Fatigue - extreme tiredness - is associated with cancer as well as its treatment. It has many causes, including the direct effects of the cancer itself, nutritional changes, anemia, changes in activity levels, worry, or, perhaps, hormones such as testosterone. This study is a survey of the amount of testosterone in the blood of men being treated for cancers that are not directly influenced by testosterone (not prostate or testicular tumors).

Testosterone is a hormone that is made by the body from teenage years through adulthood, and helps define male characteristics: sexual function, muscle building, ability to grow hair and deepen the voice. It is believed that the amount of fatigue experienced by men with cancer may be at least and in part due to reduced testosterone levels.

Male cancer patients will be recruited for this study at the time of regularly scheduled visits with their oncologists for treatment or for follow-up care. Patients who agree to participate and sign a consent will be asked to answer questions about their health, medications, vitamins & supplements, and to complete a standardized questionnaire about their quality of life. One tube of blood (8.5 cc) will be drawn at the same time as the other blood tests scheduled for that visit to avoid an additional blood draw. Various elements of the collected information will be compared with the testosterone levels to see if any meaningful patterns exist. The study sample will be drawn from a geographically diverse set of oncology practices in the US. A larger follow-up study is planned if testosterone levels are found to be lower in men with cancer than similar age men without cancer, or if low testosterone levels are associated with more fatigue.