Modifiable risk factors for breast cancer recurrence: what can we tell survivors?
The potential for recurrence causes considerable distress for breast cancer survivors. Major information sources for survivors and providers offer few clear recommendations for postdiagnosis lifestyle change related to recurrence. To design interventions to improve long-term survivors' care and quality of life, we must know what survivors are doing to prevent recurrence in the absence of solid evidence, whether survivors' perceptions and behaviors correspond to hypothesized modifiable risk factors for recurrence, and whether survivors are adopting behaviors that could otherwise be harmful to their health. Our review first addresses the general lack of consensus on the impact of specific lifestyle factors on breast cancer recurrence and the resulting equivocal lifestyle recommendations for survivors. Second, we describe inadequacies of the studies of survivors' lifestyle changes related to recurrence. Because much of the existing knowledge about modifiable risk factors for recurrence comes from studies of survivors whose participation and behavior change were potentially influenced by their concern about recurrence, we need large, population-based observational studies of randomly selected breast cancer survivors, adequately representing the target population. Critical are data on lifestyle change from prediagnosis to postdiagnosis and changes over time after diagnosis, extensive data on conventional and nonconventional treatments, and the temporal relationship between behaviors and treatments, and inclusion of the full complement of potential lifestyle risk factors for recurrence. Understanding in detail the current status of survivors' perceptions and behaviors related to modifiable risk factors for recurrence can provide considerable practical information to inform future interventions and communication strategies for breast cancer survivors.