Essay on Cancer: Top 7 Essays on Cancer

List of seven popular essays on cancer!

Content:

1. Essay on Meaning of Cancer
2. Essay on Types of Cancer
3. Essay on Cancer Stages
4. Essay on Treatment of Cancer via Chemotherapy
5. Essay on Cancer Globally
6. Essay on Unproven Methods or Medical Intervention for Cancer Treatment:
7. Essay on Cancer Prevention

Essay on Meaning of Cancer:

Cancer is generally considered to comprise more than 100 different diseases, each characterized by uncontrolled growth and spread of abnormal cells, resulting from a chain of multiple genetic changes causing a loss of typical growth controls, leading to unregulated growth, lack of differentiation, apoptosis, genomic instability, and metastasis.

The genetic alterations are caused by both external factors (tobacco, chemicals, radiation, and infectious organisms) and internal factors (inherited mutations, hormones, immune conditions and mutations that occur from metabo­lism).

To initiate or promote carcinogenesis these factors can work jointly or in sequence. Cancer knows no boundaries and is able to develop in any tissue within any organ -at any age and the frequency of cancers intensifies exponentially with age. According to Bagchi and Preuss (2005), two in five persons will be diagnosed with cancer some time in their life, and finally three out of every four families will be affected.

A long latent pe­riod of ten or more years was found to be one of the hallmarks of tumour development. No obvi­ous clinical evidence of disease can be seen dur­ing this latent period. Studies suggested that for the full development of cancer it is required that three to seven rate-limiting mutations should take place. Both animal carcinogen­esis models and human clinical data support the stepwise sequence of cancer (Fig. 5.1).

Many genes that take part in normal cells pro­cesses and therefore, cancer cells can be dam­aged by any of these genes. Multiple genetic modifications and bio­chemical defects underlie cancer development, they are crucial for converting normal cells into a cancerous cell mass with atypical growth.

It is crucial for tumorigenesis that genetic modifica­tions occur in the cells genes responsible for cell cycle progression and growth so that they can achieve the proliferative advantage. Proteins are encoded via growth-regulating genes.

Mutations in these genes will then alter levels or function of these proteins, equipped to alter cell division suc­cessfully. Oncogenes and tumour suppressors (loss of function) are two main types of genes mutated in cancer.

Essay on Types of Cancer:

There are many different types of cells in the body and all the different cells can grow into cancer. Cells from different body parts do behave differ­ently, some may grow faster or slower, some pro­duce different symptoms, others respond differ­ently to the same treatment and some might be more or less likely to spread to a specific part of the body. Cancers are divided into four main groups according to the body tissue from which they arise (Table 5.1).

Essay on Cancer Stages:

At the time of cancer diagnosis a staging is a pro­cess used to explain the degree or spread of the disease. Staging is vital for determining the selec­tion of therapy and measuring the prognosis. The size and location of the primary tumour determines a cancer’s stage and also whether or not it has spreads to the other areas of the body.

Different staging systems are used for all the different can­cer types in order to assist in describing the progress of that cancer (Bagchi and Preuss, 2005).

The different types of staging used to classify tumours are:

1. TNM — this classification system measures tumours in three ways: extent of the primary tumour (T), regional lymph node involvement (N) absence or presence, and distant metastases (M) absence or presence.

2. Once the TNM is assigned stages of I (early stage), II, III, and IV (most advanced stage) is assigned in addition.

3. Another system is used for descriptive and sta­tistical analysis of tumours: in situ — if can­cer cells do not invade deeper into the tissue and are present only in the layer of cells where they developed; invasive-if cells have spread to nearby tissue beyond the original layer; local – an invasive malignant cancer confined entirely to the organ of origin; regional – a malignant cancer that (1) has extended be­yond the limits of the organ of origin directly into surrounding organs or tissues; (2) involves regional lymph nodes by way of lymphatic system; or (3) has both regional extension and involvement of regional lymph nodes; distant- a malignant cancer that has spread to parts of the body remote from the primary tumour ei­ther by direct extension or by discontinuous metastasis to distant organs, tissues, or via the lymphatic system to distant lymph nodes (Bagchi and Preuss, 2005).

