Cancer is a disease distinguished by the uncontrolled proliferation of abnormal cells that can divide, infiltrate, and destroy normal body tissue and organs and eventually spread throughout the body. The generalized growth control mechanism of our body gets disrupted. As cells become increasingly abnormal, old or damaged cells survive when they should die, and new cells form where they are not needed. These extra atypical cells divide uncontrollably and form a mass of tissue called a tumor.
Cancer cells acquire these properties, typically by mutations in their relevant genes:
● Self-sufficient growth signals
● Insensitivity to growth-inhibitory signals
● Evasion of cell death
● Uncontrolled replicative potential
● Development of sustained angiogenesis, a process through which new blood vessels form from pre-existing vasculature
● Ability to invade and metastasize
Cancer is a genetic disease; that is, it may be inherited from our parents or be caused by changes in our genetics that control the way our cells function. These changes can arise during a person's lifetime because of damage to DNA caused by certain environmental exposures, such as UV radiation, smoking, viruses, chemicals, and radioactive materials.
Normal body DNA contains tumor suppressor genes that prevent cancer. However, cancer cells with damaged DNA do not have this gene, which leads to abnormal cell growth.
Cancer invades various parts of the body by a process called metastasis. The cancer cells break away from where they first formed and travel through the lymphatic system or blood vessels to different parts of the body. This metastatic tumor, which travels to any other body part, has the same name and cell type as the primary tumor.
Metastatic tumors can cause severe damage to bodily functions and have a high mortality rate.
There are many types of cancers. Cancer is named for the organs or tissues where the tumors are formed — brain cancer starts in the cells of the brain, and breast cancer starts in the cells of the breast.
Cancer can be divided into five categories:
It begins in the epithelial tissue of the skin or in the tissue that lines internal organs, glands, or body structures, e.g., kidneys, liver, or stomach. Thus, a malignant neoplasm emerging in the renal tubular epithelium is a carcinoma, as are the cancers arising in the skin and lining epithelium of the gut.
Carcinomas account for 85-90% of all cancers.
Types of carcinomas include:
○ Refers to a carcinoma featuring a microscopic glandular pattern.
● Squamous cell carcinoma.
○ Refers to carcinoma with features and characteristics showing squamous differentiation.
● Basal cell carcinoma
○ This refers to carcinoma triggered by exposure to ultraviolet radiation and develops in the basal cell layer of the skin.
● Adenosquamous carcinoma
○ Refers to a special type of heterogeneous tumor containing both adenocarcinoma and squamous cell carcinoma.
● Anaplastic carcinoma
○ This refers to a group of high-grade carcinomas that feature cells lacking distinct histology and cytology. These are also called as poorly differentiated or undifferentiated carcinoma.
Malignant tumors developing from connective tissues, such as cartilage, bones, muscles, are called sarcomas. Cancers of fibrous tissue origin are classified as fibrosarcoma, and a malignant neoplasm composed of bone cells is classified as osteosarcoma.
Lymphoma is the cancer of the lymphatic system, which produces white blood cells and cleans body fluids. The lymphatic system consists of the spleen, lymph nodes, thymus gland, and bone marrow.
It can be divided into two main categories:
● Hodgkin's lymphoma
● Non-Hodgkin's lymphoma
Leukemia, or blood cancer, is a cancer of bone marrow. Bone marrow produces blood cells, e.g., white blood cells, red blood cells, and platelets. The four main categories of leukemia are:
Myeloma is a cancer of the plasma cells of the bone marrow. Plasma cells help us fight infections by making antibodies against them.
● Old age
● Exposure to certain carcinogens, e.g., benzidine, betel nuts, etc.
● Unprotected sun exposure
● Radiation exposure
● Viruses (human papillomavirus) and bacterias
● Lack of physical activity
● Avoid alcohol and smoking
● Stay protected from the sun
○ Apply sunscreen
○ Cover exposed areas of your skin
○ Stay in the shade
○ Stay indoors when the sun's rays are the strongest, from 10 a.m. to 4 p.m.
● Eat a healthy, balanced diet
○ Eat plenty of fruits and vegetables
○ Limit processed meats
● Maintain a healthy weight and exercise daily for at least 15 minutes
● Get vaccinated against the viruses
● See your physician regularly so they can screen you. This increases your chances of diagnosing any possible cancers and treating them right away. Companies like https://www.shifa4u.com/ provide these screening tests. Lab tests, imaging, and radiology are done at discounted prices.
Surgery is the procedure in which a surgeon removes a tumor from the body.
● Radiation therapy
It is another treatment option that uses high doses of radiation to kill cancer cells and shrink tumors.
In chemotherapy, medication is used to kill cancer cells.
● Stem cell transplant
It is a procedure in which a patient receives healthy stem cells to replace damaged stem cells.
It is a kind of biological therapy that helps boost the body's natural defenses to fight cancer.
● Targeted drug therapy
It is a type of treatment in which drugs are designed to target specific cancer genes without affecting normal cells.