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Summary
Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms new cells as you need them, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don't need them, and old cells don't die when they should. These extra cells can form a mass called a tumor. Tumors can be benign or malignant. Benign tumors aren't cancer while malignant ones are. Cells from malignant tumors can invade nearby tissues. They can also break away and spread to other parts of the body.
Cancer is not just one disease but many diseases. There are more than 100 different types of cancer. Most cancers are named for where they start. For example, lung cancer starts in the lung, and breast cancer starts in the breast. The spread of cancer from one part of the body to another is called metastasis. Symptoms and treatment depend on the cancer type and how advanced it is. Most treatment plans may include surgery, radiation and/or chemotherapy. Some may involve hormone therapy, immunotherapy or other types of biologic therapy, or stem cell transplantation.
NIH: National Cancer Institute
Diagnosis and Tests
- Cancer Screening Overview (National Cancer Institute) Also in Spanish
- Cancer Staging (National Cancer Institute) Also in Spanish
- Computed Tomography (CT) Scans and Cancer (National Cancer Institute) Also in Spanish
- Exams and Tests for Cancer (American Cancer Society) Also in Spanish
- Fine Needle Aspiration (American Academy of Otolaryngology--Head and Neck Surgery)
- How Cancer is Diagnosed (National Cancer Institute) Also in Spanish
- Karyotype Genetic Test (National Library of Medicine) Also in Spanish
- Lactate Dehydrogenase (LDH) Test (National Library of Medicine) Also in Spanish
- Pathology Reports (National Cancer Institute) Also in Spanish
- Sentinel Lymph Node Biopsy (National Cancer Institute) Also in Spanish
- Tumor Grade (National Cancer Institute) Also in Spanish
- Tumor Marker Tests (National Library of Medicine) Also in Spanish
- Tumor Markers (National Cancer Institute) Also in Spanish
Prevention and Risk Factors
- Antioxidants and Cancer Prevention (National Cancer Institute) Also in Spanish
- Cancer Prevention Overview (National Cancer Institute) Also in Spanish
- Diet Choices to Prevent Cancer (American Academy of Family Physicians) Also in Spanish
- How Is Cancer Risk Measured? (National Cancer Institute) Also in Spanish
- Lowering Your Cancer Risk: Healthy Living for Cancer Prevention (National Institutes of Health) Also in Spanish
- Risk Factors (National Cancer Institute)
Treatments and Therapies
- A to Z List of Cancer Drugs (National Cancer Institute)
- Adjuvant Therapy: Treatment to Keep Cancer from Returning (Mayo Foundation for Medical Education and Research) Also in Spanish
- Angiogenesis Inhibitors (National Cancer Institute) Also in Spanish
- Cancer Alternative Therapies: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Cancer Chemotherapy: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Cancer Immunotherapy: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Cancer Surgery: Physically Removing Cancer (Mayo Foundation for Medical Education and Research) Also in Spanish
- Drugs Approved for Solid Tumors Anywhere in the Body (National Cancer Institute)
- Finding Cancer Care (National Cancer Institute) Also in Spanish
- Hyperthermia to Treat Cancer (National Cancer Institute) Also in Spanish
- Immunotherapy to Treat Cancer (National Cancer Institute) Also in Spanish
- Lasers to Treat Cancer (National Cancer Institute) Also in Spanish
- Photodynamic Therapy to Treat Cancer (National Cancer Institute)
- Radiation Therapy: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Support for People with Cancer: Cancer Pain Control (National Cancer Institute) - PDF
- Targeted Therapy to Treat Cancer (National Cancer Institute) Also in Spanish
- Treatment Option Overview (Carcinoma of Unknown Primary) (National Cancer Institute) Also in Spanish
- Treatment Option Overview (Extragonadal Germ Cell Tumors) (National Cancer Institute) Also in Spanish
- When Cancer Spreads: Improving Treatments for Metastasis (National Institutes of Health) Also in Spanish
Living With
- Cancer--Living with Cancer: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
Related Issues
- Adjusting to Cancer (National Cancer Institute) Also in Spanish
- Cancer Causes: Popular Myths about the Causes of Cancer (Mayo Foundation for Medical Education and Research) Also in Spanish
- Cancer Clusters (National Cancer Institute) Also in Spanish
- Chemicals in Meat Cooked at High Temperatures and Cancer Risk (National Cancer Institute) Also in Spanish
- Common Cancer Myths and Misconceptions (National Cancer Institute) Also in Spanish
- Cruciferous Vegetables and Cancer Prevention (National Cancer Institute) Also in Spanish
- Emotions and Cancer (National Cancer Institute) Also in Spanish
- Fluoridated Water (National Cancer Institute) Also in Spanish
- Hair Dyes, Other Hair Products, and Cancer Risk (National Cancer Institute) Also in Spanish
- Informal Caregivers in Cancer (National Cancer Institute) Also in Spanish
- Obesity and Cancer (National Cancer Institute) Also in Spanish
