Molecular evidence that most but not all carcinosarcomas of the uterus are combination tumors

• Published in: Cancer research (Chicago, Ill.) Ill.), 1997-12, Vol.57 (23), p.5379-5385
• Main Authors: WADA, H, ENOMOTO, T, HONGYO, T, NOMURA, T, MURATA, Y, FUJITA, M, YOSHINO, K, NAKASHIMA, R, KURACHI, H, HABA, T, WAKASA, K, SHROYER, K. R, TSUJIMOTO, M
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Base Sequence; Biological and medical sciences; Carcinoma - classification; Carcinoma - genetics; Carcinoma - pathology; Carcinosarcoma - classification; Carcinosarcoma - genetics; Carcinosarcoma - pathology; Codon; DNA Methylation; DNA, Neoplasm; Endometrial Neoplasms - classification; Endometrial Neoplasms - genetics; Endometrial Neoplasms - pathology; Exons; Female; Female genital diseases; Genes, p53; Genes, ras; Gynecology. Andrology. Obstetrics; Humans; Medical sciences; Middle Aged; Mutation; Point Mutation; Polymerase Chain Reaction; Receptors, Androgen - genetics; Restriction Mapping; Sarcoma - classification; Sarcoma - genetics; Sarcoma - pathology; Sequence Deletion; Tumors; Uterine Neoplasms - classification; Uterine Neoplasms - genetics; Uterine Neoplasms - pathology; X Chromosome
• ISSN: 0008-5472; 1538-7445

The pathogenesis of carcinosarcoma is still a subject of controversy. In the present study, molecular techniques were applied to determine the pathogenesis of uterine carcinosarcomas. The patterns of chromosome X inactivation were analyzed, targeting a portion of exon 1 of the human androgen receptor (HUMARA) in malignant epithelial and mesenchymal components. The presence of p53 and K-ras mutations were also analyzed. H&E-stained sections of paraffin-embedded, formalin-fixed tissues were microdissected to obtain both epithelial and nonepithelial lesions from 25 carcinosarcomas, and DNAs were extracted by proteinase K digestion. Following treatment with methylation-sensitive restriction endonuclease (HhaI or HpaII), PCR amplification was performed using nested primers targeted to the HUMARA locus. Mutations in the p53 gene and K-ras gene were found in eight (32%) and six (24%) tumors, respectively. The patterns of chromosome X inactivation were different between the carcinomatous and sarcomatous components of three carcinosarcomas, indicating that these three tumors represent collision tumors. By contrast, the patterns of chromosome X inactivation, K-ras sequence, and p53 sequence were identical in both carcinomatous and sarcomatous components in 21 carcinosarcomas, indicating that these 21 tumors represent combination tumors. One case produced equivocal results that precluded determination of whether it represented a collision or combination tumor. These observations show that although most carcinosarcomas are combination tumors, some develop as collision tumors. The determination of histogenesis in individual cases of carcinosarcoma using molecular markers may be worthwhile, because the result could help predict the prognosis of individual cases and help guide clinical management.