Tuesday, January 24, 2006

A particularly egregious misrepresentation of a study

I was made aware of a most interesting study today appearing in the journal Cancer, which is the official journal of the American Cancer Society. However, I wasn't made aware of it through the journal itself, but rather through a very deceptive misrepresentation of the article. The title alone got my attention: 'Miracle' cures shown to work. It begins:
Doctors have found statistical evidence that alternative treatments such as special diets, herbal potions and faith healing can cure apparently terminal illness, but they remain unsure about the reasons.
How do I know that the study is being misrepresented? It's mind-numbingly obvious from reading the the rest of the article that it is, that's why:
A study of patients with incurable lung cancer who were given weeks to live and received only low-dose radiotherapy to make their final weeks more comfortable found a small number recovered completely.

Researchers who followed 2,337 patients whose disease was too advanced for curative treatment found that 25 had survived five years and 18 had achieved "an apparent cure". They appeared to have been cured by treatment that "would not normally be considered to have any curative potential whatsoever".

The researchers, led by Michael MacManus, a consultant radiation oncologist in Melbourne, say: "Our data indicate that a chance for prolonged survival and possibly even cure exists for approximately 1 per cent of patients with non small cell lung cancer who receive palliative radiotherapy.

"It is important that the frequency of this phenomenon should be appreciated so that claims of apparent cure by novel treatment strategies or even by unconventional medicine or 'faith healing' can be seen in an appropriate context."

Unorthodox cancer cures have included vitamin C, laetrile extracted from apricot stones, and the Gershon diet of raw vegetables.

The discovery of a small group of patients who unexpectedly recovered could yield new insights into the disease, the researchers say.
Note that there was no mention in the actual study of the Gershon diet, laetrile, or any other alternative therapy "curing" anything. Instead, the study simply presented findings that a small number of "terminal" lung cancer patients (approximately 1%) were still alive five years after low dose radiation therapy given strictly for palliative purposes, even though the median survival for such patients is usually between 4 and 5 months. In fact, the study's lead author even went out of his way to state that the results of this study should allow investigators to take the claims of alternative medicine practitioners of "miracle cancer cures" in proper context, given that a small number of patients survive considerably longer than expected. If you don't believe me, look at the abstract itself, downloaded through my university (it's an e-publication ahead of print):
Unexpected long-term survival after low-dose palliative radiotherapy for nonsmall cell lung cancer

Michael P. MacManus, M.D., Jane P. Matthews, Ph.D, Morikatsu Wada, Andrew Wirth, Valentina Worotniuk, David L. Ball, M.D.

BACKGROUND
Many experienced oncologists have encountered patients with proven nonsmall cell lung cancer (NSCLC) who received modest doses of palliative radiotherapy (RT) and who unexpectedly survived for > 5 years; some were apparently cured. We used a very large prospective database to estimate the frequency of this phenomenon and to look for correlative prognostic factors.

METHODS
Patients with histologically or cytologically proven NSCLC, treated with palliative RT to a dose of 36 Gy, were identified from a prospective database containing details of 3035 new patients registered from 1984-1990.

RESULTS
An estimated 1.1% (95% confidence interval, 0.7-1.6%) of 2337 palliative RT patients survived for 5 or more years after commencement of RT, including 18 patients who survived progression-free for 5 years. Estimated median survival was 4.6 months. Five-year survivors had significantly better Eastern Cooperative Oncology Group performance status at presentation than non-5-year survivors (P = 0.024) and were less likely to have distant metastases (P = 0.020). RT dose did not appear to be a significant prognostic factor. Patients who survived 5 years without progression had an estimated 78% probability of remaining free from progression in the next 5 years.

