What is carcinoma?
Carcinoma is cancer that forms in epithelial tissue. Epithelial tissue lines most of your organs, the internal passageways in your body (like your esophagus), and your skin. Most cancers affecting your skin, breasts, kidney, liver, lungs, pancreas, prostate gland, head and neck are carcinomas.
Most people think of cancer in terms of where it forms (breast cancer, colon cancer, etc.), but this is just one way to distinguish one type of cancer from another. Scientists also classify cancers based on the types of tissue where cancer cells start growing.
Cancer classifications by tissue type include:
- Carcinoma: Cancer starts in epithelial tissue.
- Myeloma: Cancer starts in plasma cells that are inside bone marrow.
- Leukemia: Cancer starts in the bone marrow, where blood cells are made.
- Lymphoma: Cancer starts in the lymphatic system (ex., lymph nodes, spleen, etc.).
- Sarcoma: Cancer starts in connective and supportive tissue (ex., muscle, bone, cartilage, etc.).
- Mixed types: Cancer starts in more than one tissue type.
How is carcinoma classified by spread?
As carcinoma cells grow and multiply, they form solid masses called tumors. Cancer cells can break away from tumors and spread to other parts of your body (metastasize). Labels for carcinoma describe how much it has spread.
- Carcinoma in situ: The carcinoma hasn't spread.
- Invasive carcinoma: The carcinoma has spread to surrounding tissue close to where it formed.
- Metastatic carcinoma: The carcinoma has spread to other parts of your body.
What are the types of carcinoma?
There are multiple cancers classified as carcinomas. The most common carcinoma types include the following:
- Adenocarcinoma starts in the glands that line your organs (glandular epithelial cells). Glandular epithelial cells secrete fluids, like mucus and digestive juices. Most prostate cancers, breast cancers, colorectal cancers and pancreatic cancers are adenocarcinoma. Renal cell carcinoma (RCC) is a type of adenocarcinoma responsible for 85% of all kidney cancer. Hepatocellular carcinoma (HCC) is an adenocarcinoma and the most common form of liver cancer.
- Basal cell carcinoma (BCC) starts in the basal cell layer of your epidermis. The epidermis is your top layer of skin. A layer of basal cells lines the bottom of your epidermis. These cells replace the cells in the top layer of your epidermis (squamous cells) when they die. Basal cell carcinoma is the most common type of skin cancer.
- Squamous cell carcinoma (SCC) starts in your epidermis's squamous cell layer (top layer). It usually appears in those parts of your skin that receive the most sun exposure, like your face, ears, neck, arms, legs, etc. SCC can also form in the mucous membranes lining your lungs, esophagus, head and neck. It's the second most common type of skin cancer. Squamous cell carcinoma generally spreads faster than basal cell carcinoma.
- Ductal carcinoma in situ (DCIS) starts in your breast milk ducts. Milk flows through your milk ducts and to your nipple during breastfeeding (chestfeeding). Being "in situ" means that the carcinoma hasn't spread to cells outside your milk ducts. DCIS is considered noninvasive or pre-invasive breast cancer and is highly treatable.
- Invasive (infiltrating) ductal carcinoma starts in your breast milk ducts, like DCIS. Unlike DCIS, invasive ductal carcinoma has spread to nearby tissue. Untreated, it has the potential of spreading to other parts of your body via your lymphatic system and bloodstream. It's the most common type of breast cancer.
Who gets carcinoma?
Certain demographic factors may influence your likelihood of developing carcinoma.
- Age: Your carcinoma risk increases if you're 65 or older. Carcinomas are rare in children.
- Sex: Except for carcinomas affecting the breasts, carcinoma risk is higher among people assigned male at birth.
- Race/Ethnicity: Race-related risks vary by carcinoma type. People who are Black are at greater risk of certain adenocarcinomas, like lung cancer, colon cancer and prostate cancer. People of Ashkenazi Jewish descent are at the greatest risk of colon cancer. People who are white, or people with less melanin, are at greater risk of developing carcinomas related to skin.
How common is carcinoma?
Carcinoma is the most common form of cancer, making up 80% to 90% of cancer diagnoses.
Symptoms and Causes
What causes carcinoma?
