Cancer is a disease in which some of the body’s cells grow uncontrollably to form lumps or masses of tissue called tumors and spread to other parts of the body. There are over 200 different types of cancer, and each is classified on the type of cell that affects initially. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans.
It is nearly impossible to prove what cause a cancer in any individual, because most cancers have multiple possible causes. Excepting the rare transmissions that occur with pregnancies and occasional organ donors, cancer is generally not a transmissible disease,however factors that may have contributed to the development of cancer can be transmissible; such as oncoviruses like hepatitis B, Epstein-Barr virus and HIV.
The seven danger signs and symptoms of cancer are as follows:
The causation of cancer is considered multifactorial and results from the interplay between the genetic factors, environmental and behavioral factors. The various major risk factors for cancer are:
Cancer to a large extent is avoidable. Many cancers can be prevented.
While cancer is not a single disease entity all forms of cancer share the common feature of growth dysregulation where the cells grow and multiply without restraint. Thus cancers can arise from all sites of the body and the number of cancers is equal to the number of types of cells and tissues we have in our body. It is estimated that there are 200 different types of cells the human body - all of which can potentially grow into a cancer. Further cancers can behave differently even when arising out the same type of cells in the same area of the body depending on their biological characteristics. For example in case of brain tumors low grade and high grade gliomas are considered to originate from the same cell type in the same area but have dramatically different prognosis. Recent research also indicates that cancers may be different depending the different molecular pathways that are deranged in them allowing far greater variability than originially anticipated. However for the purposes of easier treatment selection and classification cancers are broadly classified into the following categories depending upon the type of tissue of origin.
While the above classification has the merit that it neatly categorizes malignancies into 3 categories with distinct approaches to management exceptions are known to occur. The art and science of treating cancer relies in the timely recognition of these atypical senarios and instituting the appropriate management. As a rule of the thumb surgery along with radiation therapy are the mainstay for the treatment of carcinomas and sarcomas while chemotherapy and radiation therapy play the major role in the treatment of leukemias/lymphomas.
The main specialties involved in the treatment of cancer are:
Cancer is usually detected by clinical examination and confirmed by various tests done in a Hospital. Visible areas in the body can be examined for any swelling or ulcer. Tests like endoscopy, ultrasound examination or CT scan can detect swelling or ulcer within the body. These tests are advised according to the symptoms of an individual. Biopsy or a needle aspiration from the suspected area usually confirms the disease by identifying the cancer cell.
Cancer is nor a contagious disease. A patient cannot transmit the disease to any other person. But, some cancers are found to occur in families. Cancers like breast cancer, colon cancer some types of thyroid cancer, etc are seen in family members. The risk varies from fist degree relative to second degree relative. Also the risk may be higher if both maternal and paternal family members has cancer.
Radiation therapy removes cancer by a form of X-rays. Thus some of the normal areas also get minimal damage. This can cause burning sensation in mouth, ulcer in mouth, dryness, abdominal cramps, diarrhea, skin discoloration etc. These changes are usually temporary. Chemotherapy uses certain drugs that act on fast dividing cells in the body like the cancer cells. Hence some other fast dividing cells are also damaged as in bone marrow, hair etc. A patient may have tiredness, risk of infection, fever, hair loss etc. These side effects also are temporary.
A patient with an early cancer can be cured completely. The chance of cure decreases as the stage of the disease increases. Patient with advanced cancers have the risk of disease coming back even after completely treating the disease. This chance is high during the initial 2-3 years after completing the treatment. Hence all the cancer patients are followed up closely for the first five years and then yearly. An early detection of a recurrence of cancer can be treated with a better chance of cure.