ASCO guidelines for breast cancer follow-up: Solid science & rational skepticism

The American Society of Clinical Oncology (ASCO), the primary professional society representing doctors who care for people with cancer, periodically publishes guidelines for common clinical situations encountered by oncologists. The ASCO guidelines are a summary of best practices based on the latest and most thorough analysis of the scientific evidence currently available. ASCO creates its guidelines using a very rigorous and time-consuming workflow by first identifying and analyzing relevant research findings, crafting them into a format that is practical and accessible for patient care, and then submitting them for multiple layers of editorial review. By comparison, guidelines from the National Comprehensive Cancer Network (NCCN), an alliance of 21 different leading cancer centers, including my own institution Johns Hopkins, are created by panels of disease experts based on their consensus opinion. Both processes have a lot of value and are widely used, and to some extent they complement each other. The NCCN guidelines are much more numerous than ASCO's, and they not only address the treatment of different cancers by primary site but also cancer detection, prevention, risk reduction, and supportive care. NCCN also provides a version of their guidelines for patients. The ASCO guidelines are fewer in number than NCCN and deal with more selective situations, and in part this is due to the different methods used for their creation.

Why are there guidelines for the management of cancer in the first place? The most important reason is that it's a way of standardizing clinical care for common tumors, and since the guidelines are created by recognized experts from respected organizations like ASCO and NCCN, there is usually little controversy that they represent best practices based on the most current knowledge. Here's a good description from an article by Drs. Irwin and Peppercorn in the November 2012 Journal of Oncology Practice entitled "Promise and Perils of Guidelines in Quality Cancer Care:"

Such guidelines are currently used to encourage high-quality, evidence-based management that will increase the use of proven interventions while curtailing use of those that lack evidence or are known to be ineffective.

As the authors point out, some evidence exists that adherence to guidelines improves patient outcomes, although that is harder to prove than you might expect. No doubt, guidelines can serve as a deterrent to inappropriate and/or costly, unnecessary care, and they potentially offer physicians protection against medicolegal risks. The authors also cite some theoretical risks of standardized treatment guidelines, which you can read in the full text of the article.

ASCO recently updated their guidelines for the follow-up care of patients with breast cancer who have completed their primary therapy, whether that is surgery, radiation, chemotherapy, or hormonal treatment, or some combination of these. Basically, the population addressed is the very large number of women (and a few men) who have completed the active phase of treatment and who have no evidence of disease, "NED" in oncologist-speak. Generally these are patients who are treated with "curative intent," meaning that their therapy was delivered with the reasonable  expectation that it would result in complete eradication of the cancer. Unfortunately, we know that does not always happen, and recurrence after primary treatment, sometimes many years later, is an unfortunate and feared event. Given how prevalent breast cancer is and how the majority of patients do end up going through one of these life-altering treatments, it is critically important to have some guidance as to the most appropriate follow-up care. These guidelines address such things as how often a patient who has completed all treatment should be seen by her doctors, what lab tests and imaging studies are recommended, and what advice patients should be given. ASCO first created these guidelines in 1997 and updated them in 1999 and 2006; this is the 2012 update. Here are the relevant links:

• The abstract of the early release article from the Journal of Clinical Oncology published online 11/5/12 (shout out to the 3 Johns Hopkins co-authors, Dr. Antonio Wolff, Dr. Tom Smith, and Elissa Bantug, herself a young breast cancer survivor who coordinates our breast cancer survivorship program)
• The full text of the JCO article 
• A summary slide set
• A surveillance flowsheet in Excel format (also available as a PDF)
• Links to Cancer.Net's patient guide on the topic

Let me try to summarize the most important recommendations. The key point is that this 2012 guideline is identical to the 2006 version, which is to say that the ASCO panel, after looking at all of the published literature between 2006 and 2012, did not identify any research findings that warranted a change in their recommendations from 2006. The foundation of follow-up for patients with early stage breast cancer treated with curative intent should be periodic clinical evaluations (i.e., doctors' visits) and mammography. The frequency of recommended follow-up visits decreases as time goes on, from every 3-6 months for the first three years, to once or twice a year for years 4-5, and annually thereafter. The follow-up care should be provided by practitioners experienced in the surveillance of breast cancer (i.e., knowledgeable about the manifestations of cancer recurrence and late effects of the treatment) and comfortable with the physical exam of the breasts, especially the irradiated breast. Note that it doesn't say this has to be an oncologist necessarily, although hand-offs between oncologists and PCP's are discussed, and the practitioner is not required to be a physician, as mid-level providers working with physicians are often quite expert in this role. The guideline gives some recommendations about the frequency of mammograms which you can read at the links above. The importance of educating patients in the signs and symptoms of cancer recurrence is mentioned, as is the importance of regular gynecology follow-up.

