Extended spectrum of cancers in PTEN hamartoma tumor syndrome.

PTEN hamartoma tumor syndrome (PHTS) is associated with increased lifetime risks of breast, thyroid, kidney, endometrial, and colorectal cancers, as well as melanoma (collectively, component cancers). We sought to characterize non-component cancers (NCC) in PHTS. Of 701 research participants with PHTS, 340 (49%) had cancer, with 101 (30%) having at least one NCC. Interestingly, 71 (70%) of those with NCC had at least one other PHTS component malignancy. Patients with pathogenic PTEN variants showed higher risks for prostate cancer and soft tissue sarcomas at younger ages than the general population. A literature survey showed independent cases of NCC in PHTS, with PTEN-related molecular changes including second-hit somatic PTEN alterations in a subset of various specimens. We recommend increased awareness regarding NCC in individuals with PHTS, particularly increased risks for prostate cancer and sarcoma. Further studies are needed to define age-related penetrance and accordingly, the appropriate strategies for cancer risk management.