Aerial Fire Retardant Is Like Avastin

Today the FDA withdrew its approval for Avastin’s use as a breast cancer treatment. The FDA’s decision was based on large-scale clinical trials that failed to show Avastin improves life expectancies or controls tumor size. The lack of any statistically significant positive benefits combined with serious side effects, such as high blood pressure and hemorrhaging, has pulled this drug from the shelves.

But, some women and physicians (some with financial connections to Avastin’s manufacturer Genentech) believe that Avastin has been effective in treating particular cases of breast cancer. One protester said that the FDA’s decision is “nothing short of a death sentence” for some women.

The problem for Avastin’s promoters is that although it is conceivable that some women might benefit from Avastin therapy — even if women, in general, do not — we do not know how to predict which women these are.

Although the FDA did not consider cost in its analysis, Avastin’s $80,000/patient/year expense also does not counsel for its unsubstantiated use.

So, how is aerial fire retardant like Avastin? The Forest Service acknowledges that no data nor studies show that fire retardant improves initial attack success or decreases average fire size. In fact, fire data for the last ten years show no correlation between firefighting effectiveness and retardant use by national forest.

Fire retardant has known serious “side effects,” like dead fish and crashed airtankers. It is expensive, too, at over $1/gallon to administer — $3,000/drop from a large airtanker.

Although it is possible that fire retardant might be effective under some circumstances, we don’t know how to distinguish those fires from every other ignition.

Just substitute “fire retardant” for Avastin in this summary:

“Many breast cancer specialists say that Avastin does appear to work very well for some patients and some advocates have said the drug should be left on the market for the sake of those patients. But Dr. Hamburg said there was no way to determine in advance who those patients are, so many women would use the drug. “The evidence does not justify broad exposure to the risks of this drug,” she wrote.

4 thoughts on “Aerial Fire Retardant Is Like Avastin”

  1. Andy- you’re not saying “fire retardant doesn’t work”, in the sense that “it is no better than water in wetting things to be inhospitable to fire” are you? Or are you saying that a fire will go through an application of fire retardant the same as there was no application? I am confused.

  2. There is no dispute that Avastin blocks the growth of new blood vessels. It was that seminal observation that suggested its use as a cancer fighter. Similarly, there is no dispute that fire retardant slows the advance of fire through some kinds of vegetation under some weather conditions. It was that seminal observation that suggested its use for firefighting.

    However, blocking the growth of new blood vessels does not guarantee that Avastin contributes to cancer therapy objectives, such as slower tumor growth or improved longevity. The statistically-valid clinical studies show it does not.

    Analogously, slowing the advance of fire does not mean that retardant contributes to fire suppression objectives, such as improving initial attack success or decreasing average fire size. No studies show it does. Nor do the available data show any correlation between retardant use and these outcomes.

    The FDA should be credited on two fronts. First, the FDA required Avastin’s manufacturer to test its drug using a statistically valid methodology. Second, the FDA based its decision on the results of those studies.

    The Forest Service has not required the first and, thus, cannot have done the second.

    • Andy, the difference between being effective on the ground in certain situations, and needing a correlative study to prove it is where I’m losing you.

      In this piece, you said (if quoted correctly)

      STAHL: The stuff works in limited applications. The retardant doesn’t put out fires. It was never designed to fight fires in residential areas. What it was designed to do is to prevent small fires from getting larger as they creep along the forest floor. And it’s pretty good at that. What it’s completely worthless at is stopping a wind-driven firestorm such as we saw in southern California in the last several days. There, the wind blows embers and burning branches for up to half a mile. The fire retardant line is only several tens of feet wide. And so in a wind-driven firestorm retardant is worthless.

      So you said it does keep small fires from becoming larger.. isn’t that a fire suppression objective?

      • In that quote, I said retardant was designed to keep small fires from getting larger (just as Avastin was “designed” to treat breast cancer). But, does retardant perform in the real world as its designers intended?

        Retardant use data provide no support. Those data show that average fire size is not correlated, or is slightly negatively correlated, with retardant use by national forest. In other words, the more retardant used by a national forest (on a normalized per acre basis), the larger the average fire size. This is true whether analyzed on a national basis or within regions — the forests that use more retardant have larger fires.

        I’m not saying that retardant use causes larger fires (although it might contribute if, for example, dollars spent on expensive retardant drops could have been spent on more effective ground forces). I am saying that retardant use causes dead fish and dead pilots. Those side effects aren’t worth it without compelling evidence (much less no evidence at all) that retardant improves firefighting outcomes.

        This stuff isn’t complicated. The measurement of a treatment’s effectiveness, whether it is a medical drug or a firefighting action, requires properly designed studies. We do them all the time in forestry. My favorite is the study that established which packaging material (paper, plastic or aluminum foil) to transport seedlings from nursery to hillside yielded the best post-planting survival. Four treatments (remember to include the control of no packaging!) with randomized (to control for environmental variables) planting on the hillside. Come back three years later when you’re ready to write your dissertation and, ta-da, instant Ph.D.!

        In sum:

        “[A]lthough there was evidence that [Avastin] slowed progression of metastatic breast cancer, there was no evidence that it extended life, or improved quality of life, and it caused adverse effects including severe high blood pressure and hemorrhaging.” Wikipedia on Avastin

        Although there is evidence that retardant slows progression of fires, there is no evidence that it reduces average fire size or improves initial attack success, and it causes adverse effects including dead fish and airtanker crashes.


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