Tuesday, July 14, 2009

Prostate Screening Rebuttal

In NEJM today there are several letters to the Editor criticizing the reports on the effectiveness of screening. We wrote about this when the reports came out two months ago. We said the PLCO trial using a PSA of 4.0 was flawed. Well it is good to see we are not the only ones who see that flaw.

The first letter to the Editor by Catalona states:

"The results of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial (ClinicalTrials.gov number, NCT00002540) by Andriole et al.1 were released prematurely, at the same time that Schröder et al.2 were reporting, on the basis of the European Randomized Study of Screening for Prostate Cancer (ERSPC) (Current Controlled Trials number, ISRCTN49127736), that screening with prostate-specific antigen (PSA) saves lives (March 26 issue). The PLCO trial is being portrayed as the underpinning for proposed changes in the mind-set of physicians and patients that prostate-cancer screening and treatment do more harm than good. However, the PLCO trial used an outdated PSA cutoff and permitted the enrollment of a large proportion of men (>40%) who had undergone prostate-cancer screening in the previous 3 years. Furthermore, more than 50% of the control subjects underwent screening during the study. Most men with abnormal results in the screening group did not undergo prostate biopsy for 1 year or more."

We said this and more. The letter by Preston states:

"It is important to recognize that the two randomized trials of PSA screening reported by Andriole et al. and Schröder et al. do not relate directly to the question of whether we should be doing PSA screening. They relate to whether screening should be expanded beyond the levels that are typical of the populations in which the trials were conducted — levels that are reflected in the control groups and in pretrial conditions.."

This is an example of the CCE, comparative clinical effectiveness, run amuck. It was obvious to anyone slightly familiar with the results that they were just outright wrong, they asked the wrong question. The great NY Times as we noted ganged on and said that PSA testing had no value. Well what else would one expect from the Times. We wrote just a few days ago also about a Times article with a woman physician saying men should just wait, watchful waiting. I always ask what would happen is a male physician said that to a woman. Yet in the same NEJM issue there was a paper on Ovarian cancer. And yes by a man. The author concludes:

"Ovarian cancer that is diagnosed on the basis of symptoms is often at an advanced stage. Early detection, which is associated with improved survival, depends on effective screening strategies. Studies have shown that screening with the use of serum tumor markers (especially CA-125), ovarian imaging with transvaginal ultrasonography, or a multimodal strategy can detect ovarian cancer at an earlier stage, but trials that have been completed to date have not included a control group for direct comparison, and no trial has yet shown improved overall survival for women undergoing screening. Pending the results of the two large ongoing, randomized, controlled trials,20,35 I would advise against screening in a patient who is at average risk, such as the woman described in the vignette."

Yet the article starts by stating:

"A 56-year-old woman presents to her physician, requesting screening for ovarian cancer. She reports the recent death of a friend from ovarian cancer at the age of 65 years. The patient has no family history of ovarian or breast cancer. The physical examination, including pelvic and rectal examination, is normal. Should the physician recommend screening for ovarian cancer?"

If a woman patient comes in and tells her physician that she is concerned and that there was a family history, then to avoid being sued, and frankly to be in good practice, the physician should perform an ultrasound and do a CA125 test. There are many false positives in post menopausal women and the costs we have argued in our analysis are not unreasonable. The risk is that ovarian cancer tends to grow at a rapid rate and 90 screening for high risk women would be recommended, despite there being little if any clinical bases for that.

This does continue to raise the risk of CCE and the dangers in a Government health care plan which inherently has rationing as a means to control costs. Death from either of these cancers is painful and debilitating and can become unnecessary if the research is done in an open and peer reviewed manner independent of Government intervention. The alternative should be unthinkable.