Selection of the most suitable type of treat­ment for a specific type of cancer can only be done when the stage of the cancer is known since it is important to decide on the right treatment for that specific stage of cancer. After a biopsy, grad­ing is done in the lab where cancer cells are graded according to how much they look like normal cells and also their aggressiveness.

Many different types of grading systems exist and depend on the type of cancer. The Cleason system is the most com­monly used grading system which is based on a number from 0 to 10, the lower the number the lower the grade.

According to Bagchi and Preuss (2005), grades under 4 mean that the cancer cells look similar to normal cells and that the cancer is less likely to be aggressive, where grades 5 to 7 are the intermediates which means that these can­cer cells do not look like normal cells and are more likely to be aggressive and more likely to grow faster and grades 8 to 10 means that the can­cer is very aggressive in growth.

The staging system of the Gleason system ac­cording to Bagchi and Preuss (2005) is as follows:

Stage 0 :(Carcinoma in Situ):

Very early cancer. The abnor­mal cells are found only in the first layer of the primary site and do not invade deeper into the tissue.

Stage I:

Cancer involves the primary site but did not spread to nearby tissue.

Stage IA:

A very small amount of cancer was found to be visible under the microscope and is found deeper in the tissue.

Stage IB:

Here a larger amount of cancer cells were found in the tissue.

Stage II:

The cancer has spread to the nearby tissue but is still found inside the primary site.

Stage IIA:

Cancer has spread beyond the primary site.

Stage IIB:

Cancer has spread to other tissue around the primary site.

Stage III:

Cancer has spread throughout the nearby area.

Stage IV:

Cancer has spread to other parts of the body.

Stage IVA:

Cancer has spread to organs close to the pelvic area.

Stage IVB:

Cancer has spread to distant organs, such as the lungs.

Recurrent:

Cancer has recurred at the same location where the original tumour was or at a different location after it has been treated and supposedly elimi­nated.

Essay on Treatment of Cancer via Chemotherapy:

Cancer treatment via chemotherapy was intro­duced more than 50 years ago into the clinic. Toxic drugs are needed in most cases of chemo­therapy treatment in patients which often result in unpleasant side effects, but the beneficial effects of these toxic drugs outweigh their adverse reac­tions.

Plant materials (edible and nonedible) have phytochemicals present which may function as chemo preventative or chemotherapeutic agents.

Modern medicine has benefited significantly from anecdotal results of their empirical methodology. Presently large numbers of illnesses are treated by choosing necessary candidates for a pharmacopeia that is inadequate. Natural products also had a major impact on cancer chemotherapy. It has been reported that more than 60% of the approved drugs for cancer treatment are natural products or derived from natural products.

There are many plant-derived anticancer agents which are in clini­cally use these days. These include the vinca al­kaloids/ natural alkaloids vinblastine and vincris­tine that were isolated in minute quantities from Catharanthus roseus G. Don. Another two semi­synthetic derivatives are etoposide teniposide of the parent compound epipodophyllotoxin, a natu­ral product, which is an isomer of podophyllo-toxin.

The medicinally used Podophyllum species (Podophyllaceae) from the Indian subcontinent, Podophyllum peltatum Linnaeus (commonly known as the American mandrake or Mayapple), and Podophyllum emodii Wallich, have been used extensively for the treatment of skin cancers and warts throughout history.

The taxanes were more recently added to the armamentarium of plant- derived chemotherapeutic agents, Paclitaxel (taxol) was isolated originally from the bark of Taxus brevifolia Nutt. Paclitaxel is used alone or in combination with other cancer drugs primarily for the treatment of ovarian, breast, and non-small cell lung cancer (NSCLC).

Furthermore it showed efficacy against Kaposi sarcoma, potential treat­ment of multiple sclerosis, psoriasis and rheuma­toid arthritis. ‘Homoharringtonine’ (HHT) was iso­lated from Cephalotaxus harringtonia var. drupacea (Sieb and Zucc.) (Cephalotaxaceae).

In China, acute leukaemia and chronic myelogenous leukaemia is treated effectively with the use of a harringtonine and HHT racemic mix­ture. Elliptinium, a derivative of ellipticine, was isolated from a Fijian medicinal plant Bleekeria vitensis A.C. Sm. (known for anticancer proper­ties) and species of several genera of the Apocynaceae family, is marketed for treatment of breast cancer in France.

