Questions & Answers

Short, plain-language answers to common questions — every answer is based on a National Cancer Institute resource, with a link to the original.

• Are pancreatic neuroendocrine tumors different from other pancreatic cancer?Pancreatic neuroendocrine tumors are less common than the exocrine type of pancreatic cancer, but they have a better prognosis.
• Are placebos used in cancer clinical trials?Placebos are rarely used in cancer treatment trials, and if they are used, you will always be told ahead of time.
• Can a blood test diagnose cancer?Blood and other lab tests can point to cancer, but they cannot confirm it on their own; a biopsy is often needed to be certain.
• Can a cancer screening test be wrong?Yes. Screening tests can give false-positive results (showing cancer when there is none) and false-negative results (showing no cancer when there is).
• Can colorectal cancer be prevented?Colorectal cancer often begins as a polyp, and finding and removing polyps can prevent colorectal cancer.
• Can Hodgkin lymphoma be cured?Hodgkin lymphoma can often be cured, according to the National Cancer Institute.
• Can men get breast cancer?Yes. Breast cancer mostly affects women aged 45 and older, but anyone with breasts can get it, though it is rare in men.
• Can metastatic cancer be treated?There are treatments for most types of metastatic cancer, often aimed at controlling its growth and relieving symptoms.
• Can nausea and vomiting from chemotherapy be prevented?Yes—antinausea medicines often prevent or relieve nausea and vomiting, and they work best when taken before treatment.
• Can you gain weight during cancer treatment?Yes—some people gain weight during treatment, more often with ovarian, breast, or prostate cancer, or from steroids and hormone therapy.
• Can you get cancer even with no known risk factors?Yes. Cancer can develop in people who have no known risk factors, and having risk factors does not mean a person will get cancer.
• Do I need testing before targeted therapy?Often yes; most of the time your tumor is tested (biomarker testing) to see if it has a target for a drug.
• Do most people need more than one cancer treatment?Most people with cancer have a combination of treatments, though some people have only one.
• Do side effects mean chemotherapy is working?No. Side effects have nothing to do with how well chemotherapy is fighting your cancer.
• Do vitamins and supplements prevent cancer?There is not enough proof that vitamins or dietary supplements can prevent cancer, and in one trial vitamin E alone increased prostate cancer risk.
• Do you need to have cancer to join a clinical trial?Not always. Most cancer trials involve people who have cancer, but prevention and screening trials may involve people at high risk or healthy volunteers.
• Does cancer always cause pain?No. Cancer often does not cause pain, which is why you should not wait to feel pain before seeing a doctor about lasting symptoms.
• Does cancer fatigue go away after treatment ends?Fatigue usually decreases after cancer treatment ends, but some people still feel it for months or years.
• Does cancer treatment always cause hair loss?No—only some chemotherapy causes hair loss, and radiation causes it only in the treated area, so ask your team about your treatment.
• Does chemotherapy always cause hair loss?Chemotherapy can cause hair loss, but it does not always, and side effects often improve after treatment ends.
• Does everyone get the same side effects from cancer treatment?No—side effects vary from person to person, even among people receiving the same type of cancer treatment.
• Does having a risk factor mean I will get cancer?No. A risk factor raises the chance of developing cancer, but it does not mean cancer is certain.
• Does prostate cancer grow slowly?Prostate cancer usually grows very slowly, which is why finding and treating it early does not always help a man live longer.
• Does sunlight cause melanoma?UV radiation from the sun, sunlamps, and tanning booths causes damage that can lead to skin cancer, and melanoma is one type of skin cancer.
• Does the machine touch me during external beam radiation?During external beam radiation, the machine does not touch you, though it can move around you.
• How can caregivers take care of themselves?Make time for yourself each day, keep up your routine, connect with others, and protect your own health so you have strength to care for others.
• How can I cope with fear and worry about cancer?Being informed often helps most—learning the facts about your cancer and treatment can reduce fear and help you know what to expect.
• How can I eat when I have no appetite during cancer treatment?Eat small high-protein, high-calorie meals every 2 to 3 hours, and use smoothies or supplement drinks when solid food is hard.
• How can I help someone with cancer?Caregiving can mean daily tasks, medical help, coordinating care, or emotional support—and every situation is different.
• How do I ask others for help as a cancer caregiver?Take an honest look at what you can and can't do, and share tasks like cooking, childcare, or driving—getting help also helps your loved one.
