Breast cancer is the leading cause of death among cancers in urban Indian women.
“Breast cancer is becoming more common. The cause is not known yet. It could be that more women are getting tested for breast cancer,” says Dr Archana Shetty of Narayana Hrudayalaya.
“Not all cases of breast cancers are genetically inherited,” says Dr Gopal Kundu, scientist at the National Centre for Cell Science, Pune.
He works on the areas related to targeted therapy using nanotechnology and chemical biology approaches, so that drugs are delivered directly to the cancer tissue.
They are also trying to develop breast cancer specific biomarkers for early diagnosis, he said.
“We need more cancer awareness programmes. Early detection is the only way to reduce mortality due to breast cancer. We need multiple programmes across the country,” he says.
Meanwhile, Dr Ryan Jensen, assistant professor of therapeutic radiology, Yale School of Medicine, New Haven, works on BRCA2 mutations in breast cancer.
He says, “Ten per cent of all cases of breast cancer is genetically inherited and, of these, about half are attributed to BRCA1 or BRCA2 mutations. These are defective genes; when normal they can repair defective DNA. Defects in DNA could be due to various reasons like UV radiation and free radicals. BRCA2 mutations result in chromosome repair defects leading to a tumour. “
According to Dr Jensen, “Breast cancer is one of the most prevalent cancers in the world. In the USA, about 1 in 8 women comes down with breast cancer.”
As Dr Gouri Chatterjee, scientist in Ryan’s lab says, “If we can find the switch for BRCA2 function, we can figure out what pathways or genes cooperate to allow cells that have lost BRCA2 to survive. We can then specifically target these genes/pathways using rationally designed drugs. A good example of this is the current use of PARP inhibitors, which selectively target BRCA2 mutant tumour cells.”
Dr Ryan says, “Cancer is not one disease but many diseases. The hardest part is when cancer cells become resistant to one type of therapy and evolve quickly. Treatment strategies may need to look at the genetic level and the molecular biology of the cell.
“Let us try and look at the genetic makeup of the tumour, knock out all pathways together, by giving more than a single drug and then, maybe, the cancer cell cannot evolve another pathway immediately and will die. It is likely that combination therapies using multiple drugs targeting several genes or pathways simultaneously will work most effectively.”
‘Survival Rate Less in India’
Dr Shetty says, “Survival rates in India are lower than in the West. There, the average rate of survival is more than 70 per cent, while in India it is about 50 per cent
Most women report only when the cancer is at an advanced stage and there is very little we can do.
“Another difference seen in India is breast cancer in the age group of 40 to 50 years, unlike 50 - 70 years in the West. Women in 30’s also report of the disease. So, it has a different biology in India”.
“If it is a small tumour, a small part of the breast can be removed by lumpectomy, followed by radiation. If cancer has spread to four lymph nodes under the armpits or is bigger than 5 cm, mastectomy is performed. Surgery is followed by radiation.”
“Surgery is definitely necessary even in small tumours or the cancer may come back,” she adds.