Archive for the ‘Cancer’ Category

SUPPORTIVE CARE OF CHILDREN WITH CANCER: DIAGNOSIS AND TREATMENT OF CHEMOTHERAPY-INDUCED PULMONARY TOXICITY

Tuesday, July 19th, 2011

Pulmonary toxicity is a significant complication of bleomycin. Less frequently methotrexate, busulfan, and CCNU have been incriminated in acute lung syndrome, which is believed to be idiosyncratic and not predictable. Radiation therapy to the lung parenchyma reduces pulmonary toxicity thresholds.Pulmonary toxicity from radiation and chemotherapeutic agents may be partially reversible. Ultimately, enough damage to the parenchymal lung tissue could result in death. I. TOXICITY OF BLEOMYCINA. Diagnosis of bleomycin toxicitySlow inspiratory vital capacity and pulmonary capillary blood volume appear to be the proper lung function assessments that specifically reflect alterations induced by bleomycin.Diffusion capacity of carbon monoxide (DLCO) is not a suitable parameter to monitor pulmonary toxicity induced by bleomycin specifically when it is part of a multidrug regimen.a. Investigators have found a poor correlation betweenDLCO and lung toxicity, and DLCO fails to predict the development of serious bleomycin lung toxicity in the majority of patients. When a low DLCO is encountered, look at other parameters as well (see b. below).The clinician should decide to continue bleomycin when it is in the best interest of patient care.i. Bleomycin may be stopped inappropriately after low DLCO measurement. DLCO <65% has a high false positive incidence when used as the standard for withholding chemotherapy.ii. When a low DLCO is encountered, examine and consider other parameters of lung function before discontinuing bleomycin.b. It is important to monitor for respiratory system and chest x-ray abnormalities during bleomycin treatment, as these will be the earliest signs of lung toxicity inmost patients.i. The combination of respiratory symptoms and an abnormal chest x-ray is the earliest manifestation in many patients.ii. Therefore, a careful history of respiratory symptoms and regular chest x-rays is more likely to detect clinically significant bleomycin lung toxicity than the DLCO.iii. Diffuse infiltration with tumor, interstitial pneumonias, generalized pulmonary infections such as Pneumocystis pneumonia, and bleomycin nodularity may have similar signs and symptoms.iv. An aggressive approach is justifiable because the consequence of stopping bleomycin in a patient with a curable cancer may be as devastating as continuing bleomycin in one at risk of bleomycin lung damage.B. Factors contributing to bleomycin toxicityThe serum half-life of bleomycin can be increased in the presence of renal dysfunction such as that induced by cisplatin. Monitor renal function closely when patients are receiving both bleomycin and nephrotoxic chemotherapeutic agents.3. The administration of oxygen in high concentrations, (e.g., during general anesthesia) may cause fulminate respiratory failure in patients previously treated with bleomycin.C. Modifications for pulmonary toxicityBleomycin lung toxicity remains an unpredictable side effect by comparison with the toxicities of many other anticancer drugs. Therefore, it would be advisable to avoid bleomycin in situations in which other drugs can be substituted without compromising results.D. Late effectsBleomycin pulmonary toxicity may be reversible. A decreased force vital capacity and DLCO in the first 15 months after treatment, in terms of long-term follow-up, did not predict outcome.*39\168\2*

THE IDENTIFIABLE CAUSES OF CANCER

Saturday, May 28th, 2011

The question the reader will ask at this point is ‘Given all this epidemiological study, do we know the causes of cancer?’ Broadly the answer is ‘yes’ in many circumstances and for many cancers, and the opportunities for prevention that this understanding generates are there to be taken. We do not always know how the factors that have been identified by the epidemiological studies discussed in this chapter link up to what is being learned in the laboratories of the molecular biologists. This connection is being made rapidly and will be increasingly clear by the end of the century. Epidemiology has been very successful in discovering or confirming which features of our lives in the Western world can be now identified as causes of cancer. Sunlight. Ultraviolet irradiation from the sun is the main cause of skin cancers, including melanoma. Alcohol. Alcohol contributes to cancers of the upper digestive tract, particularly in combination with smoking. It probably also contributes to cancers of the liver, mainly, but perhaps not exclusively, through causing cirrhosis of the liver. There is little doubt that advice on the avoidance of heavy drinking is sound if we wish to reduce cancer risk as well as the other risks with which drinking is associated.Occupations. Cancer epidemiology really began with Percival Pott and his chimney-sweeps, and, for many researchers, creating a safe workplace and eliminating risks is a central purpose of epidemiological studies. Chemical dyes and asbestos have been identified as causes of cancer and eliminated in the workplace, but constant vigilance is still in order. New and stringent regulations permitting only limited exposure to substances hazardous to health arc now in force in many Western European countries, and their extension to Eastern Europe represents a significant financial, political and medical challenge.Environmental Pollution. Most of the factors that are hazardous in the workplace arc found in lower concentrations in the general environment and may well contribute to cancer risk. Atmospheric pollution probably plays only a limited role in lung cancer, but asbestos in the general environment has undoubtedly contributed to the level of risk.*33\194\4*

