Introduction In 2012, the five most common cancers in men were lung, prostate, colorectal, gastric and liver cancers; in women, the five most common cancers were breast, colorectal, lung, cervical and gastric cancers. About one-third of cancer deaths are attributed to the following five major behavioral and dietary risks: height-body mass index, low fruit and vegetable intake, physical inactivity, tobacco use, and alcohol use. Tobacco use is responsible for about 20% of cancer deaths and about 70% of lung cancer deaths globally and is the most important cancer risk factor. Up to 20% of cancer deaths in low- and middle-income countries are attributed to viral infections such as HBV/HCV (hepatitis B and C) and HPV (human papillomavirus). More than 60% of the world’s new cancer cases each year occur in Africa, Asia, Central and South America. These regions account for 70% of global cancer deaths. The annual number of new cancer cases worldwide is expected to rise from 14 million in 2012 to 22 million in the next 20 years. Cancer is a large group of malignant diseases that can affect any part of the body, also called malignant tumors or neoplasms. A distinguishing feature of cancer is the rapid generation of abnormal cells, their growth beyond their normal boundaries, and their ability to invade adjoining parts of the body and spread to other organs, the latter of which is known as metastasis. Metastasis is the leading cause of cancer deaths. Cancer is the leading cause of death worldwide, totaling 8.2 million deaths in 2012. The most common types of cancer that cause cancer deaths: Causes of Cancer Cancer develops from a single cell. The transformation from a normal cell to a tumor cell is a multi-stage process, usually progressing from a precancerous lesion to a malignant tumor. These changes are the result of a combination of individual genetic factors and the following three types of exogenous carcinogens: Physical carcinogens, such as ultraviolet light and ionizing radiation Chemical carcinogens, such as components of asbestos, tobacco smoke, aflatoxin (a food contaminant), and arsenic (a drinking water contaminant) Biological carcinogens, such as certain viral, bacterial, or parasitic infections The WHO, through its Agency for Cancer Research (IARC) –The WHO, through its cancer research agency, the International Agency for Research on Cancer (IARC), classifies carcinogens. Ageing is another fundamental factor in the formation of cancer. The incidence of cancer increases significantly with age, mainly because specific cancer risk accumulation increases with age. Overall risk accumulation is the result of a major reduction in the effectiveness of cellular repair mechanisms with age. Cancer Risk Factors Tobacco use, alcohol use, unhealthy diet, and physical inactivity are major cancer risk factors worldwide. Some risk factors for chronic infections play a role in cancer development in low- and middle-income countries. Hepatitis B virus (HBV), hepatitis C virus (HCV) and some types of human papillomavirus (HPV) infections increase the risk of liver and cervical cancer, respectively. HIV (human immunodeficiency virus) infection greatly increases the risk of cancer such as cervical cancer. How can I reduce the burden of cancer? Knowing as much as possible about the causes of cancer and targeting interventions can broadly prevent and control the disease. Cancer can be effectively reduced and controlled by implementing evidence-based strategies for cancer prevention, early detection and management of cancer patients. Many types of cancer have a high chance of cure if detected early and treated adequately. HOW TO MODIFY AND AVOID RISK FACTORS More than 30% of cancer deaths can be prevented by modifying or avoiding the major risk factors, which include: Tobacco use Being overweight or obese Unhealthy diets, such as low intake of fruits and vegetables Lack of physical activity Alcohol consumption Sexually induced human papillomavirus (HPV) infections Hepatitis B virus (HBV) infections Ionizing and non-ionizing radiation (ultraviolet light) Urban air pollution Households Indoor smoke from solid fuel use Tobacco use is the most important risk factor for about 20% of global cancer deaths and about 70% of global lung cancer deaths. In many low-income countries, up to 20% of cancer deaths are due to hepatitis B virus and human papillomavirus infections. Cancer prevention strategies Avoid the risk factors listed above as much as possible Vaccination against human papillomavirus (HPV) and hepatitis B virus (HBV) Control of occupational hazards Reduction of exposure to non-ionizing radiation from sunlight (UV ultraviolet rays) Reduction of exposure to ionizing radiation (occupational or diagnostic medical imaging) Early detection of cancer Early detection and early treatment can be effective in reducing the mortality rate from cancer. Early detection includes the following 2 components: Early Diagnosis – Be alert for early signs and symptoms of cancers (e.g., skin, cervical, breast, colon, rectal, and oral cancers) for early diagnosis and early treatment. Early diagnosis is particularly important in situations where screening and treatment interventions cannot be implemented due to lack of effective screening methods or low resource allocation. Without any early detection, screening and therapeutic interventions, radical treatment is no longer an option for patients diagnosed at very late stages. Screening – The purpose of screening is to detect abnormal signs of specific cancers or pre-cancerous lesions through procedural tests that lead to referral for further testing or treatment, and is an effective strategy for the early diagnosis of cancer. Screening programs are particularly effective for common cancer types and include cost-effective, affordable, readily accepted, and available screening test methods that can be effective in reducing mortality in populations at risk for these cancers. Commonly used screening programs Visual inspection with acetic acid (VIA) screening for cervical cancer in low-resource settings HPV testing for cervical cancer PAP cytology testing for cervical cancer in medium- and high-resource settings Mammography screening for breast cancer in high-resource settings. Cancer Treatment A clear cancer diagnosis is essential for adequate and effective treatment, as the treatment plan for each cancer type includes one or more specific treatment modalities, such as surgery, radiation therapy, and chemotherapy. The primary goal of cancer treatment is to cure or greatly extend life. Improving the patient’s quality of life is also an important treatment goal, which can be accomplished through supportive or end-of-life care as well as psychological support. Early detection or cure of underlying cancers Some of the most common types of cancer have high cure rates if detected and treated early according to best practice guidelines, such as breast, cervical, oral cavity and colorectal cancers. Early detection or cure of certain cancers Certain types of cancer, even if they have metastasized, have high cure rates if appropriate treatment is provided, such as childhood leukemia and lymphoma, and testicular seminomas. Hospice care Hospice care is palliative treatment for symptoms caused by cancer; the goal is not a cure. Hospice care can help people live more comfortably; it is a humanitarian need for people with cancer and other fatal chronic diseases worldwide, especially those in advanced stages of the disease who have lost their chance for a cure. Physical, mental and spiritual problems can be relieved through hospice care for more than 90 percent of people with advanced cancer. Hospice Strategies Pain relief and hospice care are effective and essential public health strategies for low-income, including community- and home-based medical care patients and families. For the moderate to severe cancer pain experienced by more than 80% of patients with end-stage cancer, relaxation of control of oral morphine therapy is essential .