Connective Tissue Oncology Society

2001 CTOS Annual Meeting—Oral Presentations

GENE-EXPRESSION PROFILES IN CHONDROSARCOMAS AND CHORDOMAS
Thomas F. DeLaney¹, Brian Seed², Ramnik Xavier², Andrew L. Rosenberg³, G. Petur Nielsen³, Francis J. Hornicek⁴, Norbert J. Liebsch¹, John E. Munzenrider¹, Herman D. Suit¹
¹Dept. of Radiation Oncology, Massachusetts General Hospital, ²Dept. of Molecular Biology, Massachusetts General Hospital, ³Dept. of Pathology, Massachusetts General Hospital, ⁴Dept. of Orthopedic Surgery, Massachusetts General Hospital

OBJECTIVE: Outcome analysis of more than 200 patients each with low grade chondrosarcoma and chordoma of the skull base following high dose proton beam radiation treatment has revealed a very large difference between these two pathological tumor types. Namely, the 10 year local control results were 95% and 45% respectively. These tumors were of approximately the same size, anatomic site and received the same radiation doses. Further, they were managed by the same clinicians and physicists. We hypothesize that there are important differences in the radiation sensitivity of the constituent tumor cells of these tumors. Our research plan is to assess differences in expression profiles of those genes involved in repair of DNA and angiogenesis. This information is expected to help explain the differences in radiation sensitivity of these tumors.

METHODS: RNA from samples of 10 chordomas and 10 chondrosarcomas will be compared with a microarray of complementary DNA clones which included panels of genes known to be involved in DNA repair or angiogenesis. Statistical analyses will be used to identify a set of genes that could distinguish the very different clinical response of chondrosarcomas and chordomas to radiotherapy.

RESULTS: Tumor samples from 10 patients with chordomas and 10 patients with chondrosarcomas have been obtained. Initial RNA extraction has been successful and cDNA arrays of genes associated with angiogenesis, cellular stress, and cancer metastasis have been designed. Gene expression profiles for the tumors are in progress. Results of the analysis will be presented.

CONCLUSION: Gene expression profiles for chondrosarcomas and chordomas may elucidate differences in clinical behavior.