While 1,337 cases were reported in the city between 2001 and 2005, the study projected the number to rise to 2,664 by 2025.
The study, 'Increase in breast cancer incidence among older women in Mumbai: 30-year trend and prediction to 2025', was published in the international Cancer Epidemiology Journal in March.
"Lifestyle changes such as late marriages, delayed pregnancy and obesity are factors contributing to the rise in incidence of breast cancer among older women. Less number of children and less breastfeeding is also putting women at higher risk of breast cancer," said Dr Rajesh Dikshit, principal investigator of the study.
It predicts that from 698 breast cancer cases reported between 2001 and 2005 among the older age group, the number will rise to 1,545 cases by 2025.