Wisdom Wednesday: U.S. Cancer Treatment Guidelines ‘Often Based on Weak Evidence’

Cancer treatment guidelines produced by the US National Comprehensive Cancer Network (NCCN) are often based on low quality evidence or no evidence at all, finds a study published by The BMJ today.

The researchers, led by Dr. Vinay Prasad at Oregon Health & Science University, say their findings “raise concern that the NCCN justifies the coverage of costly, toxic cancer drugs based on weak evidence.”

These recommendations are used by US private health insurers and social insurance schemes to make coverage decisions, and guide global cancer practice, but it is not clear how the evidence is gathered or reviewed.

In the US, the Food and Drug Administration (FDA) approves all new drugs and grants new indications for drugs already on the market. The NCCN makes recommendations both within and outside of FDA approvals, but patterns of NCCN recommendations beyond FDA approvals have not been analyzed.

So Dr. Prasad and his team compared FDA approvals of cancer drugs with NCCN recommendation in March 2016 for a contemporary sample of drugs. When the NCCN made recommendations beyond the FDA’s approvals, the evidence used to support those recommendations was evaluated.

A total of 47 new cancer drugs were approved by the FDA for 69 indications over the study period, whereas the NCCN recommended these drugs for 113 indications, of which 69 (62%) overlapped with the 69 FDA approved indications and 44 (39%) were additional recommendations.
Only 10 (23%) of these additional recommendations were based on evidence from randomized controlled trials, and seven (16%) were based on evidence from phase III studies. Most relied on small, uncontrolled studies or case reports, or no offered evidence.

And almost two years after their analysis, the researchers found than only six (14%) of the additional recommendations by the NCCN had received FDA approval.



The researchers point out that 86% of NCCN guidelines members have financial ties to the pharmaceutical industry, with 84% receiving personal payments and 47% receiving research payments. “The presence of conflicted physicians has been shown to lead to more optimistic conclusions regarding disputed practices,” they say. “Thus our findings raise concern about the nature of the recommendations offered by these individuals.

My Take:
When reviewing any study it is vital to look at potential conflicts of interest and most good studies will list such conflicts. However, here is a group of oncologists that are financially dependent on recommending drugs from their employers. To do so, they just skip the evidence based studies altogether. This harkens back to the days of the traveling snake oil salesman.
The toxic effects of chemotherapy are well known. Patients often die from the treatment rather than the cancer. To learn that a large percentage of these drugs are based on little or no evidence is disheartening.

The Bottom Line:
With chemotherapy, or any other recommended treatment, you must be your own health advocate. Do your research on any therapy prior to agreeing to implementation. However, a work of caution, the internet is full of misinformation. You can find sites to support or condemn any therapy. Please look at the evidence-based data, who conducted the study and most importantly, why?

Source: Science Daily March 7, 2018