All About Cancer | causes, types, treatments, symtoms, prevention

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues.

Cancer is a process – a series of events that begin at the molecular level in the human body and continue through a journey that patients and health care providers must take to deal with the personal and medical ramifications of this disease.
When cancer develops, there is an orderly process breaks down. As cells become more and more abnormal, old or damaged cells survive when they should die, and new cells form when they are not needed. These extra cells can divide without stopping and may form growths called tumors.

In the most basic terms, cancer refers to cells that grow out-of-control and invade other tissues. Cells become cancerous due to the accumulation of defects, or mutations, in their DNA.
For various possible reasons, cells that were once healthy undergo changes that trigger them to multiply uncontrollably.

What Causes Cancer?

 Cancer is a complex group of diseases with many possible causes. In this section you can learn more about the known causes of cancer, including genetic factors; lifestyle factors such as tobacco use, diet, and physical activity; certain types of infections; and environmental exposures to different types of chemicals and radiation.

It is not generally possible to prove what caused a particular cancer, because the various causes do not have specific fingerprints.
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, the cancer may have developed for one of those reasons. Excepting the rare transmissions that occur with pregnancies and occasional organ donors, cancer is generally not a transmissible disease.

The majority of cancers, some 90–95% of cases, are due to environmental factors. The remaining 5–10% are due to inherited genetics.Environmental, as used by cancer researchers, means any cause that is not inherited genetically, such as lifestyle, economic and behavioral factors and not merely pollution.

Common environmental factors that contribute to cancer death include tobacco (25–30%), diet and obesity (30–35%), infections (15–20%), radiation (both ionizing and non-ionizing, up to 10%), stress, lack of physical activity and environmental pollutants.

• Genetics and Cancer

Some types of cancer run in certain families, but most cancers are not clearly linked to the genes we inherit from our parents. Gene changes that start in a single cell over the course of a person's life cause most cancers. In this section you can learn more about the complex links between genes and cancer.

Family Cancer : Syndromes Cancer is such a common disease that it is no surprise that many families have at least a few members who have had cancer. Sometimes, certain types of cancer seem to run in some families. But only a small portion of all cancers are inherited. This document focuses on those cancers.

Genes and Cancer : Advances in genetics and molecular biology have improved our knowledge of the inner workings of cells, the basic building blocks of the body. Here we review how cells can change during a person’s life to become cancer, how certain types of changes can build on inherited gene changes to speed up the development of cancer, and how this information can help us better prevent and treat cancer.

• Smoking and Cancer

 Smoking as now been Proofed to be the biggest preventable cause of cancer. Thanks to years of research, the links between smoking and cancer are now very clear. Smoking accounts for more than 1 in 4 UK cancer deaths, 2 in 4 Nigeria and nearly a Fifth of all Cancer cases. The good news is that many of these deaths are preventable, by giving up smoking. Speak to your GP or pharmacist

The main way that smoking causes cancer is by damaging our DNA, including key genes that protect us against cancer. Many of the chemicals found in cigarettes have been shown to cause DNA damage, including benzene, polonium-210, benzo(a)pyrene and nitrosamines.

This is already bad news, but it’s made worse by other chemicals in cigarettes. For example chromium makes poisons like benzo(a)pyrene stick more strongly to DNA, increasing the chances of serious damage. And chemicals like arsenic and nickel interfere with pathways for repairing damaged DNA. This makes it even more likely that damaged cells will eventually turn cancerous.

Smokers are also less able to handle toxic chemicals than those with healthy lungs and blood. Chemicals in cigarette smoke make it harder for smokers to neutralize or remove toxins, and can make their immune systems less effective too.

How long does it take for smoking to cause cancer? It usually takes many years, or decades, for the DNA damage from smoking to cause cancer. Our bodies are designed to deal with a bit of damage but it’s hard for the body to cope with the number of harmful chemicals in tobacco smoke. Each cigarette can damage DNA in many lung cells, but it is the build up of damage in the same cell that can lead to cancer. However research has shown that for every 15 cigarettes smoked there is a DNA change which could cause a cell to become cancerous. This is why it’s better to give up smoking sooner rather than later.

• Sun and UV

Overexposure to ultraviolet (UV) radiation from the sun or sunbeds is the main cause of skin cancer. In the UK more than 8 in 10 cases of melanoma, the most serious type of skin cancer, could be prevented through enjoying the sun safely and avoiding sunburn.