Carcinoma, like all cancer, begins when a genetic mutation (change) transforms a normal, healthy cell into a cancer cell. That cancer cell keeps multiplying and making more cancer cells. Untreated, the cancer cells can invade nearby healthy tissue. Eventually, the cancer cells may travel through your bloodstream or lymphatic system to invade other parts of your body (metastasize).
Scientists don't know what causes the mutation that leads to cancer, but certain factors may increase your risk.
What are the risk factors for carcinoma?
Risk factors vary depending on the specific type of carcinoma.
Risk factors for adenocarcinoma are significantly varied since these types of carcinoma may present in multiple organs, including your breast, prostate, pancreas, esophagus, colon/rectum, stomach, lungs, etc. Common risk factors include:
- Tobacco use.
- Drinking alcohol.
- Exposure to harmful toxins.
- Previous radiation therapy.
- Genetic mutations such as BRCA, HNPCC, FAP, etc.
Basal and squamous cell carcinoma
- Excessive exposure to UV radiation (from the sun or tanning beds).
- Light-colored skin that burns or freckles easily.
- Blue or green eyes, blonde or red hair.
- An infection with a high-risk strain of HPV.
- Previous radiation therapy.
- Exposure to harmful toxins.
Precancerous cells forming in the milk ducts inside the breast.
Ductal carcinoma (in situ and invasive)
Diagnosis and Tests
How is carcinoma diagnosed?
Your provider will conduct a thorough medical history and review your family medical history to identify factors that may increase your carcinoma risk. They will ask you about your symptoms. Your provider may recommend any of the following tests or procedures if they suspect you have carcinoma.
- Physical exam. Your provider will examine skin changes that may indicate basal cell carcinoma or squamous cell carcinoma. Breast exams allow your provider to identify abnormal growths or symptoms that may be signs of ductal carcinoma, like skin changes or nipple discharge.
- Blood tests. Blood tests can detect protein levels, enzyme levels, tumor markers and other indicators that may help your provider get closer to a diagnosis.
- Imaging. Routine imaging procedures, like a mammogram or colonoscopy, can help detect carcinoma early. Imaging can also help your provider get closer to a diagnosis or see if your cancer's spread. Imaging may include ultrasounds, mammograms, MRIs, CT scans, PET scans and X-rays. Your provider may recommend specialized imaging procedures to identify tumors impacting specific organs.
- Biopsy. A biopsy is the only way to confirm a carcinoma diagnosis. Biopsies used to diagnose carcinoma include a shave biopsy, punch biopsy, fine-needle aspiration biopsy, core needle biopsy, surgical lymph node biopsy, incisional biopsy and excisional biopsy. Though the specific technique is different, all biopsies involve your provider removing tissue that's later tested in a lab for cancer cells.
How is carcinoma staged?
An essential part of diagnosis involves staging cancer. Staging allows your provider to document a tumor's size, lymph node spread or spread to other parts of your body. It also provides important information about its spread.
- Stage 0: Cancer hasn't spread beyond where it formed. Stage 0 cancer is in situ and is often curable with prompt treatment.
- Stage 1: The tumor is more pronounced than in stage 0. Cancer hasn't spread to nearby tissues, organs or lymph nodes.
- Stage 2: The tumor is bigger than in stage 1 and may or may not have spread to your lymph nodes.
- Stage 3: The tumor is larger and has spread to nearby tissues or lymph nodes.
- Stage 4: The cancer is metastatic, which means it's spread to other organs or parts of your body.
Management and Treatment
How is carcinoma treated?
Carcinoma treatment depends on various factors, including your overall health, stage of the tumor, details of the biopsy report such as pathology, your age and what you want out of treatment. Your provider will discuss a care plan with you that matches your unique situation.
- Surgery: Your provider may remove the cancer cells or tumor and nearby healthy tissue for safe measures. They may recommend surgery if the carcinoma is confined to one area (it hasn't metastasized).
- Chemotherapy: You may receive drugs that kill cancer cells or prevent them from multiplying. Chemotherapy may accompany other treatments, like surgery or radiation. It may be used before surgery to shrink cancer cells so that they're easier to remove (neoadjuvant chemotherapy). It may be used afterward to prevent cancer cells from returning (adjuvant chemotherapy).