• How do I cope with the fear that my cancer will come back?Fear of recurrence is normal and often lessens over time; talking with your team, tracking symptoms, and a follow-up plan can help.
• How do scientists find cancer risk factors?Most risk factors are first identified in studies that compare large groups of people who develop cancer with those who do not.
• How does radiation therapy work?Radiation therapy kills cancer cells or slows their growth by damaging their DNA.
• How does surgery treat cancer?Surgery treats cancer by removing it from the body; it can remove a whole tumor, part of one, or ease symptoms.
• How is hormone therapy given?Hormone therapy may be given as pills, as injections, or through surgery to remove hormone-producing organs.
• How is immunotherapy given?Immunotherapy may be given by IV, by mouth, as a cream on the skin, or directly into the bladder, depending on the type.
• How is targeted therapy different from chemotherapy?Targeted therapy interferes with specific proteins that help tumors grow, while chemotherapy often kills all fast-dividing cells.
• How long does a pathology report take?A pathologist typically sends a pathology report to the doctor within 10 days after the biopsy or surgery.
• How long does a stem cell transplant take?A stem cell transplant can take a few months to complete, and immune recovery takes even longer.
• How long does chemotherapy last?Chemotherapy schedules vary widely and are often given in cycles of treatment followed by rest.
• How long does it take for hair to grow back after chemotherapy?After chemotherapy, hair often grows back in 2 to 3 months; after radiation therapy, in 3 to 6 months.
• How many people are diagnosed with cancer each year in the US?In 2025, an estimated 2,041,910 new cancer cases were expected to be diagnosed in the United States.
• How many types of cancer are there?There are more than 100 types of cancer, usually named for the organ or type of cell where they start.
• How many types of cancer treatment are there?There are many types of cancer treatment, including surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy, hormone therapy, and stem cell transplants.
• Is cancer a genetic disease?Yes. Cancer is caused by changes to the genes that control how cells grow and divide, though these changes are not always inherited.
• Is it normal to feel depressed after a cancer diagnosis?Sadness is a normal response, but depression is a treatable medical condition—see your doctor if signs last more than two weeks.
• Is leukemia a childhood cancer?Leukemia is the most common cancer in children under 15, but it happens most often in adults older than 55.
• Is lung cancer only caused by smoking?No. Smoking causes most lung cancers, but people who have never smoked can also develop lung cancer.
• Is melanoma the most dangerous skin cancer?Melanoma is less common than other skin cancers but much more likely to spread, and most deaths from skin cancer are caused by melanoma.
• Is prostate cancer common?Prostate cancer is the most common cancer among men in the United States and the second leading cause of cancer death among men.
• Is the cancer death rate going down?Yes. In the United States, the overall cancer death rate has declined since the early 1990s.
• Should I wait until my pain is bad before taking pain medicine?No—take pain medicine on schedule; the best way to control pain is to stop it from starting or getting worse.
• What are the benefits of joining a clinical trial?Possible benefits include helping future patients, access to a treatment under study, and close monitoring by the research team.
• What are the main risk factors for cancer?The most-studied risk factors include age, alcohol, tobacco, sunlight, radiation, obesity, diet, and several others.
• What are the side effects of cancer treatment?Side effects are problems that occur when cancer treatment affects healthy tissues or organs, and they vary from person to person.
• What are the side effects of hormone therapy?Side effects depend on the type of therapy and can differ for men and women, and often include hot flashes and fatigue.
• What are the signs of caregiver stress?Caregiver stress can cause fatigue, sleep problems, higher blood pressure, appetite or mood changes—see your doctor if changes last over two weeks.
• What are the two main types of lung cancer?The two main types of lung cancer are non-small cell lung cancer and small cell lung cancer.
• What are the two types of cells pancreatic cancer starts in?Pancreatic cancer can start in two kinds of cells in the pancreas: exocrine cells and neuroendocrine cells, such as islet cells.
• What are the types of cancer clinical trials?The main types are treatment, prevention, screening, and supportive or palliative care trials, each answering a different research question.
• What are the types of leukemia?Leukemia has several types, including acute and chronic forms defined by the blood cell involved and how fast the cancer grows.
• What are the types of radiation therapy?The two main types are external beam radiation and internal radiation, which can use a solid or liquid source.
