Cancers are classi?ed according to the type of cell from which they are derived as well as the organ of origin. Hence cancers arising within the bronchi, often collectively referred to as ‘lung cancer’, include both adenocarcinomas, derived from epithelium (surface tissue), and carcinomas from glandular tissue. Sarcomas are cancers of connective tissue, including bone and cartilage. The behaviour of cancers and their response to therapy vary widely depending on this classi?cation as well as on numerous other factors such as how large the cancer is, how fast the cells grow and how well de?ned they are. It is entirely wrong to see cancer as a single disease entity with a universally poor prognosis. For example, fewer than one-half of women in whom breast cancer (see BREASTS, DISEASES OF) is discovered will die from the disease, and 75 per cent of children with lymphoblastic LEUKAEMIA can be cured.
Incidence In most western countries, cancer is the second most important cause of death after heart disease and accounts for 20–25 per cent of all deaths. In the United Kingdom in 2003, more than 154,000 people died of malignant disease. There is wide international variation in the most frequently encountered types of cancer, re?ecting the importance of environmental factors in the development of cancer. In the UK as well as the US, carcinoma of the BRONCHUS is the most common. Since it is usually inoperable at the time of diagnosis, it is even more strikingly the leading cause of cancer deaths. In women, breast cancer was for a long time the most common malignant disease, accounting for a quarter of all cancers, but ?gures for the late 1990s show that lung cancer now heads the incidence list – presumably the consequence of a rising incidence of smoking among young women. Other common sites are as follows: males – colon and rectum, prostate and bladder; females – colon and rectum, uterus, ovary and pancreas.
In 2003, of the more than 154,000 people in the UK who died of cancer, over 33,000 had the disease in their respiratory system, nearly 13,000 in the breast, over 5,800 in the stomach and more than 2,000 in the uterus or cervix, while over 4,000 people had leukaemia. The incidence of cancer varies with age; the older a person is, the more likely it is that he or she will develop the disease. The over-85s have an incidence about nine times greater than those in the 25–44 age group. There are also di?erences in incidence between sexes: for example, more men than women develop lung cancer, though the incidence in women is rising as the effects of smoking work through. The death rate from cancer is falling in people under 75 in the UK, a trend largely determined by the cancers which cause the most deaths: lung, breast, colorectal, stomach and prostate.
Causes In most cases the causes of cancer remain unknown, though a family history of cancer may be relevant. Rapid advances have, however, been made in the past two decades in understanding the di?erences between cancer cells and normal cells at the genetic level. It is now widely accepted that cancer results from acquired changes in the genetic make-up of a particular cell or group of cells which ultimately lead to a failure of the normal mechanisms regulating their growth. It appears that in most cases a cascade of changes is required for cells to behave in a truly malignant fashion; the critical changes affect speci?c key GENES, known as oncogenes, which are involved in growth regulation. (See APOPTOSIS.)
Since small genetic errors occur within cells at all times – most but not all of which are repaired – it follows that some cancers may develop as a result of an accumulation of random changes which cannot be attributed to environmental or other causes. The environmental factors known to cause cancer, such as radiation and chemicals (including tar from tobacco, asbestos, etc.), do so by increasing the overall rate of acquired genetic damage. Certain viral infections can induce speci?c cancers (e.g. HEPATITIS B VIRUS and HEPATOMA, EPSTEIN BARR VIRUS and LYMPHOMA) probably by inducing alterations in speci?c genes. HORMONES may also be a factor in the development of certain cancers such as those of the prostate and breast. Where there is a particular family tendency to certain types of cancer, it now appears that one or more of the critical genetic abnormalities required for development of that cancer may have been inherited. Where environmental factors such as tobacco smoking or asbestos are known to cause cancer, then health education and preventive measures can reduce the incidence of the relevant cancer. Cancer can also affect the white cells in the blood and is called LEUKAEMIA.
Treatment Many cancers can be cured by surgical removal if they are detected early, before there has been spread of signi?cant numbers of tumour cells to distant sites. Important within this group are breast, colon and skin cancer (melanoma). The probability of early detection of certain cancers can be increased by screening programmes in which (ideally) all people at particular risk of development of such cancers are examined at regular intervals. Routine screening for CERVICAL CANCER and breast cancer (see BREASTS, DISEASES OF) is currently practised in the UK. The e?ectiveness of screening people for cancer is, however, controversial. Apart from questions surrounding the reliability of screening tests, they undoubtedly create anxieties among the subjects being screened.