- Radiation therapy: Radiation uses targeted energy beams, like X-rays, to kill cancer cells or prevent them from multiplying. It's often used in combination with surgery and chemotherapy. Similar to chemotherapy, radiation can be used to shrink a tumor before surgery or to kill remaining cancer cells afterward. Radiation can also help relieve symptoms depending on the type of carcinoma.
- Targeted therapy: This treatment uses drugs that target specific weaknesses or genetic changes in cancer cells. Targeted therapy can zero in on these weaknesses, killing the cancer cells or stopping them from multiplying.
- Immunotherapy: Immunotherapy helps your immune system identify cancer cells and eliminate them. Your provider may recommend immunotherapy alongside other treatments, like chemotherapy.
- Hormone therapy: Reducing the amounts of certain sex hormones circulating in your body can slow carcinoma growth. For example, long-term exposure to estrogen has been linked to breast cancer risk. Exposure to androgens has been linked to prostate cancer. Hormone therapy can lessen the impacts these hormones have on cancer growth.
Depending on your diagnosis, treatment may be curative, palliative or both. The goal of curative treatment is remission. Complete cancer remission means that the signs and symptoms of the cancer are no longer present. Palliative care can help you manage cancer symptoms. It can also empower you to feel more comfortable and confident with care decisions as you navigate life with a cancer diagnosis.
How can I reduce my carcinoma risk?
First, it helps to know potential risk factors and communicate them with your provider. For example, suppose a close family member had breast cancer. In that case, your provider may recommend early screenings or more frequent breast exams. They may recommend genetic testing to see if you have gene mutations that may indicate a greater risk of carcinoma.
Certain lifestyle behaviors can reduce your risk of some carcinoma types:
- Don't smoke or use tobacco products.
- Maintain a healthy body weight.
- Limit your alcohol intake.
- Use sunscreen with SPF 15 or higher, depending on how long you'll be outside.
- If possible, avoid being in the sun from 10 a.m. to 4 p.m.
- Avoid tanning beds.
Outlook / Prognosis
Is carcinoma serious?
Carcinoma's seriousness depends on the type of carcinoma, where it's located, when you were diagnosed, and how much it's spread, among other factors. Generally, metastatic carcinoma is more serious than carcinoma in situ. Slow-growing carcinoma like basal cell carcinoma tends to be less serious than fast-growing cancers, like Merkel cell carcinoma.
Still, your outlook depends on specific factors that only you and your provider know. Ask your provider about what your diagnosis and health mean for your prognosis.
What questions should I ask my doctor?
If you’ve been diagnosed with carcinoma, it may be helpful to ask your healthcare provider the following questions:
- What type of carcinoma do I have?
- Has it spread to other parts of my body?
- What treatments would you recommend?
- What's the goal of my treatment?
- How long will treatment take?
- What are the likely outcomes of treatment?
- How can I take care of myself during treatment?
Frequently Asked Questions
What's the difference between cancer and carcinoma?
Carcinoma is a type of cancer that forms in epithelial tissue. Other types of cancer form elsewhere, such as in connective tissue (sarcoma), bone marrow (leukemia), etc. Most cancer diagnoses are carcinoma.
Does carcinoma mean tumor?
Carcinoma cells can be treated early before multiplying and becoming a mass (tumor). Untreated, however, carcinoma usually forms a tumor. Carcinoma is different from other cancers that aren't often associated with tumors, like leukemia.
Can carcinoma be cured?
Some forms of carcinoma can be cured with early detection and early treatment. For instance, basal cell carcinoma (BCC) has a 100% five-year survival rate. This means that people with BCC are just as likely to be alive five years after diagnosis as someone without a BCC diagnosis. Squamous cell carcinoma has a similar five-year survival rate of 95%.
Talk to your provider about your prognosis based on your specific carcinoma.
A note from Cleveland Clinic
Many people who learn they have carcinoma rightfully wonder, is it serious? The honest answer can feel frustrating. It depends. Having carcinoma means that cancer has formed in a specific type of tissue. Other factors, like the size of the tumor, where it's located in your body, whether it's spread, etc., may provide better information about what's involved in your treatment plan. These details also inform the likelihood of getting rid of cancer over the long term. Ask your provider about how the characteristics of your carcinoma and your health influence your chance of remission.
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