Cancer is a group of diseases characterised by out-of-control cell growth. There are more than 100 different types of cancer. The cancer is named after the area of the body or organ where it originates.
Cancer is a group of diseases characterised by out-of-control cell growth. There are more than 100 different types of cancer. The cancer is named after the area of the body or organ where it originates. For example, if the cancer starts in the breast and spreads elsewhere, it is still called breast cancer.
Cancer occurs when the body’s normal cell division and regeneration process goes awry. Normal cells in the body follow a sequence of events - growth, division and death. This programmed cell death is called apoptosis. In cancer, this process breaks down and cells do not experience programmed death. This leads to out-of-control cell growth and division to form a mass of abnormal cells, ie, a tumour.
All tumours are not cancerous and all cancers do not form tumours. One example is leukaemia, which is cancer of the bone marrow.
Tumours can be categorised as:
- Benign tumour
- Malignant tumour
Tumours are called benign when they remain localised. Benign tumors are not cancerous and cells from such tumours do not spread to other parts of the body. Benign tumours are easy to remove by local surgery.
Malignant tumours are cancerous and grow faster than benign tumours. They can invade and destroy adjacent structures and spread to distant sites. The spreading of cancer is called metastasis.
Cancer cells spread because they do not make the substance that normal cells secrete to make them stick together. Thus, cancer cells float through the blood stream or lymphatic system to affect other parts of the body. This is called metastatic cancer, ie, cancer that has spread from its place of origin to affect another part of the body. However, the name of the cancer remains the same. If breast cancer spreads to the liver, it is metastatic breast cancer, not liver cancer.
What causes cancer
There is no single cause of cancer. What affects a certain body tissue may not affect another. For example, tobacco smoke can cause lung cancer. Overexposure to sunlight can cause melanoma, but sun exposure won’t cause lung cancer and smoke won’t cause melanoma. Here are some common triggers:
Genetics: Each cell in our body contains DNA, which controls its action. Any change or mutation to the DNA that damages the genes involved in cell division can lead to cancer. Cancer occurs when because of gene mutation, the cell is unable to correct DNA damage and unable to die.
Carcinogens: Carcinogens are cancer-causing substances that cause damage to the DNA of the cell. Tobacco, natural or man-made radiation, asbestos, some food and food additives are some of the carcinogens. For instance, the following foods and cooking methods have been linked to cancer: Barbecuing or grilling meat; charring and deep frying food; acrylamide in French fries and potato chips; microwave popcorn; artificial sweeteners and sodas; processed meat and fatty red meat; highly processed foods low in fibre.
Heredity: Cancer can be caused by genetic predisposition that is inherited from family members. Childhood retinoblastoma is the most striking example of the role of heredity.
Immune system: People who have a problem with their immune system are more likely to get some types of cancer. For instance, people who have had organ transplant and taken drugs to suppress their immune system, HIV/AIDS patients or those born with rare medical syndromes that impair their immunity.
Viruses: Though few viruses are known to cause cancer, some viruses can cause genetic changes in the cell, making them more prone to cancer.
These cancers and viruses have been linked with each other.
- Cervical cancer and human papilloma virus
- Primary liver cancer and hepatitis B and C virus
- Lymphomas and Epstein-Barr virus
Are you at risk of developing cancer
-Are you above 65? People of all ages can get cancer but frequency of cancer increases with age. As people age, there are more cancer causing mutations in cell DNA.
-Heredity: Do you have incidence of cancer in the family
-Diet and lifestyle: Do you smoke, drink or have a diet made up of a lot of red meat or processed foods
-Do you spend long hours in the sun or are exposed to workplace hazards, like chemicals or radiation
Can cancer be prevented
The risk of developing cancer depends on genes, environment and lifestyle. If the cancer is linked to certain behaviours, it may be prevented. Here are some dos and don’ts:
- Do not use tobacco to protect against mouth, throat and lung cancer
- Do not drink alcohol to protect against liver cancer
- Do not stay in the sun for too long to protect against skin cancer. When outdoors, use sunscreen.
- Eat a healthy diet with lots of fresh fruits and vegetables
- Maintain a healthy weight and lifestyle
- Find out about vaccinations that prevent viral-linked cancer
- Be screened regularly and self-examine for breast cancer
- Have regular pap smears to rule out cervical cancer
Cancer symptoms depend on the site and size of the cancer and how much it has affected the organ. If the cancer has spread, symptoms may appear in different parts of the body. Common symptoms include:
- Loss of appetite
- Unexplained weight loss
- Skin changes, like darkened skin, redness or itching
Different types of cancer
Cancer is named after the part of the body where it originates.
The most common cancers among men, globally, are:
The most common cancers among women, globally, are:
Other cancers include:
Childhood cancer (neuroblastoma,Wilms’ tumour, non-Hodgkin lymphoma, retinoblastoma)
Bile duct cancer
Gall bladder cancer
Small intestine cancer
Leukaemia (blood cancer)
Myeloma (bone marrow cancer)
What tests do you need to have done
Early detection can improve the effectiveness and success of the treatment. Depending on the type of cancer, the doctor may recommend some of the following:
- Imaging techniques such as X-rays, CT scans, MRI scans and ultrasound to locate the tumour and the organ affected by it.