What is UV?  (UV) radiation is a form of electromagnetic radiation. The main source of UV radiation (rays) is the sun, although it can also come from man-made sources such as tanning beds and welding torches. There are 2 main types of UV rays that damage our skin. Both types can cause skin cancer:

=> UVB is responsible for the majority of sunburns.
=> UVA penetrates deeper into the skin. It ages the skin, but contributes much less towards sunburn.

A third type of UV ray, UVC, is the most dangerous of all, but it is completely blocked out by the ozone layer and doesn’t reach the earth's surface.
Sunbeds give off UVA and UVB, but the mixture of the two is usually different to natural sunlight and the UV is often much stronger.

How those Sun cause Cancer: Sunlight is the main source of UV radiation, even though UV rays make up only a small portion of the sun’s rays. About 95% of the UV rays from the sun that reach the earth are UVA rays, with the remaining 5% being UVB rays. The strength of the UV rays reaching the ground depends on a number of factors, such as

• Time of day
•  Season of the year
•  Distance from the equator (latitude)
•  Altitude, Clouds, Reflection off surfaces
•  Contents of the air 

Sunburn is a clear sign that the DNA in your skin cells has been damaged by too much UV radiation. Getting painful sunburn, just once every 2 years, can triple your risk of melanoma skin cancer. Sunburn doesn’t have to be raw, peeling or blistering. If your skin has gone pink or red in the sun, it’s sun-burnt.

Sunburn is caused by UV from the sun. You can’t feel UV rays – the heat from the sun comes from infrared rays, which can’t burn you. This is why people can still burn on cool days.

• Air Pollution

Air pollution is a mixture of many different substances (solid particles and gases in the air)and the exact contents vary depending on what sources of pollution are nearby, your location, the time of year and even the weather. Sources of air pollution can be man-made, such as Vehicles emissions, chemicals from factories, dust, pollen and smoke from burning fuels. While others, such as North African desert dust and radon gas, are natural.

Air pollution is associated with an increased risk of lung cancer. Although the increased risk of cancer is small for individuals, because everyone is exposed to some air pollution

How big are We at risk? The risk depends on the level of air pollution people are regularly exposed to, but it’s hard to say exactly how much the risk is affected for the people living in a certain area. One of the best understood air pollutants is PM2.5, the risk of developing lung cancer increases as the level of PM2.5 increases.

• Alcohol

The less alcohol you drink, the lower the risk of cancer. No type of alcohol is better or worse than another, it is the alcohol itself that leads to the damage, regardless of whether it is in wine, beer or spirits.
Drinking lots of alcohol can damage the cells of the liver, causing a disease called cirrhosis. Cirrhosis can make you more likely to develop liver cancer. Alcohol can also cause highly reactive molecules, called Reactive Oxygen Species (ROS), to be produced in our cells. These molecules can damage the DNA, which could cause cancer to develop.

Drinking and Smoking will be for ever damage your health. Some even take the Two together which will lead into worse situation or cancer condition.

Why is it worse to both drink and smoke? The Answer is simply because Tobacco and Alcohol work together to damage the cells of the body. (alcohol makes it easier for the mouth and throat to absorb the cancer-causing chemicals in tobacco) So this is why you have to stop smoking and drinking Today. Smoke and drink will only multiply your high risk for the deadly Cancer.

Facts about Alcohol

• Alcohol is one of the most well-established causes of cancer
• Alcohol increases the risk of mouth, upper throat, voice box and food pipe cancers
• Breast cancer risk is increased with alcohol
• Liver cancer risk is increased with alcohol
• Bowel cancer risk is increased with alcohol
• Alcohol could cause cancer in many ways
• Smoking and drinking together further increases cancer risk
• All types of alcohol increase cancer risk
• Stick within the guidelines if you drink alcohol
• Cutting down on alcohol can reduce cancer risk
• Drinking during pregnancy may increase cancer risk in children

We are Not saying everyone who drinks alcohol will develop Cancer. But scientists have found that some cancers are more common in people who drink more alcohol than others. Alcohol causes almost 12% of cancer in most Africa Countries Every Year.

Prevention of Cancer

Basically the most proving way of preventing Cancer is to say away form it causes which as been highlighted Above. 

• Many cancers can be prevented by not
• Smoking,
• Maintaining a healthy weight,
• Not drinking too much alcohol,
• Eating plenty of vegetables,
• Fruits and whole grains,
• Vaccination against certain infectious diseases,
• Not eating too much processed and red meat,
• and avoiding too much sunlight exposure.

Cancer is often treated with some combination of radiation therapy, surgery, chemotherapy, and targeted therapy. Pain and symptom management are an important part of care.

