Hi Alistair,
I did reply to your situation to which you referred on another thread. Have you found the time to listen to the talk I linked to and recommended?
The thought raised by Tykey is worthy of consideration. Also, John noted that I had said that there was a move ahead to stop Gleason 6 as being considered as cancer. The proposal is to term it as IDLE, which stands for Indolent Lesion of Epithelial origin.
This is an abstract from a well referenced paper on the subject of treatment and overdiagnosis :- 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.
Taken from this paper which includes also includes a specific heading for Prostate :- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4322920/