Gynecol Oncol. 2022 Nov 08. pii: S0090-8258(22)01899-6. [Epub ahead of print]168 23-31
Nicola S Meagher,
Phineas Hamilton,
Katy Milne,
Shelby Thornton,
Bronwyn Harris,
Ashley Weir,
Jennifer Alsop,
Christiani Bisinoto,
James D Brenton,
Angela Brooks-Wilson,
Derek S Chiu,
Kara L Cushing-Haugen,
Sian Fereday,
Dale W Garsed,
Simon A Gayther,
Aleksandra Gentry-Maharaj,
Blake Gilks,
Mercedes Jimenez-Linan,
Catherine J Kennedy,
Nhu D Le,
Anna M Piskorz,
Marjorie J Riggan,
Mitul Shah,
Naveena Singh,
Aline Talhouk,
Martin Widschwendter,
David D L Bowtell,
Francisco J Candido Dos Reis,
Linda S Cook,
Renée T Fortner,
María J García,
Holly R Harris,
David G Huntsman,
Anthony N Karnezis,
Martin Köbel,
Usha Menon,
Paul D P Pharoah,
Jennifer A Doherty,
Michael S Anglesio,
Malcolm C Pike,
Celeste Leigh Pearce,
Michael L Friedlander,
Anna DeFazio,
Brad H Nelson,
Susan J Ramus.
OBJECTIVE: Mucinous ovarian carcinoma (MOC) is a rare histotype of ovarian cancer, with low response rates to standard chemotherapy, and very poor survival for patients diagnosed at advanced stage. There is a limited understanding of the MOC immune landscape, and consequently whether immune checkpoint inhibitors could be considered for a subset of patients.
METHODS: We performed multicolor immunohistochemistry (IHC) and immunofluorescence (IF) on tissue microarrays in a cohort of 126 MOC patients. Cell densities were calculated in the epithelial and stromal components for tumor-associated macrophages (CD68+/PD-L1+, CD68+/PD-L1-), T cells (CD3+/CD8-, CD3+/CD8+), putative T-regulatory cells (Tregs, FOXP3+), B cells (CD20+/CD79A+), plasma cells (CD20-/CD79a+), and PD-L1+ and PD-1+ cells, and compared these values with clinical factors. Univariate and multivariable Cox Proportional Hazards assessed overall survival. Unsupervised k-means clustering identified patient subsets with common patterns of immune cell infiltration.
RESULTS: Mean densities of PD1+ cells, PD-L1- macrophages, CD4+ and CD8+ T cells, and FOXP3+ Tregs were higher in the stroma compared to the epithelium. Tumors from advanced (Stage III/IV) MOC had greater epithelial infiltration of PD-L1- macrophages, and fewer PD-L1+ macrophages compared with Stage I/II cancers (p = 0.004 and p = 0.014 respectively). Patients with high epithelial density of FOXP3+ cells, CD8+/FOXP3+ cells, or PD-L1- macrophages, had poorer survival, and high epithelial CD79a + plasma cells conferred better survival, all upon univariate analysis only. Clustering showed that most MOC (86%) had an immune depleted (cold) phenotype, with only a small proportion (11/76,14%) considered immune inflamed (hot) based on T cell and PD-L1 infiltrates.
CONCLUSION: In summary, MOCs are mostly immunogenically 'cold', suggesting they may have limited response to current immunotherapies.
Keywords: Immune infiltrate; Mucinous ovarian carcinoma; Rare histotype