Cancer attributable to infections
Dr J.D. Wig
Infections play an important role in the development of certain cancers. The global burden of cancer associated with infectious agents approaches 20 per cent of all malignancies. The burden of infection-related cancers is higher in low and middle income group countries.

Shoulder instability: Early treatment prevents disability
Dr Ravinder Chadha
houlder instability is a common occurrence, encountered in a day-to-day practice. This condition entails loosening of the ligaments and capsule surrounding the shoulder joint.


Cancer attributable to infections
Dr J.D. Wig

A view of a free cancer awareness camp.
A view of a free cancer awareness camp. — A Tribune photograph

Infections play an important role in the development of certain cancers. The global burden of cancer associated with infectious agents approaches 20 per cent of all malignancies. The burden of infection-related cancers is higher in low and middle income group countries. Nearly 22 per cent of cancers are due to infections whereas in high income group countries, the figure is 7.4 per cent. In China, more than a quarter of cancerous cases were infectious in origin. The countries with lowest rates of infection-related cancers are Australia, New Zealand and the Netherlands. Thirty per cent of infection-related cancers occur in people under the age of 50 years.

There are three known cancer-causing infectious agents: viruses, bacteria and parasites. Viruses account for 64 per cent of infection-induced cancers. Infection with certain viruses, bacteria and parasites has been identified as strong risk factors for specific cancers. An international agency for research on cancer has identified infectious agents that are carcinogenic to humans. In 2008, of the 7.5 million deaths worldwide from cancer, 1.5 million were due to infections. A much higher proportion of cancer deaths is attributed to infections in low and middle income countries (20 per cent) than in high income countries (9 per cent). In a study from South Korea, 24.7 per cent of all cancer deaths were attributable to infections.

Ten infectious agents are known to increase the risk of cancer . Infectious agents of particular importance that have been identified as carcinogenic to humans are human papilloma virus (HPV), hepatitis B (HBV) and C(HCV), epstein barr virus, human herpes virus and bacterium helicobacter pylori (H. Pylori).

Human papilloma virus is associated with cervical cancer and other anogential cancer (penile, vulva, vagina, and anus). Hepatitis B and C viruses cause liver cancer. The epstein barr virus is associated with hodgkins and non-hodgkins lymphoma. Helicobacter pylori — a bacterium that causes stomach cancer.

Cancer of the uterine cervix is the most common cancer in low and middle income countries. Changing sexual behaviour leading to increasing persistent infection with high risk HPV is well established as a cause of cervical cancer. Sexually transmitted HPV high risk types have been found in approximately 70 per cent of all cases of cervical cancer worldwide. There is an urgent need for HPV-related education aimed at reducing the burden of HPV induced gentioanal cancer. HPV vaccine is now available in many countries to help prevent cervical cancer. HPV vaccine is administered to females aged between 9 and 26 years in most countries. A striking reduction in cervical high grade precancerous lesions in young women has been reported from Australia where there has been a rapid and widespread uptake of HPV vaccine by women younger than 27 years. The efficacy of vaccine against HPV is more than 90 per cent for both cervical and anal neoplasia.

In India, cervical cancer is a leading cancer among women and almost all cases show prevalence of high risk — HPV infection. HPV has also been detected in a significant proportion of anal, vaginal, penile, oral and esophageal cancer. Infection with high risk type of HPV causes more than 80 per cent cases of anal cancer.

Worldwide, over 80 per cent primary liver cancers are attributable to chronic infection with hepatitis B or C virus. People with chronic hepatitis B infection are more than 200 times more likely to develop liver cancer than uninfected people. HBV infection is common throughout Asia and Africa.

A combination of cirrhosis and viral hepatitis presents the highest risk of liver cancer development. In Taiwan, the incidence of liver cancer in children and adolescents has been substantially reduced by childhood vaccination. Iatrogenic transmission of HCV can be avoided with safer practices for injections and blood transfusion and preference of oral drug delivery over injections. In China, where most liver cancers are diagnosed, neonatal hepatitis B vaccination programmes have been expanded.

HIV-positive individuals face a greater risk of acquiring AIDS defining and non-AIDS defining cancers. The most common AIDS defining cancers are kaposi sarcoma, non-hodgkins lymphoma and cervical cancer. Non-AIDS defining cancers include anal and lung cancers.

Stomach infection with H. pylori fosters chronic inflammation and significantly increases the risk of developing peptic ulcer disease and gastric cancer. The uniform decrease of stomach cancer is commonly ascribed to both a reduction in H. Pylori infection and to improved food preservation practices and better nutrition. Epidemiological and experimental evidence strongly implicate several bacterial and parasitic agents in the promotion of colorectal carcinogenesis.The mechanisms by which bacteria contribute to cancer formation are complex.

Helminth infections definitely carcinogenic to humans are schistosoma haematobium (urinary bladder) and food-borne liver flukes — clonorchis sinensis and opisthorchis viverrini associated with inducing cancer of the bile duct and cancer of the liver. An association between schistosomiasis and urinary bladder cancer is particularly evident in Egypt.

Identifying infectious agents and implementation of preventive measures to eradicate known risk factors can lead to effective cancer prevention and could change the shape of caner burden in low and middle income regions. Effective vaccines for HPV and HBV are available. Increasing vaccine coverage should be a priority in high-burden countries. Application of public health methods for infection prevention such as vaccination, safer injection practices or antimicrobial treatment could have a substantial effect on future burden of cancer.

