Cancer is a disease characterized by uncontrolled cell growth, which has the ability to infiltrate and damage healthy cells in the body. Each body cell has a control center called the nucleus. The nucleus consists of a series of DNA chains that act as regulators of the nature and workings of each cell, including to divide.
Normally, cells will divide according to a predetermined time and with genetic traits in normal cells. But when mutations occur in cells, the genetic information of cells in the DNA chain is damaged, double-printed or even lost, during the process of cell division. In cancer, a mutation occurs in which cells will divide too much to form tumor tissue.
Types of Cancer
Based on the types of cells that are attacked, cancer can be divided into 5 groups, namely:
- Carcinoma, a cancer that originates in the skin tissue or outer layers tissue of the internal organs. Carcinoma is divided into several sub-types including Adenocarcinoma, Basal Cell Carcinoma, Squamous Cell Carcinoma, and Transitional Cell Cancer.
- Sarcomas, cancers originating from connective tissue such as bone tissue, cartilage tissue, fat tissue, muscle tissue, and blood vessel tissue.
- Leukemia, a cancer that originates from blood-forming tissues such as bone marrow. This type of cancer causes excessive production of blood cells which will then be released into the bloodstream.
- Lymphoma and Myeloma, cancer that originates from immune system cells.
- Brain cancer and the spinal cord, which is cancer originating from the central nervous system tissue.
In addition to these groupings, cancer is also divided according to the organ from which cancer tissue develops, such as lung cancer or breast cancer.
Causes of Cancer
The main cause of cancer is the mutation of DNA in cells, so that cells break themselves up with speeds that exceed normal. Finally, there is a buildup of new cells that are not needed by the body. This new cell will continue to grow into adulthood and then divide again, and so on.
In addition, mutations also occur in genes that are responsible for repairing DNA damage. Normally, this gene functions to see what abnormalities occur in DNA cells, then fix them. Because these genes have mutations, this gene is unable to repair abnormalities that exist in cells until eventually these cells become malignant. There are several factors that can cause mutations in normal cells, and can come from inside or outside the cell.
Mutations originating from within cells are generally acquired genetically from parents. While the causative factor is from outside the cell, the most common is exposure by substances that can trigger mutations (mutagen). Some substances that belong to the class of mutagen include cigarettes, radiation, virus, carcinogenic chemicals and hormone.
Mutations due to external factors can also be caused by other factors such as obesity, chronic inflammation and lack of physical activity. In general, external factors are more risky to cause cells to mutate compared to internal factors.
Symptoms of Cancer
Symptoms that arise due to cancer vary greatly, depending on the type of cancer experienced and the organs of the body that affected by cancer. Some common symptoms experienced by cancer sufferers are:
- Fatigue and feeling weak.
- Unwanted weight changes, may be a decrease or weight gain.
- Lumps begin to appear under the skin.
- Changes to the skin, such as yellowing, darkening, or flushing. It can also be a pain or a painful wound and does not heal.
- Night fever and sweating for a long time.
- Unclear bleeding and bruising.
If you experience these symptoms, especially symptoms that persist for a long time, it is recommended to consult a doctor immediately. Risk factors and history of cancer in the family also need to be consulted so that routine screening tests can be carried out, so that cancer can be diagnosed early.
Diagnosis and Division of Cancer
The earlier the cancer is diagnosed, the greater the chance of recovery for the sufferer. Therefore, it is highly recommended for people who are at risk of getting cancer to consult with doctors regarding the risk factors they have. Some steps of cancer diagnosis that doctors commonly do are:
- Physical examination. Physical examination is done to show signs of cancer. Can be an examination of lumps under the skin, changes in skin color, and swelling of the body’s organs.
- Laboratory test. Examination of blood and urine can be done to check abnormal body conditions. An example is in cases of leukemia, where doctors can carry out laboratory tests in the form of calculating complete blood cell counts to diagnose the number of leukocyte cells that increase abnormally.
- Imaging test. This test serves to map internal organs and bones without surgery. Imaging tests can be in the form of Computed Tomography (CT), bone scans, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), ultrasound examinations, X-rays, and others.
- Biopsy. This examination is done by taking a sample of tissue that is suspected of having cancer to be observed using a microscope in the laboratory. Through a microscope, the structure of the tissue sample can be observed more clearly. Normal cells are usually seen as cells of the same size and neatly arranged. While in cancer cells, the size will look different and the arrangement is not neat. Biopsy is the most accurate examination in determining whether a person has cancer or not.
After these tests and the patient is confirmed to have cancer, the doctor will determine the level (stage) of the cancer. In general, the division of cancer stages is as follows:
- Stage 1. Indicates that cancer is small and still remains in the organ where the cancer begins.
