What is cancer

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What is cancer

Cancer is a disease of the body's cells. Normally cells grow and multiply in a controlled way, however, sometimes cells become abnormal and keep growing. Abnormal cells can form a mass called a tumour

Cancer is the term used to describe collections of these cells, growing and potentially spreading within the body. As cancerous cells can arise from almost any type of tissue cell, cancer actually refers to about 100 different diseases

 

 

What causes cancer?

We do not know all of the risks and causes of cancer. However, there are a number of chemical, physical and biological agents that have been shown to trigger the mistakes in the cell blueprint that cause cancer. These are called carcinogens and include tobacco, ultraviolet (UV) radiation and asbestos.

A number of cancers share risk factors

  • One in nine cancers, and one in five cancer deaths, are due to smoking
  • A study in 2010 found that about 2.8% of cancers are related to alcohol use
  • Many cancers occur as a direct result of dietary influences
  • Infectious agents or exposure to radiation can cause cancer (especially skin cancers from UV radiation) 
  • Some cancers result from inherited ‘faulty’ genes
  • Cancer is NOT caused by injury or stress  

  • Symptoms

    Signs and symptoms caused by cancer will vary depending on what part of the body is affected.

    Some general signs and symptoms associated with, but not specific to, cancer, include:

    • Fatigue
    • Lump or area of thickening that can be felt under the skin
    • Weight changes, including unintended loss or gain
    • Skin changes, such as yellowing, darkening or redness of the skin, sores that won't heal, or changes to existing moles
    • Changes in bowel or bladder habits
    • Persistent cough or trouble breathing
    • Difficulty swallowing
    • Hoarseness
    • Persistent indigestion or discomfort after eating
    • Persistent, unexplained muscle or joint pain
    • Persistent, unexplained fevers or night sweats
    • Unexplained bleeding or bruising

      What are the most common cancer

       

       

    • The most commonly diagnosed cancer (excluding non-melanoma skin cancer) was prostate cancer, followed by breast, colorectalor bowel cancer, melanoma and lung cancer. There are more than 100 different types of cancer, but these five most common types account for 60% of all cases

      The most common cancers for men and women are listed in order below

      Men

      • Prostate
      • Bowel (colorectal)
      • Melanoma
      • Lung
      • Head and neck

      Women

      • Breast
      • Bowel (colorectal)
      • Melanoma
      • Lung
      • Uterine
      • Risk Factors
        While we have an idea of what may increase your risk of cancer, the majority of cancers occur in people who don't have any known risk factors. Factors known to increase your risk of cancer include:
         
        Your age
        Cancer can take decades to develop. That's why most people diagnosed with cancer are 65 or older. While it's more common in older adults, cancer isn't exclusively an adult disease — cancer can be diagnosed at any age.
         
        Your habits
        Certain lifestyle choices are known to increase your risk of cancer. Smoking, drinking more than one drink a day for women and up to two drinks a day for men, excessive exposure to the sun or frequent blistering sunburns, being obese, and having unsafe sex can contribute to cancer.
        You can change these habits to lower your risk of cancer — though some habits are easier to change than others.
         
        Your family history
        Only a small portion of cancers are due to an inherited condition. If cancer is common in your family, it's possible that mutations are being passed from one generation to the next. You might be a candidate for genetic testing to see whether you have inherited mutations that might increase your risk of certain cancers. Keep in mind that having an inherited genetic mutation doesn't necessarily mean you'll get cancer.
         
        Your health conditions
        Some chronic health conditions, such as ulcerative colitis, can markedly increase your risk of developing certain cancers. Talk to your doctor about your risk.
         
        Your environment
        The environment around you may contain harmful chemicals that can increase your risk of cancer. Even if you don't smoke, you might inhale secondhand smoke if you go where people are smoking or if you live with someone who smokes. Chemicals in your home or workplace, such as asbestos and benzene, also are associated with an increased risk of cancer.

      • Complications

        Cancer and its treatment can cause several complications, including:

        • Pain. Pain can be caused by cancer or by cancer treatment, though not all cancer is painful. Medications and other approaches can effectively treat cancer-related pain.
        • Fatigue. Fatigue in people with cancer has many causes, but it can often be managed. Fatigue associated with chemotherapy or radiation therapy treatments is common, but it's usually temporary.
        • Difficulty breathing. Cancer or cancer treatment may cause a feeling of being short of breath. Treatments may bring relief.
        • Nausea. Certain cancers and cancer treatments can cause nausea. Your doctor can sometimes predict if your treatment is likely to cause nausea. Medications and other treatments may help you prevent or decrease nausea.
        • Diarrhea or constipation. Cancer and cancer treatment can affect your bowels and cause diarrhea or constipation.
        • Weight loss. Cancer and cancer treatment may cause weight loss. Cancer steals food from normal cells and deprives them of nutrients. This is often not affected by how many calories or what kind of food is eaten; it's difficult to treat. In most cases, using artificial nutrition through tubes into the stomach or vein does not help change the weight loss.
        • Chemical changes in your body. Cancer can upset the normal chemical balance in your body and increase your risk of serious complications. Signs and symptoms of chemical imbalances might include excessive thirst, frequent urination, constipation and confusion.
        • Brain and nervous system problems. Cancer can press on nearby nerves and cause pain and loss of function of one part of your body. Cancer that involves the brain can cause headaches and stroke-like signs and symptoms, such as weakness on one side of your body.
        • Unusual immune system reactions to cancer. In some cases the body's immune system may react to the presence of cancer by attacking healthy cells. Called paraneoplastic syndromes, these very rare reactions can lead to a variety of signs and symptoms, such as difficulty walking and seizures.
        • Cancer that spreads. As cancer advances, it may spread (metastasize) to other parts of the body. Where cancer spreads depends on the type of cancer.
        • Cancer that returns. Cancer survivors have a risk of cancer recurrence. Some cancers are more likely to recur than others. Ask your doctor about what you can do to reduce your risk of cancer recurrence. Your doctor may devise a follow-up care plan for you after treatment. This plan may include periodic scans and exams in the months and years after your treatment, to look for cancer recurrence.
      •  

      • Prevention

        Doctors have identified several ways to reduce your risk of cancer, such as:

        • Stop smoking. If you smoke, quit. If you don't smoke, don't start. Smoking is linked to several types of cancer — not just lung cancer. Stopping now will reduce your risk of cancer in the future.
        • Avoid excessive sun exposure. Harmful ultraviolet (UV) rays from the sun can increase your risk of skin cancer. Limit your sun exposure by staying in the shade, wearing protective clothing or applying sunscreen.
        • Eat a healthy diet. Choose a diet rich in fruits and vegetables. Select whole grains and lean proteins. Limit your intake of processed meats.
        • Exercise most days of the week. Regular exercise is linked to a lower risk of cancer. Aim for at least 30 minutes of exercise most days of the week. If you haven't been exercising regularly, start out slowly and work your way up to 30 minutes or longer.
        • Maintain a healthy weight. Being overweight or obese may increase your risk of cancer. Work to achieve and maintain a healthy weight through a combination of a healthy diet and regular exercise.
        • Stop Drink alcohol
        • Schedule cancer screening exams. Talk to your doctor about what types of cancer screening exams are best for you based on your risk factors.
        • Ask your doctor about immunizations. Certain viruses increase your risk of cancer. Immunizations may help prevent those viruses, including hepatitis B, which increases the risk of liver cancer, and human papillomavirus (HPV), which increases the risk of cervical cancer and other cancers.