Public Health England (PHE) warned that one in three breast cancers are in women over the age of 70.
This age group also accounts for more than half of all breast cancer deaths annually, latest figures showed, Xinhua reported.
This came as PHE launches a new national 'Be Clear on Cancer' campaign to remind older women to visit their doctor if they spot any changes in their breasts. The campaign will see new national adverts running on TV and in the press until March 16.
Two thirds of women aged 70 and over wrongly think women of all ages are equally likely to get breast cancer, when in fact a woman's risk of breast cancer increases with age, PHE said.
Around 13,500 women aged 70 and over are diagnosed with breast cancer in England each year, yet survival rates are lower in this age group compared to younger women. Lack of awareness of symptoms other than a lump, such as changes in the shape or size of the breast, is believed to be one of the reasons for this, which the campaign aims to change.
According to experts, the earlier breast cancer is diagnosed, the higher the chance of survival - more than 90 percent of all women diagnosed with the earliest stage survive for at least 5 years. This figure is around 15 percent for women diagnosed at a late stage.