What is Cancer?

Cancer is a disorder caused by the uncontrolled growth of abnormal cells in the body. It develops when the old cells do not die; instead, they grow out of control, resulting in the formation of abnormal cells. These extra cells form a mass of tissue, which is called a tumour. Tumors can be benign (non-cancerous) or malignant (cancerous). Malignant tumors can invade nearby tissues and can also break away and spread to other parts of the body.

There are more than 100 different types of cancer and their symptoms and treatment vary depending on their type and how advanced they are. A localized cancer is believed to be at an early stage, while one that has spread is at an advanced stage. Following are the common elements considered in most of the staging systems:

  • site of the primary tumor
  • number of tumors and size of the tumor
  • lymph node involvement
  • the presence or absence of metastasis
  • tumor grade ( how closely the cancer cells resemble normal tissue cells)

Following are the five main categories of cancer:

  • Carcinomas: Carcinoma is a type of cancer, which starts in cells that form the skin or the tissue lining the organs, such as kidney or liver. They occur when the DNA of a cell is altered or damaged and the cell starts to grow uncontrollably and become malignant. They are able to spread to other parts of the body, but not always.
  • Sarcomas: Sarcoma is a tumor, which affects the connective tissue. They occur in the fat, bone, muscle, cartilage or other connective tissues. Sarcomas are relatively rare type of cancer
  • Leukaemia: Leukaemia refers to a group of cancers, which develop in the bone marrow. It occurs when there is a problem with the formation of blood cells. It generally affects the white blood cells. It results in the over-production of abnormal white blood cells. White blood cells are the part of the immune system that defends the body against infection.
  • Lymphomas: Lymphoma is a cancer of the lymphatic system. The lymphatic system is part of the germ-fighting network of the body, which includes the lymph nodes, thymus gland, spleen and bone marrow. Lymphoma can affect all these areas as well as other organs all over the body.
  • Central Nervous System Cancers: Central nervous system tumor starts when the healthy cells in the spinal cord or brain change and grow out of control to form a mass. It is problematic as it affects the thought processes and movements of a person. It can be challenging to treat because the tissues around the tumor are usually important for the functioning of the body.

Signs and symptoms of cancer depend upon the part of the body which is affected by it. Some of the general signs linked with cancer include:

  • Fatigue, Low immunity
  • lump under the skin that can be felt
  • weight changes
  • skin changes
  • bowel changes
  • a persistent cough
  • trouble breathing
  • difficulty in swallowing
  • unexplained muscle or joint pain
  • unexplained fevers
  • unexplained bleeding

Cancer is caused by mutations (changes) to the DNA within cells which results in the abnormal functioning of cells.

Causes of Gene Mutations

  • Gene mutations that are inherited from parents: Very small percentage of cancer is caused by this type of mutations.
  • Gene mutations that occur after birth: Most of the gene mutations occur after the birth. Many of factors can cause gene mutations, such as viruses, smoking, radiation, cancer-causing chemicals, hormones, and obesity.

Gene mutations occur normally during normal cell growth but they are repaired by the cells. Rarely, a mistake is missed which causes the cell to become cancerous.

Cancer-Causing Agents Include

  • Chemical Carcinogens: There are several chemicals and environmental toxins, which can cause changes in normal cellular DNA. The substances responsible for causing DNA mutations are known as mutagens (mutagens, which cause cancers, are known as carcinogens). Tobacco smoking is linked to various types of cancer and in the same way, prolonged exposure to asbestos fibers is linked with mesothelioma.
  • Ionizing Radiations: Radiations arising from radon gas and prolonged exposure to UV radiation from the sun can result in melanoma and other skin malignancies. Radiation therapy given for the treatment of a type of cancer may cause another type of cancer.
  • Bacterial and Viral Infections: Certain cancers can be caused by infections with the microorganism. Common cancers that are caused by infections are liver cancers due to Hepatitis B and C infections; gastric or stomach cancer due to Helicobacter pylori infection, cervical cancer due to infections with Human Papilloma virus (HPV) and Epstein Barr virus causing Burkitt’s lymphoma.
  • Genetic Cancers: Breast cancer and ovarian cancer genes including BRCA1 and 2 are the common examples of genetic cancers. Li-Fraumeni syndrome includes defects in the p53 gene, which results in bone cancers, brain cancers, breast cancers, soft tissue sarcomas etc.
  • Hormonal Changes: Hormonal changes in excess can lead to several cancers. For instance, changes in the female hormone level estrogen promote uterine cancer.
  • Immune System Dysfunction: Impaired immunity including HIV infection results in several cancers including non-Hodgkin′s lymphoma, and HPV-associated malignancies.

