Women's awareness of alcohol's role in boosting breast cancer risk is poor, indicates research published in the online journal BMJ Open.
Only one in five women attending breast clinics and screening appointments and only half of the staff questioned at one NHS UK centre knew that alcohol is a risk factor for breast cancer, the findings show.
This low level of awareness may not be the same everywhere, caution the researchers. But they nevertheless suggest that understanding of modifiable risk factors for the disease needs to be increased: breast clinic and screening appointments may offer the opportunity to do that.
Breast cancer is the most common cancer in the UK, with more than 54,000 new cases diagnosed and 11,000 deaths every year. Lifestyle factors account for nearly a quarter of all cases, with alcohol consumption and obesity topping the list.
Alcohol consumption is estimated to be responsible for between 5% and 11% of cases, with the risk increasing in tandem with the amount consumed, say the researchers.
They wanted to find out if women and staff using breast care services would find the provision of brief information on the health risks associated with alcohol acceptable.
They particularly wanted to know about prevailing levels of awareness of alcohol's role in breast cancer risk; and whether women were able to correctly identify alcohol units in drinks.
They drew on questionnaire and verbal feedback from 102 women attending for breast screening, 103 attending breast clinics because of symptoms, and 33 clinical staff at one UK NHS breast care centre.
Knowledge of modifiable risk factors was more or less the same in both patient groups. Around a third of participants (30%) in each group recognised obesity as a risk factor and one in two correctly identified smoking as another.
But only around one in six (16%) in the screening group, and around one in four (23%) in the breast clinic group knew that alcohol is a risk factor.
Between 60% and 73% of the women said they drank alcohol. Awareness of its role in upping breast cancer risk was significantly more likely among the breast clinic women (35%) than it was among those coming for screening (4%).
Only just over half of those who said they drank alcohol (88 out of 152; 58%) thought they knew how to estimate the alcohol content of drinks, although less than three quarters correctly estimated the alcohol content of a standard glass of wine, and just over half the amount in a pint of beer.
Asked how they felt about a 5-minute cancer prevention information session at either screening or breast clinic appointments, nearly a third (30.5%) of all the women said it would make them more likely to attend while more than two thirds (69.5%) said it would make no difference.
The preferred option, stated by 40%, was for a trained nurse to give them this information. But they voiced some concerns about feeling stigmatised and 'blamed' for drinking.
Clinical staff had better levels of awareness of breast cancer risk factors than patients, but they also had gaps in their knowledge.
Obesity was correctly identified as a risk factor by 58% (19 out of 33) of those asked, but only around half (52%) knew that alcohol also posed a risk. And less than half (45%) said they knew how much alcohol was in a drink.
But they cited various drawbacks to providing preventive information, including extra time and resource; the potential to make people anxious and contribute to the 'worried well' culture; as well as fears that it could come across as blaming and/or patronising.
The researchers acknowledge that the study involved only one breast care centre, and so may not be applicable elsewhere. And they recognise that substantial cultural and systemic changes might be needed to introduce such an approach.
But they write: "Over 20% of women aged 45 to 64 reportedly drink more than 14 units per week, so any intervention to reduce population level consumption could have a significant influence on breast cancer rates, as well as help to manage the side effects of treatment and improve the overall health of survivors."