Presentation Intervals and the Impact of Delay on Breast Cancer Progression in a Black African Population.
Abstract BACKGROUND: The help-seeking interval or the primary-care interval are points of delays in breast cancer presentation. To inform future breast cancer down-staging intervention, we described the contribution of each interval to the delay and the impact of delay on tumor progression.METHOD: Multicentered survey from June 2017 to May 2018. We hypothesized that most patients visited the First Healthcare Provider within 60days of tumor detection. Inferential statistics were by t-test, chi-square test, and Wilcoxon-Signed Rank test at p-value 0.05 or 95% confidence limits. Time-to-event was by survival method. Multivariate analysis was by logistic regression.RESULTS: Respondents were females between 24 and 95 years (n=420). Most respondents visited FHP within 60 days of detecting symptoms (230 (60%, 95% CI 53-63). Most had long primary-care (237 of 377 (64% 95%CI 59-68) and detection-to-specialist (293 (73% (95% CI 68-77)) intervals. The primary care interval (median 106days) was longer than the help-seeking interval ( median 42days ) Wilcoxon signed-rank test p= 0.001. There was strong correlation between length of primary care interval and the detection-to-specialist interval (r= 0.9, 95% CI 0.88- 0.92). Patronizing the hospital, receiving the correct advice, and having a big tumor (>5cm) were associated with short intervals. Tumors were detected early, but most became advanced before arriving at the specialist clinic. The difference in tumor size between detection and arriving at a specialist clinic was 5.0±4.9cm (95% CI 4.0-5.0). The instantaneous hazard of progressing from early to locally advanced disease was least in the first 30 days(3%). The hazard was 31% in 90 days.CONCLUSION: Most respondents presented early to the first healthcare provider, but most arrived late at a specialist clinic. The primary care interval was longer than the help-seeking interval. Most tumors were early at detection but locally advanced before arriving in a specialist clinic. Interventions aiming to shorten the primary care interval will have the most impact on time to breast cancer presentation for specialist oncology care in Nigeria.