Possible signs and symptoms include

Cancer symptoms and signs depend on the specific type and grade of cancer; although general signs and symptoms are not very specific.

• fatigue,
• unexplained weight loss,
• pain,
• skin changes,
• a lump,
• fever,
• abnormal bleeding,
• change in bowel or bladder function,
• unusual bleeding,
• persistent cough or voice change,
• prolonged cough,
• tissue masses
• change in bowel movements.

While these symptoms may indicate cancer, they may have other causes. Over 100 cancers affect humans.

There are more than 200 types of cancer. Each one is caused as a result of genetic or environmental changes, or both. Because each type of cancer is so different, it is not likely there will ever be a single screening or diagnostic test or treatment for all types. There is a wide array of treatments available. Increasingly, treatments are becoming more targeted to a specific type of cancer. With advances in molecular oncology – the study of the molecular mechanisms of cancer – and human genetics research, we will be moving more and more into the era of individualized testing and treatment for cancer.

List of cancer types in alphabetical ordered

Types of Cancer

A
Acute lymphoblastic leukemia (ALL)
Acute myeloid leukemia
Adrenocortical carcinoma
AIDS-related cancers
AIDS-related lymphoma
Anal cancer
Appendix cancer
Astrocytoma, childhood cerebellar or cerebral

B
Basal-cell carcinoma
Bile duct cancer, extrahepatic (see cholangiocarcinoma)
Bladder cancer
Bone tumor, osteosarcoma/malignant fibrous histiocytoma
Brainstem glioma
Brain cancer
Brain tumor, cerebellar astrocytoma
Brain tumor, cerebral astrocytoma/malignant glioma
Brain tumor, ependymoma
Brain tumor, medulloblastoma
Brain tumor, supratentorial primitive neuroectodermal tumors
Brain tumor, visual pathway and hypothalamic glioma
Breast cancer
Bronchial adenomas/carcinoids
Burkitt's lymphoma

C
Carcinoid tumor, childhood
Carcinoid tumor, gastrointestinal
Carcinoma of unknown primary
Central nervous system lymphoma, primary
Cerebellar astrocytoma, childhood
Cerebral astrocytoma/malignant glioma, childhood
Cervical cancer
Childhood cancers
Chondrosarcoma
Chronic lymphocytic leukemia
Chronic myelogenous leukemia
Chronic myeloproliferative disorders
Colon cancer
Cutaneous T-cell lymphoma

D
Desmoplastic small round cell tumor

E
Endometrial cancer
Ependymoma
Epitheliod Hemangioendothelioma (EHE)
Esophageal cancer
Ewing's sarcoma in the Ewing family of tumors
Extracranial germ cell tumor, childhood
Extragonadal germ cell tumor
Extrahepatic bile duct cancer
Eye cancer, intraocular melanoma
Eye cancer, retinoblastoma
Epidemics of Cancer

G
Gallbladder cancer
Gastric (stomach) cancer
Gastrointestinal carcinoid tumor
Gastrointestinal stromal tumor (GIST)
Germ cell tumor: extracranial, extragonadal, or ovarian
Gestational trophoblastic tumor
Glioma of the brain stem
Glioma, childhood cerebral astrocytoma
Glioma, childhood visual pathway and hypothalamic
Gastric carcinoid

H
Hairy cell leukemia
Head and neck cancer
Heart cancer
Hepatocellular (liver) cancer
Hodgkin lymphoma
Hypopharyngeal cancer
Hypothalamic and visual pathway glioma, childhood

I
Intraocular melanoma
Islet cell carcinoma (endocrine pancreas)

K
Kaposi sarcoma
Kidney cancer (renal cell cancer)

L
Laryngeal cancer
Leukaemias
Leukaemia, acute lymphoblastic (also called acute lymphocytic leukaemia)
Leukaemia, acute myeloid (also called acute myelogenous leukemia)
Leukaemia, chronic lymphocytic (also called chronic lymphocytic leukemia)
Leukemia, chronic myelogenous (also called chronic myeloid leukemia)
Leukemia, hairy cell
Lip and oral cavity cancer
Liposarcoma
Liver cancer (primary)
Lung cancer, non-small cell
Lung cancer, small cell
Lymphomas
Lymphoma, AIDS-related
Lymphoma, Burkitt
Lymphoma, cutaneous T-Cell
Lymphoma, Hodgkin
Lymphomas, Non-Hodgkin (an old classification of all lymphomas except Hodgkin's)
Lymphoma, primary central nervous system