As was the case for the identical 2006 version, the part that this 2012 guideline addresses that I think will generate the most interest is what is NOT recommended, which is basically all blood tests (including CBCs, chemistry panels, and tumor markers such as CA 27.29) and all imaging except breast imaging. So specifically all chest xrays, bone scans, CT scans, PET scans, and ultrasounds are not advised. To be clear, the recommendation against performing this type of testing applies to the patient that is in surveillance mode, who is coming in for a regular follow-up visit and who by definition does not have any specific symptoms. ASCO is not suggesting that doctors should forgo this type of testing as a way of evaluating a specific concern like a new symptom (say, back pain) or physical finding (such as an enlarged liver detected by the physician). Good medical practice would dictate just the opposite.

This is not a surprise, and the research supporting this has been around since the mid 1990s. And let me say as a breast cancer oncologist, I support this and have generally been practicing this way for many years. Those studies from the past basically showed that an intensive surveillance strategy of regular imaging studies and labs, when compared with a more conservative approach of periodic physical exams and mammograms alone, did not show any real advantages. The vast majority of recurrences were identified not by imaging tests, but by a symptom the woman herself notes or a physical finding the physician identifies on physical exam. Survival rates were the same between the patients followed more aggressively and those followed more conservatively, and quality of life was not any better. Yes, intensive surveillance and testing did identify more recurrences earlier, usually by no more than a few months, but it did not translate into higher cure rates or even fewer complications. Since metastatic breast cancer is incurable, all the early testing did was identify metastases a few months or so before they declared themselves either by a symptom or a physical finding.

And to take this a step further, this idea of not doing surveillance testing on patients with early stage breast cancer in the follow-up phase made it onto ASCO's Top Five list for the American Board of Internal Medicine Foundation's Choosing Wisely campaign - five commonly used practices that can and should be questioned since they are costly and lack medical justification. I cover this in a blog post from a couple of months ago.

But if there ever is an issue that I find problematic in my clinical practice, and one that raises delicate issues of patient empowerment and autonomy, physician authority and adherence to evidence-based medicine, and doctor-patient communication, it is this one. This issue about not performing certain tests is one that causes understandable tension with many of my patients, since at face value it seems illogical and inappropriate. Why wouldn't you want to detect cancer earlier? How could it be that would not improve outcome? And even if there was some uncertainty about that, why should ordering a simple blood test be an issue since the harm is perceived as minimal and potential gain great? Let me run through a few aspects of this issue that contribute to making it so challenging:

