Loss of DNA copy number of 10q is associated with aggressive behavior of leiomyosarcomas: a comparative genomic hybridization study.

Leiomyosarcomas (LMS) account for 10-20% of all soft tissue sarcomas. We analyzed 10 primary, 5 metastatic, and 2 recurrent extrauterine LMS. Genomic imbalances were detected in 15 out of the 17 tumors. The most common regions of loss were 13q (59%, 10 of 17), 10q (59%, 10 of 17), 2q (35%, 6 of 17), and 16q (29%, 5 of 17). The most common region of gain was 5p (35%, 6 of 17). High-level gain of DNA copy number was detected in 6p and 17p. Loss of function of tumor suppressor genes or the activation of oncogenes (or both of these factors) resulting from these copy number changes might play an important role in the development of extrauterine LMS. Large tumors and tumors with metastasis showed 10q deletions. Gain of 5p was detected only in G3 tumors. These findings are consistent with our earlier study on uterine LMS and indicate that loss of 10q and gain of 5p are associated with an aggressive behavior of LMS. A larger series of cases is needed to confirm these results.