Mdm2 and p53 Expression in Radiation-Induced Sarcomas of the Head and Neck: Comparison with De Novo Sarcomas

• Published in: Journal of pathology and translational medicine Vol. 48; no. 5; pp. 346 - 350
• Main Authors: Song, Min Jeong, Song, Joon Seon, Roh, Jong-Lyel, Choi, Seung-Ho, Nam, Soon Yuhl, Kim, Sang Yoon, Kim, Sung Bae, Lee, Sang-wook, Cho, Kyung-Ja
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Pathologists, Korean Society for Cytopathology 01.10.2014; The Korean Society of Pathologists and The Korean Society for Cytopathology; 대한병리학회
• Subjects: Bone cancer; Gene amplification; Mutation; Original; Pathogenesis; Radiation therapy; Sinuses; Studies; Tumors; 병리학; Cancer, radiation induced; Sarcoma; Head and neck neoplasms; Tumor suppressor protein p53; Mdm2 protein, human
• ISSN: 1738-1843; 2383-7837; 2092-8920; 2383-7845
• DOI: 10.4132/KoreanJPathol.2014.48.5.346

The pathogenesis of radiation-induced sarcomas (RISs) is not well known. In RIS, TP53 mutations are frequent, but little is known about Mdm2-p53 interaction, which is a recent therapeutic target of sarcomas. We studied the immunohistochemical expression of Mdm2 and p53 of 8 RISs. The intervals between radiation therapy and diagnosis of secondary sarcomas ranged from 3 to 17 years. Mdm2 expression was more common in de novo sarcomas than RISs (75% vs 37.5%), and p53 expression was more common in RISs than in de novo cases (75% vs 37.5%). While half of the RISs were Mdm2(-)/p53(+), none of de novo cases showed such combination; while half of de novo sarcomas were Mdm2(+)/p53(-), which are a candidate group of Mdm2 inhibitors, only 1 RIS showed such a combination. Variable immunoprofiles observed in both groups did not correlate with tumor types, except that all of 2 myxofibrosarcomas were Mdm2(+)/p53(+). In conclusion, we speculated that both radiation-induced and de novo sarcomagenesis are not due to a unique genetic mechanism. Mdm2-expression without p53 overexpression in 1 case of RIS decreases the future possibility of applying Mdm2 inhibitors on a subset of these difficult tumors.