1. Oncologists used to do this for breast cancer patients. Yes, that is very true. When I was doing my fellowship in the late 80s I think some of the regular testing was starting to wind down, but I do recall that getting annual bone scans and liver ultrasounds - and certainly "routine labs" like chem panels - was accepted without much question.
2. Oncologists do this these days for patients with other cancers. Yes, very true as well. For example, there is very good evidence that monitoring patients with colon cancer who have had primary surgery +/- chemo with CEA blood tests and periodic liver CT scans, improves outcomes by identifying liver metastases early, thereby permitting potentially curative resection of the liver lesions.
3. Some oncologists do this these days for breast cancer patients. Also very true. I see a fair number of patients who receive their care outside of Johns Hopkins, and it is not at all rare when I review their records that I can tell their doctors are ordering CA 27.29 blood tests every few months for monitoring. In fact, a rising tumor marker in the absence of any other positive findings is a common reason for referral to an academic medical center like Hopkins. When I try to diplomatically explain that this was a test that we probably wouldn't have ordered here, the patient is often confused and conflicted, particularly since that fact is irrelevant as far as they are concerned if it suggests that there is a potential problem (which I totally get).
4. The downstream consequences of false positives and enhanced anxiety are not trivial. What is not always easy to appreciate is how a relatively lousy screening test like the CA 27.29, with less than optimal specificity and sensitivity, may open up a whole range of problematic issues - over-interpretation of trivial xray findings, misattribution of physical symptoms better explained in another way to "the cancer," and the endless cycle of repeating scan after scan to follow up on an equivocal abnormality. 
5. Even though patients may intellectually understand #4, many still want these tests done for whatever assurance they can provide, and they are willing to risk the false positives. Again, I am quite sympathetic to this viewpoint which many of my patients articulate to me. But I see how it can go either way - the test can be "negative" which is reassuring for everyone, including me as the oncologist who usually is the one who ordered it, or it can be abnormal or equivocal, leading to more testing. And when the patient now finds herself on the receiving end of the latter, it's much harder to deal with that scenario than it is in the abstract.
6. Patients just want some reassurance that they are ok. The doctor asking you questions and doing regular physical exams, in this modern era of sophisticated imaging and labs, isn't very reassuring. At the completion of adjuvant chemo and radiation, virtually every patient asks me, "How do you know it worked?" In other words, how do you know I am ok? How will I be monitored to know that I remain ok? It's so disconcerting when I have to say that we only really know if chemo didn't work, and we have no way of proving that it accomplished what we wanted it to do. It's very understandable that patients want some objective evidence that they are cancer-free. That's why they are naturally inclined to expect that some type of testing - not the word of the oncologist, even when the trust factor is very high - will offer them that reassurance.
7. A negative test means that based on the performance characteristics of that test there is no evidence of cancer at that time. So a relatively insensitive test (e.g., a chest xray) offers a small degree of reassurance that everything is ok, at least in the lungs, but it is only as good as its ability to discriminate a lesion large enough for it to detect. So a chest xray is likely to miss a 4 mm lung nodule, something that is much easier to see on a CT scan but at the price of a much higher exposure to radiation. But even a CT or a PET scan or whatever the latest imaging test to come will be has a shelf life - a negative PET scan in January does little to reassure anyone in October.
8. It is increasingly being recognized that radiation from diagnostic imaging is not good for you, and it probably increases your risk of cancer a small amount. While this is true, it does seem a little incongruous when an oncologist uses this line in someone that has just gone through 20 weeks of chemo and 6 weeks of radiation which themselves can, ahem, cause cancer. I'm not trivializing the risk, but I understand some patients find this "justification" for not ordering a screening test a bit of an odd juxtaposition.
9. It is possible that a physician ordering a blood test or especially a more expensive study like a PET scan may have a financial stake in the matter, which could theoretically cloud his/her judgment. Doctors who are part owners of facilities that do PET scans or labs that run chemistry panels may benefit financially from these tests, to a greater extent than an employed physician like me, who gets $0 for any test I order. But let me say that having spent the first 17 years of my career in a private practice with an in-office lab, it is hard to believe that even subconsciously that would have influenced my decision to order a chem panel, and of course, if I really followed the guidelines, I would be going against my own financial interest. However, when this potential conflict of interest exists, it does raise the question as to why there are such variances of practice.
10. Where do cost and the ethical principle of justice fit in here? Talk about a thorny issue! When I advise a patient not to undergo a PET scan for the primary purpose of reassuring them that they are ok post-treatment, I am not doing it primarily to save dollars. In fact, that is the furthest thing from my mind in the exam room. In essentially no cases right now (and this will change with ACO's - accountable care organizations) is an insurance company telling me not to do it. At least if they deny coverage, it is transparent and the patient knows right away. But where do you draw the line? It's incredibly easy for me to order a lab test because a patient or family insists, even if I am not convinced it is medically justified. While I have a responsibility to act in good faith, for a cancer patient I can almost always "justify" a lab test for the payer. But should I? If I order a test on every patient who insists on having it done, costs paid by someone will escalate. And if thousands of my colleagues do this all over the country, it will easily be hundreds of millions of healthcare dollars spent. Should those limited dollars be spent on testing that does not improve patient outcomes, like PET scans that identify an incurable lung metastasis 4 months before it declares itself, even though it would not affect treatment decisions one bit? Or should they be spent on something better, like co-pay assistance so people don't go bankrupt paying for potentially curative treatments like Herceptin?
11. Am I really sure of the data? I started this by saying that the ASCO guidelines represented best practice. But evidence-based medicine is hardly static. It changes all the time. While no study to my knowledge has ever shown that periodic measurement of serum markers like CA 27.29 or the Circulating Tumor Cell assay used in some places affect outcome, I am pretty sure these specific issues have not all been addressed in randomized controlled trials in systematic fashion. I noted that none of the 14 manuscripts the ASCO panel looked at to update these guidelines between 2006 and 2012 specifically address these tests as a primary variable. Is it possible that some combination of lab or imaging tests may someday reveal better quality of life or even greater longevity for more heavily screened patients, especially as our treatments improve? Hardly implausible.
12. And finally, doesn't this focus on guidelines impair the trust between the doctor and patient by making the care less individualized? Doesn't the physician's judgment enter in at some point? Do guidelines always have to be followed? My answers are - yes it certainly can and does; absolutely; and absolutely not. No physician should be worshipping at the altar of "guidelines" without a thoughtful examination of their strengths, their flaws, and the needs of the patient in front of you. Medicine and certainly oncology will never be a cookbook science, and the imprecision and variability of some of these issues is as maddening to doctors and patients alike as it is inevitable.

My bottom line - I think the ASCO guidelines being discussed here are rational, reasonable, solid, and as good a blueprint as we can hope for in 2012 for this specific clinical issue. They are also as flawed and incomplete as virtually everything else in clinical medicine. I have used them as a starting point for discussion and education with my patients. Usually that goes well, but it is a process not without its tensions at times. I have tried not to draw a line in the sand, but I can think of a few occasions where there was an impasse that we could not bridge. There are few absolutes here. It's not always as straightforward as simply doing whatever test or procedure the patient wants. That's not patient-centered care. Just as I've failed if my reasoning is dogmatic and opaque to my patient, I've also failed if I do something that my training and judgment tells me is incorrect or improper. I hope and pray I can continue to grow in wisdom to make the best decisions. I need input not just from expert ASCO panelists that create these guidelines, but from the real people - my own patients - who are living with breast cancer and trying to make some sense of the madness. And if any of you have read this far, I would love to hear your comments on this blog post. Your insights are always welcome and instructive.