3. What is cancer?
Cancer is a large group of diseases with one thing in
common: They all happen when normal cells become
cancerous cells that multiply and spread.
Cancer is the second most common cause of death in the
U.S. But fewer people are dying of cancer now than 20 years
ago. Early detection and innovative treatments are curing
cancer and helping people with cancer live longer. At the same
time, medical researchers are identifying independent risk
factors linked to developing cancer to help prevent people
from developing cancer.
4. What is the difference between a
normal cell and a cancerous cell?
Normally, cells follow instructions provided by genes. Genes set down rules
for cells to follow, such as when to start and stop growing. Cancerous cells
ignore the rules that normal cells follow:
Normal cells divide and multiply in a controlled manner. Cancerous cells
multiply uncontrollably.
Normal cells are programmed to die (apoptosis). Cancerous cells ignore
those directions.
Normal cells for solid organs stay put. All cancerous cells are able to move
around.
Normal cells don’t grow as fast as cancerous cells.
5. How does cancer start in your body?
Cancer starts when a gene or several genes mutate and create cancerous
cells. These cells create cancer clusters, or tumors. Cancerous cells may
break away from tumors, using your lymphatic system or bloodstream to
travel to other areas of your body. (Healthcare providers call
this metastasis.)
For example, a tumor in your breast may spread to your lungs, making it
hard for you to breathe. In some types of blood cancer, abnormal cells in
your bone marrow make abnormal blood cells that multiply uncontrollably.
Eventually, the abnormal cells crowd out normal blood cells.
6. How common is cancer?
According to the American Cancer Society, 1 in 2 men and people assigned male at birth
(AMAB) and 1 in 3 women and people assigned female at birth (AFAB) will develop cancer. As
of 2019, more than 16.9 million people in the U.S. were living with cancer. The most common
cancers in the United States are:
Breast cancer: Breast cancer is the most common type of cancer. It mostly affects women
and people AFAB. But about 1% of all breast cancer cases affect men and people AMAB.
Lung cancer: Lung cancer is the second most common cancer. There are two types of lung
cancer: non-small cell cancer and small cell lung cancer.
Prostate cancer: This cancer affects 1 in 9 men and people AMAB.
Colorectal cancer: Colon cancer and rectal cancer affect different parts of your digestive
system.
Blood cancers: Leukemia and lymphoma are the most common blood cancers.
7. Who’s affected by cancer?
Almost anyone may develop cancer, but data show cancer cases vary based
on race and sex. According to the 2022 Annual Report on Cancer, the disease:
Affects slightly more men and people AMAB than women and people AFAB.
Affects more Black men (AMAB) than people in other racial groups.
Affects more women (AFAB) who are American Indian or Alaska natives than
people in other racial groups.
Almost anyone may develop cancer, but it typically affects people aged 60
and older.
8. What are cancer symptoms?
Cancer is a complicated disease. You can have cancer for
years without developing symptoms. Other times, cancer
may cause noticeable symptoms that get worse very
quickly. Many cancer symptoms resemble other, less serious
illnesses. Having certain symptoms doesn’t mean you have
cancer. In general, you should talk to a healthcare provider
anytime there’s a change in your body that lasts for more
than two weeks.
9. First symptoms of cancer
Some common early cancer symptoms include:
Unexplained weight loss.
Chronic tiredness.
Persistent pain.
Fever that occurs mostly at night.
Skin changes, particularly moles that change shape and size or new moles.
Left untreated, cancer may cause additional symptoms, including:
Bruising or bleeding more easily.
Lumps or bumps under your skin that don’t go away.
Difficulty breathing.
Difficulty swallowing.
10. What causes cancer?
Cancer is a genetic disorder. It happens when genes that manage cell
activity mutate and create abnormal cells that divide and multiply, eventually
disrupting how your body works.
Medical researchers estimate 5% to 12% of all cancers are caused
by inherited genetic mutations that you can’t control.
More frequently, cancer happens as an acquired genetic mutation.
Acquired genetic mutations happen over the course of your life. Medical
researchers have identified several risk factors that increase your chance of
developing cancer.
11. Cancer risk factors you can
control
Smoking: Smoking cigarettes and cigars and using e-cigarettes increases your chance of
developing lung, pancreatic, esophageal and oral cancer.
