Essential care is being denied to advanced secondary breast cancer patients, according to the charity Breast Cancer Care.
Unlike 98% of primary patients, secondary sufferers do not have access to a named health care professional for medical and emotional support.
Advanced or secondary breast cancer is where the disease has spread to other parts of the body such as the liver, lungs or bones.
Dr Peter Harvey, Chairman of the Secondary Breast Cancer Taskforce, said: "It is very disappointing that half of all patients are not given the lifeline of a dedicated nurse who can help coordinate their care.
"Clinical nurse specialists already posses many of the skills and knowledge needed, and cancer networks need to work with individual trusts and breast care teams to see how they can best provide this specialised support."
Carol Core, 53, from Peterborough, was diagnosed with primary breast cancer in 1995, and almost 10 years later she was told the cancer had spread to her spine and liver.
She said: "Some people may get information from other health care professionals, but I don't think there is as yet a uniformed approach. A key worker would alleviate some of the stress and anxiety."