Cancer

Cancer is caused by the unchecked growth and division of cells that would not normally do so, which then spread to other tissues where they cause potentially lethal damage. Cancer can spread around the body rapidly via a process known as metastasis

A Cancerous tumor is distinguished from a benign tumor, the growth of the latter being limited and unable to propagate via metastasis. However benign tumors are best removed and then monitored, as they can sometimes become malignant. The risk of cancer increases with age, and the disease is responsible for over 10% of deaths in the developed world.

Most cancer is caused by some abnormality in the genetic material of a cell. This may be due to corruption by a carcinogen (for example tobacco, radiation or chemicals), or some inherited defect in a person’s underlying genetic code. Cancer can also be caused by flaws in the process of cell division and reproduction at the level of DNA.

It is thought that some people may be genetically predisposed to develop cancer as a result of exposure to different kinds of environmental factors, and work is continuing in this area, particularly with respect to microRNA (ribo nucleic acid) and DNA methylation.

A key characteristic of cancer is that it causes standard abnormalities in two basic classes of genes. Oncogenes tend to be activated in cancerous cells, endowing them with properties that bypass the body’s built-in safeguards such as programmed cell death and interaction with the immune system. The active oncogenes can also cause hyperactive cell growth and division, as well as the ability of a cell to establish itself in environments it would not normally be able to do.

On the other hand, genes that innately suppress tumor formation are usually inactive in cancer cells, leading to the loss of whatever function the cell should have had, combined with flawed DNA replication and the ability to escape detection by the immune system.

Treatment for cancer includes chemotherapy, immunotherapy and radiation therapy, as well as surgery to remove tumors. Treatment options will depend on the type of cancer, as well as the location and viability of surgery (including an assessment of the patient’s general health). Additionally, potential new treatments for cancer are constantly under development and undergoing clinical trials.

The aim of cancer treatment is to remove the offending cancerous cells without causing unnecessary damage to the rest of the body. Hopefully this can be done by means of surgery, but often the spread of cancer via metastasis will negate this option, leaving chemotherapy and radiotherapy as the main treatment options, both of which come with their own risk of harmful side-effects. The term ‘cancer’ covers a broad range of diseases, and so treatment options will vary, and it is unlikely that a general cure for cancer will ever be practically possible.

Surgical options for the removal of cancer include mastectomy, where cancer of the breast is removed, and prostatectomy where a similar process occurs for prostate cancer. Sometimes drastic treatment will be necessary, such as the removal of an entire organ so as to make sure that the tumor is completely gone.

A single cancer cell remaining in the body can be enough to grow a new tumor, so patients will be monitored closely immediately following removal surgery and in the weeks and months to follow, to ensure that no microscopic traces of cancer remain.
Surgery may also be needed to provide an accurate diagnosis before treatment options can be assessed, or to control symptoms where complete removal of the cancer is not possible, such as possible obstruction of the bowel. This is what is known as palliative treatment.

Chemotherapy involves the use of drugs to destroy cancer cells. This usually means cytotoxic drugs, which indiscriminately target cells which divide rapidly. So chemotherapy comes with a substantial risk of harming healthy cells such as those in the intestine, which have a high rate of regeneration. However the difference between these healthy cells and cancerous cells is that the healthy cells generally have the ability to repair the damage done to their DNA, whereas cancer cells do not.

Therefore healthy cells damaged as a result of chemotherapy will usually repair themselves after the treatment ends. Drugs used in chemotherapy are various, and can inhibit cell division in different ways, such as interfering with DNA duplication or chromosomal separation. Most chemotherapy also involves a combination of different drugs which work in different ways, so as to provide the best possible chance of reaching all of the cancer cells. This process is often referred to as combination chemotherapy.

As mentioned above, sometimes the complete removal of cancerous tissue is not possible, due to the way in which cancer can spread quickly right throughout the body. In such cases, it is often possible to treat the symptoms of the cancer in order to improve a person’s quality of life.

Common symptoms of cancer include nausea and vomiting, as well as diarrhea and other general symptoms of unwellness. These can be treated by any medical professional in the usual way. Additionally, palliative care specialists can help to relieve other general or specific symptoms associated with cancer, including different types of pain and discomfort.

Morphine and oxycodone are two painkilling drugs typically used to make cancer patients more comfortable, as well as antiemetic drugs used to suppress nausea and vomiting. Advanced antiemetics, including ondansetron and aprepitant can make control of acute symptoms more practical and controllable.

Chronic pain caused by cancer is most often as a result of ongoing tissue damage due either to the disease itself, or to the treatment of the disease by either chemotherapy, radiation therapy or invasive surgery. Sometimes environmental factors can affect cancer sufferers, but this is not particularly common.

Cancer sufferers experiencing acute pain are usually doing so because all other treatment options have been exhausted and they are reaching the end of their lives. This is when palliative care specialists are employed to make them as comfortable as possible using a variety of pain management techniques.

Pain relief in this case usually involves opioids or possibly surgery. Some doctors also prefer to take pre-emptive action against pain when they know a patient will not be able to be cured.

Complimentary medicines are tried by a great many cancer sufferers as a last resort, and include vitamin A derivatives and extract from the bark of the yew tree, as well as other botanical sources. Acupuncture and psychological treatments can also be useful.