Background: Delayed presentation of symptomatic breast cancer is associated with lower survival. Understanding of the factors that influence delay is important for the development of strategies to shorten delays. We did a systematic review to assess the quality and strength of evidence on risk factors for delays by patients and providers.
Methods: We generated hypotheses about the relation between each putative risk factor and delay, against which we tested studies. We did searches to identify papers containing original data related to risk factors for delays by patients (n=86) and providers (n=28). We critically appraised the papers for inclusion in the review according to predefined criteria. The small number of studies of adequate quality did not allow formal meta-analysis. We therefore assigned strength of evidence according to a combination of the number and size of studies supporting, not supporting, or refuting the hypotheses.
Findings: Most studies were deemed to be of poor quality and were excluded. Among 23 studies of adequate quality, however, there was strong evidence for an association between older age and delay by patients, and strong evidence that marital status was unrelated to delays by patients. Younger age and presentation with a breast symptom other than a lump were strong risk factors for delays by providers. Moderate evidence was shown for several other factors.
Interpretation: The strength of the current evidence is inadequate to inform the development of specific strategies to shorten delays by patients or providers. Clarification of the findings of this review through a major programme of primary research is urgently required.