Malignant tumour of the testis, or testicle. Although relatively rare, testicular cancer is the most common malignancy for men between the ages of 20 and 34. It typically affects men between 15 and 39 years old. A developmental abnormality of males in which one or both testes fail to descend into the scrotum about the time of birth increases the risk of developing the cancer later in life. The most notable symptom of testicular cancer is the formation of a painless lump in either testis. Treatment usually consists of the surgical removal of the cancerous testis, followed by radiation therapy or chemotherapy if the cancer has metastasized.
Learn more about testicular cancer with a free trial on Britannica.com.
In the United States, between 7,500 and 8,000 diagnoses of testicular cancer are made each year. Over his lifetime, a man's risk of testicular cancer is roughly 1 in 250 (four tenths of one percent, or 0.4%). It is most common among males aged 15-35 years, particularly those in their mid-twenties. Testicular cancer has one of the highest cure rates of all cancers: in excess of 90%; essentially 100% if it has not metastasized. Even for the relatively few cases in which malignant cancer has spread widely, chemotherapy offers a cure rate of at least 85% today. Not all lumps on the testicles are tumors, and not all tumors are malignant; there are many other conditions such as Epididymal cysts, Hydatid of Morgagni, and so on which may be painful but are non-cancerous. All unusual lumps or pain in the testicles should be checked by a physician.
Incidence among African Americans doubled from 1988 to 2001 with a bias towards seminoma. The lack of significant increase in the incidence of early-stage testicular cancer during this timeframe suggests that the overall increase was not due to heightened awareness of the disease.
Although testicular cancer is most common among men aged 15-40 years, it has three peaks: infancy, ages 25-40 years, and age 60 years.
Germ cell tumors of the testis are the most common cancer in young men between the ages of 15 and 35 years.
A major risk factor for the development of testis cancer is cryptorchidism (undescended testicles). Other risk factors include inguinal hernia, mumps orchitis . Physical activity is associated with decreased risk and sedentary lifestyle is associated with increased risk. Early onset of male characteristics is associated with increased risk. These may reflect endogenous or environmental hormones.
Symptoms may include one or more of the following:
The nature of any palpated lump in the scrotum is evaluated by scrotal ultrasound, which can determine exact location, size, and some characteristics of the lump, such as cystic vs solid, uniform vs heterogeneous, sharply circumscribed or poorly defined. The extent of the disease is evaluated by CT scans, which are used to locate metastases. Blood tests are also used to identify and measure tumor markers that are specific to testicular cancer. AFP alpha1 feto protein, Beta-HCG, and LDH are the typical markers used to identify testicular cancer. The diagnosis is made by performing an orchiectomy, surgical excision of the entire testis along with attached structures epididymis and spermatic cord; the resected specimen is evaluated by a pathologist. A biopsy should not be performed, as it raises the risk of migrating cancer cells into the scrotum. The reason why inguinal orchiectomy is the preferred method is that the lymphatic system of the scrotum links to the lower extremities and that of the testicle links to the retroperitoneum. A transscrotal biopsy or orchiectomy will potentially leave cancer cells in the scrotum and create two vectors for cancer spread, while in an inguinal orchiectomy only the retroperitoneal route exists.
An incorrect diagnosis is made at the initial examination in up to 25% of patients with testicular tumors and may result in delay in treatment or a suboptimal approach (scrotal incision) for exploration.
The differential diagnosis of testicular cancer requires examining the histology of tissue obtained from an orchiectomy specimen. Orchiectomy, rather than transcrotal biopsy, is preferred to reduce the risk of spill and thus the risk of metastasis, in the event that the tumor is malignant. For orchiectomy, an inguinal surgical approach is preferred.
Before 1970, the young man with recurrent testicular cancer was destined to have rapid progression and death from disseminated disease. Currently, although 7000 to 8000 new cases of testicular cancer occur in the United States yearly, only 400 men are expected to die of the disease. Much of this improvement is due to advances in adjuvant therapy.
Due to the risk of subsequent metastasis, post-surgical adjuvant therapy may be offered to the patient following orchiectomy. The type of adjuvant therapy depends largely on the histology of the tumor and the stage of progression at the time of surgery. These two factors contribute to the risk of recurrence, including metastasis. Adjuvant treatments may involve chemotherapy, radiotherapy or careful surveillance by frequent CT scans and blood tests by oncologists.
Although testicular cancer can be derived from any cell type found in the testicles, more than 95% of testicular cancers are germ cell tumors. Most of the remaining 5% derive from Leydig cells or Sertoli cells. Thus, the focus of diagnosis is on determining which germ cell tumor is present. Correct diagnosis is necessary to ensure the most effective and least harmful treatment. To some extent, this can be done via blood tests for tumor markers, but differential diagnosis requires examination of the histology of a specimen by a pathologist.
After removal, a testicular tumor is staged by a pathologist according to the TNM Classification of Malignant Tumors as published in the AJCC Cancer Staging Manual. Testicular cancer is categorized as being in one of three stages (which have subclassifications). The size of the tumor in the testis is irrelevant to staging. In broad terms, testicular cancer is staged as follows:
Also: Intratubular germ cell neoplasms (the in-situ stage of germ cell tumors)
In most patients with testicular cancer, the disease is cured readily with minimal long-term morbidity.
While it may be possible, in some cases, to remove testicular cancer tumors from a testis while leaving the testis functional, this is almost never done, as more than 95% of testicular tumors are malignant. Since only one testis is typically required to maintain fertility, hormone production, and other male functions, the afflicted testis is almost always removed completely in a procedure called inguinal orchiectomy. (The testicle is almost never removed through the scrotum; an incision is made beneath the belt line in the inguinal area.) Most notably, since removing the tumor alone does not eliminate the precancerous cells that exist in the testis, it is usually better in the long run to remove the entire testis to prevent another tumor. A plausible exception could be in the case of the second testis later developing cancer as well.
In the case of nonseminomas that appear to be stage I, surgery may be done on the retroperitoneal/Paraaortic lymph nodes (in a separate operation) to accurately determine whether the cancer is in stage I or stage II and to reduce the risk that malignant testicular cancer cells that may have metastasized to lymph nodes in the lower abdomen. This surgery is called Retroperitoneal Lymph Node Dissection (RPLND). However, this approach, while standard in many places, especially the United States, is falling out of favor due to costs and the high level of expertise required to perform the surgery. The urologist may take extra care in the case of males who have not fathered children, to preserve the nerves involved in ejaculation.
Many patients are instead choosing surveillance, where no further surgery is performed unless tests indicate that the cancer has returned. This approach maintains a high cure rate because of the growing accuracy of surveillance techniques.
Lymph node surgery may also be performed after chemotherapy to remove masses left behind, particularly in the cases of advanced initial cancer or large nonseminomas.
Chemotherapy is the standard treatment for non-seminoma when the cancer has spread to other parts of the body (that is, stage II or III). The standard chemotherapy protocol is three, or sometimes four, rounds of Bleomycin-Etoposide-Cisplatin (BEP). This treatment was developed by Dr. Lawrence Einhorn at Indiana University. An alternative, equally effective treatment involves the use of four cycles of Etoposide-Cisplatin (EP).
While treatment success depends on the stage, the average survival rate after five years is around 95%, and stage I cancers cases (if monitored properly) have essentially a 100% survival rate (which is why prompt action, when testicular cancer is a possibility, is extremely important).
Less than five percent of those who have testicular cancer will have it again in the remaining testis. A man who loses both testicles will normally have to take hormone supplements (in particular, testosterone, which is created in the testicles), and will be infertile, but can lead an otherwise normal life.