- Blood samples are analysed for signs of cancer, which may include cancer cells, protein or other substances released by cancer cells. Examples of bloods tests include:
Complete blood count: This common blood test is used to measure haemoglobin, red blood cells, white blood cells and platelet count. An abnormal cell count may indicate blood cancer.
Tumour Markers: Some tumours release substances called tumour markers, which can be detected in the blood. Examples of tumour markers include prostate-specific antigen (PSA) for prostate cancer, cancer antigen 125 (CA 125) for ovarian cancer, alpha-fetoprotein (AFP) for liver cancer and human chorionic gonadotropin (HCG) for germ cell tumors, such as testicular cancer and ovarian cancer.
Blood protein test:This test can detect certain abnormal immune system proteins that are elevated in people with multiple myeloma.
- Endoscopy to look for abnormalities in the body
- Biopsy: Extracting cancer cells and seeing them under a microscope is the only absolute way to diagnose cancer.
Different stages of cancer
Cancer staging is a process to determine how far the cancer has spread. The staging of cancer helps to decide the treatment and make an informed prognosis.
TNM (Tumour, Node, Metastasis) system is the most common cancer staging method.
T (1-4) indicates the size and extent of the tumour
N (0-3) indicates the spread of the tumour to nearby lymph nodes
M (0-1) indicates whether the cancer has spread to other parts of the body
Overall stage grouping: Overall stage grouping is also referred to as Roman Numeral staging. This system uses numerals to describe the progression of the cancer.
- Stage 0: Carcinoma in situ (absence of invasion of tumour cell to surrounding tissue)
- Stage I: Cancers are localised to one part of the body. Stage I cancer can be surgically removed if small enough.
- Stage II: Cancers are early locally advanced. Tumour is larger than stage I but has not started to spread to the surrounding tissue. Stage II cancer can be treated by chemotherapy, radiation or surgery.
Stage III: Cancers are also locally advanced but the cancer is in late stages. Cancer cells can found in the lymph nodes. Stage III can be treated by chemotherapy, radiation or surgery.
- Stage IV: Cancers have often metastasized, or spread to other organs or throughout the body. Stage IV cancer can be treated by chemotherapy, radiation or surgery.
The options depend on the type of cancer, how far it has spread, age, lifestyle and the health status of the patient. There is no single treatment for cancer and doctors often combine different types of treatment.
Surgery is the oldest known method of treating cancer. Surgery is quite effective if the cancer has not spread or metastasised. Surgery is often combined with other forms of therapy, like radiotherapy and chemotherapy.
Chemotherapy is generally used when the cancer has spread (metastasised) to other parts of the body. The aim of chemotherapy is to kill the cancer cells or stop them from growing. To do this, the cancer cells are treated with drugs (either pills or intravenous drugs) that interfere with the cell division process. The problem is that these drugs can harm normally rapid growing cells also. Chemotherapy is undertaken in cycles so that the body gets recovery time between cycles. Chemotherapy has lots of side effects, like nausea, vomiting, appetite change, pain, hair loss, anaemia and fatigue.
High-energy rays and other charged particles are used to kill cancer cells by damaging their DNA. Radiotherapy can cure cancer if the cancer is localised. Radiation therapy can be used in combination with other cancer treatments to prevent recurrence of the primary malignant tumour (as in early stages of breast cancer). Side effects include skin changes like dryness, peeling or blistering, fatigue, plus other side effects depending on the part of the body being treated.
Drugs are used to target cancer-specific genes or proteins without harming normal cells.
Immunotherapy aims to get the body’s immune system to fight the tumour. It works by pumping up the body’s immune system to attack cancer cells or by injecting a man-made immune system protein.
This is still a new therapy. The goal of gene therapy is to repair or replace damaged genes in cancer cells.
Food and Nutrition
Cancer and cancer treatments can be harsh on the body. Lack of appetite is common during cancer treatment. Healthy food choices can boost and improve recovery. Here are some tips:
- Eat small meals
- Include lots of fresh fruits and vegetables in the diet
- Choose whole grain bread and cereals
- Pick lean meat and fish over red meat and processed meat
It is not only safe to exercise moderately during the treatment, it is good for you. Moderate exercise, for instance, a walk or riding a stationary bike, can improve physical fitness, boost mood and self-confidence and reduce fatigue. In fact, recent studies suggest that higher levels of physical activity lower the risk of re-occurrence of cancer. Yoga can help to reduce stress.
Take charge: Your Action Plan
- Be informed. Learn as much as you can about your condition. Talk to your doctor about your condition, treatment and prognosis. Read up about the cancer, so you know what questions to ask your doctor. Speak to other patients to find out what treatments and therapies have worked for them. Being informed keeps you in charge of your health and treatment.
- Nourish your body. Make sure you are giving your body the nutrition it needs. Eat, even if you don’t feel like it.
- Exercise moderately when you are able to
- Stay positive. Join a support group. Talk to people facing similar challenges. To family and friends about your feelings. Read books that offer encouragement. (Note to editor: link to books list)
- Stay focused on your treatment with timely follow-ups and healthy lifestyle.
Know your support team: Who can help you stay healthy
Counsellor or mental health practitioner
Other specialists depending on your condition