Scottsdale, Arizona - Compared with other types of cancer, testicular cancer is rare. However, testicular cancer is the most common cancer in male Americans between the ages of 15 and 34.  While the cause of testicular cancer is not well understood, there are some factors that can raise a man’s risk. Key risk factors are age and a condition known as cryptorchidism, where one or both of the testes are in the abdomen instead of in the scrotum.

The testes form in the abdominal area during fetal development. They usually descend into the scrotum before birth. Men who have a testicle that never descended are at greater risk of testicular cancer even if the testicle has been surgically relocated to the scrotum.

Most testicular cancers begin in the germ cells — the cells in the testicles that produce immature sperm. But what causes germ cells to become abnormal and develop into cancer is not known. A personal or family history of the disease increases the risk of testicular cancer. Conditions that cause the testicles to develop abnormally, such as Klinefelter syndrome, raise that risk, too. The disease also tends to be more common in white men.

Fortunately, testicular cancer is unique among almost all cancers in that cure rates are more than 90 percent, even when the cancer has spread beyond the testes. Surgery, radiation and chemotherapy can effectively treat testicular cancer. The specific course of treatment is based on the type of cancer, the patient’s age, and the patient’s other medical conditions.

In general, there are two types of testicular cancer: seminoma and nonseminoma. Doctors can determine which type a patient has after surgery is done to remove the testicle. Seminomas tend to be less aggressive than nonseminomas. Seminomas can occur in all age groups, but when an older man develops testicular cancer, it is more likely to be seminoma. Radiation therapy can be very effective for seminomas with advanced disease.

Nonseminoma tumors tend to develop earlier in life and grow and spread rapidly. Several different types of nonseminoma tumors exist. They include choriocarcinoma, embryonal carcinoma, teratoma and yolk sac tumor. Nonseminomas are less sensitive to radiation therapy, so chemotherapy is a mainstay of treatment for this type of testicular cancer.

The stage of testicular cancer also has an impact on treatment. If the cancer is stage I, it has not spread beyond the testicle and can be treated with surgery alone. Stage II testicular cancer has spread to lymph nodes in the abdomen. Stage III means the cancer has spread to organs other than the nodes, or the tumor that has spread to lymph nodes is high grade.

Regardless of the type or stage of testicular cancer, surgery to remove the testicle is the first step in treatment in almost all cases. With Stage II or III disease, further therapy is needed after the initial surgery.

Since chemotherapy, radiation therapy and further surgery are all possible, it is strongly recommended that patients be treated in high-volume cancer centers where multispecialty teams of doctors work together to coordinate care. Even though the high success rates that have been achieved in treating testicular cancer mean that treatment recommendations have been standardized, studies have shown that cure rates for testicular cancer are highest when patients are treated at high-volume cancer centers. - Alan Bryce, M.D., Hematology/Oncology, Mayo Clinic, Scottsdale, Arizona.