Lung cancer screening is one of my least favorite topics to discuss because it's probably one of the biggest areas where there is a gulf between the medical establishment's party line and the expectations of many patients and advocates. I tackled a discussion of screening a few years ago that included the anticipated benefits as well as the challenges with LC screening (nowadays really focusing on low dose, spiral CT). That was probably about the most frustrating topic I've pursued, initially heralded after my post on the arguments in favor of screening, but feeling like I was being vilified as a kitten torturer in the responses I received after my post about the thorny issues with it.

There is no doubt that LC screening is an important issue, and it has become one of the most central causes for many non-profits in the LC world. I think that it's an easily identifiable, understandable issue that provides a tangible thing to do that can give people a sense of control in an otherwise largely uncontrollable situation.

But last week, the story emerged that PSA screening for prostate cancer appears to provide somewhere between little and no survival benefit for men. One large trial suggested a very small benefit, in which nearly 50 patients would need to be treated to save the life of one from prostate cancer, and another trial didn't show a survival benefit. After lung cancer, prostate cancer is the next most common focus of my practice, and I can assure you that I find this very easy to believe. I see many men who are exceptionally likely to do well, begging the question of whether they underwent surgery or radiation or some other alternative for no benefit, but who have had a permanent compromise of their sexual function, urinary continence, and other issues important to their quality of life (and I probably see only a small minority of the patients who are exceptionally likely to do well and never even see an oncologist). I also see men with prostate cancer who undergo aggressive treatments for prostate cancer but have a virulent enough cancer that even screening efforts and timely, aggressive interventions can't save them from their cancer. In between, the numbers suggest one in 50 men may be saved from a truly life-threatening cancer.

There are several important points I'd make. One, very much in the range of the obvious, is that lung cancer is not prostate cancer. The balance of virulent vs. indolent cancers is far more skewed to the virulent side in lung cancer. The consequences of further workup and aggressive treatment are very different for lung nodules than removing or destroying the prostate. The fact that screening became routine for prostate cancer never mandated that screening should be done for lung cancer. The counterpoint is also true: the rather unimpressive results of screening in prostate cancer don't taint the potential value screening for lung cancer.

Another point is that it's not valid to say that screening works for every kind of cancer as a justification to do it for lung cancer without showing the value particularly for lung cancer. Screening for cancer in general often detects a lot of suspicious findings, some of which turns out to be cancer, and a smaller subset turns out to actually improve survival. Colon cancer is one that is quite effectively screened with a colonoscopy. There's no question that breast cancer and prostate cancer are diagnosed in tens of thousands of unsuspecting people because of screening, but the true survival benefit is far less iron-clad. And then there's lung cancer...

Where does lung cancer screening fit in? I strongly suspect that screening can help, but I would have said the same thing about prostate cancer screening, even though anyone directly involved in the field would find it extremely easy to believe that many men were being heavily over-treated. Over the last decade or more, literally hundreds of thousands of men have undergone prostate surgery or radiation that hasn't made a difference in their survival but may have compromised other aspects of their lives.

At the very least, asking the question of how valuable LC screening really is shouldn't be viewed as traitorous behavior. There are serious consequences in terms of anxiety and risk from the workup that emerge when a person is found to have an ambiguous lung nodule. The Q&A discussion forum includes many examples. There are potentially very large costs to be undertaken by a health care system that cannot afford to assume new large costs that don't provide a clear value. If LC screening does what we'd want it to do, a very compelling argument can be made that it's worth assuming the costs, both monetary and the risks/side effects of chasing down many more nodules that ultimately prove to be benign than we do now.

But prostate cancer screening had been fairly established for more than a decade, based on a combination of imperfect data, wishful thinking, and strong advocacy ahead of the actual data. In that interval, the vast majority of these men who underwent screening haven't experienced an improvement in survival but have experienced the adverse effects of treatments whose costs have been tremendous. Perhaps that situation should cause us to reflect that the deliberate debate about the evidence is a valuable approach and that turning it into a political cause isn't the wisest long-term strategy.