Some countries have more cancer cases and some have less, some have one type of cancer, some have another. There are various types of cancers, each with its own special properties, the race it effects, the age, the sex and the different part of the body.

AS and A Level Healthcare

Mihajlo (Michael) Najdovski 2107931E

Cancer

Michael Najdovski 2107931E

RMIT University

Department of Applied Biotechnology & Environmental Biology

ONPS 1031 Molecular Biology

Contents

Abstract

Introduction

Properties of Cancer

Diagnosis

Treatment

Prevention

Summary

References

Abstract

Cancer is a major contributor to deaths around the world. Some countries have more cancer cases and some have less, some have one type of cancer, some have another. There are various types of cancers, each with its own special properties, the race it effects, the age, the sex and the different part of the body.

Introduction

Cancer is a progressive disease and as such it will be fatal if it is not treated effectively. Cancer (in most cases) arises from a single cell. All cancer cells have mutations or changes affecting one or more oncogenes in the cells. These mutations or changes are usually caused by a foreign source such as cigarette smoke or sunlight. Because of these mutations some genes may not function properly. Normal cells replicate and eventually die so space is preserved and life goes on. With cancer cells, due to mutations somewhere along the genes, after their time of working and replicating, they do not die, they continue replicating and grow over each other and form a tumour. This continues to grow and eventually interferes with the normal function of vital organs in the body. This will eventually cause death. Treatment is usually by surgical removal of the cancer cells and/or different types of drugs. Complications may also arise here. Prevention is the best way to go about it but it may be harder than it sounds.

This papers aim is to inform about cancer, diagnosis, treatment and prevention in a short overview.

Properties of Cancer

Normal cells have a routine life. For example the normal cells of the gut, first divide to form two daughter cells, one like the parent cell (still capable of cell division), and the other cell matures to complete a function, no capability of division and a fixed life span. When its life span is up, it will die and the other cell will just multiply again and the cycle continues and the gut remains the same size because there is a certain number of cells in the gut. With cancer cells, more of them have the parental type characteristics and so the cells can divide in greater numbers so the gut grows with the overflow of cells and becomes cancerous and ceases to function properly after a while.

Normal cells also need outside information (growth factors) that tell them to divide. In almost all cancers, the cells learn how to avoid these growth factors which tell them to divide and to stop so therefore they have nothing to say stop. One way to avoid these growth factors is to produce your own.

Normal cells do not transform into cancer cells by a single change. Cancer cells evolve into a tumour as a result of many sequential changes. These changes take time, usually years to decades from when the patient was first exposed to the carcinogen until the patient starts showing symptoms.

The body can recognise abnormalities and has natural resistance systems against the cancer cells. There are various types of systems, one being the natural killer (NK) cells. They kill everything which is not normal. But this does not work in later stages of cancer as the cancer is too big to control. Also if the cancer exhibits surface antigens, the immune system will recognise it and try to destroy it.

Although many factors may contribute to cancer development, cancer is a genetic disease and is caused by genetic alterations in certain genes. Cancer development is associated with oncogene over expression and inactivation of tumour suppressor genes. One of these genes is the p53 tumour suppressor gene. It plays an important role in preventing cancer development, by killing potential tumour cells. Mutations within the p53 gene, leading to the loss of p53 activity, are found in about half of all human cancers, while many of the tumours that retain wild type p53 carry mutations in the pathways that allow full activation of p53. In either case, the result is a defect in the ability to bring a p53 response in cells undergoing oncogenic stress. Significant advances have been made recently in our understanding of the molecular pathways through which p53 activity is regulated, bringing with them fresh possibilities for the design of cancer therapies based on reactivation of the p53 response(Vousden, KH. 2002). One of the causes of oncogene over expression is mutation in the regulatory regions or in the genes encoding transacting factors that have regulatory roles on oncogenes. However, the most noticeable genetic alteration causing oncogene over expression is gene amplification (Schwab, M. 1998). In some cancers, accumulation of oncogene and tumour suppressor gene mutations appear to be critical to tumour development(Fearon ER. 1990)), which is the continued rapid replication of cancerous cells upon each other.

Once the mutations occur and replication leads to tumour growth, the cells may spread throughout the body. The original cancer cell replicates and with the replication it passes on the mutations to every other cell that is a result of the initial replication. This renders all the cells cancerous and unable to carry out normal functions such as termination. This means all these cells can become a tumour. Cancer cells do not adhere to each other very firmly and can penetrate the boundaries of adjacent tissues. For this reason cancer cells tend to spread beyond their original position to the ...

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Diagnosis

Signs that a person has cancer are usually non existent or hard to find, unless it is advanced. With skin cancers it is advised to look for changes on the skin, such as moles appearing, changing colour or shape. Self examination is advised for a range of other cancers. Breast cancer may be detected in this way, although a mammogram is usually advised every so many years when a female reaches a certain age. CAT scans are usually done to discover cancers and routine check ups can also help. A person knows their body best so any changes should be checked out.

Other signs other cancer include fatigue, headaches, weight loss, loss of appetite, nausea, vomiting, and so on. It is best to visit the doctor if in doubt.

