Here's what you need to know Published Nov. 23, 2010 By National Cancer Institute and American Cancer Society KEESLER AIR FORCE BASE, Miss. -- Testicular cancer forms in tissues of the testis, one of two egg-shaped glands inside the scrotum that produce sperm and male hormones. It accounts for only 1 percent of all cancers in men. It's estimated that this year, 8,480 new cases will be diagnosed and 350 deaths will occur. It's one of the most treatable and curable cancers. The survival rate for men with early-stage seminoma, the least aggressive type of testicular cancer, is more than 95 percent. The disease-free survival rate for Stage II and III cancers is slightly lower, depending on the size of the tumor and when treatment is begun. Symptoms may include discomfort or pain in the testicle or a feeling of heaviness in the scrotum; dull ache in the back or lower abdomen; lump, swelling or enlargement of a testicle or a change in the way it feels; or excess development of breast tissue (however, this can occur normally in adolescent boys who don't have cancer). A physical examination typically reveals a firm lump in one of the testicles.When the doctor holds a flashlight up to the scrotum, the light doesn't pass through the lump. Other diagnostic tests may include abdominal and pelvic CT scans, blood tests for tumor markers, X-rays and ultrasounds.