Significant changes in the treatment of cancer of the testis have occurred over the past several decades. These changes are mainly the result of the development of effective chemotherapy regimens for nonseminomatous cancer and new imaging techniques and tumor markers for cancer detection and staging. These advances have made testicular cancer one of the most curable of all cancer types, with disease-specific 5-year survival rates of about 95%. 

 

The discovery of effective chemotherapeutic agents for germ cell tumors has also affected the indications for radiation therapy in the management of cancer of the testis. Although radiation therapy still plays a major role in the treatment of patients with pure seminoma, its role in the management of nonseminomatous tumors has diminished considerably. This page focuses on the current status of radiation therapy in the management of the primary tumors of the testis, including seminomas, nonseminomas, stromal cell tumors, and lymphomas.

 

Incidence

Testicular cancer is an uncommon tumor, with only about 7000 new cases diagnosed each year in the United States. The number of new cases, however, has increased significantly over the past 30 years, from 3.2 cases per 100,000 in 1976 to 4.6 cases per 100,000 in 1996 and to 5.7 cases per 100,000 in 2004. Testis cancer is the most common cancer in males between the ages of 15 and 35. However, the incidence peaks somewhat later for seminomas (35 to 40 years) than for nonseminomas (25 to 30 years). Testis cancer is much more common in whites (7.0 cases per 100,000 in 2004) than in blacks (1.0 cases per 100,000 in 2004).

 

Considerable variation is evident in the incidence of testis cancer geographically. The Scandinavian countries, for example, report almost 10 times as many new cases per capita as do Japan or Puerto Rico. The populations that have the highest incidence of seminoma also have the highest incidence of nonseminoma and vice versa. A slight familial predilection is evident for this disease; testicular cancer is somewhat more common in identical twins or family members of a patient with a testis tumor than it is in men without a family history of this disease.

 

Approximately 10% of patients with testicular cancer have a history of cryptorchidism and patients with cryptorchidism have about 35 times the risk of testicular cancer as patients with normally descended testicles. The risk of cancer in a cryptorchid testis is directly related to the degree of maldescent. The incidence is approximately 1 in 20 if the testis is located intra-abdominally and 1 in 80 if it is located in the inguinal canal. Testicular cancer is slightly more common in the right testis than the left, and this differential correlates with the increased incidence of cryptorchidism in the right testis. 

 

Most investigators believe that the high incidence of germ cell malignancies in patients with cryptorchidism is related to a developmental defect. Evidence for this opinion includes the observations that a significant percentage (5% to 10%) of the cases of cancer associated with cryptorchidism occur in the contralateral, normally descended testis, and that approximately one fourth of patients who have a testicular cancer in a cryptorchid testis have carcinoma in situ in the other testis.

 

Overall, approximately 1% to 3% of testicular cancer cases are bilateral, and more than one half of patients with bilateral tumors have a history of cryptorchidism. Approximately 5% of patients with germ cell tumors of the testis have carcinoma in situ in the contralateral testis, and in many of them, invasive cancer eventually develops in the second testis. Bilateral testicular cancer may occur synchronously or metachronously, with the second cancer usually appearing within 2 years of the original diagnosis. However, cancer in the second testis has occurred up to 15 years after the first cancer.