Aspirin for cancer prevention - Aspirin and colorectal cancer

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Nutrition, Health & Wellness

Aspirin for cancer prevention

Home > Vitamin E and prostate health > Aspirin and colorectal cancer prevention

Uses of aspirin for prevention of cancer in general and colorectal cancer in particular have been examined in recent epidemiological studies. The findings support use of aspirin for colorectal cancer prevention. The exact mechanism of malignant tumor prevention by aspirin is not well understood. Probably by inhibiting prostaglandin synthesis, these non-steroidal anti-inflammatory drugs may be activating immune reactions and inhibiting the synthesis of tumour promoters.

     Aspirin (acetylsalicylic acid) has been in use as an analgesic, antipyretic and anti-inflammatory agent. In low-dose it is recommended for prevention of cardiovascular disease related problems like ischemic stroke or myocardial infarction (heart attack).

Image of colorectal region

Aspirin for cancer prevention

     Research data have shown that daily aspirin may help in prevention of several malignant tumors and the risk of local and distant metastasis.
In two meta-analysis led by Professor Peter Rothwell of the Nuffield Department of Clinical Neurosciences, University of Oxford and his colleagues, published in The Lancet (Volume 379, Issue 9826, Pages 1602 - 1612, 28 April 2012) and The Lancet Oncology (Volume 13, Issue 5, Pages 518 - 527, May 2012) found that regular use of aspirin reduces the long-term risk of several malignant tumors and the risk of distant metastasis; the short-term reductions in malignant tumor incidence and mortality add to the case for daily aspirin in prevention of malignant tumors.

Aspirin for colorectal cancer prevention in Lynch syndrome

     Lynch syndrome (HNPCC) is due to autosomal dominant genetic mutations impairing DNA mismatch repair. Apart from colorectal region Lynch syndrome can affect many of the visceral organs, brain and skin. Individuals with Lynch syndrome have 80% lifetime risk of affliction of colorectal region and 66% of these in the proximal region. Prof Sir John Burn MD and colleagues in their research published in The Lancet (Volume 378, Issue 9809, Pages 2081 - 2087, 17 December 2011) interpreted that "600 mg aspirin per day for a mean of 25 months substantially reduced cancer incidence after 55·7 months in carriers of hereditary colorectal cancer. Further studies are needed to establish the optimum dose and duration of aspirin treatment."

     There are other ways of prevention of these colorectal malignant tumors. It is advised that people above 50 years should get themselves tested for precancerous polyps. If found their surgical removal will help in the avoidance of formation of malignant tumors.

     The epidemiological studies have shown a consistent relationship between aspirin use and colorectal malignant tumor prevention. However various research aspects, like optimum dosage requirements, ideal duration of therapy, risks involved in long-term use and effects on termination of therapy, require further elaborate studies.

     Considering its known side effects like allergies, increased risk of developing hemorrhagic stroke or peptic ulcer disease, aspirin is not suitable for every individual. Only when the benefits of treatment outweigh the risks involved, its use for prevention of colorectal cancer should be considered in individuals prone to aspirin allergies, high blood pressure, ulcers, hemophilia (bleeding disorder) or hemorrhages.


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Aspirin and colorectal cancer prevention

References:
1. Prof Sir John Burn MD et al, Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial, December 2011, doi:10.1016/S0140-6736(11)61049-0

Daily health news - Diesel engine exhaust causes cancer - IARC

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Nutrition, Health & Wellness

Diesel engine exhaust causes cancer WHO > Diesel engine exhaust fumes and health effects like cancer

IARC, considering the health effects of diesel engine exhaust fumes on humans, has classified it as carcinogenic to humans (cancer causing). The International Agency for Research on Cancer (IARC), is the cancer research and monitoring arm of the World Health Organization (WHO). On June 12 2012, IARC, after a week-long meeting of international experts on carcinogenic health effects of diesel engine exhaust fumes, has made a press release announcing the classification of diesel engine exhaust as carcinogenic to humans. The classification was announced from Lyon, France, after considering the scientific findings on the health effects and cancer-causing potential of diesel exhaust fumes.

Now diesel fumes find a place among other known listed items with carcinogenic effects like tobacco smoke, solar radiation, UV radiation, mustard gas, chronic infection with Hepatitis B/C virus, postmenopausal estrogen therapy, formaldehyde, ethanol in alcoholic beverages, asbestos, benzene, arsenic and arsenic compounds.