Following factors are known to increase the risk of cancer:

  • Age: Usually the people who are diagnosed with cancer are 65 or older because cancer can take decades to develop. However, cancer is not an adult disease; it can be diagnosed at any age.
  • Habits: Certain lifestyle selections can increase the risk of cancer such as smoking, drinking excessive alcohol, excessive exposure to the sun and being obese.
  • Family History: A very small portion of cancers develop due to an inherited condition. If a person has cancer common in his family, then the possibility of mutations to pass from one generation to next increases.
  • Health Condition: Certain health conditions like ulcerative colitis can noticeably increase the risk of developing some types of cancers.
  • Environment: The environment around may contain harmful chemicals such as asbestos and benzene at your workplace, which can increase the risk of cancer.

Cancer diagnosis includes:

Cancer Screening

Diagnose of cancer at an early stage can provide the best chance for a cure. Ask your doctor about the appropriate screening tests for you depending on your risk factors for cancer.

Other Diagnosis

Cancer may be diagnosed by your doctor by using one or more approaches:

  • Physical Exam: Doctor may examine the areas of your body for lumps, which may indicate the presence of a tumor. Also, your doctor looks for abnormalities like changes in skin color, which may indicate the occurrence of cancer.
  • Laboratory Tests: Urine and blood tests may help the doctor to detect the abnormalities which may arise to the presence of cancer.
  • Imaging Tests: Imaging tests such as computerized tomography (CT) scan help the doctor to observe the bones and internal organs in a noninvasive way.
  • Biopsy: During a biopsy, a sample of cells is collected by the doctor for testing in the laboratory. In maximum cases, a biopsy is the only way to diagnose cancer.

Cancer Stages

Once a person is diagnosed with cancer, the doctor will work to verify its stage. Depending upon the stage of cancer, treatment options and chances for cure are determined.

There are many treatments for cancer and many of them involve the combination of therapies. Following are some of the cancer treatments:

  • Chemotherapy: Chemotherapy is usually used in combination with other treatments.
  • Radiotherapy: Radiotherapy uses high energy radiation to demolish or hinder the growth of cancer cells.
  • Surgery: Surgery is usually done in combination with chemotherapy and radiotherapy to ensure that all the cancer cells are removed from the body.
  • Immunotherapy: Immunotherapy is a drug treatment, which focuses on the immune system of the body to attack cancer.
  • Hormone therapy: Hormone therapy is commonly used for breast and prostate cancers. Sometimes, it involves the surgical removal of hormone-producing glands.

Preventing cancer by choosing a healthy lifestyle is one of the most effective ways to build a cancer-free future:

  • Avoid too much exposure to the sun: Harmful ultraviolet rays from the sun can elevate the risk of skin cancer.
  • Eat a healthy diet: Prefer to eat a diet rich in vegetables and fruits.
  • Exercise regularly: Regular exercise is associated to reduce the risk of cancer.
  • Maintain a healthy body weight: Obesity increases the risk of cancer.
  • Limit alcohol consumption: If you are a person who drinks alcohol often then limit your consumption.
  • Schedule cancer screening exams: Consult your doctor to know the cancer screening exams best for you. Talk about the immunizations that may help you to prevent cancer-causing viruses.