testicular cancer

▪ disease

Introduction

      disease characterized by uncontrolled growth of cells within the testis, the reproductive organ that produces sperm. Although testicular cancer represents only 1 percent of all cancers, it is the most common malignancy for men between the ages of 20 and 34. It most often affects men between 15 and 39 years of age. In the United States, approximately 7,500 new cases are diagnosed each year. Testicular cancers are broadly classified as seminomas or nonseminomas based on their appearance and other characteristics. About 30 percent of testicular cancers are seminomas, and they tend to respond well to treatment. Nonseminomas, including yolk-sac tumours (tumour), embryonal carcinomas, and choriocarcinomas, are generally less responsive to treatment than seminomas. Typically, more than one type of nonseminoma will be present within the same tumour.

Causes and symptoms

      Most cases of testicular cancer arise in individuals who have no known risk factors for the disease. An important known risk factor is a developmental abnormality that consists of a failure of one or both testes to descend into the scrotum, which normally takes place around the time of birth. The abnormality, called cryptorchidism, occurs in up to 10 percent of one-year-old boys, and it is associated with a 5- to 10-fold increased risk of testicular cancer, even if the condition is corrected with surgery.

      Testicular cancer is typically noticed by the patient as a painless lump in either testis. This lump can be associated with swelling of the scrotum, pain and discomfort in the scrotum, or a dull ache in the lower abdomen. Because these symptoms are not specific to cancer, they should be investigated by a physician.

diagnosis and prognosis

      The initial investigation of a suspicious lump may involve blood tests and imaging studies. Different types of testicular cancer are associated with an increase in specific substances in the blood, including alpha fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase. ultrasound may be used to determine the size and location of a tumour in a testis and may help distinguish cancer from a benign condition. Ultimately, diagnosis of cancer requires removal of the testis and examination of the tissue under a microscope.

      The prognosis depends on the type of testicular cancer found and the extent to which it has spread. Both types tend to metastasize first to the local lymph nodes of the pelvis (pelvic girdle) and subsequently to distant sites such as the lungs (lung cancer). Seminomas have a cure rate greater than 95 percent when detected early. Nonseminomas tend to spread more quickly and behave more aggressively than seminomas, but they can be cured in more than 90 percent of cases. A dramatic increase in the cure rate, particularly for patients with nonseminomas, has been achieved largely through improved chemotherapy introduced in the mid-1970s.

Treatment

      As with many cancers, treatment involves a combination of surgery, chemotherapy, and radiation therapy, depending on the type and spread of the original cancer. Virtually all testicular cancer is diagnosed and treated initially by surgically removing the affected testis (orchiectomy). Fortunately, the removal of one testis usually does not affect fertility. If the cancer has spread into the pelvic region or beyond, radiation or chemotherapy may be added to the treatment. Seminomas tend to respond very well to radiation therapy alone, even after the cancer has spread into the pelvis. Nonseminomas often require the addition of chemotherapy.

Prevention

      Undescended testes are usually moved into the scrotum surgically before puberty to help prevent the development of cancer. Otherwise, regular self-examination and physical examination by a physician for testicular cancer can lead to early detection, which provides the best opportunity for a cure.

David C. Williams

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