• What can I do about taste changes during cancer treatment?Marinades, herbs, tart flavors, and non-metal utensils can help when cancer treatment changes how food tastes; changes often improve after treatment.
• What cancers does hormone therapy treat?Hormone therapy is used to treat prostate and breast cancers that use hormones to grow.
• What do positive and negative margins mean on a pathology report?A negative (clean) margin means no cancer cells at the edge of removed tissue; a positive (involved) margin means cancer cells were found there.
• What does cancer prevention mean?Cancer prevention is action taken to lower the chance of getting cancer, such as avoiding known causes and making healthy lifestyle changes.
• What does it mean to be a cancer survivor?A person is a cancer survivor from the time of diagnosis through the rest of life, including those living with cancer and those free of it.
• What does the stage of a cancer mean?The stage describes the extent of a cancer—how large the tumor is and whether it has spread—and helps doctors plan treatment.
• What does TNM staging mean?In the TNM system, T describes the main tumor, N describes nearby lymph nodes with cancer, and M describes whether the cancer has spread.
• What foods help with nausea during cancer treatment?Cold foods, bland starchy foods, and ginger foods and drinks are easy on the stomach and may ease nausea during treatment.
• What happens in a phase 1 clinical trial?In a phase 1 trial, researchers test whether a new treatment is safe, what its side effects are, and the highest dose people can tolerate, in a small group.
• What is a biopsy?A biopsy is a procedure in which a doctor removes a sample of abnormal tissue so a pathologist can examine it, often the only way to confirm cancer.
• What is a polyp in colorectal cancer?A polyp is a growth inside the colon or rectum, and colorectal cancer often begins as one of these growths.
• What is a stem cell transplant?A stem cell transplant restores blood-forming stem cells destroyed by high doses of chemotherapy or radiation therapy.
• What is graft-versus-host disease?Graft-versus-host disease can occur after a donor transplant when the donor's white blood cells attack the recipient's cells.
• What is immunotherapy?Immunotherapy is a type of cancer treatment that helps your immune system fight cancer.
• What is minimally invasive surgery?Minimally invasive surgery uses a few small cuts and a camera called a laparoscope, and usually has a shorter recovery than open surgery.
• What is targeted therapy?Targeted therapy is a cancer treatment that targets proteins that control how cancer cells grow, divide, and spread.
• What is the difference between a screening test and a diagnosis?Screening tests look for cancer in people without symptoms and are not meant to diagnose cancer; an abnormal result usually leads to more tests.
• What is the difference between benign and malignant tumors?Benign tumors do not spread into nearby tissue, while malignant (cancerous) tumors can invade nearby tissue and spread to distant parts of the body.
• What is the difference between Hodgkin and non-Hodgkin lymphoma?Hodgkin and non-Hodgkin lymphoma are the two main types of lymphoma; Hodgkin can often be cured, while the outlook for NHL depends on the specific type.
• What questions should I ask before joining a clinical trial?Ask about the trial's purpose, its risks and benefits, your rights and privacy, the costs, and how it could affect your daily life.
• What should I eat during cancer treatment?During treatment you often need extra protein and calories, so a good cancer diet may differ from a typical healthy diet.
• When should I see a doctor about possible cancer symptoms?See a doctor if symptoms do not get better after a few weeks; do not wait to feel pain, because cancer often does not cause pain.
• Where does breast cancer start?Breast cancer starts in the breast and can begin in the milk ducts, the milk-making lobules, the nipple, or other breast tissue.
• Where does cancer most often spread?Cancer can spread almost anywhere, but the most common sites are the bone, liver, and lung.
• Why does cancer treatment make you so tired?Cancer fatigue is extreme tiredness caused by the cancer, its treatments, and related side effects, and it isn't fully relieved by rest.
• Why does immunotherapy cause side effects?Immunotherapy side effects often happen when the revved-up immune system also acts against healthy cells.
• Why is metastatic breast cancer in the lung not called lung cancer?Metastatic cancer keeps the name of the original cancer, so breast cancer that spreads to the lung is called metastatic breast cancer, not lung cancer.
• Will I become addicted to pain medicine for cancer?Most people with cancer who take strong pain medicine use it safely; needing more or having withdrawal symptoms is not the same as addiction.
• Will I feel pain during cancer surgery?Anesthesia keeps you from feeling pain during surgery, though the cuts can be painful as they heal afterward.