Epidemiologic evidence of slow growing, nonprogressive or regressive breast cancer: A systematic review

Abstract

The general aim of this systematic review is to mitigate breast cancer (BC) overdiagnosis and overtreatment. The specific aim is to summarize available data on the occurrence and features of indolent invasive or in situ (DCIS) BC, and precisely survival of untreated cases, prevalence of occult cancers found in autopsies, frequency of regressive BC. PubMed, Embase and Cochrane Library were systematically searched up to 3/31/2014. Eligibility criteria were: cohort studies, case-control studies, uncontrolled case series assessing survival in women with a diagnosis of BC who did not receive treatment compared to treated women; case series of autopsies estimating the prevalence of undiagnosed BC; cohort studies, case-control studies, uncontrolled case series, case reports assessing the occurrence of spontaneous regression of BC in women with a confirmed histology diagnosis. Untreated BC: 8 cohort studies and 12 case series (3593 BC) were included. In three controlled cohort studies (diagnoses 1978-2006), the 5-years overall survival was 19-43%. Occult BC: 8 case series (2279 autopsies) were included. The prevalence of invasive BC undiagnosed during lifetime range was 0-1.5%, while for DCIS the range was 0.2-14.7%. Spontaneous regression: 2 cohort studies, 3 case reports, 1 case series included. In the cohort studies the relative risk of regression for screen detected compared with nonscreened BC was estimated as 1.2 and 1.1. It seems plausible that around 10% of invasive BC are not symptomatic during life, and that one fith of BC patients if untreated would be alive after 5 years. Around 1 of 10 screen-detected BC may regress according two studies.There is a long standing debate on breast cancer (BC) natural history.1,2 A model suited to the current understanding of cancer biology includes cases with rapid development or early dissemination, cases likely to progress slowly if untreated, and indolent or regressive lesions. 3BC screening has contributed to the understanding of the complexity of the natural history of the neoplastic process. It allowed to detect early preclinical stages and to improve the diagnostic process aiming at identifying and treating those conditions most likely associated with morbidity and mortality.

Risk stratification in breast cancer screening: Cost‐effectiveness and harm‐benefit ratios for low‐risk and high‐risk women

“…In MISCAN, breast cancer starts with the development of preclinical ductal carcinoma in situ (DCIS), which may progress through the invasive successive stages T1a, T1b, T1c and T2+ (semi‐Markov process). A very small fraction of DCIS is assumed to regress 13 …”

“…A very small fraction of DCIS is assumed to regress. 13 Model outcomes are first estimated for a situation without screening, in which breast cancers can be detected when in the clinical detectable phase or progress to the next preclinical stage. Hereafter, mammography screening and improvements in survival after screen-detection are modelled.…”

Modeling Ductal Carcinoma In Situ (DCIS): An Overview of CISNET Model Approaches

“…One model (model W) allows regression of pre-clinical DCIS as well as invasive disease ( Figure 1D). Although the regression of breast cancer, especially invasive disease, is controversial, there is some evidence supporting the possibility of regressing tumors, including epidemiological evidence 23 and a case report on the regression of breast cancer on imaging. 24 Most of the CISNET models have used data from the Surveillance, Epidemiology, and End Results (SEER) Program, 25 typically age-specific incidence over time, combined with data from other sources (Wisconsin cancer registry for model W, Dutch data for model E) to estimate DCIS parameters; although, one model used data from another source (Norwegian data for model D).…”

Estimate of false-positive breast cancer diagnoses from accuracy studies: a systematic review

“…The impact of false-positive histological diagnosis on unnecessary treatment, as well as that of overdiagnosis,66 is not negligible and of importance in clinical practice.…”