If complete surgical removal of the tumour is not possible because of its location or because spread from the primary site has occurred, an operation may nevertheless be helpful to relieve symptoms (e.g. pain) and to reduce the bulk of the tumour remaining to be dealt with by alternative means such as RADIOTHERAPY or CHEMOTHERAPY. In some cases radiotherapy is preferable to surgery and may be curative, for example, in the management of tumours of the larynx or of the uterine cervix. Certain tumours are highly sensitive to chemotherapy and may be cured by the use of chemotherapeutic drugs alone. These include testicular tumours, LEUKAEMIA, LYMPHOMA and a variety of tumours occurring in childhood. These tend to be rapidly growing tumours composed of primitive cells which are much more vulnerable to the toxic effects of the chemotherapeutic agents than the normal cells within the body.
Unfortunately neither radiotherapy nor currently available chemotherapy provides a curative option for the majority of common cancers if surgical excision is not feasible. New e?ective treatments in these conditions are urgently needed. Nevertheless the rapidly increasing knowledge of cancer biology will almost certainly lead to novel therapeutic approaches – including probably genetic techniques utilising the recent discoveries of oncogenes (genes that can cause cancer). Where cure is not possible, there often remains much that can be done for the cancer-sufferer in terms of control of unpleasant symptoms such as pain. Many of the most important recent advances in cancer care relate to such ‘palliative’ treatment, and include the establishment in the UK of palliative care hospices.
Families and patients can obtain valuable help and advice from Marie Curie Cancer Care, Cancer Relief Macmillan Fund, or the British Association of Cancer United Patients.
www.cancerbacup.org.uk
www.mariecurie.org.uk... cancer
The disease is transmitted by the anopheles protozoa. Old cases present with fever, jaundice, diarrhoea and confusion.
Symptoms: incubation 2-5 weeks. Onset sudden, with shivering and high fever (104°F), headache, vomiting. Symptoms recur every 2-3 days. Blood sample examination confirms.
Treatment. Drugs once useful in the fight against malaria are losing their effectiveness. Drug resistance becomes a major problem; in which case the remedies of antiquity have something to offer.
Alternatives. Yarrow was once regarded as the Englishman’s Quinine. Nettle tea (Dr Compton Burnett). Prickly Ash (Ellingwood). Barberry, Chiretta, Peruvian bark BHP (1983). Mountain Grape (Berberis aquifolium) (Ellingwood). Wild Indigo, cases of extreme prostration (Dr Wm Boericke).
Sweet Wormwood. The Chinese Qing Hao (Artemisia annua) proved beneficial for millennia before Quinine arrived on the scene. Its re-discovery by Professor Nelson is declared ‘very effective’.
Formula. Liquid Extracts: Boneset 1; Yarrow 1; Barberry half; Valerian half. Few drops Tincture Capsicum. Dose: 1-2 teaspoons every 2 hours.
Malaria was rife in parts of America, especially Arkansus. During the Civil War it was difficult to obtain Quinine and various alternatives were tried. Where symptoms of chills and intermittent fever presented, Gelsemium gained considerable reputation as a substitute, also as a preventative. A favourite prescription was three drops tincture in a little brandy every 2-3 hours before the chill, and repeated every hour.
Dr M.H. Grannell, Sinaloa, Mexico. “I do not doubt that I treat more malaria than any other five physicians in the United States. My sole remedy, unless other indications present themselves, is Gelsemium. I give the following with never-failing results: 30 drops Tincture Gelsemium in 4oz water. Dose: 1 teaspoon hourly.” (Ellingwood, June 1920)
Thomas Nuttall, botanist. In 1819, when on tour in Arkansus, relieved a malarial attack with decoction of Boneset.
David Hoffman, MNIMH. 1 teaspoon Peruvian bark in each cup boiling water; infuse 30 minutes. Thrice daily.
Diet. 3-day fast.
