What are the testicles?

The testicles, also called testes (singular testis) or gonads, are the male sex glands.

They are located behind the penis in a pouch of skin called the scrotum. The testicles produce and store sperm, and they also serve as the body’s main source of male hormones. These hormones control the development of the reproductive organs and other male characteristics, such as body and facial hair, low voice, wide shoulders and libido.

What is cancer?
Cancer is a group of more than 100 diseases. Although each kind differs from the others in many ways, every type of cancer is a disease of some of the body’s cells. In our case, we call it testicular cancer, but as many as 14 different types of cancer can start in the testicle.

Healthy cells that make up the body’s tissues grow, divide, and replace themselves in an orderly way. This process keeps the body in good repair. Sometimes, however, some cells lose the ability to limit and direct their growth. They grow too rapidly and without any order. Too many cells are produced, and tumours are formed. Tumours can be either benign or malignant.

Benign tumours are not cancer. They do not spread to other parts of the body and are seldom a threat to life. Benign tumours can often be removed by surgery, and they are not likely to return. Some tumours of the testicle are benign, but most are not.

Malignant tumours are cancer. They can invade and destroy nearby healthy tissues and organs. Cancerous cells can also spread, or metastasise, to other parts of the body and form new tumours.

What is Testicular Cancer?
Cancer that develops in a testicle is called testicular cancer. When testicular cancer spreads, the cancer cells are carried by blood or by lymph, an almost colourless fluid produced by tissues all over the body. The fluid passes through lymph nodes, which filter out bacteria and other abnormal substances such as cancer cells. Doctors use CT scans of the abdomen and chest in an attempt to determine if the cancer has spread to the lymph nodes or lungs.

According to the New Zealand Ministry of Health statistics, 137 (34 Maori) cases of testicular cancer were diagnosed in the NZ in 2013 and 6 men died (0 Maori) from testicular cancer in 2013.

Most testicular cancers are found by men themselves, by accident or while doing a testicular self-examination. The testicles are smooth, oval-shaped, and rather firm. Men who examine themselves regularly (once a month) become familiar with the way their testicles normally feel. Any changes in the way they feel from month-to-month should be checked by a doctor, preferably a Urologist.

In men under 60, 95% of testicular tumours originate in the germ cells, the special sperm-forming cells within the testicles. These tumours fall into one of two types, seminomas or nonseminomas.

Other rarer forms of testicular cancer include leydig and sertoli cell tumours. These tumours are much harder to treat and patients diagnosed with them should absolutely get a second opinion from an expert.

Men over the age of 60 can still get a germ cell tumour, but they are more likely to get leukemia, lymphoma, or a benign tumour called spermatocytic seminoma.

Unless otherwise noted, all the information on this web site concerns testicular germ cell tumours.

There are three stages of testicular cancer:

  • Stage I–The cancer is confined to the testicle.
  • Stage II–The cancer has spread to the retroperitoneal lymph nodes, located in the rear of the body below the diaphragm and between the kidneys.
  • Stage III–The cancer has spread beyond the lymph nodes to remote sites in the body, including the lungs, brain, liver and bones.

Pure Seminomas account for about 40% of all testicular cancer and are made up of immature germ cells. Usually, seminomas are slow growing and tend to stay localized in the testicle for long periods.

Nonseminomas are a group of cancers that often occur in combination with one another, including choriocarcinoma, embryonal carcinoma, immature teratoma and yolk sac tumours. Nonseminomas arise from more mature, specialized germ cells and tend to be more aggressive than seminomas.

Can Testicular Cancer be cured?
Don’t ever say that there hasn’t been progress in the war against cancer. In 1970, 90% of testicular cancer patients with metastatic disease died of their cancer. By 1990, due of the introduction of chemotherapy drugs such as cisplatin, the numbers had basically flipped. Now almost 90% of men with metastatic disease are cured of their cancer.

Specifically, the survival rate for men diagnosed with Stage I seminoma is about 99%. The survival rate for men with Stage I non-seminoma is about 98%. Cure rates for Stage II tumours range above 90%, while cure rates for Stage III tumours vary between 50-80%.

In addition to Stage, a variety of institutions have created classifications of Good and Poor risk tumours.

Good risk tumours are generally those that have not spread outside of the retroperitoneal lymph nodes or lungs and do not have overly elevated tumour markers.

Poor risk tutors generally have very high tumour markers or have spread outside of the lungs and lymph nodes. As you might expect, the survival rate for good risk tumours is high (more than 90%), while the survival rate for poor risk tumours is lower (50-60%).

What are the causes of testicular cancer?
To date, no one really knows. Researchers study patterns of cancer in the population to discover whether some people are more likely than others to develop certain cancers. If they can learn what causes the disease, they may be able to suggest ways to prevent it.

At this time, there is no known way to prevent testicular cancer.

Testicular cancer is not contagious: no one can “catch” it from another person. Exactly what causes this disease is unknown and seldom can it be explained why one person gets it while another doesn’t. Research does show that some men are more likely than others to develop testicular cancer. For example, the risk is higher than average for boys born with their testicles in the lower abdomen rather than in the scrotum (called undescended testicles or cryptorchidism). The cancer risk for boys with this condition is increased regardless of whether the condition is corrected, and in fact, the risk exists even in the normal testicle. The theory is that the increased risk of testicular cancer is due to whatever caused the undescended testicle, not just by the fact that the testicle was undescended.

In New Zealand there are higher rates of testicular cancer in Maori men than in European, Asian or Pasifika men. However the reasons for this are not known.

Research has also shown that testicular cancer is sometimes linked to certain other rare conditions in which the testicles do not develop normally. There is even some line of thought that pollutants may be contributing to this problem, evidenced by the considerable increase in occurrences over the last few decades and paralleled with industrial growth and waste.

Some men whose mothers took a hormone called DES (diethylstilbestrol) during pregnancy to prevent miscarriage have testicular abnormalities. But scientists have never proven that prenatal exposure to DES (or any other female hormone) increases the risk of testicular cancer. To date, this link has never been verified.

Some patients with testicular cancer have a history of injury to the scrotum. But again, no one knows whether such an injury can actually cause cancer. Many doctors think such an injury simply calls attention to a tumour that was already growing.


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