Cancer is the uncontrolled growth of abnormal cells anywhere in a body. These abnormal cells are termed as cancer cells, malignant cells, or tumor cells. These cells can infiltrate normal body tissues. Many cancers and the abnormal cells that compose the cancer tissue are further identified by the name of the tissue that the abnormal cells originated from (for example, breast cancer, lung cancer, colon cancer). Cancer is not confined to humans; animals and other living organisms can get cancer too. Below is a schematic that shows normal cell division and how, when a cell is damaged or altered without repair to its system, the cell usually dies. Also shown is what occurs when such damaged or unrepaired cells do not die and become cancer cells and show uncontrolled division and growth — a mass of cancer cells develop. Frequently, cancer cells can break away from this original mass of cells, travel through the blood and lymph systems, and lodge in other organs where they can again repeat the uncontrolled growth cycle. This process of cancer cells leaving an area and growing in another body area is termed metastatic spread or metastasis. For example, if breast cancer cells spread to a bone, it means that the individual has metastatic breast cancer to bone. This is not the same as “bone cancer,” which would mean cancer had started in the bone.
The following is a listing of major causes and is not all-inclusive as specific causes are routinely added as research advances:
Chemical or toxic compound exposures: Benzene, asbestos, nickel, cadmium, vinyl chloride, benzidine, N-nitrosamines, tobacco or cigarette smoke (contains at least 66 known potential carcinogenic chemicals and toxins), asbestos, and aflatoxin
Ionizing radiation: Uranium, radon, ultraviolet rays from sunlight, radiation from alpha, beta, gamma, and X-ray-emitting sources
Pathogens: human papillomavirus (HPV), EBV or Epstein-Barr virus, hepatitis viruses B and C, Kaposi’s sarcoma-associated herpes virus (KSHV), Merkel cell polyomavirus, Schistosoma spp., and Helicobacter pylori; other bacteria are being researched as possible agents.
Genetics: A number of specific cancers have been linked to human genes and are as follows: breast, ovarian, colorectal, prostate, skin and melanoma; the specific genes and other details are beyond the scope of this general article so the reader is referred to the National Cancer Institute for more details about genetics and cancer.
It is important to point out that almost everyone has risk factors for cancer and is exposed to cancer-causing substances (for example, sunlight, secondary cigarette smoke, and X-rays) during their lifetime, but many individuals do not develop cancer. In addition, many people have genes that are linked to cancer but do not develop it. Why? Although researchers may not be able to give a satisfactory answer for every individual, it is clear that the higher the amount or level of cancer-causing materials a person is exposed to, the higher the chance the person will develop cancer. In addition, the people with genetic links to cancer may not develop it for similar reasons (lack of enough stimulus to make the genes function). In addition, some people may have a heightened immune response that controls or eliminates cells that are or potentially may become cancer cells. There is evidence that even certain dietary lifestyles may play a significant role in conjunction with the immune system to allow or prevent cancer cell survival. For these reasons, it is difficult to assign a specific cause of cancer to many individuals.
Cancer can cause many different symptoms. These are some of them:
- Skin changes, such as:
- A new mole or a change in an existing mole
- A sore that does not heal
- Breast changes, such as:
- Change in size or shape of the breast or nipple
- Change in texture of breast skin
- A thickening or lump on or under the skin
- Hoarseness or cough that does not go away
- Changes in bowel habits
- Difficult or painful urination
- Problems with eating, such as:
- Discomfort after eating
- A hard time swallowing
- Changes in appetite
- Weight gain or loss with no known reason
- Abdominal pain
- Unexplained night sweats
- Unusual bleeding or discharge, including:
- Blood in the urine
- Vaginal bleeding
- Blood in the stool
Any affecting Organ:
There are three main categories of cancer: Carcinomas begins in the skin or tissues that line the internal organs. Sarcomas develop in the bone, cartilage, fat, muscle or other connective tissues. Leukemia begins in the blood and bone marrow
Prevention / Treatment:
Cancer risk tends to increase with age. Some existing health conditions that cause inflammation may also increase your risk of cancer. An example is ulcerative colitis, a chronic inflammatory bowel disease. Knowing the factors that contribute to cancer can help you live a lifestyle that decreases your cancer risks. According to experts, these are the seven best ways to prevent cancer:
- Stop using tobacco and avoid secondhand smoke.
- Eat a healthy, balanced diet.
- Limit your intake of processed meats.
- Consider adopting a “Mediterranean diet” that focuses mainly on plant-based foods, lean proteins, and healthy fats.
- Avoid alcohol, or drink in moderation. Moderate drinking is defined as one drink a day for women of all ages and men older than 65, and up to two drinks a day for men 65 years of age and younger.
- Keep a healthy weight and stay active by getting at least 30 minutes of physical activity every day.
- Stay protected from the sun.
- Cover up with clothing, sunglasses, and a hat, and apply sunscreen frequently.
- Avoid the sun between 10 a.m. and 4 p.m. This is when the sun’s rays are at their strongest.
- Stay in the shade as much as possible when you’re outside.
- Avoid tanning beds and sunlight, which can damage your skin just as much as the sun.
- Get vaccinated against viral infections that can lead to cancer, such as hepatitis B and HPV.
- Don’t engage in risky behaviors. Practice safe sex and don’t share needles when using drugs or prescription medications. Only get tattoos at licensed parlors.
- See your doctor regularly so they can screen you for various types of cancer. This increases your chances of catching any possible cancers as early as possible.