Health care conundrum: When cancers are harmless

A new paper in the Journal of the National Cancer Institute raises an interesting health care conundrum for cancer care: up to 25% of breast cancers, 50 of lung cancers, and 60% of prostate cancers that are detected by screening may represent overdiagnosis. This is not a radical new finding made in haste, the authors, one of whom was my biostatistics professor in grad school, have in fact been studying this phenomenon for decades. But it is a finding that raises especially interesting challenges in how we perceive, screen for, and treat diseases.

What the paper found was that in those cases and frequencies mentioned above, cancers detected very early would, if left untreated, never develop to cause symptoms or threaten health, and the patient would die of some other, non-cancer related cause. How is this possible? Two forces conspire to create the quandary: The amazing power of our bodies, and the amazing power of technology. On the one hand, screening technologies are getting so good that we are able to locate ever-smaller abnormalities that fit the general definition of being “cancerous.” And yet we are finding that in many cases, the body is able to detect and destroy aberrant cell growth on its own in a not-insignificant percentage of cases. So we are increasingly able to detect and label as cancer abnormalities that the body is often able to neutralize on its own, or that would never grow to a life-threatening stage.

Is there harm in treating something, even if it wouldn’t have turned deadly? In short, yes. Cancer treatment is never a nice experience, and may involve radical surgeries, such as breast removal, and of course powerful chemical and radiation treatments. In some cases the treatments themselves result in death or new cancers. And there’s also the stress, fear and discomfort involved.

The health care conundrum occurs when deciding how to use this information. The authors of this new paper call for more research, as well as carefully informing patients of the possibilities and likelihoods that their cancer’s may not actually be life threatening. The trouble, of course, is that we can’t yet tell the harmful abnormalities from those that might kill us. What fascinates me is, even if informed of the possibilities that a potential cancer is harmless, how would I respond? How would you respond? Would this new knowledge give you some hope, sway you to opt for a less aggressive approach? Would it further confuse you and ad to the stress of the decision making process? We have been raised in a world that wages wars on cancer, and malignancies constantly rate among the most frequent causes of death. Is it possible that we know a lot less about this thing called cancer than we’d lke to admit? It appears so.

Photo credit: Annie Cavanagh. Wellcome Images