Prostate cancer update: Discuss delaying treatment with your doctor

A new paper enters the cancer screening fray: Shappley, W.V. III, Kenfield, S.A.,Kasperzyk, J.L., Qiu, W., Stampfer, M.J., Sanda, M.G., and Chan, J.M. 2009. Prospective study of determinants and outcomes of deferred treatment or watchful waiting among men with prostate cancer in a nationwide cohort. Journal of Clinical Oncology 27:4980-4985.

The study, which showed no statistical difference in outcome between cancer patients who deferred treatment and those that did not, was weak in many ways. The most obvious problem was that it was not controlled, but instead compared men who made their own decisions either to monitor their cancer for awhile, or to treat immediately. This led to not only a skew in sample size (the waiting group was 10% of the total) but in significantly different initial pathologies in the groups.

But, in a way, the unequal comparisons show why this study is important. The patients who chose to wait had were unsurprisingly older, and had cancers at an earlier stage, with lower Gleason scores. So from one perspective, it is easy to say that the waiters did as well as the treated because their cancers were less likely to progress anyway. If the treatment group had more aggressive cancers, those men were still likely to die, despite treatment.

From another perspective, though, this study demonstrates exactly the pathologies for which deferred treatment, or “watchful waiting,” makes sense. As an accompanying editorial (Zietman, A., 2009. Evidence-based medicine, conscience-based medicine, and the management of low-risk prostate cancer. J Clin Oncol 27:4935) points out:

Contemporary data do show that local failure is now infrequent after radical treatment but it is also true that symptomatic local progression is unlikely even without treatment and thus little, in reality, is gained.

It is easy to fall into the trap that if I was treated, and I got better, it must have been because of the treatment. This study is important because it clearly demonstrates the fallacy of that reasoning.

Another important point of perspective is that the percentages of both death or metastasis after an 8-year follow-up were comfortingly low: death rates ranged from 0.72% to 4.5%, and metastasis rates ranged from 2.6%-10.5%. Thus, even with sample sizes of 2989 in the treated group and 342 in the waiting group, there were too few events to show any statistical difference in outcomes:

We found the relative risk to be similar between the patient groups, but the numbers of metastases and deaths as a result of PCa were low, potentially underpowering this analysis.

But what does “underpowering” mean in this context? It means you have to collect a whole lot of data to find any significance in the effect you are looking for. Some people think this means that researchers have a responsibility to collect enough data to find a statistical effect. But someone actually trying to place what is being studied in a biological context might notice that if an event you are trying to measure (in this case metastasis or death from prostate cancer) is so rare that you need a giant sample to detect a difference in the event between groups (in this case treated or untreated men), then how important is that event really, in the large scheme of things?

Very important, would say many people injecting themselves in the current health care debate. If one life can be saved by treating dozens more men, we shouldn’t even question it. We all have a bias if ours is the life being saved, and so at an individual level, some consider any amount of time and expenditure to save it is worth it – even necessary. This, precisely, is what the outraged charges of “rationing” are all about. The logic goes: if even one life is lost because a bureaucrat says that a group of people with a particular diagnosis cannot have a particular treatment, it is a moral travesty.

But of course this argument can be shown to be fallacious at its logical conclustion. Putting aside the curious lack of outrage by the “anti-rationers” at the fact that nearly 50,000,000 people in this country are rationed completely out of any but emergency care (and many of them die due to this current rationing), anyone with any intellectual honesty at all understands that unless you want to give everyone a complete body scan every week, an absurd proposition for many obvious reasons, a lot of people are going to continue to unfortunately die from cancers that weren’t “caught early” – because many cancers grow too fast to catch them early, under current yearly screening guidelines. Limiting screening to yearly visits for just a few cancers is rationing. We have rationing now, and under any possible system, we always will. The only rational point of contention is where to draw the line. Anyone who claims that line is obvious and absolute, for any type of screening, is disingenuous and talking through his hat, because anyone’s location of the line is based on their own preferred cost/benefit ratio, a matter purely of opinion.

Except, there really is only so much money out there. So even the most vocal of the “anti-rationers” will recognize that a barrier to constantly increasing care, based on cost, is eventually reached.

The accompanying editorial contained some surprisingly forthright statements that need to be discussed in the mainstream health media. For example:

The training of resident doctors has to date been so focused on cure, and the culture of early detection/early treatment so deeply ingrained, that it is little wonder that this shift in thinking is yet to reflect itself in everyday practice. What is respectfully acknowledged at major meetings and in editorials is not, in the daily reality of the clinic, being applied to patients…

The PCPT (Prostate Cancer Prevention Trial) trial reported in 2004 demonstrated that systematic needle biopsy could find prostate cancer in 27% of all men with a normal prostate-specific antigen (PSA).

It may sound surprising, given the shrillness of the current debate, but the idea that cancer exists at at least a low and nondangerous level in many of us is not a new one. A 1985 autopsy study in Finland (Harach, H.R. Franssila, K.O., and Wasenius, V.-M., 1985. Occult papillary carcinoma of the thyroid. A normal finding in Finland. A systematic autopsy study. Cancer, 56(3):531-538) found carcinomas in the thyroids of 36 out of 101 people who died of other causes. The prevalence of tumors, or their size, was not correlated with age, suggesting that thyroid cancers arise at a young age, and most do not progress:

To conclude, the smallest forms of OPC [occult papillary carcinoma] of the thyroid are, according to our series, so common in Finland, possibly also in other countries, that they can be regarded as a normal finding.

The authors conclude by suggesting that doctors avoid using the word “cancer” in regard to any small tumors found in the thyroid, because it is so loaded down with baggage that results in overtreatment. So none of this is new. It is just becoming highly relevant as we discuss what to do about medical costs that are spiraling out of control, and leaving more and more ruined lives in their wake.

Bottom line: if you look for potential problems through scans of perfectly healthy people, you are going to find a lot of them. The logical extension for those who are demanding more and more screenings (to be paid for by somebody else) is constant full body scans. And setting aside the impossibility of this, imagine the disaster of overtreatment that would ensue as we treat more and more asymptomatic conditions.

And as a final note, putting more and more money into screening does nothing to solve the problem that we are focusing too much on looking for and treating disease, rather than health itself. The same amount of money spent on prevention rather than treatment can help a whole lot more people. But, as another commentary (Esserman, L., Shieh, Y. and Thompson, I. 2009, Rethinking screening for breast cancer and prostate cancer, Journal of the American Medical Association 302(15):1685-1692) points out, the entire medical culture of the U.S. causes this:

Three barriers hinder the acceptance of prevention: failure of physicians to make clear to patients (and patients to understand) their individual risk of cancer, the belief that early detection and “cure” are ensured with screening, and organized medicine’s focus on treatment rather than prevention.

If Tea-Partiers really want to have control over their own health care, demanding more screening is not the way to do it. Instead, they should educate themselves about what the actual value of screening is, and know before they screen how they would approach treatment. They just might find themselves rationing their own care.

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