Objectives We investigated whether changes in mammographic technique and screening policy have improved mammographic sensitivity, and elongated the mean sojourn time, since the introduction of biennial breast cancer screening in Nijmegen, the Netherlands, in 1975. Methods Maximum likelihood estimation, non-linear regression, and Markov Chain Monte Carlo simulation were used to estimate test sensitivity, mean sojourn time, and underlying breast cancer incidence in four time periods, covering 40 years of breast cancer screening in Nijmegen (1975–2012). Results Maximum likelihood estimation generated an estimated test sensitivity of approximately 90% and a mean sojourn time around three years, while the estimates based on non-linear regression and Markov Chain Monte Carlo simulation were 80% and four years, respectively. All three methods estimated a rise in the underlying breast cancer incidence over time, with approximately one case more per 1000 women per year in the final period compared with the first period. Conclusions The three methods showed a slightly higher mammographic sensitivity and a longer mean sojourn time in the last period, after the introduction of digital mammography. Estimates were more realistic for the more sophisticated methods, non-linear regression and Markov Chain Monte Carlo simulation, while the simple closed form approximation of maximum likelihood estimation led to rather high estimates for sensitivity in the early periods.

Objectives: To The aim of this study was to provide an overview of published mathematical estimation approaches to quantify the duration of the preclinical detectable phase using data from cancer screening programs.Methods: A systematic search in of PubMed and Embase was conducted for original studies presenting mathematical approaches using screening data. The studies were categorized by mathematical approach, data source, and assumptions made. Furthermore, estimates of the duration of the preclinical detectable phase of breast and colorectal cancer were reported per study population.Results: From 689 publications, 34 estimation methods were included. Five distinct types of mathematical estimation approaches were identified: prevalence to incidence ratio prevalence-toincidence ratio (n=8), maximum likelihood estimation (n=16), expectation-maximization algorithm (n=1), regression of observed on expected (n=6) and Bayesian Markov-cChain Monte Carlo estimation (n=5). Fourteen studies used data of from a both screened and an unscreened populations, whereas nineteen 19 studies included only information from a screened population.Estimates of the duration of the preclinical detectable phase varied between two 2 and seven 7 years for breast cancer within the HIP study (annual mammography and clinical breast examinations in women aged 40-64 years) and two 2 and five 5 years for colorectal cancer within the Calvados study (a one guaiac fecal occult blood test in men and women aged 45-74 years).Conclusions: Different types of mathematical approaches lead to different estimates of the duration of preclinical detectable phase duration. We advise researchers to use the method that matches the data available, and to use multiple methods for estimation when possible, as since no method is perfect.

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Background The major goal of routine follow‐up in oropharyngeal squamous cell carcinoma (OPSCC) patients is the asymptomatic detection of new disease in order to improve survival. This study evaluated the effect of routine follow‐up on overall survival (OS). Methods A retrospective cohort of 307 consecutive OPSCC patients treated with curative intent between 2006 and 2012 was analyzed. The effectiveness of routine follow‐up was studied by comparing treatment‐intent and OS in patients with asymptomatically versus symptomatically detected new disease. Results Three‐ and five‐year risks of new disease were 29% (95% CI: 24–34) and 33% (95% CI: 27–39). Of the 81 patients with locoregional recurrence or second primary head and neck cancer, 8 (10%) were detected asymptomatically with no difference in OS with those detected with symptoms. Conclusions Asymptomatic detection of new disease during routine visits was not associated with improved OS. The focus of follow‐up should be on providing psychosocial care and rehabilitation.

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