Treatment

Many different views exist about the treatment of cancer. Different cultures have varying views. One of the more popular views, which is also being researched in more depth is the well known Chinese or herbal medicine. Many people are turning to this as an alternative therapy that is safer and healthier to use compared to the administering of toxic chemicals into the body such as in chemotherapy. One of these popular alternative ingredients is broccoli. It is a well known cancer fighting ingredient. It has many anticancer properties and a recent study found that broccoli, when chewed, releases and enzyme from the ruptured cells that produces a class of potent chemicals called sulphoraphanes. These chemicals inhibit the oxidising enzymes that damage DNA and potentially cause cancer (Obesity, Fitness & Wellness Week. 2003. Nutrition; Knockout broccoli fights cancer). Alongside broccoli is garlic and a range of other plant products that play their own special part in fighting cancer.

A more common treatment to cancer, although more dangerous and painful, is surgically removing the cancer. This procedure often works better in cases of tumours rather than spreading cancer. This is because a large chunk of mass is easier to remove rather than cells here and there. Usually the procedure works but is accompanied by chemotherapy or other treatments because of the fact that the cancer cells do not adhere to each other very firmly and once the cancer is removed from the subject, if even one cancer cell is left behind, it will replicate and pass on the mutations to its progeny which will again become a tumour. Sometimes chemotherapy may be used prior to surgery to make the tumour smaller.

Chemotherapy is another treatment which is very often used in cancer patients. It is a dangerous and toxic procedure which requires taking toxic chemicals into the body and often has bad side effects. Everyone’s cancer is different and so is the chemotherapy. Chemotherapy might be given as a pill, a flu shot or intravenously into the vein. You may take chemotherapy once a day, once a week, or even once a month, depending on the type of cancer you have and the chemotherapy you are taking. Some drugs used are milder than others and do not cause too many serious side effects. Other drugs on the other hand cause more serious side effects. This is because they are more stronger and they destroy any cells that are dividing rapidly and this is where the signs are visible. Hair loss occurs because hair cells divide rapidly and so are killed by the drugs, bone marrow cells are killed and lead to a variety of problems such as lowered immune system because of white cell drop, anaemia, prolonged blood clotting times and so on. A sore mouth and dry skin are common because of cell death in those areas and also nausea and vomiting occur because of killing of stomach cells. So we can see that it is a dangerous thing to use chemotherapy. Along side chemotherapy there is also radiation therapy and some other methods. Radiation therapy is using radiation to destroy the cancer cells. This also has downsides because if not accurate the beam of radiation, which is also dangerous to normal tissue, might damage the normal tissues which may also become cancerous.

As we progress into the future newer technologies are emerging in the fight against cancer. A new technology that is being tested is the new CyberKnife Full Body Stereotactic Radiosurgery System non- invasively ablates tumours and other lesions through precise delivery of high energy X-rays. It uses an advanced image-guidance system to verify tumour position throughout radiation delivery to ensure accurate targeting of radiation without the need for rigid immobilization of the patient. The radiation is precisely directed to the tumour while minimizing radiation exposure to nearby healthy tissue. The elimination of rigid immobilization, which in the past was achieved with a metal head frame attached to the patient's skull, also enables the CyberKnife to treat tumours located throughout the body (Medical Devices & Surgical Technology Week. 2003. Radiosurgery; Medical centre now offering new full-body tumour treatment). Because of the non invasive procedures, CyberKnife will be able to treat many spinal lesions located in areas that are surgically difficult to access because of proximity to the spinal cord. It is also a valuable treatment option for patients who have received prior radiotherapy or are medically inoperable and not candidates for open surgery.

Other emerging technologies such as NeoPharm's proprietary NeoLipid technology use tumour nutrition sources to get drugs inside of the tumour. Cancerous cells require a source of nutrition for growth, NeoLipid uses lipids that the cancer recognises as a food source (Drug Week. 2003. Cancer Therapies; New preclinical data released for novel liposomal drug formulations). The lipids contain certain drugs in them which are anti cancer drugs or tumour suppressors and when the cancer cells take in the lipid as food they also take in the drug which poisons them.

As we see the future is full of new and improved ideas waiting to be discovered.

Prevention

Prevention of cancer is easier said then done if you read all the information. According to the books, you have to have strong will power or don’t enjoy things that many people do. Basically eating junk food will give you cancer, enjoying the sun will lead to cancer, being overweight will give you cancer, eating burnt foods will give you cancer, not eating the right foods will give you cancer. This is all rubbish. You can still enjoy the fine things in life as long as it is in moderation. Avoiding smoking plays a big role in the health of individuals and eating the right foods does help to prevent cancers. As long as people are careful it should be alright. Sunscreen in the sun, moderate alcohol consumption, some exercise. A recent study showed that fat content of the body is related to increased numbers of cancers. Too much body fat can influence cancer and cancer mortality a number of ways. It increases the amount of oestrogen in the blood, increasing the risk of cancers of the female reproductive system. It increases the risk of acid reflux, which can cause cancer of the oesophagus. It raises levels of insulin, prompting the body to create a hormone which causes cells to multiply (Obesity, Fitness & Wellness Week. 2003. Obesity; Losing weight may prevent cancer deaths, study finds).

One of the most simple ways to prevent cancer is regular screening. If the cancer is caught at the early stages it may be treated easily. Regular screening will save many of lives.

Summary

Cancer is one of the most commonly known killers of the modern world. It becomes what it is usually due to neglect of the body and causes a wide range of diseases. Treatments are available and if used in time may prove to be very effective in treating the cancer. The future looks to bring new and improved technological advances that will be more effective, efficient and safe at treating cancers. Although treatments are available the best measure to take against cancer is prevention. This can be done by eating right and living well.

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