CONCLUSIONS
Approximately 1% of patients with proven NSCLC survived for > 5 years after palliative RT, and many of these patients appeared to have been cured by a treatment usually considered to be without curative potential. Because of the potential for long-term survival, doses to late-reacting normal tissues should be kept within tolerance when prescribing palliative RT in NSCLC.
If you read the paper itself, you see that all the investigators did was to study patients with advanced "incurable" lung cancer treated for palliative purposes only, following them to see how long they survived. They followed 2,337 such patients, of which 2,297 completed enough of the course of radiation therapy to be counted in the final analysis, for five or more years and observed that there were 24 five year survivors, approximately 1.1%. Of these, 18 had no evidence of disease progression at five years. Of the known five year survivors, 32% survived another five years, or approximately 0.35% of the total (which means that the 24 five year survivors weren't all apparent "cures"--as the news article called them--because more than half of them still went on to die of their disease). Survival was not correlated with radiation dose. The only characteristic that survival seemed to correlate with was performance status (a measure of general health and ability to handle activities of daily living) and having no distant metastases at the time of the commencement of treatment. The authors speculate that these patients may represent a very small subset of non-small cell lung cancer patients whose tumors are either highly responsive to radiation or not biologically aggressive. The money paragraph is this:
Our data indicate that a chance for prolonged survival and possibly even cure exists for approximately 1% of patients with NSCLC who receive palliative RT. This is a very small proportion, but lung cancer is a very common malignancy. It is important that the frequency of this phenomenon should be appreciated, so that claims of apparent cure by novel treatment strategies or even by unconventional medicine or faith healing can be seen in an appropriate context. All patients in this study had histologic or cytologic diagnoses of NSCLC in an appropriate clinical context. It is possible that errors could have been made in diagnosis in a proportion of cases, but it is very unlikely that all of the cases were misdiagnoses. In many of these patients, biopsy specimens were generous, including some surgical cases. It is well known that conventional cytologic or histopathologic tumor morphology is, by itself, a poor predictor of treatment response in NSCLC. The phenomenon reported here is potentially an important one, in that a subset of patients with NSCLC appears to have disease that is curable with minimal therapy and that prospective identification of such patients could potentially profoundly influence treatment.
There are two possibilities. One possibility is that the reporter just straight out lied about the findings of the study. However, an equally plausible explanation is that the reporter accurately reported the results of this very interesting study, and then his editor inserted text to represent the study as supporting "miracle cures," either because of bias or just to "spice up" the story. Consider: The first sentence is jarringly inconsistent with the rest of the story. After all, the article even included the money quote about how this study demonstrates that there is a small, but real, subset of lung cancer patients who are "cured" by palliative low dose radiation therapy and how this observation should be taken into account when evaluating claims for lung cancer "cures," either due to new conventional treatment or due to alternative therapy or faith healers. Given how common lung cancer is, there are probably a fair number of these patients out there, some of whom undoubtedly attribute their good fortune to some alternative medicine or other. (Also, given how rare these long term lung survivors are, there almost certainly aren't as many such patients as there are breast cancer patients, whose testimonials I discussed long ago, but certainly enough for alties to point to.) Another obviously out of place sentence is this one: "Unorthodox cancer cures have included vitamin C, laetrile extracted from apricot stones, and the Gershon diet of raw vegetables." Nowhere in the study or even the description of the study is any mention of alternative medicine other than the one I cited, and certainly nowhere in the article is an indication that any "miracle cures" from alternative medicine were observed or even possible. In fact, it should be emphasized that every single patient analyzed received conventional therapy; i.e., radiation therapy. Consequently, even if the use of alternative medicine had been identified as a factor associated with long term survival of these patients, that observation would not have shown that alternative medicine had any value on its own for "curing" lung cancer.

My guess is that the reporter probably interviewed Dr. MacManus and did a straightforward story about this study, and then the editor inserted the two sentences in question and gave the article its dubious title. The title is a lie, pure and simple, and the "spin" put on the article is such an obvious hack job that I stand in awe that the editor and/or the reporter could think its readers are so incredibly stupid that they won't see the disconnect between what the study actually says and how it has been represented. Nonetheless, right here I make this not-so-bold prediction: It won't be long before this news story describing this study makes appearances on altie websites, Usenet newsgroups (like misc.health.alternative), and perhaps even in other media sources, offered by alties as "proof" that alternative medicine can "cure" lung cancer.

Just watch.

And if you ever happen to see this study being misused that way, feel free to respond with a link to this blog posting.

7 example(s) of insolence returned:


At 1/24/2006 8:57 AM, Blogger she falters to rise said...

A friend once had an editor force a line into his scientific publication in a highly respected journal. It was a line regarding a link between the data and autism, yet the data had nothing to do with autism. Of course several groups jumped on the line and started making all sorts of unfounded extrapolations.

People just don't always think.

 

At 1/24/2006 9:06 AM, Anonymous Dave Harmon said...

If an editor, especially a supposed "science editor", backstabbed me like that, I'd probably be looking for a new outlet for my writings.

 

At 1/24/2006 6:21 PM, Blogger ebohlman said...

There was considerable discussion of this article on the Healthfraud list, and at least one member has written to the Belfast Telegraph to complain.

I suspect the culprit is pandering to readers who merely skim stories; the misleading information is in the most visible and memorable spot, whereas the truth is buried down in the "nerd stuff." Even if someone reads the whole article, the fraudulent part may still leave an impression due to its favorable position. It's rather like those documentaries about the 1950s where the voiceover painstakingly emphasizes that real life then wasn't at all like "Father Knows Best" or "Leave It To Beaver" while the screen is showing visual images of those fictitious shows; the producers know full well that most viewers' minds will resolve the conflict in favor of the images (and therefore perceive today's real world as a dreary and scary place, thus making the fake world offered by the commercials look even more attractive).

I wonder how much altie advertising the Telegraph runs; this could well be a case of the sales department dictating policy to the editorial department.

 

At 1/24/2006 11:27 PM, Blogger Impatient Patient said...

Dear Insolence

One time my husband and I were told that the mind could cure the body of cancer and it could cure my husbands back pain caused by an entrapped sciatic nerve root. I was disturbed that anyone could think this, let alone a psychologist at a Worker's Comp Institution. I was waiting for the ducks to fly by after he said it, and I am still pissed off two and a half years later. It is called blame the patient....

 

At 1/25/2006 6:58 AM, Anonymous Anonymous said...

The same story is also on The Independent by the same writer, J.Laurance, health editor. The story makes the same claims about alternative therapies so I think that mr. Laurence is the only one to blame in misrepresenting this study.

http://news.independent.co.uk/uk/health_medical/article340393.ece


Pun the librarian

 

At 1/30/2006 1:10 AM, Anonymous Anonymous said...

Dear Orac

You are very perceptive (more so than the health editor of the Independent in this instance. I am the first author of the paper in Cancer. As you rightly point out, it has been grossly misrepresented by the Independent. I have emailed them asking for a retraction or correction but have received no reply. I will take this further; the Independent is generally an excellent newspaper and it should not invest its authority in such a poor article.

Michael Mac Manus

 

At 2/16/2006 10:49 AM, Anonymous Anonymous said...

hey, great minds think alike:

http://www.badscience.net/?p=204

ben goldacre

 

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