Leukemia is very difficult to diagnose early, and the causes of most forms of leukemia are unknown. Symptoms include fatigue, increased bruising, weight loss, repeated infections, and bleeding. Bone marrow transplantation has been successful in treating some forms of leukemia. Symptoms rarely appear early on rendering early detection very difficult. Symptoms include a persistent cough, chest pain, blood-streaked sputum, and recurring pneumonia or bronchitis.
Smoking is the greatest risk factor for lung cancer.
See cancer risk factors for additional information. Since there is not an effective screening method for lung cancer available, once symptoms are diagnosed the disease frequently is at a more advanced stage. Treatment is difficult and often is a combination of chemotherapy, radiation therapy, and surgery. If the cancer is localized, surgery is usually the primary treatment method. The incidence rates of non-Hodgkin's lymphoma have increased significantly over the past 30 years.