- PREVENTION OF CANCER
- SPREDING OF CANCER
- EFFECTS OF HORMONE
body is made up of cells. All cancers begin in cells, which are fundamental unit of life. To understand cancer, it’s useful to know what happens when normal cell become cancer cells. Your body is made up of several types of cells. These cells grow and produce more cells in a well-controlled manner, as they are needed to keep the body healthy. However, due to certain reasons this normal condition is interrupted, which leads to an abnormal behaviour by the cells, typically in one part/organ of the body, where cells continue to multiply and live beyond their lifespan. These are referred to as the ‘cancerous cells.’ Term ‘cancer’ is used to describe a medical condition, where there is:
- Abnormal & uncontrolled multiplication of the body cells
- Genesis is typically in one organ/part of the body
- These mutant cells can migrate and invade other parts of the body through blood and lymph
- Manifestation of the disease is the form of a tumour – a group of mutant cells that form a tissue
- These can affect all living cells in the body and at all ages in both genders
- The cause is multi-factorial and the disease process differs at different sites.
Signs and symptoms
The Symptoms of cancer metastasis depend on the location of the tumour.
When cancer begins it invariably produces no symptoms with signs and symptoms only appearing as the mass continues to grow or ulcerates. The findings that result depend on type and location of the cancer. Few symptoms are specific, with many of them also frequently occurring in individuals who have other conditions. Cancer is the new “great imitator”. Thus it is not uncommon for people diagnosed with cancer to have been treated for other diseases to which it was assumed their symptoms were due. Metastasis: Symptoms of metastasis are due to the spread of cancer to other locations in the body. They can include enlarged lymph nodes (which can be felt or sometimes seen under the skin and are typically hard), hepatomegaly (enlarged liver) or splenomegaly (enlarged spleen) which can be felt in the abdomen, pain or fracture of affected bones, and neurological symptoms.
MALIGNANT TUMOURS ARE CANCEROUS
Cells in these tumours can invade nearby tissues and spread to other parts of the body.
- The spread of cancer from one part of the body to another is called ‘metastasis’
- Most cancers are named after the organ or type of cell in which they originate. For example, cancer that begins in the stomach is called stomach cancer. The extent of the growth of cells lies in the originating tissue and its invasion to nearby lymph nodes and its spread to distant organs determines the seriousness, the impact and the line of treatment of the disease. This assessment is referred to as ‘staging’ of the cancer. Usually cancer of the blood and bone marrow such as leukemia do not form tumours.
WAYS TO PREVENT CANCER
Avoid smoking, whether it be actual smoking or second hand smoke, we hear a dozen times a day how bad cigarettes are for us. They also increase the risk of being diagnosed with lung cancer. Smoking is the most significant risk factor for cancers, and this can be reduced. Did you know that smoking can increase your risk of many other cancers?
Eat fruits and veggies: they are rich in antioxidants which help repair our damaged cells. Green veggies, orange and yellow fruits, and other vegetables are your best bet.
Limit your alcohol intake: Drinking excessive amounts of alcohol regularly increases your risk factor for cancer. Studies suggest that men who consume 2 alcoholic drinks per day and women, who have 1 alcoholic drink per day, significantly increase their risk factors for certain types of cancer.
Exercise for cancer prevention: Being overweight greatly increases your risk factor for developing cancer. So, exercising to maintain or reaching your ideal weight is one of the best defences against cancer.
Practice safe sex: Unsafe sex can result in the infection of the HPV virus, a known cause for cervical cancer and a risk factor for many other cancers. HPV is a virus transmitted through sexual intercourse.
How cancer spreads
Scientists reported in Nature Communications that they have discovered an important clue as to why cancer cells spread. It has something to do with their adhesion properties. Certain molecular interactions between cells and the scaffolding that holds them in place (extracellular matrix) cause them to become unstuck at the original tumour site, they become dislodged, move on and then reattach themselves at a new site.
The researchers say this discovery is important because cancer mortality is mainly due to metastatic tumors, those that grow from cells that have traveled from their original site to another part of the body. Only approx10% of cancer deaths are caused by the primary tumours. The scientists, say that finding a way to stop cancer cells from sticking to new sites could interfere with metastatic disease, and halt the growth of secondary tumours.
