Peritoneal Carcinosarcoma and Ovarian Papillary Serous Carcinoma Are the Same Origin: Analysis of TP53 Mutation and Microsatellite Suggests a Monoclonal Origin

Ovarian Carcinosarcoma and Concurrent Serous Tubal Intraepithelial Carcinoma With Next-Generation Sequencing Suggesting an Origin From the Fallopian Tube

Background. Ovarian carcinosarcomas are rare aggressive biphasic tumors. Evidence suggests that these tumors are monoclonal and that the sarcoma component is derived from a stem cell undergoing divergent differentiation. Currently, there remains a paucity of data regarding its origin, with few reports suggesting an association with serous tubal intraepithelial carcinoma (STIC) by immunohistochemistry and genetics. Objective. We sought to determine the relationship of carcinosarcoma to high-grade serous carcinoma and STIC by investigating for similar mutation signatures through next-generation sequencing. Methodology. A case of carcinosarcoma with associated high-grade serous carcinoma and STIC was macrodissected, and next-generation sequencing was performed on each component separately. Results. The STIC, high-grade serous carcinoma component, and chondrosarcoma component were all diffusely positive for p53 and p16 by immunohistochemistry. Next-generation sequencing demonstrated an identical TP53 gene c.376-1G>A 5' splice site pathogenic mutation in all 3 components. Conclusions. Our findings suggest that carcinosarcomas may also originate from the fallopian tube.

Progression inference for somatic mutations in cancer

Computational methods were employed to determine progression inference of genomic alterations in commonly occurring cancers. Using cross-sectional TCGA data, we computed evolutionary trajectories involving selectivity relationships among pairs of gene-specific genomic alterations such as somatic mutations, deletions, amplifications, downregulation, and upregulation among the top 20 driver genes associated with each cancer. Results indicate that the majority of hierarchies involved TP53, PIK3CA, ERBB2, APC, KRAS, EGFR, IDH1, VHL, etc. Research into the order and accumulation of genomic alterations among cancer driver genes will ever-increase as the costs of nextgen sequencing subside, and personalized/precision medicine incorporates whole-genome scans into the diagnosis and treatment of cancer.