Natural products for can­cer chemotherapy are often very potent but have limitations in terms of solubility in aqueous sol­vents and they show narrow therapeutic indices, this caused the termination of a large number of pure natural products such as bruceantin and maytansin (isolated from Maytenus serrata).

Development of new derivatives from natu­ral products with improved antiproliferative profiles and chemo preventive activities is essential, but it can only happen if their molecular mecha­nism of action, their effects on cellular signalling process is entirely understood as well as their struc­ture-activity relationships.

Revival is taking place in medicinal botanicals (including herbal rem­edies) as part of complementary medicine for dis­ease prevention and therapy as conventional medi­cations have high costs, side effects and therapeu­tic limitations. Therefore, there are great interests and enthusiasm in naturally occurring phyto- chemicals for cancer chemoprevention.

Essay on Cancer Globally:

Each year cancer is newly diagnosed in 10 mil­lion people worldwide and account for 7.1 mil­lion deaths (12.5% of the global total). It is sec­ond to cardiovascular disease as a cause of death in developing countries, which causes overall 10% of all deaths in the world. People usually regard it as a problem of the developing world, but more than half of all cancers are seen in the three-quar­ters of the world’s population who live in the de­veloped countries.

According to the World Health Organization (WHO) global cancer rates could increase by 50% to 15 million by 2020. This sharp and alarming increase in cancer rates both in de­veloped and developing is due to steadily aging populations in countries, present trends in smok­ing prevalence along with the growing adoption of unhealthy lifestyles (WHO, 2003),

Malignant tumours were responsible for 12% of the nearly 56 million deaths worldwide. lt de­veloped in 5.3 million men and 4.7 million women. Altogether 6.2 million died, in the year 2000. In developing countries cancer has ap­peared as a main public health problem. How­ever, the likelihood of being diagnosed with can­cer in developed countries is twice as high as in developing countries.

The highest overall can­cer rates for industrial nations are: United States of America (USA), Italy, Australia, Germany, The Netherlands, Canada and France, and the lowest cancer rates for developing countries were North­ern Africa, Southern and Eastern Asia (WHO, 2003).

Lung cancer is the most common cancer worldwide, accounting for 1.2 million new cases annually, of which the main cause is smoking and other causes include domestic and industrial pol­lution. A clear linear dose-response relationship exists between magnitude of cancer and the pe­riod of smoking as well as the amount smoked.

Cancer of the breast follow lung cancer by, just over 1 million cases; colorectal, 940 00; stom­ach, 870 000; liver, 560 000; cervical, 470 000; oesophageal, 410 000; head and neck, 390 000; bladder, 330 000; malignant non-Hodgkin lym­phomas, 290 000; leukaemia, 250 000; prostate and testicular, 250 000; pancreatic, 216 000; ova­rian, 190 000; kidney, 190 000; endometrial, 188 000; nervous system, 1 75 000; melanoma, 133 000; thyroid, 123 000; pharynx, 65 000; and Hodgkin disease, 62 000 cases.

One should how­ever note that the three leading killers differ from the three most common forms of cancer. Of all the cancer deaths in the world, according to the WHO (2003) the three leading killers are: lung cancer responsible for 1 7.8% fatal cases, then stomach cancer at 10.4% and liver cancer at 8.8%.

More than a quarter of deaths are attributed to cancer in many countries. As many as one third of cancers worldwide could be prevented by healthy lifestyles, and tobacco use the most pre­ventable cause of cancer in the world.

Although, childhood cancers (aged one to 14) are rare and largely curable if detected early through modern molecular and imaging technology e.g. PET scan­ning for lymphomas, the treatment options is lim­ited. Cancer causes the second most deaths, in children worldwide. Three in five children (80 116 or 92%) still die in developing countries be­cause of cancer and 133 931 (83%) cases are newly diagnosed each year. In developed coun­tries childhood cancers are newly diagnosed in 26 864 (17%) children and account for 6 863 deaths annually (Tynes et al., 2003).

Essay on Unproven Methods or Medical Intervention for Cancer Treatment:

Regardless of widespread positive research data from experimental and preclinical studies the ex­isting importance and potential of botanical medi­cines used in cancer treatment remains largely untapped, but at the same time it is recognized with the rising of an integrative model. Multiple factors including, historical, political, and cultural factors in conjunction with confusion within the principles and practice of botanical medicine are invariably responsible for this.

