Unfortunately I feel that paper is flawed largely because of their patient sampling.
Page 2 Figure 2.
The number of patients being observed is highly skewed towards the first 5 years.
So skewed it makes you wonder where did all the patients go after 3 years.
From 550 at year 1, 300 at year 3, and about 175 at year 5.
I suspect like many watch and wait studies, a significant proportion of people get frustrated with W&W and seek other specialists and options. They are then lost to follow up and excluded from the stats.
When you look at this paper and see how many patients they have lost to follow up by 5 years, it skews the results. I think the rule of thirds... one third are stable or shrink, one third grow slowly, and one third grow more rapidly is closer to reality. With the number of people lost to follow up by 5 years, it certainly makes me wonder whether the authors of this paper were actually left with the one third that are suitable for W&W.
The four references are listed directly after this statement on this paper "tumor growth occurring beyond the fifth year of observation is very rare, but is, however, still observed"
https://link.springer.com/article/10.1007/s40136-014-0064-7I am not sure how they can make that claim based on the references they have provided.
I think a more suitable statement would have been, people with growing tumors rarely stay with our institution beyond 5 years, but we do have some.
Please understand I am not anti W&W. I have noticed however there are biases built into so many papers.
Length of the study, Sample Sizes, Patient Selection, Age, Tumor Size, Tumor location, and the criteria they use to measure success or failure. When it comes to surgery, many of the stats come from the worlds best, and that may not reflect what happens locally. Radiosurgery, tumor sizes, age, location, affect results significantly.