Women are confused and feel misled about ways of detecting breast cancer, research shows.
Women concluded they did not know what to look for
Official information is vague, ambiguous and culturally insensitive, according to a report in the Journal of Medical Ethics.
This leaves women totally unsure of what to look for, the London study revealed.
Breast cancer experts say health information needs to be streamlined to avoid confusion.
The study, carried out in east London, analysed official information provided in leaflets and websites relating to the three detection methods currently in use - breast screening, breast self examination and breast awareness.
Breast screening by mammogram at three-yearly intervals is available to all women aged between 50 and 64.
Breast self examination, which has been phased out in the UK, relies on a woman to use self diagnosis, using information given by a health professional or found in leaflets.
Breast awareness, introduced in 1991, is not a medical technique, but emphasises body awareness where women are urged to check for any unusual changes in their breasts, while bathing, showering and dressing.
Women from the multi-cultural borough of Hackney in east London, were asked to assess the contents of leaflets and websites where the three methods of detection were described.
Their concerns were raised during 20 focus group discussions, some of which were held in English and some in other languages.
"Not one focus group participant said she was confident what to look for," said report author Professor Naomi Pfeffer from the London Metropolitan University.
She also pointed to a number of "inconsistencies, ambiguities and gaps" in literature promoting self examination and breast awareness.
One example was the fact that pain and tenderness was dismissed as a normal part of the menstrual cycle, yet also cited as a warning sign.
Another was a leading cancer charity's website which urged women to look out for pain and discomfort, but then said pain without other symptoms was unlikely
to be due to cancer.
Guidance also covered only what to look for before and after the menopause, not while it was taking place, said Professor Pfeffer.
There was no advice for women taking hormone replacement therapy, which affects breast tissue consistency.
Leaflets conveyed the wrong idea that breast cancer occurs mostly in younger women, by providing illustrations showing firm, young breasts rather than those of older women.
Professor Pfeffer was also critical of screening programme information which said women who fell outside a certain age range would not be invited for X-rays, but could request them.
This advice failed to convey any sense of urgency, she
Guidance on what to look for was addressed exclusively to white women.
One black woman pointed this out by saying: "Some people say it's the colouring of the breast but in black women it's a bit hard to talk about colouring".
Experts at Breast Cancer Care, which has been the leading provider of breast cancer information and support across the UK for 30 years, are alarmed by the findings.
Breast Cancer Care's joint chief executive Christine Fogg said: "We are aware that there is still a lot of confusion surrounding breast self-examination versus breast awareness and this is leading to women receiving mixed messages.
"We strongly feel that all sources of health promotion information, within the UK, should focus solely on breast awareness.
"Breast awareness is not about a daily routine and being constantly vigilant.
"It is about knowing what is normal for you so any unusual changes are noticed and looking at and feeling your breasts from time to time."
The charity agrees with Dr Pfeffer that the screening programme information, which suggests women outside the target age range can request an appointment, can be confusing.
Ms Fogg said: "We believe information produced by the Department of Health and NHS breast screening programme should stress that women over 70 need to remain breast aware once they leave the screening programme and that they can still request to be screened after this age."