New Evidence Clashes with New Evidence, While Old Wins

Today’s headlines from the AP were a bit misleading: “Study Sees Benefit from More Extensive Breast Cancer Surgery.” A presentation at the American Society of Clinical Oncology (ASCO) at the end of May described a prospective, randomized trial led by Yale Cancer Center, addressing breast conservation technique. “More extensive surgery” is the misleading part, conjuring up images of a return to the Halsted radical mastectomy. In fact, the clinical trial was merely adding “thin shavings of the lumpectomy cavity” to reduce the chance of returning to the operating room for “positive margins.” In the study, returns to the operating room for wider excision were cut in half by the “shaving” technique. Commentary indicated this was a “new” and revolutionary concept that will impact as many as 100,000 women per year.

 

Prospective randomized trials are the mainstay of evidence-based medicine, so we have a “new” standard of care proposed. But wait a minute! This very issue was recently addressed by a large consensus panel with multi-expert firepower, and for the first time since breast conservation was introduced, the verdict came loud and clear – You don’t need to do anything more than what was done in the original NSABP B-06 trial in the 1970s. Unless ink touches tumor cells, there’s no need to re-excise. This “new” standard (in fact, about 35 years old) was adopted by the Society of Surgical Oncology (SSO) and the American Society for Therapeutic Radiology and Oncology (ASTRO) in 2013 after a meta-analysis was performed on local recurrence rates as related to margin status.

 

So, we have high quality evidence about to appear in the New England Journal of Medicine that suggests one should do more at the time of surgery to get better margins, while high quality evidence also suggests a surgeon doesn’t need to do anything more than get the tumor out with no ink touching tumor cells on final pathology.

 

For those of us who were practicing surgeons at the time breast conservation was introduced, there was considerable caution used in patient selection. At the time, according to B-06 protocol, if you didn’t get clear margins on the first attempt, the patient was returned to the operating, not for re-excision, but for mastectomy. This prompted many of us to be compulsive in attention to detail to make sure we got clear margins the first time around.

 

Having done a year of surgical pathology, I was very comfortable with how tissue was processed and how it subsequently appeared on the microscope slide. So, early on, circa 1989, I adopted a compulsive approach where I would submit the primary lumpectomy specimen to the pathologist for inking of margins, but then I would take an additional 5mm (or so) shaving around the lumpectomy cavity at those margins where the lumpectomy specimen interfaced with breast tissue (as opposed to fat, muscle, or skin). I would then orient these shavings and place India ink myself on the new “outer rim” while in the operating room so that the pathologist could “bread-loaf” the shaving and give me a report on the second set of margins. Not only did this give me greater assurance of margin status, but it also afforded the opportunity to re-create the tumor and its extensions in a 3-dimensional pattern.

 

In the academic setting, we once debated whether a return to the operating room for wider excision should be listed as a surgical complication. I explained how I kept my returns to the OR to a minimum, and a colleague was astounded at the ‘wasted’ time in the operating room: “You can’t possibly be doing that on every lumpectomy patient.” He was wrong.

 

A few years later, at a breast cancer meeting, a prominent breast surgeon described how he was using this exact same technique. At the end of his presentation, he said, “There are four of us doing this now.” Wow. Certainly, he meant, “In my limited circle of academic friends who are breast surgeons, there are four of us doing it now.” But it came across as a terribly constricted view of the world. Nonetheless, it helped validate what I was doing at the time (even if only five of us were doing it instead of four).

 

My decision to perform breast conservation in this fashion was 100% rational thought based on my experience in the pathology lab coupled to what I was learning about tumor growth patterns for different histologic types. Does it really take a prospective, randomized trial before we can practice medicine wisely?

 

It say it all too frequently – “I’m not opposed to evidence-based medicine. I’m opposed to the glorification of evidence-based medicine to the exclusion of rational thought.” And believe it or not, one sees such exclusion on a regular basis.

 

In this case, a prospective, randomized trial is being regarded as an historical moment in the annals of breast conservation surgery (okay, that’s a bit of a stretch) – a “new” concept – but in fact, common sense arrived at the same conclusion 25 years ago (for at least 5 of us).

 

And what do we do now with the 2013 recommendation from a Who’s Who list of experts who told us “no ink on tumor” is good enough. Paraphrased: “Don’t worry about close margins. Don’t worry about the method of pre-op imaging to design a roadmap for accurate lumpectomy. Go in, get the tumor out, and don’t be concerned about your margin status unless ink touches a tumor cell, exactly what the NSABP said in the 1970s.”

 

Those who want prospective randomized trials for everything we do in medicine are going to be sorely disappointed. We will never have “high quality” evidence for every situation. Rational thought is the tool that fills in the blanks, and while empiricists love to point out examples where rational thought failed miserably, I have no trouble coming up with examples where pure empiricism failed miserably. Good science is not synonymous with empiricism – it is a blend of empiricism and rationalism. Unfortunately, humans are not particularly good at balancing opposing concepts.

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