The backbone of ovarian cancer treatment is platinum-based chemotherapy and aggressive surgical debulking. New therapeutic approaches using immunotherapy via immune checkpoint blockade, which have demonstrated clinical efficacy in other tumor types, have been less promising in ovarian cancer. To increase their clinical efficacy, checkpoint inhibitors are now being tested in clinical trials in combination with chemotherapy.
Here, we evaluated the impact of cisplatin on tumor immunogenicity and its in vivo roles when used alone or in combination with anti-PD-L1, in two novel murine ovarian cancer cell models. The 2F8 and its platinum-resistant derivative 2F8cis model, display distinct inflammatory profiles and chemotherapy sensitivities, and mirror the primary and recurrent human disease, respectively. Acute and chronic exposure to cisplatin enhances tumor immunogenicity by increasing calreticulin, MHC class I, antigen presentation and T cell infiltration. Cisplatin also upregulates PD-L1 expression in vitro and in vivo, demonstrating a dual, paradoxical immune modulatory effect and supporting the rationale for combination with immune checkpoint blockade. One of the pathways activated by cisplatin treatment is the cGAS/STING pathway. Chronic cisplatin treatment led to upregulation of cGAS and STING proteins in 2F8cis compared to parental 2F8 cells, while acute exposure to cisplatin further increases cGAS and STING levels in both 2F8 and 2F8cis cells. Overexpression of cGAS/STING modifies tumor immunogenicity by upregulating PD-L1, MHC I and calreticulin in tumor cells. Anti-PD-L1 alone in a platinum-sensitive model or with cisplatin in a platinum-resistant model increases survival. These studies have high translational potential in ovarian cancer.
ObjectiveUterine carcinosarcoma (UCS) is a rare type of high-grade endometrial cancer (EC) that has been understudied with population-based statistics due to its rarity. This study examined temporal trends in the proportion of UCS among women with EC.MethodsThis is a retrospective observational study examining The Surveillance, Epidemiology, and End Results program between 1973–2013. Primary EC cases were eligible for analysis, and a time-specific proportion of UCS was examined during the study period.ResultsUCS was seen in 11,000 (4.7%) women among 235,849 primary EC cases. Mean age at UCS diagnosis increased from 65.9 to 71.7 years between 1973–1989 and then decreased from 71.7 to 67.0 years between 1989–2013 (both, p<0.001). Proportion of Black women significantly increased during the study period (11.9%–20.0%, p<0.001), whereas the proportion of White women decreased from 86.0% to 60.5% between 1987–2013 (p<0.001). There was a significant increase in the proportion of UCS among primary EC from 1.7% to 5.6% between 1973–2013 (p<0.001). Among type II ECs (n=76,118), the proportion of UCS also increased significantly from 6.0% to 17.5% between 1973–2013 (p<0.001). An increasing proportion of UCS was seen in both young and older women but the magnitude of interval increase was larger in the older age group between 1973–2013 (<60 years, from 1.3% to 3.3%. p<0.001; and ≥60 years, from 2.6% to 7.0%, p<0.001).ConclusionOur study demonstrated that the proportion of UCS has significantly increased among EC, accounting for more than 5% in recent years.
Adjuvant chemotherapy appears to be effective to control both local- and distant-recurrences in stage I UCS; adding radiotherapy to chemotherapy may be effective to control local-recurrence when the tumor exhibits multiple risk factors.
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