Med-Surg Immune System, part 9: Tumor Classification

In this article, we cover how to classify tumors, which is an important part of your knowledge on cancer in a Med-Surg or Critical Care class, exam, or floor! There are three ways to classify tumors:

1. Tissue type, which is the type of body tissue in which the cancer originates — and there are five main types of cancer.
2. Grading, which is similarity of a cancer to its tissue of origin
3. Staging, which is the progression or extent of disease

Cancer and tumor classification are covered in our Medical-Surgical flashcards (Immune system), and Cathy’s videos follow along with the cards.

Medical-Surgical Nursing - Flashcards

Medical-Surgical Nursing - Flashcards

4.888535031 / 5.0

(314) 314 total reviews

Regular price $69.95

Regular price Sale price $69.95

Unit price /  per 

Tissue type - The five types of cancer

The five main types of cancer you need to know about are:

1. Carcinoma
2. Sarcoama
3. Leukemia
4. Myeloma
5. Lymphoma

Each of these types can be further broken up, and we cover some of those common sub-categorizations in the sections below.

It’s important to note that the way we refer to cancers in everyday life (e.g., “lung cancer”, “cervical cancer”) can be somewhat broad, and all cases of these cancers do not necessarily fit cleanly into one category. This is because body parts can be made of multiple types of tissues.

For example, some lung cancers are adenocarcinomas while some are squamous cell carcinomas. See the table below for more information.

Carcinoma

Carcinomas make up the majority of cancers, around 80-90%, and that’s because carcinomas originate in the epithelial tissue, and epithelial tissue is everywhere in your body. Epithelial tissue lines your body’s surfaces (e.g., skin), lines your body cavities (e.g., mouth), and makes up many of the glands and organs in your body. There are two main carcinomas to know about, adenocarcinomas and squamous cell carcinoma.

Because carcinomas make up the majority of cancers, most of the cancers that we will cover in our immune system series are carcinomas.

Adenocarcinomas

Adenocarcinomas are cancers originating from glands (adeno = gland) that typically secrete substances, e.g., mucus, or breast milk. Lung cancer and breast cancer are cancers that are usually classified as adenocarcinomas.

Squamous cell carcinoma

Squamous cell carcinoma originates in the squamous epithelium, which is the layer of epithelial tissue that protects you, and can be found in the mouth, lips, and in the middle layers of the skin. The word squamous refers to the shape of the cells and means flat, or a greater width than height (which would be a flat shape).

The term “squamous cell carcinoma” is most commonly used to describe squamous cell carcinoma of the skin, which we cover in our video on skin cancer. However, squamous cell carcinoma can occur in the mouth, esophagus, lungs, or other places where squamous epithelial cells are found.

Sarcoma

Sarcomas are cancers that originate in the supportive or connective tissues of the body, including bones, muscle, tendon, cartilage and fat. Sarcomas are usually broadly grouped into bone-related and soft-tissue related sarcomas. Some examples of bone-related sarcomas that you should know about are osteosarcoma and chondrosarcoma.

Confusingly, “Kaposi’s sarcoma” (which we briefly touched on in this series as a symptom of AIDS) is not considered a true sarcoma.

Osteosarcoma

Osteosarcoma is a cancer that originates in the bone. This is easy to deduce because the prefix osteo- means bone.

Chondrosarcoma

Chondrosarcoma is a cancer that originates in the body’s cartilage. This one is easy to decode if you know that the prefix chondro- means cartilage. We created our Medical Terminology flashcards to make breaking down words like chondrosarcoma into its parts easy, so you never have to be confused by an unfamiliar word on an exam!

Leukemia

Leukemia is a type of cancer that originates in the bone marrow. We cover leukemia in depth in our article on hematologic cancers.

Myeloma

Myeloma is a type of cancer that originates in the plasma cells specifically, within the bone marrow. Both leukemia and myeloma happen in the bone marrow, but myeloma is exclusively the plasma cells. Check out our article on multiple myeloma for more depth on this subject.

Lymphoma

Lymphoma is a type of cancer that originates in the lymphatic glands or nodes, or in organs like the thymus or spleen that are part of the lymphatic system. Check out our article on Hodgkin’s vs. non-Hodgkin’s lymphoma for more information on lymphoma.

Common cancers with classifications

Tumor grading

Tumor grading is another classification method whereby a tumor is compared to its tissue of origin and graded on a 1-4 scale. For example, if a tumor is found in the breast, the cells of that tumor will be compared to the cells of the surrounding breast tissue.

A grade one tumor means the cancer is “well-differentiated” and resembles the tissue of origin. A grade four tumor means the cancer has no similarity at all to the tissue of origin, and looks like something else entirely.

A tumor’s grade is an indication of how fast it is likely to grow or spread. A grade one tumor is likely to grow and spread slowly. In contrast, a grade four tumor is likely to grow and spread quickly and poses a more immediate danger to the patient.

Tumor staging (TNM methodology)

You have likely heard something like “Stage 4 cancer” in the past. In this section, we will explain tumor staging, which is a little different than overall cancer staging.

We stage tumors with a T, N, M scale, and then those results are combined with other factors that are specific to the cancer, to get the cancer stage. Tumor staging is used with cancers marked by solid tumors, and is not applicable to leukemia.

T for tumor (T1 through T4)

The T in TNM staging is for tumor — pretty easy to remember! The T score refers to the size of the tumor, and can be T1, T2, T3, or T4. A t1 tumor would be a pretty small tumor, and a large tumor would rate a T4.

We have to be vague here and use “small” and “large” because how small or large a tumor is is quite relative to the body part or organ that is impacted. For example, a T3 tumor of the breast is larger than 50mm, while a T3 tumor of melanoma is between 2-4mm.

T may also indicate location relative to other body part landmarks, rather than size. In prostate cancer, a T3 tumor means that the tumor has grown outside of the prostate.

N for node (N0 through N3)

N is for node and lymphatic system involvement. The N directly corresponds to the number of regional lymph nodes involved in the cancer.

N0 means that no lymph nodes have been affected, N1 is one lymph node with cancer, N2 is two lymph nodes with cancer, etc.

M for metastasis (M0 or M1)

M is for metastasis, or spreading, and this can be thought of as a binary, because it is either 0 or 1. It may also be helpful to think of this as a boolean value, meaning it is either true or false. M0 means the cancer has not metastasized, and M1 means that the cancer has metastasized.

Putting it all together

Using this simple TNM staging system, there are at least (4 x 3 x 2) TNM 24 combinations, and for a certain type of cancer, these will be grouped into stages. Realistically, there can be more types than this as the tumors may be measured by other factors depending on the type of cancer. But, knowing what TNM staging is and how to break down the different scores that make up TNM stages will be helpful to you as you come across descriptions of tumors.

For example, if you see a tumor that is T4, N2, M0, you will know that it is a relatively large tumor, affecting two lymph nodes, but it has not metastasized.

Cathy’s teaching on HIV/AIDS is intended to help prepare you for Medical-Surgical nursing exams. The Medical-Surgical Nursing video series is intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI and NCLEX.