The writer, a former Head of the Department of General Surgery, PGI, is now associated with Fortis Hospital, Mohali.


Shoulder instability: Early treatment prevents disability
Dr Ravinder Chadha

Shoulder instability is a common occurrence, encountered in a day-to-day practice. This condition entails loosening of the ligaments and capsule surrounding the shoulder joint. In certain cases, the unstable shoulder joint actually slips out of the socket and becomes dislocated. If left untreated, this could lead to chronic disability and arthritis of the shoulder joint.

The shoulder joint is actually a ball and socket joint. The shoulder blade acts as the socket while the head of the humerus (upper arm bone) bone acts as the ball. Surrounding the ball and socket joint is the capsule and ligaments. In addition, a group of muscles known as the “Rotator Cuff” cross the shoulder joint which collectively hold the shoulder joint in position. This helps, rather reinforces, the shoulder’s stability. Instability happens whenever a force overcomes the strength of the rotator cuff muscles and ligaments of the shoulder.

The shoulder could encounter instability, subluxation and dislocation.

Instability causes slipping.

Subluxation- Humerus head slips partially out of the socket and then returns to its normal position.

Dislocation is complete loss of articulation of humeral head in glenoid cavity. In nearly all dislocations, the humeral head slips out in front of the glenoid.

Causes of shoulder instability

A fall or a direct blow to the shoulder or outstretched hand can cause this problem. The shoulder may return to normal but often the joint remains unstable. The ligaments and cartilage around the glenoid becomes stretched/torn. This renders them ineffective to keep the shoulder in the socket when moving.

Shoulder instability may also occur gradually over time due to repeated stress to the shoulder joint associated with repetitive shoulder movements. Abnormal biomechanics such as poor throwing (while playing cricket) or faulty swimming stroke. This usually happens with sports requiring repeated overhead activities such as cricketers, tennis players, swimmers, etc.

Shoulder instability is found in individuals suffering from generalised ligaments’ laxity throughout the body. This usually is since birth.


There may be no symptoms at all.

There might be pain during certain activities, pain on rest particularly at night.

Clicking sound in the shoulder during certain movements.

Loss of power, feeling of weakness.

Apprehension that the shoulder may dislocate specially with abduction/external rotation.

In severe cases of shoulder instability, there is recurrent subluxation, dislocation of the shoulder. This may be associated with shoulder pain and occasionally a “dead arm” sensation which typically resolves after a few minutes’ rest.

In severe cases, relatively minor activities such as yawning or rolling over in the bed may result in subluxation and dislocation.


Acute cases require sling – up to age 20 years (3-4 weeks); age 20-30 years (2-3 weeks); more than 30 years (1-2 weeks); more than 40 years (3-5 days) in order to avoid frozen shoulder.

Activities which place large amounts of stress through the shoulder joint like overhead activities vis-à-vis throwing, swimming and bench press should be restricted. This allows the body to initiate the healing process and prevent further tissue damage.

Shoulder shrugs, scapular protraction, retraction and depression can help.

Pendulum exercises are also useful.

Rotator cuff or close chain isometric exercises are very effective.

Appropriate treatment of patients with shoulder instability is essential to ensure speedy recovery. Once the condition becomes chronic, healing slows down significantly, resulting in markedly increased recovery time. In cases of recurrent shoulder subluxation or dislocation that is unresponsive to conservative treatment, surgical repair of the shoulder joint capsule may be indicated to stabilise the shoulder.

The writer is a former doctor/physiotherapist, Indian Cricket Team.


Health Notes
Three servings of milk per day can protect bones from breaking

London: Three servings of milk or yoghurt a day can make bones stronger, according to a new study led by an Indian-origin researcher. US-based academics found middle-aged people who ate at least three servings a day had higher bone mineral density, resulting in bones that were less likely to break, the Telegraph reported. However, they found that no such positive effect from eating cream or ice-cream. Dr Shivana Sahni, of the Hebrew SeniorLife Institute of Ageing Research, which is affiliated with Harvard University, said: "Dairy foods provide several important nutrients that are beneficial for bone health." — ANI

Obesity may up risk of MS in kids and teen girls

Washington: Being obese may increase the risk of developing multiple sclerosis (MS) in children and teenage girls, according to new research. "Over the last 30 years, childhood obesity has tripled," said study author Annette Langer-Gould, MD, PhD, with the Kaiser Permanente Southern California Department of Research and Evaluation in Pasadena and a member of the American Academy of Neurology. "In our study, the risk of pediatric MS was highest among moderately and extremely obese teenage girls, suggesting that the rate of pediatric MS cases is likely to increase as the childhood obesity epidemic continues," Langer-Gould added. For the study, researchers identified 75 children and adolescents diagnosed with pediatric MS between the ages of 2 and 18. Body mass index (BMI) from before symptoms appeared was obtained. — ANI

Family history key to heart health

Washington: Family history is one of the strongest predictors of heart disease, according to an expert. "If you look at how heart disease occurs, about 80 per cent takes place in people with a strong family history," said University of Alabama at Birmingham (UAB) Department of Epidemiology Professor and Chair Donna Arnett. Arnett, who is serving as the president of the American Heart Association (AHA), said this message goes hand in hand with following the AHA's "Life's Simple 7": getting active, controlling cholesterol, eating better, managing blood pressure, losing weight, reducing blood sugar and quitting smoking. — ANI