New article in Cancer journal linking CFS to some froms of cancer

[alex3619]

http://chronicfatigue.about.com/b/2012/06/08/cancer-risk-linked-to-chronic-fatigue-syndrome.htm

In this it says: "Through use of medical records and Medicare claims, researchers discovered the risk of non-Hodgkin lymphoma (NHL), late in life, was 29 times greater in those with ME/CFS. The risk of other forms of cancer did not appear to be elevated."

It was pointed out in the comments though that the real risk is still uncertain, this is only a place to start.

Based on this http://seer.cancer.gov/statfacts/html/nhl.html it can be seen that the incidence of lymphoma is 19.6 per 100,000 though there are subgroups. Allowing for a tentative 29 fold increase, the incidence of lymphoma in CFS can be approximated to 568 per 100,000. That is about 1 in 176, though the figure may not hold in a younger group or between sexes.

Using an age adjusted death rate of 6.6 per 100,000, an estimation of deaths in CFS might be 191 per 100,000. Again, this is only tentative.

I mistakenly opened a new thread on this here:

http://forums.phoenixrising.me/index.php?threads/lymphoma-more-common-in-cfs.19566/#post-299494

I was interested because of an increased discussion of polycloncal B cell expansion, especially by Lipkin on 18th September speech.

Bye, Alex

PS Anciendaze pointed out on the other thread that the 29 fold increase is a mistake in the article on this. It was due to a misinterpretation of the figures, and the real increase is very much smaller.

 

[Enid]

Well I have complications - hopefully not this though - it is accepted (4 Docs in my family) that lack of diagnosis and treatment of an early pathology can indeed well lead to others. Catch early their motto - one thing leads to others. Knowledgeable and intuitive systems understanding no doubt of the interaction of all systems.

 

[Holmsey]

Here's the full paper.

 

[Holmsey]

When reading this paper we should consider -

a) Reasonable odds ratios – it is not just about statistical significance, but the size of the effect. A swift glance at this one apparenlty shows that the ORs are not very large, this is important especially with rare cancers such as NHL.
b) Certainty that we are dealing with different stages along the same pathway – one reason for the so called link between depression and cancer is that depression is actually an early sign of many cancers. That consideration should be applied to any suggested link between cancer and CFS, because the symptoms of CFS definitely are a precursor of several cancers.
c) Confounding. Always a problem but particulary so when we don't have a know pathology for ME/CFS – so both the ME/CFS and cancer might be caused by a third factor. For example, depression might make you more liable to drink or smoke, or alternatively cancer might be a side effect of a given treatment. Wouldn’t have thought that was likely for CFS, but confounding is very difficult to control.
d) Reproducability and plausibility. Most cancers have incredibly long latency periods, and most claims linking substance A with cancer B are very short term , so care needs to be given in considering a purely statistical link.

 

[alex3619]

Something in the full paper about CFS association with other conditions. The association with transfusions and Rheumatoid Arthritis is high, both have p values under 0.0001.

Bye, Alex

 

[Rooney]

I worry about my cbc labs stating high lymphocytes. I know it is about infections, but isn't it also a risk for lymphoma? I'll see my CFS dr. soon and will ask.

 

[Xandoff]

My sister was diagnosed with stage four non hodgkins lymphoma when she was twenty, she beat the Cancer but the effects of radiation and chemo for a year took a terrible toll on her. She just passed at he age of 54 last spring. I have a sister with Chrohns who was diagnosed with epstein barr when she was sixteen. I became ill with ME CFS at 52. I am currently taking GcMAF. For me, I think my family illnesses are all genetic. Oddly enough I was the only sick kid in my family of six kids with 65 allergies and chronic asthma. Time will tell all.

 

[anciendaze]

I want to state that the figure of 29 times the risk looks like a serious misunderstanding. An odds ratio merely approximates a risk ratio when dealing with things that are very rare. The ratio is based on the probabilities p/(1-p) for each of the two situations. If p is close to zero 1-p will be close to 1.00. An odds ratio of 1.29 is not the same as a risk ratio of 1:29. It is closer to a 29% increase in risk, though not exactly the same. This is reasonable considering the diagnostic uncertainties in the information on which the analysis was done. We don't know how many of those diagnoses were in error. Lumping people with different conditions into the CFS category will naturally dilute the results.

For me, the important message is the statistical significance, a P value of 1.7 x 10^-6. (Pearson test, not the p above.) The result, though modest, is very hard to explain as a chance variation. The number of people reporting is too large to make this likely. At least some people in that group have a life-threatening physical disease. At this time the only way to separate them from the rest of the group is to wait for unmistakable signs of cancer.

 

[alex3619]

Hi anciendaze, it never twigged they were getting the 29 fold from the 1.29. If it had I would have seen the issue. Thanks for pointing it out. I agree the numbers are so huge that the results can be considered somewhat reliable. This was US official data for many years, though it does rely on doctors correctly diagnosing the disorder, which is always problematic. Bye, Alex

 

[Sherlock]

An odds ratio of 1.29 is not the same as a risk ratio of 1:29. It is closer to a 29% increase in risk, though not exactly the same.

Amen to that, the writer of that article made a HUGE gaffe. Note that a commenter there pointed out the gaffe and the author did not correct the error. Moral: be wary of all non-authoritative sources.

Speaking of which, the use of OR (not RR) reminded me of this from wikipedia:

Confusion and exaggeration

Odds ratios have often been confused with relative risk in medical literature. For non-statisticians, the odds ratio is a difficult concept to comprehend, and it gives a more impressive figure for the effect.[13] However, most authors consider that the relative risk is readily understood.[14] In one study, members of a national disease foundation were actually 3.5 times more likely than nonmembers to have heard of a common treatment for that disease - but the odds ratio was 24 and the paper stated that members were ‘more than 20-fold more likely to have heard of’ the treatment.[15] A study of papers published in two journals reported that 26% of the articles that used an odds ratio interpreted it as a risk ratio.[16]
This may reflect the simple process of uncomprehending authors choosing the most impressive-looking and publishable figure.[14] But its use may in some cases be deliberately deceptive.[17] It has been suggested that the odds ratio should only be presented as a measure of effect size when the risk ratio can not be estimated directly.[18]

 

[Sherlock]

While the association between inflammation/hyperplasia is often noted, note also that the TNF-blocker etanercept, which can be thought of as an anti-inflammatory, has a boxed warning about increased risk of lymphoma. It's mainly in the setting of RA, which carries increased risk by itself anyway, but still worth noting.

 

[anciendaze]

...Moral: be wary of all non-authoritative sources...

Be wary of all sources, with or without authority. You don't have to be an authority yourself to actually read the material and check the numbers.

Bookies regularly exploit misunderstandings about odds and probability ratios to their own profit.

I keep hoping to reform medical use of statistics to stop researchers from using parametric statistics designed for normal distributions on distributions which are manifestly not normal distributions.

For other examples of authoritative statements you might consider these: 1) the idea of exploiting nuclear energy is "sheer moonshine"; 2) talk of space travel is "utter bilge". I'll let others dig up the exact quotes and circumstances. Suffice it to say that the speakers were considered authorities at the time they spoke. They had incredibly bad timing.

 

[snowathlete]

What I find reassuring is that they are even trying to make a comparison between the two illnesses. In the past all the bull about our illness would stop anyone thinking of or even wanting to have an association with our illness. Looks like progress to me and it's right that it's looked at.