Introduction
Cancer is one of the most feared diseases, affecting millions of people worldwide. Interestingly, cancer is not a modern disease. Evidence of cancer has been found in ancient Egyptian mummies and described in ancient texts. However, the frequency of cancer has increased significantly in modern times, likely due to lifestyle changes, environmental factors, and increased life expectancy.
Despite its complexity, understanding the basics of cancer can empower individuals to take preventive measures and seek appropriate treatments. This article provides a simple overview of what cancer is, how it is caused, the types of cancer, and the various treatments available.
What is Cancer?
Cancer in simpler terms can be defined as the uncontrolled growth and spread of abnormal cells in the body. Normally, cells grow, divide, and die in an orderly fashion. This cycle is managed by the DNA present in the cell. The DNA is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide. Mistakes in these instructions (genetic mutation), disrupts the cell cycle which leads to uncontrolled growth of cells, resulting in the formation of a mass of tissue called a tumor. Tumors can be benign (non-cancerous) or malignant (cancerous). Malignant tumors invade nearby tissues and can spread to other parts of the body, a process known as metastasis.
Causes of Cancer
Cancer is primarily caused by genetic mutations. These mutations can be inherited from parents or acquired at a later stage in life. Acquired mutations are often a result of environmental factors such as:
Smoking: Tobacco smoke contains carcinogens that can damage DNA and lead to cancer.
Radiation: Ultraviolet rays from the sun and other sources of radiation can cause mutations.
Viruses: Certain viruses can insert their DNA into human cells, causing mutations.
Carcinogens: Chemicals in the environment, such as asbestos and benzene, can cause cancer.
Lifestyle Factors: Obesity, poor diet, lack of exercise, and excessive alcohol consumption can increase cancer risk
As society has industrialized, exposure to various carcinogens has increased. Modern lifestyles, with increased consumption of processed foods and sedentary habits, also contribute to the higher incidence of cancer today compared to ancient times.
Types of Cancer
There are >100 types of cancer and it can develop in almost any part of the body. Types of cancer are usually named for the organs or tissues where the cancers form. For example, lung cancer starts in the lung. Here are some common types:
Carcinomas: These cancers start in the skin or tissues that line internal organs. Examples include breast, lung, prostate, and colon cancer.
Sarcomas: These are cancers of the bone, cartilage, fat, muscle, blood vessels, or other connective tissues. Example includes Osteosarcoma, one of the most common cancer of bones.
Leukemias: These cancers begin in the blood-forming tissue of the bone marrow and do not form solid tumors. Instead, the abnormal white blood cells increase in the blood and bone marrow, crowding out normal blood cells. The low level of normal blood cells can make it difficult for the body to get adequate oxygen to it's tissues, control bleeding, or fight infections.
Lymphomas and Myelomas: These cancers begins when healthy cells of the immune system change and grow rapidly out of control.
Central Nervous System Cancers: These cancers start in the tissues of the brain and spinal cord.
Symptoms of Cancer
Cancer symptoms vary depending on the type and location of the cancer. Common symptoms include:
Lumps or thickening in the breast or other body parts that can be felt under skin
Unexplained weight loss
Persistent fatigue
Pain that does not go away
Changes in skin appearance, such as yellowing, darkening or redness of the skin, sores that won't heal, or changes to existing moles
Persistent cough, hoarseness, or troubled breathing
Persistent indigestion or discomfort after eating
Persistent, unexplained muscle or joint pain
Changes in bowel or bladder habits
Unusual bleeding or discharge
Diagnosis and Staging
Diagnosing cancer typically involves imaging tests, biopsies, and laboratory tests. Staging describes the size of the cancer and how far it has spread. The most common staging system is the TNM system:
T (Tumor): Size and extent of the primary tumor.
N (Node): Number of nearby lymph nodes that have cancer.
M (Metastasis): Whether the cancer has spread to other parts of the body.
Another common staging is the Number staging system: It uses the TNM system to divide cancers into four stages. Cancer stages range from I (small, localized cancers) to IV (advanced cancers that have spread).
Treatments for Cancer
Cancer treatment depends on the type, stage, and the location of the cancer, as well as the patient’s overall health. Common treatments include:
Surgery: Removal of the tumor and surrounding tissues.
