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Gastric bypass surgery cuts cancer risk, researchers say


3 Star

Gastric bypass surgery cuts cancer risk, researchers say

Our Review Summary

This was a story reporting on presentation of data suggesting that an additional benefit that may be gleaned from having weight loss surgery is a reduced cancer risk.  It failed to mention that the results reported on were part of an oral presentation and have therefore not been through adequate peer review and should be considered as preliminary.  The story did include several quotes from experts in the field tempering the enthusiasm of some of the other quotes. 

The story devoted a lot of space describing study results about reductions in various cancer incidences that were statistically insignificant.  Many readers will not understand the term ‘statistically insignificant’, especially when coupled with statements of relative risk reductions of 50, 60 or 70%.  By presenting only relative – not absolute – risk, the story made the differences seems quite large when in reality they might be the difference of only one or two and certainly might be the result of chance rather than an effect of the procedures discussed. (Overall cancer cases were reported but were not broken down by cancer type.  So we don’t know what a 70% reduction in pancreatic cancer, for example, really means.)


Does the story adequately discuss the costs of the intervention?


The story provided cost comparisons for two of the procedures for weight loss.  In addition, there was some discussion at the end of the piece about insurance coverage not being certain in some areas/circumstances.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

The story did not do an adequate job detailing the benefits of the treatment (weight loss surgery).  While reporting on one group’s weight loss experiences, the story failed to document the broader experience about weight loss.  The focus of the story was an oral presentation at a scientific meeting about the impact of weight loss surgery on cancer rates.  These were presented as relative rather than absolute risks which inflates their seeming importance.  

The issue of relative vs. absolute risk reduction is very important here. The issue of statistical significance is also important because the lack of significance here indicates that we don’t know for sure that surgery reduces the risk of all of the types of cancer mentioned.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

The story did not adequately address the harms that may occur as a result of the treatment.  While the incidence of ‘life-threatening’ events is down for the one group presenting its comparative outcomes over time, this may or may not be representative for other groups.  In addition, there are a number of longer term consequences of weight loss surgery that affect quality of life.  

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

The story lead off with a misleading statement about the impact of weight loss surgery on cancer when it stated that weight loss surgery ‘decreases the incidence of cancer by 80%’.  Later in the piece it was explained that the study found that the affect on many of the various different cancers examined were not statistically significant.  But by presenting the relative reduction in risk rather than the absolute reductions, the importance of the data is inflated.

In addition, the results discussed in this story were presented as part of an oral presentation.  As such, they have not received adequate peer review and thus ought to be considered, at best, preliminary. 

Does the story commit disease-mongering?


There was no overt disease mongering about obesity or cancer.

Does the story use independent sources and identify conflicts of interest?


The story did a good job of identifying and interviewing individuals with points of view that provided some balance to the unbridled optimism of the study author.

Again, though, if the story was based on a presentation at a scientific meeting, the study results have not been subjected to adequate peer review, and may be preliminary. This should have been noted in the article. 

Does the story compare the new approach with existing alternatives?

Not Satisfactory

The story included information about two forms of weight loss surgery.  Although the story mentioned that most people who have surgery for weight loss have tried a number of diets previously to the procedure, there was really an inadequate discussion about options for weight loss, especially in the absence of details on the population for whom guidelines would recommend that weight loss surgery was an appropriate option.

Does the story establish the availability of the treatment/test/product/procedure?


The story presented gastric banding and gastric bypass as generally available which was supported by the data on the number of procedures completed last year.  In addition, there was some discussion at the end of the piece about some issues that may arise with insurance approval.

Does the story establish the true novelty of the approach?


The story adequately reflected the current utilization of the two weight loss surgical procedures discussed.

Does the story appear to rely solely or largely on a news release?


The story does not appear to rely on a press release.

Total Score: 6 of 10 Satisfactory


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