Mutagen sensitivity as an indicator of soft tissue sarcoma risk.

The etiology of soft tissue sarcoma is poorly understood. Exposure to environmental chemicals may play a role, but the data are not clear. We compared a group of soft tissue sarcoma patients with healthy controls to determine whether the mutagen sensitivity assay, a simple chromosome aberration assay using the radiomimetic bleomycin, might be useful to identify patients at risk for soft tissue sarcoma. Patients with a diagnosis of soft tissue sarcoma at Memorial Sloan-Kettering's outpatient clinic signed informed consent and donated 30 ml of blood. Controls were selected from the general population of Connecticut by random digit dialing. Unrepaired DNA damage was assessed for 100 metaphase spreads for each individual, with the number of breaks in chromatids being counted as breaks per cell (b/c). The 20 cases with soft tissue sarcoma had 1.03 mean b/c and the controls had 0.88 b/c (P = 0.16). Patients with soft tissue sarcoma were 5.7 times more likely to be mutagen sensitive than controls (P = 0.01), as determined after dividing subjects into sensitive or not sensitive groups based on the median b/c among controls. As mutagen sensitivity has been shown to be associated with a number of cancers and appears to reflect genetic susceptibility, this assay may be an appropriate biomarker for radiation sensitivity or it may be a marker of susceptibility to soft tissue sarcoma. Larger studies should be undertaken to assess these possibilities.