Treatment by or in liaison with a general medical practitioner. ... malaria
Ultrasound is replacing ISOTOPE scanning in many situations, and also RADIOGRAPHY. Ultrasound of the liver can separate medical from surgical JAUNDICE in approximately 97 per cent of patients; it is very accurate in detecting and de?ning cystic lesions of the liver, but is less accurate with solid lesions – and yet will detect 85 per cent of secondary deposits (this is less than COMPUTED TOMOGRAPHY [CT] scanning). It is very accurate in detecting gall-stones (see GALL-BLADDER, DISEASES OF) and more accurate than the oral cholecystogram. It is useful as a screening test for pancreatic disease and can di?erentiate carcinoma of the pancreas from chronic pancreatitis with 85 per cent accuracy.
Ultrasound is the ?rst investigation indicated in patients presenting with renal failure, as it can quickly determine the size and shape of the kidney and whether there is any obstruction to the URETER. It is very sensitive to the presence of dilatation of the renal tract and will detect space-occupying lesions, di?erentiating cysts and tumours. It can detect also obstruction of the ureter due to renal stones by showing dilatations of the collecting system and the presence of the calculus. Adrenal (see ADRENAL GLANDS) tumours can be demonstrated by ultrasound, although it is less accurate than CT scanning.
The procedure is now the ?rst test for suspected aortic ANEURYSM and it can also show the presence of clot and delineate the true and false lumen. It is good at demonstrating subphrenic and subhepatic abscesses (see ABSCESS) and will show most intra-abdominal abscesses; CT scanning is however better for the retroperitoneal region. It has a major application in thyroid nodules as it can di?erentiate cystic from solid lesions and show the multiple lesions characteristic of the nodular GOITRE (see also THYROID GLAND, DISEASES OF). It cannot differentiate between a follicular adenoma and a carcinoma, as both these tumours are solid; nor can it demonstrate normal parathyroid glands. However, it can identify adenomas provided that they are more than 6 mm in diameter. Finally, ultrasound can di?erentiate masses in the SCROTUM into testicular and appendicular, and it can demonstrate impalpable testicular tumours. This is important as 15 per cent of testicular tumours metastasise whilst they are still impalpable.
Ultrasonic waves are one of the constituents in the shock treatment of certain types of gallstones and CALCULI in the urinary tract (see LITHOTRIPSY). They are also being used in the treatment of MENIÈRE’S DISEASE and of bruises and strains. In this ?eld of physiotherapy, ultrasonic therapy is proving of particular value in the treatment of acute injuries of soft tissue. If in such cases it is used immediately after the injury, or as soon as possible thereafter, prompt recovery is facilitated. For this reason it is being widely used in the treatment of sports injuries (see also SPORTS MEDICINE). The sound waves stimulate the healing process in damaged tissue.
Doppler ultrasound is a technique which shows the presence of vascular disease in the carotid and peripheral vessels, as it can detect the reduced blood ?ow through narrowed vessels.
Ultrasound in obstetrics Ultrasound has particular applications in obstetrics. A fetus can be seen with ultrasound from the seventh week of pregnancy, and the fetal heart can be demonstrated at this stage. Multiple pregnancy can also be diagnosed at this time by the demonstration of more than one gestation sac containing a viable fetus. A routine obstetric scan is usually performed between the 16th and 18th week of pregnancy when the fetus is easily demonstrated and most photogenic. The fetus can be measured to assess the gestational age, and the anatomy can also be checked. Intra-uterine growth retardation is much more reliably diagnosed by ultrasound than by clinical assessment. The site of the placenta can also be recorded and multiple pregnancies will be diagnosed at this stage. Fetal movements and even the heartbeat can be seen. A second scan is often done between the 32nd and 34th weeks to assess the position, size and growth rate of the baby. The resolution of equipment now available enables pre-natal diagnosis of a wide range of structural abnormalities to be diagnosed. SPINA BIFIDA, HYDROCEPHALUS and ANENCEPHALY are probably the most important, but other anomalies such as multicystic kidney, achondroplasia and certain congenital cardiac anomalies can also be identi?ed. Fetal gender can be determined from 20 weeks of gestation. Ultrasound is also useful as guidance for AMNIOCENTESIS.
In gynaecology, POLYCYSTIC OVARY SYNDROME can readily be detected as well as FIBROID and ovarian cysts. Ultrasound can monitor follicular growth when patients are being treated with infertility drugs. It is also useful in detecting ECTOPIC PREGNANCY. (See also PREGNANCY AND LABOUR.)... ultrasound
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