Radiation Therapy: Using high-energy rays to kill cancer cells.
Chemotherapy: Using medicines to kill cancer cells or stop their growth.
Hormone Therapy: Blocking cancer cells from getting the hormones they need to grow.
Targeted Therapy: Using medicines or other substances to precisely identify and attack cancer cells.
Immunotherapy: Helping the immune system fight cancer.
Stem Cell Transplant: Replacing diseased bone marrow with healthy stem cells.
Prevention and Early Detection
Many cancer deaths can be prevented by avoiding risk factors such as smoking, maintaining a healthy diet, and exercising regularly. Early detection through screening tests like mammograms, colonoscopies, and PAP smears can catch cancer at an early stage when it is most treatable.
Make an appointment with the doctor if you have any persistent signs or symptoms that concern you. If you don't have any signs or symptoms, but are still worried about your risk of cancer, discuss your concerns with your doctor.
Conclusion
Cancer is a complex disease with many types and causes. Understanding what cancer is, how it develops, and the available treatments can help individuals take proactive steps in prevention and seek timely medical intervention. Advances in medical research continue to improve cancer diagnosis, treatment, and survival rates, offering hope to those affected by this disease.
Despite being an ancient disease, the increasing frequency of cancer in modern times highlights the importance of awareness and early detection. By making informed lifestyle choices and supporting ongoing research, we can work towards reducing the impact of cancer on our lives and communities.
References
Torre LA, Siegel RL, Ward EM, Jemal A. Global cancer incidence and mortality rates and trends--An update. Cancer Epidemiology Biomarkers & Prevention. 2015;25(1):16-27. doi:https://doi.org/10.1158/1055-9965.epi-15-0578
Roy PS, Saikia BJ. Cancer and cure: A critical analysis. Indian Journal of Cancer. 2016;53(3):441-442. doi:https://doi.org/10.4103/0019-509X.200658
Wang JJ ., Lei KF ., Han F. Tumor microenvironment: Recent advances in various cancer treatments. European Review for Medical and Pharmacological Sciences. 2018;22(12):3855-3864. doi:https://doi.org/10.26355/eurrev_201806_15270
Zaimy MA, Saffarzadeh N, Mohammadi A, et al. New methods in the diagnosis of cancer and gene therapy of cancer based on nanoparticles. Cancer Gene Therapy. 2017;24(6):233-243. doi:https://doi.org/10.1038/cgt.2017.16
Chene G, Lamblin G, Le Bail-Carval K, et al. Lucy’s cancer(s): A prehistorical origin? Gynecologie, Obstetrique & Fertilite. 2016;44(12):690-700. doi:https://doi.org/10.1016/j.gyobfe.2016.10.001
Dobosz P, Dzieciątkowski T. The Intriguing History of Cancer Immunotherapy. Frontiers in Immunology. 2019;10(2965). doi:https://doi.org/10.3389/fimmu.2019.02965
Hajdu SI. A note from history: Landmarks in history of cancer, part 1. Cancer. 2010;117(5):1097-1102. doi:https://doi.org/10.1002/cncr.25553
Acs B, Rantalainen M, Hartman J. Artificial intelligence as the next step towards precision pathology. Journal of Internal Medicine. 2020;288(1):62-81. doi:https://doi.org/10.1111/joim.13030
Cancer - Symptoms and causes. Mayo Clinic. Published April 27, 2021. https://www.mayoclinic.org/diseases-conditions/cancer/symptoms-causes/syc-20370588#:~:text=Cancer%20refers%20to%20any%20one
What is cancer? Cancer Research UK. Published December 16, 2014. https://www.cancerresearchuk.org/about-cancer/what-is-cancer#:~:text=Cancer%20is%20when%20abnormal%20cells
What Is Cancer? National Cancer Institute. Published October 11, 2021. https://www.cancer.gov/about-cancer/understanding/what-is-cancer
Cancer: Symptoms, Stages, Types & What It Is. Cleveland Clinic. Published September 8, 2021. https://my.clevelandclinic.org/health/diseases/12194-cancer
Cancer. World Health Organization. Published 2019. https://www.who.int/health-topics/cancer#tab=tab_1 Assessed and Endorsed by the MedReport Medical Review Board