Young women across the city continue to undergo mammograms for suspected breast lumps, on the advice of their doctors. A mammogram is an X-ray of the breast in which the tissue is compressed to give images of tumours that cannot otherwise be detected.

The test is effective only for people above 40, due to changes in muscle density with age.

"Mammograms are routinely prescribed by doctors in Calcutta for young women," said R.N. Sain, chief radiologist, Belle Vue. "Not only do they not work, but frequent exposure to radiation can affect other body parts, including the ovum," he warns.

"Young breast tissue is condensed, so a mammogram is of no use before the age of 40 years," said radiotherapist Subir Gangopadhyay.

Surgical gastroenterologist Sanjay De Bakshi has treated a 16-year-old girl who has had two mammograms. "I tried to tell her that simple pain need not mean breast cancer," said De Bakshi.

Every year, 1,500 new breast cancer cases are reported in Calcutta. Around 70 per cent of them have had multiple mammograms. Doctors say 90 per cent of such patients are diagnosed with non-malignant fibro cysts.