Why cancer strikes more women than men in India.

Pedro_P

AFP
For oncologists worldwide, India can look like a puzzling outlier when it comes to cancer.
For one, despite reporting more than 1.5 million new cases every year, India's cancer rate remains lower than, say, the economically advanced US. That's about 100 cases per 100,000 people compared with 300 in the US.
This may be easier to explain: Indians are a vastly younger people and as people get older, the chances of getting cancer get higher. But survival rates are poor - barely a third of patients survive beyond five years or more after being diagnosed with the disease.
What is more difficult to explain is why more women in India are diagnosed with cancer than men, according to a new study published in The Lancet Oncology. Men report a 25% higher incidence of cancer than women all over the world, but India bucks this trend.
Sharp rise
Having said that, more men die of cancer in India than women.
But that is because breast, cervical, ovarian and uterine cancer, that account for more than 70% of the cancers in women in India, allow higher chances of survival on treatment. Indian men suffer largely from lung or oral cancer - both related to smoking and ingesting tobacco - which are more virulent with lower survival rates.
Breast cancer is now the most common cancer among women in India, accounting for 27% of all cancers among women. Oncologists say there has been a sharp uptick in cases in the last six years.
At 45-50 years, the peak age of onset of breast - and ovarian cancer - in India appears to be a decade younger than the peak age (above 60 years) in high-income countries. This could be due to genetic and environmental factors.
Cancer is, at times, a genomic disease. Studies have shown the BRCA1 and BRCA2 genes usually increase a woman's risk of breast cancer four to eightfold and can explain why some families have lots of relatives diagnosed with breast cancer.
But less than 10% of the breast cancers in India are inherited, so genomic screening may not be very useful to find out the cause in the vast majority of female cancers.
Then there are regional variations.
The incidence of breast cancer is the highest, for example, in the capital, Delhi, but oncologists are not sure why. They can only speculate about increased awareness and higher rates of diagnosis, and not much more.
Dr Ravi Mehrotra, director of the National Institute of Cancer Prevention and Research and one of the authors of the study, believes that known risk factors for breast cancer - high-fat diet, obesity, late marriage, fewer children, inadequate breast feeding - may be leading to more cases in what is a rapidly urbanising country.
Also, he says, many women may be diagnosed late because of lack of awareness and reluctance to go to doctors...
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