What is Cancer?

What is Cancer?

Cancer is a disease in which normal cells in the body grow abnormally rapidly. Dividing and multiplying, these cancer cells can form tumors, spreading to other parts of the body and destroying healthy tissue.

Cancer is the second leading cause of death in the United States. There are more than 100 types of cancer, generally named for where in the body cancer originated—breast, prostate, and lung cancer being three of the most common.

Fortunately, with new treatments and technologies, cancer survival rates are increasing. It’s important to recognize the causes and symptoms of cancer, as prevention and early detection can be key players in winning the fight against the disease.

Stages of Cancer


Cancer is typically categorized into four stages (I-IV), depending on the tumor’s size and how far cancerous cells have spread throughout the body:

  • Stage I: The cancer is confined to a small area. It hasn’t spread to the lymph nodes or other cells
  • Stage II: The cancer has grown in size but hasn’t spread to other tissues
  • Stage III: The cancer has grown larger and may have spread to the lymph nodes or other tissues
  • Stage IV: The cancer has metastasized—spread to other tissues or organs within the body

There is also stage zero, the presence of localized, abnormal but noninvasive cells. Most doctors consider cancers in stage zero to be pre-cancerous and highly treatable. Other types of cancer, including lymphoma, brain, multiple melanomas, and blood cancers, have their own staging systems.

Types of Cancer


Cancers can be categorized into five main types:

  • Carcinoma - The most common form of cancer, which begins in the skin or the tissue covering the glands and internal organs. Common types of carcinoma include:
  • Sarcoma - Cancer that starts in the soft and connective tissues of the body, including muscles, fat, joints, nerves, tendons, blood and lymph vessels, bone, and cartilage.
  • Lymphoma - Cancer that begins in the lymphatic system, a network of glands and vessels that help prevent infection, including the white blood cells or lymphocytes. The main forms of lymphoma are:
  • Leukemia - Cancer affecting the blood. Leukemia starts when healthy blood cells experience abnormal changes and grow uncontrollably.
  • Melanoma - Cancer of the skin. Abnormal cells, pigmented and irregularly shaped, appear and grow on the epidermis.

In addition to breast, prostate, colon, lung, melanoma (skin), and blood cancers (leukemia), abnormal cells can appear in many other areas throughout the body, causing:

Learn more about the various types of cancers and how we treat them.

Symptoms of Cancer


Cancer symptoms can vary from case to case, depending on the type of cancer. In the earlier stages, some people may not experience any symptoms at all.

The general early signs and symptoms of cancer can include:

  • Chronic fatigue
  • Unexplained weight loss
  • Chronic pain
  • Loss of appetite
  • Nausea or vomiting
  • Fever and/or night sweats
  • Changes in the skin, including a new mole or a persistent sore
  • Jaundice, or a yellowing of the eyes and skin
  • A lump in the breast or other areas of the body
  • Persistent headaches
  • Hearing or vision issues
  • Chronic hoarseness or cough

These symptoms do not mean you have cancer but consult your doctor if you are experiencing them.

What Causes Cancer?


Many factors can contribute to the causes of cancer, including:

  • Smoking/use of tobacco products can lead to lung, esophageal, oral, and laryngeal cancer
  • Unhealthy diet. Too much sugar or high-fat foods can increase your risk
  • Lack of exercise, especially if it leads to being overweight or obese
  • Ultraviolet radiation, or too much time in the sun, greatly increases the chances of skin cancer
  • Toxic environments. Exposure in the home or workplace to pesticides, asbestos, and radon can contribute to the development of cancerous cells
  • Hormone therapy may increase some women’s risk for breast and other cancers

Risk Factors for Cancer

Risk Factors

Anyone can get cancer. But there are known risk factors, both inherited and behavioral, that can make some individuals more likely to develop cancer than others, including:

  • Family history - It is possible that certain cancer-causing gene mutations can be inherited
  • Age - While one can get cancer at any age, the risk for developing the disease does increase in ages 65 and older
  • Habits - Smoking, excessive alcohol consumption, and too much sun exposure (sunburns) are all linked to cancer development
  • Excess body fat - Being overweight can increase the risk for developing certain cancers, including colorectal, uterine, esophageal, pancreatic, kidney, and post-menopausal breast cancer
  • Health conditions - Some people with pre-existing issues such as low immunity or ulcerative colitis could be at higher risk for developing cancer
  • Certain viruses - A small number of viruses have been linked to an increased risk of particular types of cancer, including HIV, Human papilloma viruses (HPV), and Hepatitis B and C

Cancer Prevention


There is no set list of rules one can follow to avoid cancer. But there are some habits and actions that may help reduce the likelihood of cancer forming, including:

  • Proper diet and nutrition
  • Regular exercise
  • Maintaining a healthy weight
  • Limiting alcohol intake
  • Quitting smoking
  • Keeping up to date on vaccinations
  • Reducing exposure to harmful chemicals
  • Avoiding sun exposure/wearing sunscreen
  • Scheduling regular exams to detect cancer—mammograms, colonoscopies, etc.
  • In some cases, a baby aspirin per day (please consult your doctor)
Get Care

Trust NewYork-Presbyterian for Cancer Care

If you are experiencing signs and symptoms of cancer, it’s essential to seek medical advice as soon as possible. NewYork-Presbyterian is one of the leading cancer centers in the nation. Our top-notch doctors and oncologists can expertly identify cancer symptoms and offer various diagnosis and cancer treatment options.

Don’t hesitate to reach out to us for more information about compassionate cancer care at NewYork-Presbyterian.