TRANS-FATS

Friday, January 14th, 2011
One of the reasons why omega-6 fats may be a problem for breast cancer is that as they are so unstable, and are often the subject of chemical extraction processes that damage the oils, they may become
I the source of rogue ‘free radicals’ – damaging compounds which corrupt healthy cells. In this way they may initiate cancer in the first place, and also burden the body’s immune system. Another reason may be an excess of omega-6 fats when compared to omega-3 fats, probably due to our reliance on margarines and vegetable cooking oils.
Under particular suspicion are the so-called unsaturated fats-hydrogenated or partially hydrogenated margarines. These have undergone a process to turn a liquid oil (such as sunflower oil) into a fat which is solid at room temperature. This is why I call them ‘so-called’ as they have become ‘honorary’ saturated fats by processing. They are even more problematic than natural saturated fats since they contain ‘trans-fats’ which are highly damaging. Margarines are cheap and stable and are therefore beloved of food manufacturers. Manufactured products such as biscuits, potato crisps, pies, cakes and pastries will have hydrogenated fats as an ingredient because they allow for a long shelf-life. While manufacturers claim that a small percentage of their overall ingredients have been turned into trans-fats (2-17 per cent), what they don’t tell you is that it has been shown that these fats accumulate in women’s breasts, and particularly so in women with breast cancer. Here they can damage cell membranes and interfere with correct hormone and prostaglandin function.
Trans-fats are also created when oils are extracted by chemical processes, a process which is used as an alternative to pressing which would provide a low yield, or where the appearance or flavour of the oil needs to be altered. For example, grape seed oil or avocado oil is naturally dark and unpleasant-tasting in the raw, so chemical solvents are used to extract the oils. As com has a low fat content, extremely high temperatures and toxic solvents are used to extract the oil efficiently, and the same is often true of soya oil. These processes make the oils high in trans-fats and chemical residues.
*69\240\2*

TRANS-FATSOne of the reasons why omega-6 fats may be a problem for breast cancer is that as they are so unstable, and are often the subject of chemical extraction processes that damage the oils, they may becomeI the source of rogue ‘free radicals’ – damaging compounds which corrupt healthy cells. In this way they may initiate cancer in the first place, and also burden the body’s immune system. Another reason may be an excess of omega-6 fats when compared to omega-3 fats, probably due to our reliance on margarines and vegetable cooking oils.     Under particular suspicion are the so-called unsaturated fats-hydrogenated or partially hydrogenated margarines. These have undergone a process to turn a liquid oil (such as sunflower oil) into a fat which is solid at room temperature. This is why I call them ‘so-called’ as they have become ‘honorary’ saturated fats by processing. They are even more problematic than natural saturated fats since they contain ‘trans-fats’ which are highly damaging. Margarines are cheap and stable and are therefore beloved of food manufacturers. Manufactured products such as biscuits, potato crisps, pies, cakes and pastries will have hydrogenated fats as an ingredient because they allow for a long shelf-life. While manufacturers claim that a small percentage of their overall ingredients have been turned into trans-fats (2-17 per cent), what they don’t tell you is that it has been shown that these fats accumulate in women’s breasts, and particularly so in women with breast cancer. Here they can damage cell membranes and interfere with correct hormone and prostaglandin function.     Trans-fats are also created when oils are extracted by chemical processes, a process which is used as an alternative to pressing which would provide a low yield, or where the appearance or flavour of the oil needs to be altered. For example, grape seed oil or avocado oil is naturally dark and unpleasant-tasting in the raw, so chemical solvents are used to extract the oils. As com has a low fat content, extremely high temperatures and toxic solvents are used to extract the oil efficiently, and the same is often true of soya oil. These processes make the oils high in trans-fats and chemical residues.*69\240\2*

YOUR CANCER YOUR LIFE – DESTRUCTION OF NORMAL TISSUES; METASTASIS (ABILITY TO SPREAD)

Tuesday, May 12th, 2009

This is one of the most frightening things about cancer. Cancer cells have the ability to separate from the original or primary growth, and get into blood or lymph vessels. They can then travel through the blood or lymph system to far distant parts of the body where they lodge. These cells can, in turn, multiply to form what we call secondary growths.

Cancer cells have one other characteristic feature which is not shared by normal cells. They can invade and destroy surrounding tissues. For example, a cancer growing in a bone will replace and destroy normal bone, softening and weakening it. A cancer growing in the liver will destroy normal liver cells, reducing the liver’s ability to carry out its normal job of clearing waste products from the bloodstream. A cancer growing in the lungs will damage normal lung tissues so it is harder to breathe and the transfer of oxygen into the blood is less efficient.

Normal cells exist peacefully side by side with their neighbours. Cancer cells damage and destroy them.

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