The timeliness of lung cancer care: A systematic review of systematic/scoping reviews on time intervals and their impacts on cancer outcomes.

Abstract

e18572 Background: Lung cancer is characterized by the aggressive nature and lack of early noticeable symptoms, highlighting the importance of timely care for lung cancer. This systematic review of systematic and scoping reviews provides the summary of review-level results related to the length of time intervals and the impact of these intervals on oncological outcomes. Methods: Eligible articles included published systematic or scoping reviews and meta-analyses that used systematic searching to investigate the length of time intervals and their impact on patient survival and disease stage at diagnosis in original studies on lung cancer, based on at least one interval involving the date of diagnosis as the start/endpoint. Articles were searched via PubMed, Embase, Web of Science, and the Cochrane Library (date range: from database inception to 6 August 2020) (PROSPERO identifier: CRD42020203530). Results: From 1395 identified publications, we included a total of 8 systematic/scoping reviews published in 2002-2018 (7 on length of intervals, 5 on survival/stage impact). For the length of intervals, these reviews found that intervals across countries/medical facilities are heterogeneous and often longer than recommended by guidelines. For the survival/stage impact, the results from these reviews indicated mixed (positive, negative, or no) associations between time intervals and patient survival/disease stage at diagnosis. We further summarized study-level results and confirmed the finding of mixed associations based on 36 eligible original studies from over 100 studies included in these reviews. Methodologically, review authors pointed out large variations in time intervals (96 unique variations) and methods used to measure intervals. Based on the reviews, we found that the intervals in studies were normally investigated cross-sectionally, rather than temporarily (to demonstrate the trend of intervals’ length over time). Conclusions: Current evidence indicates that patients with lung cancer may experience diagnosis and treatment delays, however, the association results between the length of intervals and lung cancer survival and stage are paradoxical. To minimize avoidable delays, future studies should keep updating the length of intervals and provide the trend analysis of the intervals over time, as part of cancer surveillance to guide future policy making and clinical practice. To improve the quality of future original studies and systematic reviews, specific guidelines and corresponding studies related to study design and methodology (e.g. types of time intervals, measures of time intervals, statistical analysis strategy) are warranted, especially underscoring the effect of “waiting time paradox” when investigating the impact of time intervals on patient outcomes.