No silver bullet for diverse enemy: cancer


Controlling health care costs is one of the most difficult problems facing society. Because we are often talking about life-and-death decisions for ourselves or our loved ones, we unquestioningly accept that more is better. It is not always the case that marshalling more expensive technologies to the cause is justified.

Being a medical physicist specializing in radiation therapy, I have witnessed over the past 35 years the fruitful efforts of very bright people to improve cancer treatments. I was attracted to this field while doing my graduate research in physics at the Los Alamos National Laboratory Meson Physics Facility.

I was a bit nave in those early years. It seemed beams of negative Pi mesons might be "the magic bullet" for radiation therapy. I wanted to be a part of the endeavor to develop powerful tools and methods to kill cancer while minimizing side effects.

I can say now that there will be no single magic bullet. Whether talking about improved surgical techniques, better chemotherapeutic drugs, exotic radiation beams or improved drugs, there will be no single therapy that eradicates this disease.

This is so because cancers are a collection of different malignancies. They have some commonalities, but also many dissimilarities. Progress and cures will come piecemeal, one cancer type at a time. In some instances, in place of cures, we will need to accept long-term control and management of cancers.

Perhaps if cancer were really just one disease, having one elusive cure, the cost of finding that single magic bullet would be less intimidating. The reality is cancer care is expensive, in part, because a multitude of approaches must be explored, each tailored to a specific cancer.

Great progress has been made. Cancer survival rates continue to improve. But it has been a battle waged on many fronts, one small step at a time. But a single magic bullet -- 100 percent effective and without side-effects -- is unlikely to be found.

Though therapies can be made much more tolerable than only a few years ago, all therapies have side effects. Surgeons, no matter how enlightened and sophisticated their methods, must cut through healthy tissue and often remove organs or tissues vital to normal function.

Modern radiation therapy treatment machines enable optimization of dose delivery while minimizing the impact on healthy tissue. However, there is always some collateral damage. Even the newest chemotherapeutic agents and drugs designed to target specific genetic mutations have their side effects.

The costs of these quests for cures can be astronomical. Society is increasingly confronted with choices about how much it is willing to pay for incremental improvements in outcomes.

Institutions make huge investments to improve the quality of their services. No one wants to be seen as not having the latest state-of-the-art capability.

Those services must then be marketed to the public. It can be a competitive environment. Patients are often ill-equipped to evaluate what is often characterized as cutting-edge technology unmatched by other health care providers.

These are forces that can lead to escalating costs for marginal returns. What forces are in play to rein in unnecessary costs? How will society recognize when a particular pursuit has reached a point of diminishing returns -- that is, when its escalating cost outstrips the marginal improvement in outcome?

A very good example of hype and misapplication of a very expensive technology is the use of proton beams to treat prostate cancer. Proton beams are generated in fairly large linear accelerators. The cost of a proton accelerator, the ancillary equipment to assure optimal application of the beam and the facility to house the service is on the order of $100 million.

Radiation therapy has been used for treating prostate cancer for decades. Every innovation over the past four decades in the delivery of radiation dose from small gantry-mounted linear accelerators has improved prostate treatments.

Their high energy X-ray beams can be made to conform the radiation dose to the shape of the prostate gland. This was initially accomplished by shaping beams with high density blocks and later with multi-leaf collimators.

As computer control of such collimators developed, a variety of innovative treatment techniques became available. The latest version of these intensity-modulated radiation therapy (IMRT) techniques is called volumetric modulated arc therapy (VMAT).

With these techniques the radiation dose can be placed with great precession where it is needed while minimizing doses to normal tissue.

Accelerators having this capability cost approximately $3 million to $4 million. The total cost for a facility with VMAT capability is on the order of one-tenth the cost of a proton facility. Given the cost differential between proton therapy and IMRT, is the extra cost of proton therapy justified by better outcomes?

In principle, proton beams would appear to have some advantages. Proton treatments were initially developed to exploit some advantages they might have for treating small tumors. This capability would be especially useful for tumors in the head and neck. These tumors are typically adjacent to healthy structures that must be spared unacceptable collateral radiation dosage.

As a percentage of all cancers, the number of tumors for which protons would seem to be clearly superior is small. Given the small volume of appropriate patients, there is probably need for no more than about a dozen proton facilities for the entire United States.

Many more than this have been built or are planned, sometimes more than one in a large city. How have those driven to be perceived as ahead of the pack come to pay for their expensive proton accelerators? Unfortunately, the answer has been to increase utilization by treating many of the nearly a quarter-million men diagnosed annually with prostate cancer.

Use of protons would not seem to be justified by clinical results. A recent article published in the April 18 issue of the Journal of the American Medical Association concludes IMRT treatments are as effective as proton treatments.

Furthermore, IMRT patients had lower rates of gastrointestinal side effects -- rectal bleeding or diarrhea. This is just where proton prostate treatments were supposed to excel. Yet, a course of treatment at a proton facility costs roughly $100,000, more than twice that of IMRT.

Patients want the best for their loved ones. The costs, whether paid individually, through an insurance policy or by Medicare or Medicaid, is typically dismissed. But when more than 15 percent of our gross domestic product is spent on health care, the impact of the costs of expensive, marginally better, if better at all, treatments become prohibitive.

Technological advances in medicine are crucial, but, when misapplied, can result in crippling costs and an erosion of public confidence. It is a pattern one sees all too often.




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