M
Macroglobulinemia, Waldenström
Male breast cancer
Malignant fibrous histiocytoma of bone/osteosarcoma
Medulloblastoma, childhood
Melanoma
Melanoma, intraocular (eye)
Merkel cell cancer
Mesothelioma, adult malignant
Mesothelioma, childhood
Metastatic squamous neck cancer with occult primary
Mouth cancer
Multiple endocrine neoplasia syndrome, childhood
Multiple myeloma/plasma cell neoplasm
Mycosis fungoides
Myelodysplastic syndromes
Myelodysplastic/myeloproliferative diseases
Myelogenous leukemia, chronic
Myeloid leukemia, adult acute
Myeloid leukemia, childhood acute
Myeloma, multiple (cancer of the bone-marrow)
Myeloproliferative disorders, chronic
Myxoma

N
Nasal cavity and paranasal sinus cancer
Nasopharyngeal carcinoma
Neuroblastoma
Non-Hodgkin lymphoma
Non-small cell lung cancer

O
Oligodendroglioma
Oral cancer
Oropharyngeal cancer
Osteosarcoma/malignant fibrous histiocytoma of bone
Ovarian cancer
Ovarian epithelial cancer (surface epithelial-stromal tumor)
Ovarian germ cell tumor
Ovarian low malignant potential tumor

P
Pancreatic cancer
Pancreatic cancer, islet cell
Paranasal sinus and nasal cavity cancer
Parathyroid cancer
Penile cancer
Pharyngeal cancer
Pheochromocytoma
Pineal astrocytoma
Pineal germinoma
Pineoblastoma and supratentorial primitive neuroectodermal tumors, childhood
Pituitary adenoma
Plasma cell neoplasia/Multiple myeloma
Pleuropulmonary blastoma
Primary central nervous system lymphoma
Prostate cancer

R
Rectal cancer
Renal cell carcinoma (kidney cancer)
Renal pelvis and ureter, transitional cell cancer
Retinoblastoma
Rhabdomyosarcoma, childhood

S
Salivary gland cancer
Sarcoma, Ewing family of tumors
Sarcoma, Kaposi
Sarcoma, soft tissue
Sarcoma, uterine
Sézary syndrome
Skin cancer (non-melanoma)
Skin cancer (melanoma)
Skin carcinoma, Merkel cell
Small cell lung cancer
Small intestine cancer
Soft tissue sarcoma
Squamous cell carcinoma – see skin cancer (non-melanoma)
Squamous neck cancer with occult primary, metastatic
Stomach cancer
Supratentorial primitive neuroectodermal tumor, childhood

T
T-Cell lymphoma, cutaneous – see Mycosis Fungoides and Sézary syndrome
Testicular cancer
Throat cancer
Thymoma, childhood
Thymoma and thymic carcinoma
Thyroid cancer
Thyroid cancer, childhood
Transitional cell cancer of the renal pelvis and ureter
Trophoblastic tumor, gestational

U
Unknown primary site, carcinoma of, adult
Unknown primary site, cancer of, childhood
Ureter and renal pelvis, transitional cell cancer
Urethral cancer
Uterine cancer, endometrial
Uterine sarcoma

V
Vaginal cancer
Visual pathway and hypothalamic glioma, childhood
Vulvar cancer
W
Waldenström macroglobulinemia
Wilms tumor (kidney cancer), childhood

Cancer Treatment And Survival

Early detection through screening is very useful for cervical and colorectal cancer. The benefits of screening in breast cancer are controversial.
Once a diagnosis has been made, and cancer has been confirmed, the next part of the cancer journey is the treatment.

There are three main ways to treat cancer: surgery, cancer drugs (chemotherapy), and radiation.  Surgery  is the removal of tumours, While the goal of chemotherapy and radiation is to stop or slow the growth of cancer cells.

Cancer drugs can prolong life or increase a patient’s quality of life by reducing symptoms. While Radiation therapy is the use of a certain type of energy (radiation) from X-rays, gamma rays and electrons to destroy cancer cells. In high doses, radiation destroys cells in the area being treated. It does this by damaging the DNA in cancer cell genes, making it impossible for them to grow and divide. During radiation therapy, both cancer cells (which are growing in an uncontrolled way) and healthy cells are affected, but most healthy cells can repair themselves.

The chance of survival depends on the type of cancer and extent of disease at the start of treatment. In children under 15 at diagnosis the five-year survival rate in the developed world is on average 80%. For cancer in the United States the average five-year survival rate is 66%.