Gastrointestinal stromal tumors and second primary malignancies before and after the introduction of imatinib mesylate

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal malignancy of the gastrointestinal tract. GISTs may coexist with different types of cancer, either synchronous or metachronous (1). Most GISTs develop in a sporadic fashion, but familial occurrence, such as neurofibromatosis and Carney-triad, has also been reported (2). The overall frequency of second tumors in different series varied from 4.5% to 33%. The most frequent types of GIST-associated cancers were gastrointestinal carcinomas (47%), lymphoma/leukemia (7%), carcinomas of prostate (9%), breast (7%), kidney (6%), lung (5%), female genital tract (5%), carcinoid tumors (3%), soft tissue and bone sarcomas (3%), malignant melanoma (2%) and seminoma (1%) (1,3-5).