Hold the Champagne
The breast cancer field has a certain rational exuberance these days. A spate of new drugs has been added to the old therapies, and the cure word is in the air for early disease. Medical scientists are taking a bow and basking in the sunshine of their hard-earned success. This success shows that the formula for publicly funded medical research of the past 60 years really works: That is, if you fund it, they will come. Breast cancer research commands more government dollars than any other cancer; in turn, it has become a magnet for the best talent, the most elite medical centers, the most ambitious drug development efforts. And let's applaud the women who turned pink ribbons into a crusade of talking, walking, racing, and prowling the halls of government in search of public and political support for their disease.
But before we break open the champagne, we cannot forget that the toughest stuff is still ahead. Look at the 40,000 women who die of metastatic breast cancer each year--and for that matter, the more than half a million men, women, and children who face a similar fate because of cancer's brutal march through their bodies. For what makes cancer a terror and a killer is its reckless and remorseless invasion of nearby and distant organs, most notably the liver, lungs, bones, and brain. At this advanced stage, the more than 100 different kinds of cancer behave more like one. If we want to cure cancer and not only tame early disease, we have to block its most central feature, the ability to spread wildly. Solve the problem of metastasis, and you solve the problem of cancer.
In this regard, breast cancer research has provided some unique insights, ones that have been observed thus far in a few other aggressive cancers such as leukemia and brain tumors. Provocative evidence shows that the mighty and lifesaving stem cell may hold the keys to the dark world of cancer. Scientists discovered malignant primitive stem cells sparsely scattered throughout breast cancer tumors and their metastases. And it is only this small group of stem cells--not the other faster-growing ones that make up the bulk of the tumor--that have the ability to take root and grow when transplanted into lab mice. These stem cells turned bad are the immortal seeds of cancer's growth and spread, the self-renewing brood that can easily move about, survive distant travel in blood or lymph, create the means to drill through dense tissue and poke holes in bones, and lay down a blood supply to keep the new nest nourished and expanding. Some scientists suggest that the small population of hidden stem cells with unique genetic signatures may be the better target for preventing and treating metastatic cancer.
Unified assault. Further along are efforts to block metastases by choking off new blood vessel formation, to boost the natural immune system with drugs and vaccines, and to make tissue invasion-proof with anti-inflammatory or bone-building agents. These approaches cut across tumor type. It is encouraging that the new drug Avastin, which inhibits tumors' ability to make new blood vessels, offers some benefit not only in metastatic breast cancer but also to advanced cancers of the colon, prostate, kidney, pancreas, and ovary. Clearly, a unified assault on metastatic disease is no pipe dream. And there are storied examples of durable cures: In testicular cancer the most advanced metastatic disease can melt away with chemotherapy. And in rare but documented cases, widely disseminated melanoma and renal cell cancers have inexplicably vanished in spontaneous remissions, presumably in the wake of an immune assault. No doubt, taking on the metastases challenge is a tough one and demands the wellspring of energy, passion, and personal edge that has powered the war on breast cancer.
Indeed, breast cancer has been the high-water mark of resolve to fight cancer. Since 1991, taxpayers have spent almost $10 billion studying this cancer. In 2005 that amounts to an annual research expenditure of $23,474 per life lost from breast cancer. If you compare that with lethal cancers that almost always show up in an advanced stage, such as lung, pancreas, ovary, and liver, we invest in them an embarrassing 15 percent of that amount. Consider lung cancer, by far the biggest killer of both men and women. Research on this demon claims only $1,829 per lost life. If we really want to race to the cure, we must solve the mystery of metastases--and that level of resolve is just not up to the job.
This story appears in the June 13, 2005 print edition of U.S. News & World Report.