Dumb "research" ?

The fact that an institution is world-renowned as a treatment centre is no guarantee that research emanating from that source is bound to be irreproachable. If you have a brain the same size as a gnat's or venture into areas you know little about and don't try to find out about that terrain, or, more frequently, you have an idea which you don't think through before designing a study, then you, too, can produce 'research findings' that aren't worth the paper that they shouldn't have been written on.

I was amazed to come across a paper from the Urology Dept. at M.D.Anderson which pronounced:
"Our findings suggest that overweight and obese patients with renal cell carcinoma have a more favorable prognosis than patients with a normal BMI."

This paper, entitled "Prognostic value of body mass index in patients undergoing nephrectomy for localized renal tumors" appeared in 2004 and has been followed by others in various parts of the world trying to throw light on its mysterious finding. Since obesity is probably the highest risk factor predisposing to RCC it seemed surprising that it could confer a benefit in survival of RCC.

It appears to me to be easy to resolve the conundrum when one realises that that 2004 paper did not show what the authors claimed, as a result of their proceeding on the basis of a false assumption, or, rather, definition from the very outset. They classified their patients into 3 groups by BMI and defined as "normal" any BMI less than 25. Tell the hundreds of millions of starving people of south-east asia and Africa that any BMI under 25 is "normal".

As soon as one puts together the basic facts that are known about the age distribution of RCC patients, the sarcopenia of ageing and the complex relationship between BMI and both morbidity and mortality, the idiocy of the paper's study design is glaringly obvious.

The abstract of the paper concluded with the breathlessly expressed optimism that "If others confirm our finding that a high BMI confers a survival advantage to patients undergoing nephrectomy, BMI may prove to be an important prognostic factor in renal cell carcinoma."

Unsurprisingly, subsequent studies have NOT confirmed their imaginary discovery. A paper from Heidelberg University in 2008 entitled "The influence of body mass index on the long-term survival of patients with renal cell carcinoma after tumour nephrectomy" followed the WHO classifications of BMI category and concluded: "While underweight patients had a significantly worse prognosis than those of normal weight, overweight or obese patients had a similar outcome to that of patients of normal weight." which is what the intelligent observer might expect.

It's a pity when a poorly thought out piece of "work" gets published in a respectable journal and then spawns a number of 'me too' investigations before its inadequacy is demonstrated to the unwary. Here, for example, it led to a paper in Korea published as recently as 2010 reporting "Our findings suggest that overweight and obese Korean patients with renal cell carcinoma have more favorable pathological features and a better prognosis than those with a normal body mass index." It's striking that the actual wording is virtually identical, mutatis mutandis, with that in the 2004 paper. Their BMI cut-offs were different (e.g. 'obese' = BMI over 27.5) reflecting the different body composition of asian populations and the greater risk for them of degenerative diseases at lower obesity thresholds. However, the same fundamental error was made, with all BMIs below 23 (representing more than a third of their cohort) being treated as 'normal'.

I've composed this message for two reasons. One is that it identifies totally spurious information that could be directly damaging to RCC patients. The other is the more general academic point that you need to bring your own brain to bear on what you are told in order to try to sort the wheat from the chaff and should always maintain a degree of skepticism when presented with facts that could have importance for you.