Diet: Eating high-fat or high-sugar foods can increase your risk for many types of cancer.
You’re also more vulnerable to disease if you don’t get enough exercise.
Environment: Exposure to toxins in your environment — such as asbestos, pesticides and
radon — can eventually lead to cancer.
Radiation exposure: Ultraviolet (UV) radiation from the sun significantly increases your
risk of developing skin cancer. Over-exposure to radiation treatment can also be a risk
factor.
Hormone therapy: Women and people AFAB taking hormone replacement therapy may
have an increased risk for breast cancer and endometrial cancer.
12. How can I reduce my risk of developing
cancer?
You can reduce your risk by changing some of your lifestyle choices:
If you smoke or use tobacco, try to stop. Ask a healthcare provider about smoking cessation
programs that can help you quit tobacco.
Follow a diet plan that’s healthy for you. If you want help managing your weight, ask a
healthcare provider about nutritional guidance and weight management programs.
Add exercise to your daily routine. Exercise may boost your immune system so it provides
more protection against cancer.
Avoid toxins, including asbestos, radon and pesticides.
Protect yourself against sun damage.
Have regular cancer screenings.
13. Diagnosis and Tests
How do healthcare providers diagnose cancer?
Healthcare providers begin a cancer diagnosis by doing a
comprehensive physical examination. They’ll ask you to
describe your symptoms. They may ask about your family
medical history. They may also do the following tests:
Blood tests.
Imaging tests.
Biopsies.
14. What are the four stages of cancer?
Most cancers have four stages. The specific stage is determined by a few different factors, including
the tumor’s size and location:
Stage I: The cancer is localized to a small area and hasn’t spread to lymph nodes or other tissues.
Stage II: The cancer has grown, but it hasn’t spread.
Stage III: The cancer has grown larger and has possibly spread to lymph nodes or other tissues.
Stage IV: The cancer has spread to other organs or areas of your body. This stage is also referred to
as metastatic or advanced cancer.
Though stages one through four are the most common, there’s also a Stage 0. This earliest phase
describes cancer that’s still localized to the area in which it started. Cancers that are still in Stage 0 are
usually easily treatable and are considered pre-cancerous by most healthcare providers.
15. Management and Treatment
How do healthcare providers treat cancer?
Chemotherapy:Chemotherapy is one of the most common cancer treatments. It uses powerful drugs to destroy cancer cells.
You may receive chemotherapy in pill form or intravenously (through a needle into a vein). In some cases, providers may be
able to direct chemotherapy to the specific area affected.
Radiation therapy:This treatment kills cancer cells with high dosages of radiation. Your healthcare provider may combine
radiation therapy and chemotherapy.
Surgery:Cancerous tumors that haven’t spread may be removed with surgery. Your healthcare provider may recommend
therapy. This treatment combines surgery with chemotherapy or radiation to shrink a tumor before surgery or to kill cancer
cells that may remain after surgery.
Hormone therapy:Sometimes, providers prescribe hormones that block other cancer-causing hormones. For example, men
and people assigned male at birth who have prostate cancer might receive hormones to keep testosterone (which
contributes to prostate cancer) lower than usual.
Biological response modifier therapy:This treatment stimulates your immune system and helps it perform more effectively. It
does this by changing your body’s natural processes.
Immunotherapy for cancer:Immunotherapy is a cancer treatment that engages your immune system to fight the disease. The
treatment may be called biological therapy.
Targeted therapy for cancer: Targeted therapy is a cancer treatment that targets the genetic changes or mutations that turn
healthy cells into cancer cells.
Bone marrow transplant: Also called stem cell transplantation, this treatment replaces damaged stem cells with healthy
ones. Autologous transplantation uses your supply of healthy stem cells. Allogeneic transplantation uses stem cells donated
by another person.
16. What are cancer treatment side
effects?
Healthcare providers may use several different treatments,
sometimes combining treatments based on your situation.
Common cancer treatments include:
Anemia.
Nausea and vomiting.
Fatigue.
Pain.
17. What are cancer survival rates?
Survival rates are estimates based on the experiences
of large groups of people who have different kinds of
cancer. Like prognoses, cancer survival rates vary based
on cancer type, stage and treatment. According to the
most recent data from the National Cancer Institute,
68% of people with any kind of cancer were alive five
years after their diagnosis.