• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Stomach Cancer

Extracts from this document...


Stomach Cancer - it's causes and treatments Stomach cancer is a worldwide killer, causing the deaths of around 1 million people per year, with around 9000 of those being in the UK. Whilst incidence is decreasing in the developed world this is due to better diet rather than better treatment so it is important that effective treatment is available. It is a multifactorial disease, having many risk factors and predisposing factors but no definitive causes. This account outlines some of the risk factors of stomach cancer and then goes on to detail current treatments. Prevalence and types of stomach cancer The significance of stomach cancer varies worldwide, with different reports describing it as either the 2nd or 4th largest cancer worldwide, accounting for just under 9% of new cases but nearly 11% of deaths each year. However it should be noted that overall incidence rates have been decreasing since the 1930s, but this is mainly due to a larger drop in distal stomach cancer, which is unfortunately coupled with an increase in cancer of the cardia and gastro-oesophageal junction (see figure 1 for the structural divisions of the stomach). ...read more.


Thus infection with H pylori is considered 'necessary but not sufficient' to cause stomach cancer. The relative risk of H pylori infection is 2.5, and prevalence is almost double in developing countries, compared to the developed Western world. One of the most compelling arguments for the involvement of H pylori in stomach cancer comes from a Japanese study in which no individuals without the bacterium developed stomach cancer, compared to 2.9% of those with the bacterium, even those who were asymptomatic for ulceration and dyspepsia. H pylori infection damages the gastric mucosa, which predisposes the individual to carcinogenesis. Whilst initial levels of H pylori in atrophic gastritis (which often leads to cancer) are high, by the time that the more significant damage that leads to cancer has occurred, H pylori levels have dropped, due to the unsuitable gastric conditions. The progression from regular H pylori infection to stomach cancer involves several stages, through metaplasia and dysplasia to carcinoma. These final stages have largely unknown causes so it is imperative that the disease is caught at the earlier H pylori infection and gastric atrophy stages so that effective intervention may occur. ...read more.


If the cancer is detected early, however, survival can be better than 90%. In advanced stages of the disease surgical resection cannot remove all of the metastases, perhaps contributing to the poor prognosis. Chemotherapy 5-fluorouracil based chemotherapy is recommended in advanced stage stomach cancer that cannot be treated with surgery. However, even though it represents the most effective chemotherapy currently available, median survival rates are only in the region of 6-10 months. Other suitable drugs for the advanced stage cancer include doxorubicin and cisplatin, which have a response rate of between 19 and 86% as single agents. However more success on the chemotherapeutic front comes from combination therapy, with the most commonly used combination therapy being 5-fluorouracil and cisplatin, with an over 50% success rate being reported in a 2005 study. It has also been suggested that COX-2 inhibitors might be chemoprotective in stomach cancer, acting to inhibit the apoptosis and possibly consequent carcinogenesis aggravated by the COX-2 enzyme. Conclusion Whilst H pylori has a significant impact on the development of stomach cancer it is not necessarily causative. Instead it is deemed as producing an environment conducive to carcinogeneis. Basically anything that can damage the gastric mucosa will greatly increase the chance of stomach cancer developing. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    Neurology and Behaviour. Focus question: Is there an increase in the perception and ...

    5 star(s)

    such as choosing participants with the same exposure to the items in the images may have allowed for more accurate and representative results. As this was not controlled it may have allowed for severe infrequencies in data between each participant as the ratings would not be reflective of the genders


    * 2 pipettes (10cm3 ±0.5) * Pipette (1cm3 ±0.05) * DCPIP solution * Ascorbic acid solution (concentration 0.1%, 500cm3 ±1) * Bottle of distilled water * 8 filters * Fruit press * dropper Method: 1. Label the test tubes, then slowly pipette 1 cm3 of DCPIP into each test tube.

  1. Gene Therapy

    He synthetically created a retrovirus that existed solely to deliver therapeutic DNA during gene therapy and had no reproduction sequence. The retrovirus contained only the new DNA that had been spliced into it and did not contain any viral DNA that could possibly make the patient sick.

  2. IB Biology notes on infection and the body's responses.

    goal of vaccination is to produce an immune response without disease 1. vaccine may contain pathogen that has been treated so that it is less virulent, i.e. Less able to cause disease a. often referred to as the attenuated pathogen 2.

  1. The effect of pvc piping on the breathing/heart rates of male year 12 students

    This experiment will examine at what length of pipe both breathing and heart rates are optimized without crossing these thresholds. Since straws are relatively limiting in length, adaptable PVC piping can be used as a substitute. 1.2.1 Controlling variables (table 1)

  2. How does the distribution of Plantago maior differ?

    1 11 38 2 2 40 20, near the pathway 1 3 20 2 2 20 3 4 22 4 4 19 5 2 15 6 1 20 7 1 14 I joined the group which investigated Plantago major in Bielanski Forest.

  1. Should Animals have the same rights as Humans? Both animals and humans exhibit behaviours ...

    I would also experiment with three dimensional as opposed to two dimensional shapes to see what the impact of this is. All of Pavlov's data was once regarded as both reliable and valid as it had been published in a respected science journal.

  2. Genes of fruit fly practical write up

    Wild type body and Black body Table 2.2.3 F1 WW WW ww Ww Ww ww Ww Ww F2 W w W WW Ww w Ww ww Table 2.2.4 Sex Phenotype Observed Hypothesis tested Expected (E-O)2/E Level of Significance Female Wild type 449 3 445 0.0334 0.8075 male Wild type 446

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work