Why use placebo for cancer drug testing?

[question everything]

The American Society for Clinical Oncology met last week in Orlando, and we are going to read about promising new drugs to fight cancers.

In today's WSJ was the following item:

"In a study with Sutent, the once-a-day pill proved effective in stanching growth of a rare stomach cancer called GIST (for gastrointestinal stromal tumor) in 385 patients who had developed resistance to the blockbuster cancer drug Gleevec from Novartis. In the randomized study, two-thirds of the patients got Sutent and the others got a placebo."

Why, why do they use placebo for the control group? What kind of a monster design a study where severely ill cancer patients are denied anything? Why not use the standard treatment - whatever it is - for the control group?

What am I missing?

[kwolf68]

1. Your control Group

Never gets whatever is being tested.

[spindoctor]

2. standard scientific methodology

Without a control group, there is no measurable result. Without a placebo, there is no control group (alternative medication might make their situation worse compared to the treated group).

[mia]

3. the placebo effect

http://skepdic.com/placebo.html
"A person's beliefs and hopes about a treatment, combined with their suggestibility, may have a significant biochemical effect. Sensory experience and thoughts can affect neurochemistry. The body's neurochemical system affects and is affected by other biochemical systems, including the hormonal and immune systems. Thus, it is consistent with current knowledge that a person's hopeful attitude and beliefs may be very important to their physical well-being and recovery from injury or illness."

[kwolf68]

4. This posters handle is

Question Everything so he's being consistent. :)

[Sapphire Blue]

5. This isn't specific to cancer studies... it's typical in any study

Those who agree to these studies are informed that they may receive either an 'experimental' treatment or a placebo.

Google 'drug trials'

[mia]

7. and the subjects of the study don't know if they're getting

the treatment or the placebo. So everyone thinks they'll get better.

If the results don't significantly favor the treatment effect, then the drug isn't worth taking, considering the possible negative effects of the medication.

The power of the mind is incredible.

[Maru Kitteh]

6. usually cancer patients in a study have exhausted other available means

and don't have anything to lose, but you are right, it's cruel.

[Warpy]

8. The Chinese agree with you

and find it unethical to use placebo studies in sick people. They do double blind studies on healthy volunteers to determine the overall safety of medications, but once they get to the sick, they test the drug without using placebos.

Arguments can be made for both sides, that the use of a placebo in the control group gives you a hard number for the "placebo effect," the fact that some patients convince themselves that the drug is the real one and manage to get better. It also shows the difference in death rates between the study drug and whatever else has been used.

Double blind drug trials are generally used in addition to other treatment in the trials I've seen, or are done with conventional treatment plus placebo in one group and placebo conventional treatment plus study drug in the other.

There may be studies out there where conventional treatment is withheld from a control group with life threatening illness, but I've never participated in one.

[Psephos]

9. Do you mean PRC? That's surprising...

...they seem to have some seriously challenged ethics regarding other medical issues. For example, they do quite a business in "harvested" organs from prisoners. Their suppression of SARS data and news turned an outbreak into an epidemic. Their policies regarding the number of children a family may have - and what should be done to women who violate it - are draconian, to say the least.

Anyway, thanks for the post. The world is full of surprises.

Peace.

[question everything]

10. Thank you. Yes, I know that there is a need for a control group

but the drugs tested are supposed to be an improvement on current treatment - chemotherapy that just nukes everything, I suppose.

So why not have the control group the one with the standard treatment? Or would that mean that they would know who they are?

I know that recently there were some studies that stopped in the middle when the new treatment was so much better that it was considered inhumane to continue with the placebo group.

I was just struck by that sentence when I read the story.

[OzarkDem]

11. Couple of things

Without having read the actual study, I can't say for certain.

But normally, in Phase 2 or 3 cancer clinical trials, patients receive either the experimental drug, or standard therapy.

Either the reporter used the wrong wording and referred to standard therapy as placebo, or the experimental drug was being tested in combination with other chemotherapy drugs. In that case, the control may receive only the standard combination and a placebo.

Just a thought.

[The Traveler]

12. Design of experiments

The double blind methodology not only establishes the worthiness (or unworthiness) of a candidate drug, but also helps identify side effects.

Remember, the test subjects for this kind of thing sign up for the experiment ... in most cases because standard treatments were not working for them. I think a lot of "terminal" cancer patients go for this arrangement because a) it gives them a chance at survival they would not otherwise have and b) because the knowledge gained may save someone else some day. That was my father's rationale, some 25 years ago.

[question everything]

15. That takes a lot of courage, and generosity by people like your father.

Thanks for sharing this.

[Turn CO Blue]

13. I think it would be an unusual practice. In the asthma studies

my daughter has participated in, they either get the "typical" treatment of their regular dosage, or the new medicine being studied at varied levels of dosage.

The liability would be HUGE if an asthmatic child died during the study due to being denied proper treatment.

I can't imagine that this study and using placebo is typical practice for cancer patients. Usually, you would want to study the new treatment against the standard results of standard therapy.

Dying participants "do not a good study make"!

[Sapphire Blue]

14. A patient goes into these studies with eyes wide open, hoping to receive

the promising experimental treatment, while knowing there's a good possibility that they won't. Patients enter studies for various reasons... hope for improvement, remission, a cure, or, in some cases, a gift to those who will follow... and keeping in mind the experimental treatment might well be a failure... so everyone in these studies is taking a risk. It would be cruel if patients weren't informed of the risks, but they are... and base their decisions on whether they are willing to take the risks.