An illustration of typical
polycyclic aromatic hydrocarbons
Earlier in 1988, IARC had classified diesel exhaust fumes as "probably carcinogenic to humans". The review of the classification was recommended in 1998. The requirement of the review was further re-emphasized by findings of US National Cancer Institute, published on March 6, 2012 on 'Heavy Diesel Exhaust Linked to Lung Cancer Deaths in Miners (https://www.cancer.gov/).
The research findings are from the 'Diesel Exhaust in Miners Study' (DEMS) taken up in 1992 by jointly by National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH).
The study was done on non-metal miners and it revealed that the increasing exposure to diesel engine fumes had serious health effects and risk of death from lung carcinoma increased with increased exposure.
In everyday life most of us get exposed to these diesel engine fumes either through occupation or through the ambient air.
Diesel engine fumes contain obnoxious gases and fine particles of carbon surrounded by polycyclic aromatic hydrocarbons (PAH) that enter the body through mouth and nose and leave a coating of deposits in the lungs.
Though the human body removes these particles by coughing, The effects of continuous exposure to these deposits causes cancer.

The results of this study are important not only to miners but also to millions of workers working in environments heavy with diesel engine fumes, people living in very congested cities, people working in underground transit systems and people exposed to traffic snarls for considerable time.

Now that the adverse health effects are known, it is time for enforcing environment guidelines for engine exhaust fumes.
Introduction of more efficient engines and machinery with low diesel exhaust emissions, improved ventilation of closed work places and use of appropriate respiratory protective equipment will go long way in reversing negative health effects caused so far by diesel engine exhaust fumes and protect ourselves from lung cancer.

Vitamin E and Prostate Cancer - Raised risks in vitamin E supplements

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Nutrition, Health & Wellness

Vitamin E and prostate cancer Does vitamin E supplementation increase the risk of prostate cancer?
The risk of prostate cancer was found to increase when vitamin E supplements were given for a long period. JAMA (the Journal of the American Medical Association) published a study on the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and concluded that "Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men."

Vitamin E in the form 'Alpha-Tocopherol' increases prostate cancer risk

The initial report of SELECT trial found no reduction in the occurrence of this cancer either with selenium (200 μg/d from L-selenomethionine) or with vit. E (400 IU/d of all rac-α-tocopheryl acetate). However in the longer follow-up studies the occurrence of prostate malignancy in healthy SELECT subjects has established a relationship of this cancer with 'all rac-α-tocopheryl acetate'.

The point to be noted here is that 'all rac-α-tocopheryl acetate' was the form of alpha-Tocopherol used in this SELECT trial. In fact vit. E is a group of compounds which are fat-soluble and comprise four types of tocopherols and four types of tocotrienols. In natural food all the eight types are present in different proportions.

Alpha-Tocopherol constitutes the major source of vit. E in European diets while in North American diet gamma-tocopherol is the major constituent. Though early research had focussed on alpha-tocopherol, of late the higher beneficial traits of gamma-tocopherol and tocotrienols are being recognized.

Vitamin E in the form of Tocotrienols has been found to help in prevention of cancer, reduction of cholesterol, protection from stroke-induced brain cell injury, lowering tumor formation, protection against DNA and cell damage and suppression of cancer of pancreas, breast, prostate gland and skin.

Vitamin E in the form 'Gamma-tocotrienol' is effective against prostate cancer

Recent studies by Luk Su et all have reported that vit. E in the form of Gamma-tocotrienols (γ-T3) can be an effective therapeutic agent against  prostate cancer stem cells (CSCs) and advanced stages of malignancy. Alpha-tocopherol is found to interfere with tocotrienols benefits by interfering with their absorption and increasing their catabolism.

Synthetic alpha-tocopherol is produced and marketed as vit. E supplement whereas synthetic tocotrienol is not produced as a supplement though technically possible. Further research in these lines and production and marketing of alternatives like Gamma-tocotrienols is required.

It can be safely concluded that vitamin E as 'Alpha-Tocopherol' increases the risk of prostate cancer while in its 'Gamma-tocotrienol' form can be an effective therapeutic agent against this malignancy.