Testicular Cancer in 4 easy steps

So there's a party going on in your testicles, and you have no idea what's going on. We get it, Cancer can be confusing as balls, but we're here to help! If you want to know some of the science behind what testicular cancer is, you're in the right place. We've created an easy 4 step process to understanding the basics of testicular cancer:

  • Step 1: What are balls?

  • Step 2: What is a tumor?

  • Step 3: How does it spread?

  • Step 4: What are "Cancer Stages"?


Step 1: What are balls?

Balls. Nuts. Family jewels. Dangly bits. Gonads. Or some other pet name you've given them that we're okay with not knowing. Whatever you call them, testicles are the mini sperm and testosterone factories between men's legs, and before we go any further, you should probably know a thing or two about them!

Behold the testicle!

in all it's cross-sectioned and annotated glory!

Ballsy, huh? Photo courtesy of www.cancer.ca

Ballsy, huh? Photo courtesy of www.cancer.ca

Some terms you may want to know:

  • Epididymis: Site of sperm storage and maturation.
  • Rete Testis: Carries sperm from the seminiferous tubules to the efferent ducts.
  • Spermatic Cord: Suspends the testis in the scrotum and contains structures that run to and from the testis, such as the vas deferens.
  • Seminiferous Tubules: Site of Sperm production.
  • Tunica Vaginalis: Layer surrounding the tunica albuginea.
  • Tunica Albuginea: Fibrous membrane surrounding the testis
  • Lymphovascular network: Lymphatic channels, which connect to lymph nodes or blood vessels.
  • Scrotum: The outermost layer of skin covering the testis, which cools the testicles slightly below body temperature to allow proper sperm development.
 

Step 2: What is a tumor?

If you haven't Googled it yet, Cancer is a disease caused by an uncontrolled division of abnormal cells in a part of the body (which in this case, is the testicle). Translation? Imagine a house party... you have a few friends over, you have a few laugh's, maybe order some pizza, everything is great. This is a normal healthy party (or a healthy testicle). But then suddenly... people you don't know just start showing up uninvited, and they keep coming and coming until the house is full and the party starts spilling into the neighborhood until it's total mayhem. This is an unhealthy party (or an unhealthy testicle). It might look something like this:

Utter chaos. Photo courtesy of the movie "Project X" by Warner Brothers.

Utter chaos. Photo courtesy of the movie "Project X" by Warner Brothers.

So there's a party going on in your testicles... and everyone's invited? Gross. So who is at this party anyway? Well, the most common type of testicular cancer are germ cell tumors, which are tumors arising from any biological cell that can develop into a sperm or egg. Some rarer types include non-germ cell tumors, and cancers that start in another part of the body first and spread to the testicle.

NOW STAND BACK - WE ARE GOING TO TALK SOME SCIENCE!!

The six most common germ cell tumors are:

  • Yolk Sac
  • Choriocarcinoma
  • Sarcomatoid
  • Seminoma
  • Embryonal
  • Malignant Teratoma

Embryonal carcinoma is the most frequently found component of germ cell tumors containing a mix of different cell types. Testicular tumors are often composed of a combination of the different cell types listed above. Tumors, which consist of multiple cell types are considered mixed germ cell tumors.

Seminomas are slow growing, while non-seminomas, specifically choriocarcinoma and the sarcomatoid types grow faster. Pure tumors only consist of one cell type. For example, pure seminomas do not contain any other germ cells.

Malignant teratomas are masses that look to contain all 3 layers of a developing embryo: endoderm (innermost layer), mesoderm (middle layer) and ectoderm (outermost layer).

Yolk sac cancers are given their name due to the cells’ similar appearance to the yolk sac of an early developing embryo. It is the most common testicular cancer found in children.

Less commonly found are non-germ cell tumors, which include the following cell types:

  • Leydig cells: Also called interstitial cells that produce the male hormone testosterone.
  • Sertoli cells: Responsible for the nourishment of sperm cells.

