What Causes Testicular Cancer?

Causes and Risk Factors for Testicular Cancer

WHAT IS TESTICULAR CANCER?

There are several rare forms of primary testicular cancer such as lymphoma and stromal tumors as well as other cancers, which can spread (metastasize) to the testicles such as lung cancer. For the purpose of this article, we will be discussing the most common types of testicular cancer known as germ cell cancers. These make up 95% of all testicular cancers. More information on testicular cancer basics can be found here.

WHAT ARE THE RISK FACTORS FOR DEVELOPING TESTICULAR CANCER?

First of all, testicular cancer is a relatively rare form of cancer. It ranks only 25th in most common cancers types, accounting for about 0.5% of all new cancer diagnoses. Probably the single greatest risk factor for developing testicular cancer is age, unless gender is taken into account of course. It most commonly affects males between 15-35 years of age. Testicular cancer before puberty or after age 50 is a very rare event. Click here for detailed statistics of testicular cancer.

One of the most established risk factors for the development of testicular cancer is cryptorchidism. In normal male development, the testes typically descend down the inguinal canal into the scrotum by birth. When the testes do not enter the scrotum by four months after birth, cryptorchidism (or hidden testis) is present. Although it is uncertain exactly why this contributes to testicular cancer, it increases the risk significantly.

The risk of developing testicular cancer in one's lifetime is around 0.4%. This risk is increased by nearly 8 times for someone with cryptorchidism. 

Having had testicular cancer before is another significant risk factor for developing a totally new episode of testicular cancer. The risk of developing testicular cancer in one's lifetime is around 0.4%.

 In someone who has had testicular cancer, the lifetime risk of developing cancer in the remaining testis increases to about 2%.

Race is also a potential risk factor. White males are at highest risk of developing cancer with a likelihood over 4 times greater when compared to black males. Asian and Pacific Islander males are also at a lower risk of Hispanic males having a risk approaching that of white males.

Considered to be a precursor for testicular cancer, a tissue growth known as testicular carcinoma in situ, evolves into an invasive cancer 50% of the time within 5 years.

Normally males have both an x and y chromosome. In a condition known as Klinefelter syndrome, an extra x chromosome is present and is also considered to be a risk factor for testicular cancer. More information regarding Klinefelter syndrome can be found here.

CAN YOU INHERIT THE RISK FROM YOUR PARENTS?

The short answer is yes, although an inherited gene has not been identified. Nevertheless, there appears to be definite familial component.

The relative risk for developing testicular cancer in someone who has an affected first-degree relative is relatively increased to about 6 to 10 times the risk of the general population.

WHAT CAN YOU DO TO DECREASE THE RISK?

Some risk factors are considered modifiable, i.e., you can do something about them. The modifiable risk factors for testicular cancer are few. Surgery can be performed for cryptorchidism, which can reduce the risk for developing testicular cancer. Many risk factors are not modifiable. Age, gender, race and family history are not something we can change. 

WHAT ABOUT SCREENING FOR CANCER IN HIGH-RISK POPULATIONS?

There is no approved screening for testicular cancer, even in high risk populations. The reasons for this are several-fold. For one, the testes are externalized and easily felt for lumps or other abnormalities such as scrotal swelling. A monthly testicular self-exam is considered sufficient screening, especially for higher-risk populations as outlined above. Secondly, even when testicular cancer has spread, it can usually be cured with standard treatments, making early detection of less importance than in other cancer types. Please see this article for more information on the signs and symptoms of testicular cancer.

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