Beyond the First Cancer: Secondary Malignancies Associated With Soft Tissue Sarcomas

Background Advances in treatment as well as personalized treatment options based on mutational analysis have led to increased survival for patients with soft tissue sarcomas (STSs). Given improved outcomes, patients are at risk of developing a secondary malignancy. There is a paucity of data in patients with STS and their risk of secondary malignancies. Method A retrospective review of a prospective database (2000-2024) of patients with an STS identified 97 patients with at least one additional malignancy. Clinicopathologic and treatment characteristics were analyzed. Results Of the 97 patients, STS was the first cancer in 32 (33%) and was associated with a secondary cancer in 65 (67%) patients. The most common cancers diagnosed after an initial diagnosis of an STS was prostate (21.8%), sarcoma (15.6%), breast (9.4%), and melanoma (9.4%). Cancers of the prostate (23.1%), breast (13.8%), colorectal (10.7%), and melanoma (9.2) were the most common tumors preceding a diagnosis of STS. Six patients with a prior history of prostate cancer received radiation and all patients developed a sarcoma in the radiated field. Similarly, 7 patients with breast cancer received radiation, of which 3 patients developed an STS in the radiated field. Nineteen (19.6%) patients developed three malignancies, which 6 (31.6%) were found to have a genetic mutation. Conclusion Patients with STSs are at risk of developing a secondary malignancy, most commonly, prostate, breast, and melanoma. Patients who are cured from their first malignancy should be followed indefinitely due to the risk of developing a second primary malignancy in the future.