Carcinoma Explained: Types, Stages, Treatment, and More

Medically Reviewed By Julie Scott, DNP, ANP-BC, AOCNP
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Carcinoma is a type of cancer that starts in your epithelial tissues. Epithelial tissues are located under the surface of your skin, and they also line or cover the digestive tract, blood vessels, and other organs. The most common types of carcinomas are highly treatable. There are many different types of carcinomas, and carcinomas can spread to other parts of the body as well. This article provides more information on what carcinoma is, what symptoms of carcinoma can look like, and how it is diagnosed and treated.

What is carcinoma?

Person looking in mirror examining face with hand on cheek
Brkati Krokodil/Stocksy United

Carcinomas account for 80–90% of all cancer diagnoses. For instance, breast cancer and prostate cancer are both types of carcinomas.

Carcinomas begin in epithelial tissues, but they can spread to other parts of the body. Carcinomas tend to form solid tumors.

Many forms of carcinoma appear in secreting organs or glands. For instance, breasts (which secrete milk) and lungs (which secrete mucus) are areas where carcinomas can develop.


Carcinomas are divided into two major subtypes. These are:

  • adenocarcinomas, which develop in an organ or gland
  • squamous cell carcinomas, which develop in the skin


Carcinoma is a very common type of cancer. For instance, the following are all types of carcinomas:

Some specific examples of carcinomas include the following.

  • Renal cell carcinoma: This is the most common type of kidney cancer. Cancerous cells typically develop in the lining of the tubes of the kidney and may grow into a tumor. The cancer may form in one or both kidneys.
  • Ductal carcinoma in situ: This is considered a type of precancer and is not invasive. The abnormal cells are only located in the milk duct and have not spread anywhere else.
  • Invasive ductal carcinoma: This type of cancer makes up 70–80% of all breast cancers and occurs when the cancer cells have spread into the breast tissue.
  • Basal cell carcinoma (BCC): BCC affects round basal cells in the lower part of the epidermis, which is the surface level of the skin. These cells produce new skin cells. BCC tends to grow slowly, rarely spreads to other parts of the body, and is highly treatable.
  • Squamous cell carcinoma (SCC): SCC is the second most common type of skin cancer. It affects the flat, scale-like squamous cells in the epidermis, the lining of the hollow organs in the body, and the lining of the respiratory and digestive tracts. Most cancers of the anus, cervix, head and neck, and vagina are SCC. It is the second most common form of skin cancer after BCC and is highly treatable.
  • Merkel cell carcinoma: This is a very rare form of skin cancer.

Risk factors

General risk factors for carcinomas include:

  • a family history of cancer
  • UV exposure from the sun and from tanning beds
  • age, as the older you are, the higher your risk of skin cancer
  • exposure to carcinogens, including asbestos, tobacco smoke, and industrial chemicals
  • infection with viruses such as the human papillomavirus (HPV), hepatitis, or the Epstein-Barr virus
  • obesity
  • tobacco use
  • regular alcohol use


The best way to help prevent cancer is to lower your risk factors and to have regular cancer screenings. The American Cancer Society provides guidelines for routine screening for cancer according to age. For instance, routine mammograms are recommended for females with breasts beginning at age 40 years.

General guidelines for cancer prevention also include:

  • avoiding tobacco
  • eating a diet rich in foods that contain phytochemicals and antioxidants
  • maintaining a moderate weight
  • engaging in physical activity
  • managing stress
  • avoiding alcohol
  • using sunscreen and wearing protective clothing

Getting an early diagnosis can lead to a better treatment outcome.


To diagnose carcinoma, your doctor will go over your symptoms, the results of any screening tests done, and your family history. They will also perform a physical assessment in the office.

From there, you may expect your doctor to order additional tests, such as:

Learn what a dermatologist does here.


Staging your cancer can help your doctor prepare a treatment plan that is best for you. Staging can tell you the cell type, the size of the tumor, and whether or not the cancer has spread to the nearby lymph nodes or to a different part of the body.

The most common way to stage cancer is by using the TNM staging system, which gives information about the tumor, and the 0–4 staging process, which describes how far the cancer has spread.

The TNM system

  • T describes the size of the main, or primary, tumor.
  • N is for the number of lymph nodes near the tumor that have cancer.
  • M describes whether or not the cancer has metastasized, or spread to other parts of the body.

0–4 staging

  • Stage 0: Abnormal cells are present but have not spread. At this stage, the growth is not cancer, but it may develop into cancer.
  • Stages 1, 2, and 3: Cancer is present. The higher the number, the farther it has spread and the larger the tumor.
  • Stage 4: The cancer has spread to distant parts of the body.

Self-examination for skin cancer

The best time to do a skin self-exam is after a bath or shower. Examine your entire body naked, from the top of your head to your toes, for any moles or skin blemishes. Be sure to check between skin folds and the bottoms of your feet.

Look for specific signs, such as:

  • a spot, bump, wart, or mole that seems to be growing
  • a sore that does not heal after several weeks
  • a rough or scaly patch
  • changes in size, shape, or color of any moles or spots
  • irregularly shaped moles or spots
  • a mole with any bleeding or discharge
  • dark lines or discoloration on the nails

If you notice something that concerns you, you can have it checked by a doctor. Additionally, you can schedule yearly skin checks with a dermatologist.

Treatment options

Treatment options for carcinomas depend on what type of cancer is present, whether or not it has spread, and if there are any other medical conditions present.

Treatment options for cancer include:

  • Chemotherapy: Chemotherapy medications destroy fast growing cancer cells. These medications can be given alongside other treatment options.
  • Radiation therapy: High dose radiation is targeted toward cancer kills in order to kill them. Like chemotherapy, radiation therapy can be used with other types of treatment.
  • Surgery: In some cases, surgery can remove the cancerous area or areas in the body.
  • Immunotherapy: This treatment helps the immune system fight off cancer cells.
  • Hormonal therapy: Hormone therapy aims to stop or slow cancers that are fueled by certain types of hormones.
  • Biomarker testing: This type of testing can provide genetic information about your type of cancer to help guide treatment.

Learn what to expect from chemotherapy here.


Carcinoma is a type of cancer that starts in your epithelial tissues. Epithelial tissues are present in the skin as well as on the lining and covering of the organs.

Many types of carcinoma are treatable, and with any type of cancer, the earlier it is identified, the better the chance of treating it will be. Regular skin self-exams and screening tests as recommended according to your age and risk can help diagnose carcinoma and ensure early and effective treatment.  

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Medical Reviewer: Julie Scott, DNP, ANP-BC, AOCNP
Last Review Date: 2022 May 31
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