Immunohistochemical analysis of thymic carcinoma focusing on the possibility of molecular targeted and hormonal therapies

• Published in: General thoracic and cardiovascular surgery 2012-12, Vol.60 (12), p.803-810
• Main Authors: Omatsu, Mutsuko, Kunimura, Toshiaki, Mikogami, Tetsuya, Hamatani, Shigeharu, Shiokawa, Akira, Masunaga, Atsuko, Kitami, Akihiko, Suzuki, Takashi, Kadokura, Mitsutaka, Morohoshi, Toshio
• Format: Article
• Language: English
• Subjects: Adult; Aged; Biomarkers, Tumor - analysis; Biopsy; Breast cancer; Cardiac Surgery; Cardiology; Chemotherapy; Classification; Epidermal growth factor; Epidermal Growth Factor - analysis; Female; Histology; Humans; Immunohistochemistry; Male; Medicine; Medicine & Public Health; Middle Aged; Neoplasms, Glandular and Epithelial; Original Article; PPAR gamma - analysis; Receptor, Epidermal Growth Factor - analysis; Receptor, ErbB-2 - analysis; Receptors, Androgen - analysis; Receptors, Estrogen - analysis; Receptors, Progesterone - analysis; Surgical Oncology; Thoracic Surgery; Thymoma - metabolism; Thymoma - pathology; Thymoma - therapy; Thymus Neoplasms - metabolism; Thymus Neoplasms - pathology; Thymus Neoplasms - therapy; Tumors
• ISSN: 1863-6705; 1863-6713
• DOI: 10.1007/s11748-012-0160-x

Objective Thymic carcinoma is a rare mediastinal malignant tumor, and in many patients, the tumor is detected in an inoperable advanced stage. Even when chemotherapy is administered to such patients, the patients show a poor response. We investigated new biomarkers of therapeutic molecular targets. Methods This study included 44 patients diagnosed and treated for primary thymic epithelial tumors at Showa University Northern Yokohama Hospital, Showa University Hospital, and Showa University Fujigaoka Hospital from 2003 to 2011. We investigated new biomarkers of therapeutic molecular targets, such as the peroxisome proliferator-activated receptor γ (PPARγ), insulin-like growth factor 1 receptor (IGF1R), epidermal growth factor receptor (EGFR), estrogen receptor (ER), progesterone receptor (PgR), androgen receptor (AR), human epidermal growth factor type 2 (HER2)/neu, CD44, and L-type amino acid transporter 1 (LAT1), in thymic tumors. Result Immunohistochemical analysis showed that the PPARγ positivity rate in thymic carcinoma was 32 %, which was significantly higher than that in thymoma (4 %). The IGF1R positivity rate in thymic carcinoma was 73 %, which was significantly higher than that in thymoma (27 %). Conclusion Therefore, by examining the expressions of PPARγ and IGF1R, it would be possible to identify therapy-responsive patients and to improve results of thymic carcinoma treatment.