Addressing overdiagnosis and overtreatment in cancer: a prescription for change

Abstract

A vast range of disorders--from indolent to fast-growing lesions--are labelled as cancer. Therefore, we believe that several changes should be made to the approach to cancer screening and care, such as use of new terminology for indolent and precancerous disorders. We propose the term indolent lesion of epithelial origin, or IDLE, for those lesions (currently labelled as cancers) and their precursors that are unlikely to cause harm if they are left untreated. Furthermore, precursors of cancer or high-risk disorders should not have the term cancer in them. The rationale for this change in approach is that indolent lesions with low malignant potential are common, and screening brings indolent lesions and their precursors to clinical attention, which leads to overdiagnosis and, if unrecognised, possible overtreatment. To minimise that potential, new strategies should be adopted to better define and manage IDLEs. Screening guidelines should be revised to lower the chance of detection of minimal-risk IDLEs and inconsequential cancers with the same energy traditionally used to increase the sensitivity of screening tests. Changing the terminology for some of the lesions currently referred to as cancer will allow physicians to shift medicolegal notions and perceived risk to reflect the evolving understanding of biology, be more judicious about when a biopsy should be done, and organise studies and registries that offer observation or less invasive approaches for indolent disease. Emphasis on avoidance of harm while assuring benefit will improve screening and treatment of patients and will be equally effective in the prevention of death from cancer.

Figure 1. Models of tumour progression can affect screening benefit

(A) A linear model of tumour progression presumes that cancer progresses from early events (atypia or in-situ disease) to late-stage or metastatic disease and death, and that early detection is crucial to reduce mortality. (B) A variable model presumes that cancer can have variable progression on the basis of biology and that the range of disorders spans from indolent to slowly or rapidly progressive. Screening might lead to overtreatment and harm, benefit, or have a minimal effect, respectively.

Figure 2. Biology affects tumour type, behaviour, and effect of screening and treatment

(A) Tumours that develop are controlled by several biological variables, and are the result of complex interactions among tumour subtypes, their microenvironment, and other factors shown here—eg, exposures to things in the environment that can cause cancer. (B) Tumour type and behaviour affects screening outcomes; the term indolent lesion of epithelial origin, or IDLE, can be used for indolent tumours if they can be identified at diagnosis or after a period of observation.

Figure 3. Factors that can reinforce decisions for aggressive screening and treatment

In the face of complicated evidence, physicians and patients make decisions in an environment in which intervention and aggressive behaviour is rewarded. The potential beliefs and effects shown here are for prostate cancer screening.