American Cancer Society (ACS) Provides a wide range of materials on cancer; site includes the  Cancer Resource Center, a listing of separate ACS sites on many specific types of cancer;  general guidelines for prevention and early detection; and the annual statistical publication  Cancer Facts and Figures.

American Institute for Cancer Research Provides information on lifestyle and cancer prevention, especially nutrition.

Association of Cancer Online Resources Creates, hosts, and manages cancer-related mailing lists.

Canadian Cancer Society Provides general information about what cancer is and how to prevent it as well as materials about common cancers and resources for cancer patients and their families.

Cancer Care Provides help with medical information, counseling and referrals, and free educational materials.

Cancer Guide: Steve Dunn's Cancer Information Page Links to many good cancer resources on the Internet and advice about how to make best use of information.

Cancer News Provides links to news and information on many types of cancer.

CancerWEB Provides information on many different aspects of cancer research and treatment; site also includes an extensive,  searchable medical dictionary.

CDC Cancer Prevention and Control Includes information about CDC programs to prevent and control cancer, fact sheets about selected cancers, surveillance data, and an extensive set of links.

CDC National Center for Chronic Disease Prevention and Health Promotion: Cancer Provides general information about cancer risk factors and prevention.

Harvard Center for Cancer Prevention Provides a variety of resources and publications, including several major reports on cancer prevention. The report on Causes of Human Cancer includes separate sections on all major risk factors, including smoking, diet, obesity, genetic susceptibility, UV light, and infectious agents.

Memorial Sloan-Kettering Cancer Center Provides information about the prevention, detection, and treatment of many forms of cancer.

National Cancer Institute (NCI) Provides information on prevention, treatment options, screening, and clinical trials. Its  CancerNet site has information for both consumers and health professionals; the Surveillance, Epidemiology, and End Results (SEER) site has statistics on incidence and survival for different types of cancer. A searchable directory of cancer genetics specialists who are trained to provide genetic counseling is also available from the NCI.

National Comprehensive Cancer Network (NCCN) A network of cancer centers that develops standards of cancer care and provides patient information.

National Marrow Donor Program Provides information about becoming a marrow donor to help people with certain types of cancer and blood diseases.

New York Online Access to Health (NOAH): Cancer Provides information about cancer—causes, symptoms, types, treatments, clinical trials—and links to related sites.

Oncolink: The University of Pennsylvania Cancer Center Resources Contains information on different types of cancer and answers to frequently asked questions.

American Academy of Dermatology Provides information on skin cancer prevention.

American Lung Association: Lung Cancer Includes information about the causes detection, treatment, and prevention of lung cancer.

CDC National Colorectal Cancer Action Campaign Provides information about the development of colorectal cancer, advice about early screening tests, and links to related sites.

College of American Pathologists: Pap Smears Provides information about Pap smears and their role in the prevention of cervical cancer; a yearly e-mail reminder service is also available.

Harvard Center for Cancer Prevention: Colon Cancer Risk Index An online risk assessment for colon cancer that also provides lifestyle advice for preventing cancer.

Leukemia Society of America Provides educational materials, publications, and links to other resources about leukemia, lymphoma, Hodgkin's disease, and myeloma.

MelanomaNet An online melanoma resources for physicians and the general public.

National Cervical Cancer Coalition. Provides information about pap tests, pelvic exams, HPV infection, and the diagnosis and treatment of cervical cancer.

National Oral Health Information Clearinghouse: Special Care Publications Provides information about the effects of spit tobacco use and guidelines for detecting oral cancer.

National Prostate Cancer Coalition Includes links to information about prostate cancer and answers to frequently asked questions.

Prostate Pointers: Provides basic information about prostate cancer and links to support groups.

Susan Komen Foundation: Breast Health Provides information about breast cancer and about noncancerous breast conditions.

Testicular Cancer Resource Center Provides information and support, including materials on testicular self-exam, diagnosis, and treatment.

CDC Choose Your Cover Skin Cancer Prevention Initiative Provides facts about UV light and information about skin cancer prevention.

DES Action USA Provides information about DES and the health risks for DES daughters and sons.

Environmental Protection Agency/UV Index Includes information about the UV index and the effects of sun exposure, with links to sites with daily UV index ratings for cities in the United States and other countries.

FDA Consumer: Seven Steps to Safer Sunning Provides advice for safer sun practices and a description of a skin self-exam to help with early detection of skin cancer.

Genetics of Cancer Provides information to help people understand the genetic basis of cancer.

National Cancer Institute (NCI): 5-A-Day Program Provides information on the national "5 A Day For Better Health" program that promotes greater consumption of fruits and vegetables. The following related sites provide tips and recipes to help people eat more fruits and vegetables, information about nutrient content, and special resources for kids and educators:

National Human Genome Research Institute Provides information about the status and implications of the Human Genome Project, which is mapping the entire human genome. Additional information is available at the Web sites of the Department of Energy and the Oak Ridge National Laboratory. The National Library of Medicine has posted a map of the human genome.

National Oceanic and Atmospheric Administration (NOAA)/Environmental Protection Agency (EPA) Ultraviolet (UV) Index Provides information on UV index from over 50 monitoring stations throughout the United States; information on current UV index levels as well as yearly patterns are available.

National Safety Council Environmental Health Center: Hazardous Chemicals Provides fact sheets on many hazardous chemicals, including cancer-causing agents such as arsenic, benzene, and asbestos.

National Toxicology Program The federal program that creates an annual report listing those substances that are known or reasonably assumed to cause cancer in humans.

NLM National Center for Biotechnology Information: Genes and Disease—Cancer Provides information about the general role of genes in cancer as well as materials on specific types of cancer and specific genes.

USDA Food and Nutrition Information Center In addition to a general, searchable database for all foods, this site also has special  food composition data on carotenoids, trans fatty acids, isoflavones (soy products), and other nutrients of concern for cancer prevention.