In solving a problem of this sort , the grand thing is to be able to reason backwards. That’s very useful accomplishment,and a very easy one, but people do not practice it much”—— Sherlock Holmes, in Sir Arthur Conan Doyle’s A study in Scarlet
One may not believe but I come across people regularly fearing cancer so much that they don’t want even to hear or know about it as if closing eyes and ears will prevent occurrence of these real Emperor of All Maladies- the CANCER!
Trying to figure out the cause of this disease, Cancer, and to dissect out ways to not to get caught by this disease unawares or to catch the cancer in it’s very infancy, is the real challenge!
As you know broadly there are two sets of diseases, the communicable and Non - communicable. Communicable diseases are largely infectious diseases caused by variety of organisms which include virus causing COVID 19 to protozoa causing malaria to Helminthic infection leading to Ascariasis or Round worm disease.
The Non- Communicable diseases are growing group of life style related diseases which include Diabetes mellitus, High blood pressure, Cardiovascular, kidney or liver diseases besides the Cancers. They are direct fallout of blind adoption of so called modern lifestyle, dietary patterns, social and psycho sexual behaviours influenced by hereditary factors applicable to each individual uniquely. Cancer is only the second most frequent cause of death in America and other western countries after cardiovascular diseases (trauma excluded) .
Data before the COVID pandemic, suggest that people inhabiting the developing world are rapidly catching up with the economically advanced countries of the west after their economic revival.
Every year there are around 10 million deaths and 20 million new cases of Cancer of various types are added globally. It is projected to reach 40 million yearly of new cases by 2040. The numbers are getting accelerated by increasing population load, environmental factors and predisposition of non-modifiable factors such as increasing longevity, gender specificity .family and genetic predisposition etc.
In India currently, 8 lac new cases are being registered and we all know that it is only the tip of the iceberg! Sadly many more are neither being diagnosed, registered nor being treated!
Epidemiological studies have shown that 70 to 90 per cent Cancers have diverse environment relationships and the rest are primarily of genetic origin. However, both influence each other.
Life style related factors such as increasing obesity in the population, physical inactivity, inappropriate dietary habits are the most important factors in causation of Cancer and these are fortunately correctable if given proper attention.
In recent years Obesity on its own ,added by general physical inactivity and quiet sitting for hours watching TV and social media platforms, have added to the misery.
BMI (Body Mass Index is the ratio of weight in Kg and height in meter squared = Kg/m2) above 25 is overweight and above 30 is obesity which is proportionate to rising numbers of cancer patients . Efforts to bring the BMI number to healthy range is mandated at every age as it helps not just cancer prevention but all non-communicable diseases and consequent healthy long life.
Vigorous exercise for more than 150 minutes a week or moderate physical exercise for over 300 minutes a week, is the recent update on physical exercise requirement as recommended by American cancer society in June 2021. Exercise should be a mix of Aerobic such as walking speedily or jogging as well as anaerobic exemplified by weightlifting.
Tobacco is the most important identifiable cause responsible for about 40 to 50 per cent of all cancers in men and 20 per cent in women.
India has besides tobacco smoking, the added burden of tobacco chewing and consuming raw in several forms in different cultural regions. Lip, Mouth and lung cancers are largely the fallout of excessive tobacco use. Supari (Acacia Nut) consumption has also been implicated in oral cancer.
Alcohol in all forms cause cancer irrespective of its source, however it’s permissible limit has been fixed to two drinks for males and one drink for females in a day. One drink is equivalent to 14 gms or 0 .6 ounce of pure ethyl alcohol which is present in 12 ounces of beer, 5 ounces of wine or 1.5 ounce of 80 proof distilled spirits. 4 drinks in a day is called heavy drinking.
Cancers of Head-Neck, esophagus, stomach, colorectal, liver etc , are strongly related in both sexes and Breast in females to alcohol consumption . This association is clearer with heavy drinkers.
Diet full of green leafy vegetables, colourful fruits whole grains, dairy products and fish provide protection against cancer and also against all other non-communicable diseases.
Deep frying and grilling produce trans - fatty acids. Grilling at very high temperature specially of red meats have been associated significantly with the process called DNA methylation and increased production of polycyclic Aromatic Hydrocarbons ( PAH ) and Heterocyclic Amines( HCA) which is directly associated with cancer risk . It is interesting to note that comparable high temperature grilling and deep frying of poultry and fish consumption has not been associated with significantly heightened cancer risk.
In Obesity, reducing diet should consist of low calorie with adequate protein roughage, fibres and plenty of water. Carbohydrate reduction is the key to all weight reducing diets. Three meals a day is not required especially for those who want to reduce weight. Free sugar and aerated sweet drinks should be excluded . It has become popular with younger generation due to huge commercial advertisements.
Very hot food should not be consumed as it is associated with stomach and oesophageal cancer risk, most prevalent in Japan and adjoining countries.
Prevention through regular screening for different cancer types should be brought into practice. Simple measures such as self-inspection of breast and self-administered Pap smear and now much better HPV-DNA test for uterine cervix is very useful in early diagnosis of preventable cancers in females. Cancer of uterine cervix can be eradicated from the population by vaccination against causative Human Papilloma virus. Viral hepatitis B and C both lead to cancer of liver. Hepatitis B has a very effective vaccine to prevent the disease. Both need screening to detect early and can be treated successfully if required.
In Males, prostate cancer can be picked up early by easily available blood test known as blood PSA (Prostate Specific Antigen) level.
Presently, we have an array of blood and genetic testing available which help immensely in picking up cancers much earlier in life where-ever family and genetic history indicates such possibilities.
The author is former Professor and Head of Medicine at RIMS, Ranchi, Jharkhand.