Primary testicular tumors are the most common solid malignant tumor in men 20 to 35 years of age in the United States. For unknown reasons, the incidence of this cancer—principally, testicular seminomas—increased during the last century. Over the past decade, the incidence of testicular cancer has risen approximately 1.2% per year, although the rate of increase has been slowing. Germ cell cancers account for more than 90% of all testicular cancers. Approximately 9,000 new cases have been diagnosed in United States every year, although only about 400 deaths have occurred annually.
In patients with localized disease, painless swelling or a nodule in one testicle is the most common presenting sign. A dull ache or heavy sensation in the lower abdomen could be the presenting symptom. Patients with disseminated disease can present with manifestations of lymphatic or hematogenous spread. See Presentation.
Ultrasound can distinguish intrinsic from extrinsic testicular lesions and can identify masses within testes. Once the diagnosis of testicular cancer is suspected, a high-resolution CT scan of the abdomen and pelvis and a chest x-ray are ordered as part of the initial staging workup. Radical inguinal orchiectomy is the definitive procedure to permit histologic evaluation of the primary tumor and to provide local tumor control. See Workup.
Initial therapy is selected according to the following features of the cancer:
Risk stratification (good, intermediate, or poor risk)
Histology (seminoma versus nonseminoma)
With stage I seminoma, cure can sometimes be achieved by radical inguinal orchiectomy alone. Patients with more advanced disease require adjuvant chemotherapy or radiation therapy. See Treatment and Medication.
Testicular cancers are very sensitive to chemotherapy and are curable even when metastatic. Cure rates for good-risk disease are 90%-95%. However, patients cured of testicular cancer have approximately a 2% cumulative risk of developing a cancer in the opposite testicle during the 15 years after initial diagnosis. The risk of subsequent contralateral testis tumors appears to be higher in men whose primary tumor was a seminoma than in those with nonseminomatous primary tumors.
In the past, metastatic testicular cancer was usually fatal, but advances in treatment, including high-dose chemotherapy and stem cell rescue, have considerably improved the prognosis. Indeed, testicular cancer is a bright spot in the oncological landscape and is now considered the model for the treatment of solid tumors.