excluded (p = 0.08). Among patients found to have a BRCA1/2 mutation, Non-Hispanic Whites were more likely to undergo cancer screening and risk-reducing surgery compared with all other ethnicities (p = 0.04). Minority patients were more likely to utilize genetic services following a cancer diagnosis and less likely due to family cancer history, suggesting a missed opportunity for mutation detection and cancer prevention in this population. Efforts to eradicate racial/ethnic disparities in early access to genetic testing and guided cancer prevention strategies are essential.