The evidence base in support of breast cancer surveillance guidelines: Flying without a net?

Abstract

25 Background: There are a growing number of breast cancer survivors, and they are often followed by primary care providers (PCP). With limited specialized cancer knowledge, PCPs may rely on guidelines (GL), but surveillance recommendations vary based on source. The data informing post-treatment surveillance is limited. We reviewed the evidence in support of varying breast cancer surveillance recommendations found in national GLs. Methods: We included breast cancer GLs containing surveillance recommendations from professional societies and government organizations in North America, the UK, and Europe (2010-5). We used online search engines and organization websites to identify GLs. Surveillance testing recommendations were recorded; relevant citations for each recommendation were identified and classified by evidence type. Results: We identified 6 breast cancer GLs from US, UK, and Europe; all recommended mammography. Other recommendations varied, with contradictory recommendations regarding MRI and US. Overall, 13 systematic reviews (SR) were cited; 9 related to mammography. One SR of MRI and one of mammography were cited by 2 GLs; remaining SRs were each cited by 1 GL. Other references included 34 primary studies, 9 narrative reviews and 11 older GLs. Among 23 surveillance testing recommendations from the 6 GLs, the highest level of supporting evidence was a SR in 44% and a primary study in 22%; the remainder cited no direct evidence. At times, the same citation supported contradictory recommendations in different guidelines. Conclusions: Evidence for surveillance recommendations is often low-level and cited references vary across GLs; the same evidence is used to support contradictory recommendations. Better evidence and its more consistent application would facilitate high quality breast cancer survivorship care.