A rare type of testicular cancer can also be Extragonadal, where the primary tumor forms in another organ first. These tumors often start in lymph nodes located in the abdomen (the retroperitoneum) or between the chest and the lungs (the mediastinum). Cancers originating from other organs that spread to the testis are known as secondary cancers. For example, prostate cancer that has spread to the testis is called metastatic prostate cancer. This means the cancer found within the testicles is a secondary prostate cancer and will therefore also be considered prostate cancer too. Testicular cancer that originated in the testicle and spread elsewhere is considered metastatic testicular cancer. 

So what does this mean?

What this means is that tumors, just like a house party, can be a combination between all sorts of different types. This means depending on who shows up to the party, your treatment will be tailored to best treat what's inside the tumor. 

 

STEP 3: How does it spread?

Like any out of control house party, if things start getting too crowded, the party is going to start to spill over and spread. The part starts on the main floor... spreads to the kitchen... then the bedrooms... until eventually the whole house, the backyard, and the neighbour's pool are part of the party.

Similarly, testicular tumors generally start within the testis and slowly invade structures within the testicle, such as the layers surrounding the testis, specifically the tunica albuginea. The likely course of the cancer depends on which neighboring structures are affected by the cancer. The tumor may grow into any of the structures shown in Step 1.

If the party gets too big though, it's not going to stop at just the testicle. The first stop on this destructive house party from hell? The Lymph Nodes. This is what your Lymph node system looks like:

Tumors that invade the lymphovascular network have a higher chance of relapse, meaning that the testicular cancer may come back in nearby lymph nodes or other organs. Metastatic forms of testicular cancer often spread to lymph nodes found in the retroperitoneal (inferior vena cava and descending aorta below the two kidneys) mediastinal (between the two lungs), pelvic (primarily the Inguinal and Iliac lymph nodes) or supraclavicular (found above the collar bone) regions of the body. 

This is the first place the party can spread.

This is the first place the party can spread.

Testicular cancer that has spread to other organs most frequently invades the lungs, but may also affect the liver, bones, brain, adrenal glands and other organs in rare circumstances. Cancer that has spread to lymph nodes near the back of the abdomen can press against nerves, which can cause persistent pain.

 

Step 4: what are cancer "stages"?

So how out of control is this house party... we need a way to describe it. Is it more "Netflix and Chill"? Or full on Las Vegas? Thankfully they've already figured out a way to do this, and you may have heard people talk about, Stage 1, Stage 2, Stage 3? Here's a handy graphic!

The various stages of Testicular cancer

The various stages of Testicular cancer

  • Stage 0: hasn’t spread at all (party is still in the living room)
  • Stage 1: spread locally (the party has spread to the kitchen)
  • Stage 2: spread to regional lymph nodes (the party is all over the house)
  • Stage 3: spread to distant organs, such as the distant lymph nodes, lungs, bone etc. (the party has spread to the neighborhood)

*note that testicular cancer does not have a fourth stage. Tumors from the testicle that have spread to distant organs are referred to as Stage III.

 

Handy... but how did they come up with it?

Cancer Staging is used to describe how the cancer has grown and if it has spread to other parts of the body. Testicular cancer is staged based on the results of the surgery to remove the primary testicular tumor, tumor markers in the blood and imaging tests, such as Computed Tomography (CT) scans. The TNMS system, which was created by the American Joint Committee on Cancer (AJCC), is based on four characteristics:

  • T: Spread of the primary tumor within the affected area.
  • N: Number of nearby lymph nodes affected.
  • M: Indicates if metastasis (the spread of cancer) occurred.
  • S: Tumor marker levels within the blood (serum), specifically for testicular cancer these are:
    • Alpha-fetoprotein (AFP): AFP is a glycoprotein associated with fetal development, being produced in both the liver and yolk sac.
    • Beta-human chorionic gonadotropin (bHCG): bHCG is a hormone associated after the embryo’s implantation along the uterine wall. Normal progression of pregnancy will see b-HCG levels shoot up. 
    • Lactate dehydrogenase (LDH): LDH can be found in areas of tumor initiation, supporting the mass with basic metabolic needs to grow.

For detailed staging information click here!