- Paraneoplastic Syndromes (National Institute of Neurological Disorders and Stroke)
- Physical Activity and Cancer (National Cancer Institute) Also in Spanish
- Stay Away from Tobacco (American Cancer Society) Also in Spanish
- Stress and Cancer (National Cancer Institute) Also in Spanish
- Vaccinations and Flu Shots for People with Cancer (American Cancer Society) Also in Spanish
- Vitamin D and Cancer Prevention (National Cancer Institute) Also in Spanish
- When Cancer Returns (National Cancer Institute)
Specifics
- General Information about Extragonadal Germ Cell Tumors (National Cancer Institute)
- Metastatic Cancer: When Cancer Spreads (National Cancer Institute) Also in Spanish
- Occupational Cancer (National Institute for Occupational Safety and Health)
Genetics
- BAP1 tumor predisposition syndrome: MedlinePlus Genetics (National Library of Medicine)
- Bloom syndrome: MedlinePlus Genetics (National Library of Medicine)
- Cowden syndrome: MedlinePlus Genetics (National Library of Medicine)
- DICER1 syndrome: MedlinePlus Genetics (National Library of Medicine)
- Genetic Testing for Hereditary Cancer Susceptibility Syndromes (National Cancer Institute)
- Genetics of Cancer (National Cancer Institute) Also in Spanish
- Peutz-Jeghers syndrome: MedlinePlus Genetics (National Library of Medicine)
- Rhabdoid tumor predisposition syndrome: MedlinePlus Genetics (National Library of Medicine)
- Understanding Genetic Testing for Cancer Risk (American Cancer Society) Also in Spanish
- Werner syndrome: MedlinePlus Genetics (National Library of Medicine)
Videos and Tutorials
- Understanding Cancer Prognosis (National Cancer Institute)
Statistics and Research
- About Cancer Clinical Research (National Cancer Institute) Also in Spanish
- Annual Report to the Nation on the Status of Cancer, 1975-2014, Featuring Survival (National Cancer Institute)
- Beyond Basic Blood Tests: A Window Into Your Health (National Institutes of Health) Also in Spanish
- Cancer Care Gets Personal: How Tumor Treatments Are Changing (National Institutes of Health) Also in Spanish
- Cancer Care Widens Its Reach: Reducing Cancer Health Disparities (National Institutes of Health) Also in Spanish
- Cancer Clinical Trials at the National Institutes of Health Clinical Center (National Cancer Institute) Also in Spanish
- Cancer Data and Statistics (Centers for Disease Control and Prevention)
- Cancer Statistics (National Cancer Institute) Also in Spanish
- NIH Study Offers Insight into Why Cancer Incidence Increases with Age (National Institute of Environmental Health Sciences)
- Obesity and Cancer (Centers for Disease Control and Prevention) Also in Spanish
- State Cancer Profiles (National Cancer Institute)
- Statistics and Graphs: Cancer Survivorship (National Cancer Institute)
Clinical Trials
- Clinical Trials Information for Patients and Caregivers (National Cancer Institute) Also in Spanish
- ClinicalTrials.gov: Carcinoma (National Institutes of Health)
- ClinicalTrials.gov: Neoplasms (National Institutes of Health)
Reference Desk
- Dictionary of Cancer Terms (National Cancer Institute) Also in Spanish
- National Cancer Institute News (National Cancer Institute)
Find an Expert
- American Cancer Society
- Choosing a Cancer Doctor (American Cancer Society) Also in Spanish
- National Cancer Institute Also in Spanish
- NCI - Designated Cancer Centers (National Cancer Institute) Also in Spanish
- Organizations that Offer Cancer Support Services (National Cancer Institute) Also in Spanish
Children
- Cancer in Children: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Childhood Adrenocortical Carcinoma Treatment (National Cancer Institute) Also in Spanish
- Childhood Carcinoma of Unknown Primary Treatment (National Cancer Institute) Also in Spanish
- Childhood Cardiac (Heart) Tumors Treatment (National Cancer Institute) Also in Spanish
- Childhood Midline Tract Carcinoma with NUT Gene Changes Treatment (National Cancer Institute) Also in Spanish
- Childhood Multiple Endocrine Neoplasia (MEN) Syndromes Treatment (National Cancer Institute) Also in Spanish
Men
- Cancer and Men (Centers for Disease Control and Prevention) Also in Spanish
Women
- Cancer and Women (Centers for Disease Control and Prevention) Also in Spanish
Patient Handouts
- Cancer (Medical Encyclopedia) Also in Spanish
- Cancer and lymph nodes (Medical Encyclopedia) Also in Spanish
- Cancer treatment - preventing infection (Medical Encyclopedia) Also in Spanish
- Cancer treatment -- early menopause (Medical Encyclopedia) Also in Spanish
- Cancer treatments (Medical Encyclopedia) Also in Spanish
- How to research cancer (Medical Encyclopedia) Also in Spanish
- How to tell your child that you have cancer (Medical Encyclopedia) Also in Spanish
- Hyperthermia for treating cancer (Medical Encyclopedia) Also in Spanish
- Laser therapy for cancer (Medical Encyclopedia) Also in Spanish
- Photodynamic therapy for cancer (Medical Encyclopedia) Also in Spanish
- Targeted therapies for cancer (Medical Encyclopedia) Also in Spanish
- Understanding your cancer prognosis (Medical Encyclopedia) Also in Spanish
- Your cancer care team (Medical Encyclopedia) Also in Spanish
- Your cancer diagnosis - Do you need a second opinion? (Medical Encyclopedia) Also in Spanish