Multiple primary malignancies in association with soft tissue sarcomas.

Abstract

Modern cancer treatment has increased the survival of patients with various malignancies substantially. One of the late sequelae of successful treatment is the development of a second malignant tumor. However, in many cases of second primary tumors, exposure to chemotherapy or radiation therapy is not evident, and it should be postulated that the putative mechanism for the development of the second tumor is different. In the current series, the association between soft tissue sarcoma (STS) in adults and the development of other primary malignancies was studied. A retrospective search of the data files of 610 patients with STS or bone sarcomas who were treated at the study institution between January 1995 and December 1999 was performed. All files regarding patients with STS who developed a second malignant tumor were retrieved for analysis. Of 375 patients with STS, 28 (7.5%) developed other malignant neoplasms either before or after the diagnosis of STS. STS as the first tumor occurred in 14 patients (ages 16-72 years). Only three patients were treated with chemotherapy for their sarcoma. Radiation therapy was administered to five patients as an adjuvant to surgery for the first tumor. The second tumor types mainly included STS and renal cell carcinoma. The time interval between the diagnosis of the STS and the second malignancy was 0 (for synchronous tumors) to 21 years. Three patients developed a third primary tumor within 3 years after the diagnosis of the second tumor. The median overall survival was > 78 months. Fourteen patients (ages 35-87 years) had a first primary tumor other than STS (mainly breast carcinoma and genitourinary malignancies). The second tumors (mainly STS) appeared within 0 (for synchronous tumors) to 27 years. The median overall survival for the 14 patients in this group from the time of diagnosis of the first tumor was > 102 months. The phenomenon of two or three primary neoplasms developing in patients in whom one of the tumors was STS occurs at a rate of 7.5%, a significantly higher rate than that reported for the occurrence of STS among the general cancer population (1%). The majority of cases occur incidentally. The clinical implication includes the need to search for an occult second primary tumor in patients with STS as an integral part of their follow-up. This is especially true in patients with primary malignant fibrous histiocytoma who demonstrate a risk for developing a renal cell carcinoma.