An informed decision? Breast cancer patients and their knowledge about treatment

Although involving women in breast cancer treatment decisions is advocated, there is little understanding of whether women have the information they need to make informed decisions. The objective of the current study was to evaluate women's knowledge of survival and recurrence rates for mastectomy and breast conserving surgery (BCS) and the factors associated with this knowledge.

We used a population-based sample of women diagnosed with breast cancer in metropolitan Los Angeles and Detroit between December 2001 and January 2003. All women with ductal carcinoma in situ and a random sample of women with invasive disease were selected (N=2382), of which 1844 participated (77.4%). All participants were mailed surveys. The main outcome measures were knowledge of survival and recurrence rates by surgical treatment type.

Only 16% of women knew that recurrence rates were different for mastectomy and BCS, and 48% knew that the survival rates were equivalent across treatment. Knowledge about survival and recurrence was improved by exposure to the Internet and health pamphlets (p<0.01). Women who had a female (versus male) surgeon, and/or a surgeon who explained both treatments (rather than just one treatment) demonstrated higher survival knowledge (p<0.01). The majority of women had inadequate knowledge with which to make informed decisions about breast cancer surgical treatment.

Previous explanations for poor knowledge, such as irrelevance of knowledge to decision making and lack of access to information, were not shown to be plausible explanations for the low levels of knowledge observed in this sample.

These results suggest a need for fundamental changes in patient education to ensure that women are able to make informed decisions about their breast cancer treatment. These changes may include an increase in the use of decision aids and in decreasing the speed at which treatment decisions are made.