- Stage 2. Indicates that the cancer has not spread to the surrounding tissue, but the size of the cancer is greater than stage 1. In some types of cancer, stage 2 means the cancer cells have spread to the lymph nodes closest to the cancer organ.
- Stage 3. The size of the cancer is greater than stage 2 and cancer cells have begun to spread to other tissues or organs, and to lymph nodes around cancer.
- Stage 4. Indicates that the cancer has spread to other organs or tissues.
In addition to the stage level system, also known as the TNM staging, the details are as follows:
- T – Tumors. Describes cancer size and spread of cancer to surrounding tissues. To describe the size of cancer is used numbers 1, 2, 3, 4, with number 1 indicating the smallest and the 4th largest size.
- N – Nodus. Describes the spread of cancer to lymph nodes (lymph nodes) around cancer. To describe the spread of cancer, numbers 0, 1, 2, 3 with 0 indicate that the cancer has not spread to the lymph nodes and 3 indicates that many lymph nodes have cancer.
- M – Metastasis. Describes the spread of cancer to other organs. The number 0 indicates that the cancer has not spread to other organs and the number 1 indicates that the cancer has spread to other organs.
In the case of cancers diagnosed in the early stages, a condition can be found in the form of abnormal cells in the body. This collection of cells can develop into cancer in the future, but is too small to form a tumor. This condition is called Dysplasia or Carsinoma in Situ which in the division of cancer is called as stage 0 cancer.
Determination of the level of malignancy and spread of cancer is a very important part in cancer diagnosis because it will determine the type of treatment that is most effective for patients.
Various types of cancer treatment have been found and used for cancer patients. The type of treatment that doctors will apply depends on several things, such as the type of cancer, stage of cancer, location of cancer, general health condition of the patient, and patient demand. The doctor will give consideration regarding the advantages and risks of each treatment. The treatment commonly used are as follows:
- Surgery. The purpose of surgery is to eliminate cancer tissue that is in the body to the maximum extent possible.
- Chemotherapy. Is a cancer treatment using chemical compounds in the form of drugs.
- Radiotherapy. Is a cancer treatment using high-energy rays to kill cancer cells. Radiotherapy can use radiation from outside the body (External Beam Radiation Therapy) or planted in the patient’s body (Brachytherapy).
- Stem Cell Transplantation. Stem cell transplants are also called bone marrow grafts that play a role in producing blood cells. Transplanted stem cells can come from patients or from stem cell donors. In addition to replacing bone marrow that has an abnormality or malignancy, stem cell transplantation can also be done to provide opportunities for doctors to use higher doses of chemotherapy in other types of cancer.
- Immunotherapy. Immunotherapy is also known as biological therapy which aims to help the immune system recognize cancer cells and then kill them. Cancer cells that are not fought by the immune system can spread uncontrollably and endanger patients.
- Hormone therapy. Some types of cancer can appear by triggering hormones such as breast and prostate cancer. Lowering or eliminating levels of this hormone in the body can stop the growth of cancerous tissue.
- Targeted drug therapy. Giving drugs that can kill abnormal cells without attacking healthy cells.
Like the treatment of other diseases, cancer treatment has side effects on the body. One side effect is that it can reduce the number of blood cells in the body and slow down blood production. At the beginning of treatment, the number of white blood cells will decrease. Under normal conditions, white blood cells that experience death will be replaced with new white blood cells for a week or two. However, cancer treatment that is being carried out can slow down the regeneration process of white blood cells. This condition can weaken the patient’s immune system so that patients are more susceptible to secondary infections due to weakened immune system.
Red blood cells normally have around three months of age so the process of regenerating red blood cells is slower than white blood cells. Cancer treatment, especially chemotherapy can reduce the number of red blood cells so that people who do not have the risk of anemia can get anemia. If there are very few red blood cell counts, blood transfusion can be done for patients.
Platelets can also decrease due to cancer treatment. Symptoms of decreased blood platelets can be observed from the occurrence of nosebleeds, bruises, or a red rash on the skin. These side effects can be overcome by giving platelet transfusion to patients. Generally after long-term patients receive chemotherapy, platelets take longer to increase to normal than other blood cells.
In some cases, cancer cells can be resistant to cancer treatment so it is more difficult to treat. Cancer cell resistance arises due to mutations that occur in cancer cells continuously so that the genetic nature of cells changes. If this happens, the doctor will provide some type of treatment combination to the patient. However, in some rarer cases, even after a combination of treatments, cancer still has resistance. This condition is called multi drug resistance.
Some things that can be done to prevent cancer include stop smoking, avoid excessive sunburn, regulate a healthy diet, exercise regularly, maintain weight, reduce and stop drinking alcohol, schedule routine cancer screening and vaccination consultation with a doctor.