THE RECENT PBS series “The Emperor of All Maladies” did a superlative job of explaining the impact of a cancer diagnosis, and chronicling the story of the brave patients, families, physicians and researchers who have pioneered treatments for 50 years. The documentary rightly emphasized the accelerating pace of discovery of mechanisms of cancer, the dazzling dissection of the genetic events that cause normal cells to go awry and become cancerous, and the potential for this knowledge to lead to treatments for some specific cancers.
But the focus on treatment gave short shrift to a big piece of the story.
While watching, I was reminded of a tale with a similar title — "The Emperor's New Clothes." In the Hans Christian Andersen tale, the emperor is told by his tailors that his new suit would be invisible to anyone unfit for their position. His courtiers, of course, praise the magnificence of the non-existent garments. Eventually, a child points out that the emperor is naked.
In searching for a cure for cancer, we have repeatedly climbed on various bandwagons. They include the radical mastectomy for breast cancer, high-dose chemotherapy, immunotherapy, and — more recently — molecularly "targeted" therapies. In each case, it took someone with courage to point out the limitations or futility of the approaches.
Hope is critical to cancer patients and those treating them, but hope that is not rooted in the facts risks becoming an illusion. As Mikkael Sekkeres of the Cleveland Clinic has commented, we should not delude ourselves into believing targeted therapies will be a panacea for cancer treatment.
Where the series (and the book that inspired it) fails is in its emphasis on finding treatments and cures to solve the problem of cancer. Treatments are, of course, of paramount importance to anyone diagnosed with cancer, but from a national or global perspective, there should be more investment in preventing cancer. As "The Emperor of All Maladies" notes, more than 50 percent of cancers worldwide are thought to be preventable.
The graph of the trends in US deaths from the most common cancers over the last half century is dominated by declines resulting from changes in lifestyle and early detection. Lifestyle changes partly account for steady drops in deaths from cancers of the stomach and liver, uterine and cervical cancer, colorectal cancer, as well as more recent declines in lung, breast, and prostate cancer deaths. Other factors include the less frequent occurrence of certain infectious causes of cancer, and the earlier detection of cancers combined with greater access to the standard appropriate treatments — such as surgery, radiotherapy, and chemotherapy. For the most common cancers, few of these mortality reductions can be attributed to new drugs, with the exception of the role of anti-estrogens such as tamoxifen in the lowering of breast cancer deaths.
This doesn't mean investment in basic research is not critical, and that new therapies are not needed, particularly for cancers we do not know how to prevent or can't detect early. Increased attention to cancer prevention and early detection, however, would avoid much unnecessary suffering and reduce the numbers of patients who enter the genomic lottery of whether their cancer will be treatable with available drugs.
On a global scale, the need for cancer prevention is even more urgent. With much larger populations and longer life expectancies in low- and middle-income countries, the numbers of future cancer patients will overwhelm already overstretched medical facilities. Two-thirds of cancer deaths in 2020 are expected to occur in these countries. In these locations, preventable causes are even more predominant – smoking, certain vaccine-preventable infections, and some types of treatable infections. But the reality is that the number of daily smokers is still increasing as tobacco companies market aggressively in low- and middle-income countries. In addition, vaccination rates for hepatitis B virus and human papilloma virus — the major causes of liver and cervical cancer — are low. And treatment for helicobacter pylori — the infection that is a major cause of stomach cancer — is rare. Investments in scaling up these types of cancer prevention are needed along with expanding access to treatment, and would permit the treatment resources to become more widely available to a smaller number of patients – numbers that in global terms will still represent a major challenge.
New drugs are needed, too, but even effective, inexpensive drugs such as tamoxifen are still scandalously hard to find in low-income countries. Even worse is the paucity of cheap, but proven drugs for pain relief when patients are dying of cancer.
The continued and necessary focus on improving the treatment of cancer, and the dazzling science behind this, should not blind us to the potential for cancer prevention, or distract us from the scaling up of relatively simple early detection solutions that have been available for decades. As we admire the emperor's parade of new discoveries and potential breakthrough medicines, we need to be like the clear-eyed child with the courage to point out the obvious – a cancer prevented does not need to be cured.
David J. Hunter is the Vincent L. Gregory Professor of Cancer Prevention at the Harvard TH Chan School of Public Health, and a professor of medicine at Harvard Medical School.
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