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Mayo Clinic news release on cancer-related blood clots lives in data-free zone


3 Star

Mayo researchers say oral apixaban safe and effective for treating blood clots in cancer patients

Our Review Summary

A brief news release from the Mayo Clinic does a disservice to an interesting yet unpublished study that demonstrates an oral anticoagulant medication might be a good solution for preventing blood clots in cancer patients. The release discusses a conference presentation given at the American Society of Hematology annual meeting, but doesn’t mention any numerical data or describe how the study was conducted. It focuses mostly on the problems associated with commonly used injectable medication heparin, and how an oral medication might be better for patient quality of life. But the news release dedicates only one small paragraph at the end to the actual findings of the study, leaving readers with questions about study design and potential harms of the new treatment. 


Why This Matters

Cancer patients, especially those with advanced cancers or certain types of cancer, are at increased risk of developing blood clots. This study evaluated a new treatment for patients with cancer who have developed blood clots. This new therapy is an oral blood thinner that is approved for other conditions, but not this one. Standard therapy for blood clots associated with cancer is a low molecular weight heparin that is injected daily under the skin. Clearly, having a medicine that would be as or more effective and could be taken by mouth would be a great advantage to patients.

The striking absence of any data in the news release could have been easily remedied. We looked up the abstract of the conference presentation upon which this is based and found some data. But journalists may not look that far and patients and consumers aren’t likely to either. And they shouldn’t have to; the data should be in the release.


Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

The news release did not discuss the costs of apixaban or how it compares to the cost of the injectable medication heparin. According to GoodRx, the average cost of apixaban is $424, while the average cost of heparin is $189 (these costs do not reflect insurance coverage). There is also no generic version of apixaban (sold under the brand name Eliquis) available yet. The release did quote the study author saying that a downside to heparin injections is that they “are expensive at nearly $100 per day,” however no information was provided about how apixaban costs compare. 

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

Not Satisfactory

The news release was vague and did not include any absolute numbers. The lead author said that quality of life surveys showed that patients preferred apixaban over heparin, but there was no information about whether the medication was equally effective at preventing blood clots. The abstract of the conference presentation actually does show that apixaban may have been more effective than heparin; none of the patients that received apixaban had major bleeding, and fewer had deep vein blood clots than those that received heparin. These concrete numbers should have been included in the news release.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

While a lot of emphasis was placed on potential benefits of apixaban, no harms were mentioned. The release talks about the limitations of the comparator but not apixaban. It certainly seems that there are fewer side effects from apixaban than heparin, particularly because there are no injection-related issues (such as bruising, pain and swelling) from the oral medication. Yet this does not mean that apixaban is completely harmless; like other anti-coagulant medications, one of the side effects is major bleeding which can quickly become dangerous if not treated.

In this study, patients receiving apixaban had fewer subsequent blood clots and didn’t appear to have higher rates of bleeding — the main complication of any blood thinner. Several caveats should be mentioned: first, this was a relatively small trial and included a range of different cancers. Follow-up studies are needed to confirm these results in more patients across a range of different cancers. Second, though it wasn’t statistically significant, more patients in the apixaban group had died at 6 months (15.9% vs. 10.6%). Future studies should examine this further.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The news release said next to nothing about how the study was actually conducted. The only details we get are that it was a 6-month study, and that participants took monthly quality of life surveys. But how many participants were there? Was this study randomized? Nothing else is noted in the news release. The conference abstract once again sheds some light: 287 patients with different types of cancer were involved and randomized to receive either apixaban or heparin for 6 months. While this may have been a robust study, we get no sense of that from the news release.

Does the news release commit disease-mongering?


No disease mongering here. The release briefly notes how many cancer patients are affected by blood clots (1-in-5) which is useful context.

Does the news release identify funding sources & disclose conflicts of interest?

Not Satisfactory

The news release does not mention any conflict of interests or funding sources. The website with the conference presentation abstract lists that the lead author received research funding from pharmaceutical company Pfizer.

Does the news release compare the new approach with existing alternatives?


The news release compares apixaban to low molecular weight heparin (LMWH), although as mentioned above it does not discuss any harms of apixaban or quantify any of the health benefits with numbers. It does do a good job, however, of discussing possible problems with LMWH and why apixaban might be a good alternative medication.

Does the news release establish the availability of the treatment/test/product/procedure?


The release notes that apixaban, a member of a new class of “blood thinners called ‘direct oral anticoagulants’ have become available.” Both oral and injectable anti-coagulant medications are now widely available at hospitals and clinics where they are administered to patients.

Does the news release establish the true novelty of the approach?


The release addressed novelty with this statement: “it was unclear whether these drugs could be used safely in cancer patients until now.”

This research is clearly aimed at using apixaban for a new indication that isn’t yet FDA approved. Other research has focused on apixaban for those with cancer but no clots. Here the focus is on secondary prevention for cancer patients that already have blood clots.

Total Score: 5 of 10 Satisfactory

Comments (1)

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Fred Shirley

December 7, 2018 at 9:20 am

Great article thanks for being objective Fred