Though there are several types of testicular cancer, 95% of testicular cancers are what we call germ cell tumors. These are tumors that arise from the sperm-producing cells within the testicle. Of germ cell tumors, we tend to categorize testicular cancers into two broad categories. And this includes seminoma and nonseminomatous germ cell tumors.
Seminomas are one category. Nonseminomatous germ cell tumors are another category. Within that particular category, there are various types of cancers that can exist. These include things like embryonal carcinoma, teratoma, choriocarcinoma and yolk sac tumors. These are all categorized as nonseminomatous germ cell tumors.
Now, why is it important to distinguish the two? The main reason, we know that seminomas respond well to radiation therapy. We also know that nonseminomatous germ cell tumors do not respond well to radiation therapy. So what type of cancer you have, very important because it dictates and determines the types of therapies that are available to you.
Seminomas can also respond well to chemotherapy. However, if you have a mixture of the two types, including seminoma and some nonseminoma, then we treat that as what's called a "mixed germ cell tumor" and it would be treated more as a nonseminomatous germ cell tumor that does not respond well to radiation. So, many of those patients may undergo chemotherapy.
But these are the general broad categories. And these are the reasons we separate them into these categories. Now the ultimate treatments that are required really depend on the type of cancer you have, the level of what we call "tumor marker elevation". Tumor markers are proteins produced by testicular tumors in some cases. Snd they can also guide what types of therapies are required, and also what we call the stage of the cancer.
How extensive is it? How far has it spread? Has it spread to the abdominal area? Has it spread to the chest area or beyond? So the stage, the type of cancer you have, the status of your tumor markers, will all determine the types of therapies that may be required for you. But seminomas and nonseminomas have two different categories of treatments and that's why we distinguish the two categories.