10566 Background: Metastases from GIST usually affect liver and peritoneum. Extra-abdominal metastases may occur in a limited proportion of pts. Only anecdotal reports describe rare metastatic sites (MS), to lungs, bone and distant soft tissues. Methods: We reviewed a group of 278 pts with advanced/metastatic GIST treated with tyrosine kinase inhibitors over a 7 years period with a view to unusual MS. Results: Thirteen pts (5%), M/F:10/3, median age 50 yrs (34–68 y), developed uncommon MS in a median time of 42 months from their primary diagnosis (0–120 m). Nine pts showed bone metastases along with peritoneal and/or hepatic lesions. All but four pts had also other unusual sites: 2 had pulmonary lesions, 1 had subcutaneous nodules, 1 had a lesion to parotid gland, and pt had lesions to spleen and lungs. In addition to these 9 pts with bone plus other metastases, other two pts had an histologically confirmed bone recurrence as the only metastatization site. In 4 pts, bone metastases were histologically confirmed. In the others, imaging and evidence of progression elsewhere were used as clinical criteria for diagnosis of bone metastatization. With regard to all pts, the most frequent bone sites were spine and pelvis, while ribs and femurs were rare. In four pts, radiation therapy was done, with pain relief. Nine pts died of disease progression after a median time of 17 months (3–40 m) from bone metastases diagnosis. Two pts with a single bone lesion are alive and still on imatinib treatment. Finally, one pt had mediastinal, retrorbital and brain lesions in addition to abdominal metastases, after therapy with imatinib and PTK787. Sunitinib was started with a partial response in all MS. This pt died due to massive bleeding during treatment. Last pt died in few months after parotid gland and subcutaneous metastases diagnosis. Conclusions: Imatinib has dramatically improved GIST prognosis. This is likely to result in a higher number of unusual MS, as observed in other tumors responding to medical therapies in their advanced stages. Rare MS in our series were bones, lungs, subcutaneous tissues, spleen, parotid gland and brain. These cases did not exceed 5% of all cases. [Table: see text]
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Dec 31, 2009
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