All over the world cancer patients use vari­ous forms of treatments, drugs and other unproven or questionable methods such as homeopathy, folk medicines, vitamins, healing “psychological” treat­ments, herbs, different dietary patterns rich in fruit, vegetables and herbs. In German speaking coun­tries a high frequency (52%-65%) of complemen­tary or conventional methods are used as curative or alternative treatment.

Some products or medi­cine are country specific (in the Netherlands the Moerman diet, Ayurvedic medicine in India, Chi­nese medicine) and others are however used worldwide: mistletoe and vitamins. From countries in Asia, Africa and the entire Africa there is a lack of data although it is-know that traditional/folk medi­cine are used there.

Complementary and/or alternative methods are ones that include diagnostic tests, methods of treatment or preventative treatments which are not scientifically tested or proven. Most of the time these methods or treatments for cancer are either unique or extra treatments (complementary to clas­sical ones) that can be given either according to classical concepts of cancer treatment or accord­ing to a new concept of the world and life.

It was found that women and the members of the upper socioeconomic class (in the Western countries) are more frequently using these unproven methods since they are sometimes expensive. Unproven methods or treatments, easily accessed worldwide via the Internet, are mostly used by patients with a chronic or terminal disease.

Essay on Cancer Prevention:

The WHO world cancer report pro- vides clear evidence that healthy lifestyles and public health action, governments and health prac­titioners could stem this trend, and prevent as many as one third of cancers worldwide.

If we all take action now today we can prevent one third of all cancers, cure another third and provide good pal­liative care to the remaining third. Cancer chemoprevention is defined as pharmacological intervention with synthetic or naturally occurring compounds that may prevent, inhibit, or reverse carcinogenesis, or prevent the development of invasive cancer.

Examples of where this immediate action can make differences are as follows:

1. The reduction of tobacco (major preventable cause) and alcohol consumption. Complete prevention is possible for all cancers due to cigarette smoking and excess alcohol con­sumption.

2. A healthy lifestyle and diet which consists of frequent high fruit and vegetable consump­tion (more than 400 g/day) and physical ac­tivity is the second preventable cause of can­cer. An overall energy imbal­ance is the result of a Western lifestyle (highly caloric diet, rich in fat, refined carbohydrates and animal protein) together with low physi­cal activity. In western countries, approxi­mately 30% of cancers are caused by dietary factors and in developing countries about 20%.

About 20% of all cancers could be prevented with a healthy diet. Daily consumption of fruit, vegetables and herbs such as broccoli, grapes, cabbage, sprouts, peanuts, ginko biloba, and garlic prove to re­duce the incidence of cancer especially stom­ach cancer associated with Helicobacter py­lori.

It was also found that woman could re­duce the risk of ovarian cancer by 60% with a dietary supplement derived from ginko biloba and a daily sulphide supplement can reduce DNA damage in breast epithelial cell, treated with carcinogens produced when protein-rich foods are cooked at high tempera­tures.

3. Early detection through screening especially for breast, cervical, colon, rectum, cervix, prostate, oral cavity, and skin may cure can­cer. Today more than 80 per cent of all cer­vical cancer deaths occur in developing coun­tries because they do not have excellent pub­lic health infrastructure.

Other good examples are that of breast cancer which is detected by mammography, it may reduce breast cancer mortality by 25 to 30 per cent and in nation­wide screening programmes a reduction of 20 per cent appears feasible.

‘Lower mortality rates for prostate cancer due to screening by assessment of serum prostate specific antigen (PSA) levels, but early lesion management is still extremely invasive. A colonoscopy for colon cancer is considered the gold standard although extensive medical resources are needed for use in population-based screen­ing programmes.

4. Curb infections which cause cancer, because up to 23% of malignancies in developing countries are caused by infectious agents. These agents include hepatitis B and C virus (liver cancer), Helicobacter pylori (stomach cancer) and human papilloma viruses (cervi­cal and ano-genital cancers).

Roughly eight per cent of all malignancies at some stage in cancers are caused by chronic infections in developed countries. The so­lution designed for preventing these cancers could be vaccinations. In high-incidence countries it was shown that liver cancer could be prevented by Hepatitis B virus (HBV) vac­cination and in a few years time vaccination might be possible for human papilloma virus (HPV).