What causes cancer
Cancer is ultimately the result of cells that uncontrollably grow and do not die. Normal cells in the body follow an orderly path of growth, division, and death. Programmed cell death is called apoptosis, and when this process breaks down, cancer begins to form. Unlike regular cells, cancer cells do not experience programmatic death and instead continue to grow and divide. This leads to a mass of abnormal cells that grows out of control.
Cancers are primarily an environmental disease with 90–95% of cases attributed to environmental factors and 5–10% due to genetics. Environmental, as used by cancer researchers, means any cause that is not inherited genetically, not merely pollution. Common environmental factors that contribute to cancer death include tobacco, diet and obesity, infections, radiation, stress, lack of physical activity, and environmental pollutants.
It is nearly impossible to prove what caused a cancer in any individual, because most cancers have multiple possible causes. For example, if a person who uses tobacco heavily develops lung cancer, then it was probably caused by the tobacco use, but since everyone has a small chance of developing lung cancer as a result of air pollution or radiation, then there is a small chance that the cancer developed because of air pollution or radiation.
Up to 10% of invasive cancers are related to radiation exposure, including both ionizing radiation and non-ionizing ultraviolet radiation. Additionally, the vast majority of non-invasive cancers are non-melanoma skin cancers caused by non-ionizing ultraviolet radiation.
Further information: Alcohol and cancer and Smoking and cancer the incidence of lung cancer is highly correlated with smoking. Cancer pathogenesis is traceable back to DNA mutations that impact cell growth & metastasis. Substances that cause DNA mutations are known as mutagens, and mutagens that cause cancers are known as carcinogens. Particular substances have been linked to specific types of cancer. Tobacco smoking is associated with many forms of cancer, and causes approximately 90% of lung cancer.
Some hormones play a role in the development of cancer by promoting cell proliferation. Insulin-like growth factors and their binding proteins play a key role in cancer cell proliferation, differentiation and apoptosis, suggesting possible involvement in carcinogenesis.
Hormones are important agents in sex-related cancers such as cancer of the breast, endometrium, prostate, ovary, and testis, and also of thyroid cancer and bone cancer. For example, the daughters of women who have breast cancer have significantly higher levels of estrogen and progesterone than the daughters of women without breast cancer.
Most cancers are initially recognized either because of the appearance of signs or symptoms or through screening. Neither of these lead to a definitive diagnosis, which requires the examination of a tissue sample by a pathologist. People with suspected cancer are investigated with medical tests. These commonly include blood tests, X-rays, CT scans and endoscopy.
Further information: List of cancer types and List of oncology-related terms Cancers are classified by the type of cell that the tumour cells resemble and are therefore presumed to be the origin of the tumour. These types include:
Carcinoma: Cancers derived from epithelial cells. This group includes many of the most common cancers, particularly in the aged, and include nearly all those developing in the breast, prostate, lung, pancreas, and colon.
Sarcoma: Cancers arising from connective tissue (i.e. bone, cartilage, fat, nerve), each of which develop from cells originating in mesenchymal cells outside the bone marrow.
Blastoma: Cancers derived from immature “precursor” cells or embryonic tissue. Blastomas are more common in children than in older adults.
Benign tumours (which are not cancers) are named using -oma as a suffix with the organ name as the root. For example, a benign tumour of smooth muscle cells is called a leiomyoma (the common name of this frequently occurring benign tumour in the uterus is fibroid). Confusingly, some types of cancer use the -noma suffix, examples including melanoma and seminoma. Some types of cancer are named for the size and shape of the cells under a microscope, such as giant cell carcinoma, spindle cell carcinoma, and small-cell carcinoma.
Vaccines have been developed that prevent some infection by some viruses. Human papillomavirus vaccine decreases the risk of developing cervical cancer. The hepatitis B vaccine prevents infection with hepatitis B virus and thus decreases the risk of liver cancer.
Surgery is the primary method of treatment of most isolated solid cancers and may play a role in palliation and prolongation of survival. In localized cancer surgery typically attempts to remove the entire mass along with, in certain cases, the lymph node in the area. For some types of cancer this is all that is needed to eliminate the cancer.