Prognostic and Therapeutic Uncertainty in Lymphedema
The recent Lymphatic Research Symposium with Dr. Babak Mehrara brought to light a very difficult subject for both clinicians and patients: how to address the potential risks regarding onset and management of lymphedema. It is my belief that the answers aren’t as clear and simple as presented, and the data supporting various risk factors can be found on either side of the fence. Without strong Level 1 studies clearly showing something to be fiction or fact, an argument can be made for either hypothesis. This creates a very difficult dilemma for physicians and other clinicians when confronted with a patient following treatment for breast cancer, whether it be sentinel node biopsy, axillary dissection and/or radiation to the axilla: how and when to discuss the risk of lymphedema.
Whether or not certain risk factors are worth knowing about, the first discussion needs to be around the fact that there is some level of lymphedema risk for patients who have the above procedures. Studies have placed the risk from 1% to greater than 50% after 25 years - but the risk is never 0%. The problem is even greater because prophylactic therapy for lymphedema such as complete decongestive therapy (CDT), bandaging, lifestyle changes and compression garments have all been claimed to be anywhere from harmful to causing significant decrease in the onset and progression of the disease.
When existing studies are rigorously reviewed, it becomes clear that the level of evidence-based medical studies is wanting. That leaves the clinicians and patients with two major questions: how or whether a clinician should convey understanding of the possible risks for developing lymphedema and how should the use of lymphedema risk reduction methods be presented. The answers to both of these questions are complicated by the need to present an understanding of risk and the problem of making decisions in the face of insufficient medical data.
Most people have significant difficulties in trying to understand risk. Everyone will answer differently to questions like: “Should I take an airplane when I have a 1 in 11,000,000 chance of dying?”, “What about crossing the street?”, or even “Is it worth placing a $100 bet in this hand of blackjack?” Studies have shown most people to be risk averse, even if the gain is large and the risk very small.
Given the level of risk aversion in the general population, it is likely that any risk, if it is greater than zero, will be interpreted by the patient as something to be avoided. In the case of risk avoidance and lymphedema, there are no valid studies that put the risk of lymphedema at zero by at least 5 years after the procedure. The risk is likely 5-50% 25 years after the surgery and/or radiation, depending on the procedure. The range is large and uncertain, but would clearly be of concern to many. Although it might result in an over-reaction, unnecessarily withholding this information would not be appropriate, in my opinion.
After the issue of overall risk for lymphedema is discussed, the question of what advice can be given to a patient to reduce the risk or perceived risk of developing lymphedema must come next. It is clear that other than extrapolating risks from known biophysical responses (such as infection and inflammation increasing capillary flow, which is known to increase lymph flow, which could increase the possibility of lymphedema formation in a compromised lymph vasculature), there is insufficient data that any of the recommended, or refuted, risk-avoidance procedures are supported by conclusive Level 1 or Level 2 evidence-based medical studies.
It has been suggested that by not informing patients of risk and not instructing in any program to possibly reduce that risk, that the patient will be more comfortable and less anxious. While this may be true for some, this assumption has never been investigated. It is my belief that most patients will have the opposite reaction. If the physician is able to educate their patients about the risks, and the uncertainty around those risks, then the patient will be empowered to make their own decisions as to whether the changes are worth the costs to their post breast cancer lifestyle.
The possible benefit of educating the patient of the potential risks is that the patient will likely be thankful, since understanding alone can bring some feeling of control. Since the published studies do not clearly prove that risk reduction practices are, or are not, helpful in reducing risk or disease. The imperative of “Do no harm!” is not helpful in this case because harm could be caused with either decision (or even from withholding information), depending on what is finally proven.
This issue can be viewed in the same way that one approaches the purchase of insurance. One buys insurance to reduce the cost of a bad event occurring, but the cost of the insurance is always part of the decision. Like insurance, it is not clear whether you will ever get the benefits for the efforts spent in trying to reduce the chances of lymphedema occurring. However, having to change your lifestyle is never easy and just like with financial costs, people may find some possible and acceptable while others are not. The National Lymphedema Network (NLN) has published numerous recommendations for risk reduction practices, and abiding by them can be seen like insurance against the risk of lymphedema.
The uncertainty of whether the NLN recommendations for lymphedema are effective does reduce the potential gain from an investment in following these recommendations. Unfortunately, without any Level 1 studies that conclusively prove any risk factor, a patient-centric criteria must be used. The factors for this calculation include: 1. Psychological Burden, 2. Financial Cost, and 3. Lifestyle Cost.
Psychological Burden is a difficult one to assess. The question of whether or not educating a patient will create an environment where the patient feels overwhelmed by either the information, the requirements to avoid risk, the inability or refusal to make those changes, or a combination of the above is difficult to answer for any clinician (or patient!) Who is to say which patients will react poorly or well? The decision will ultimately have to return to whether or not education is believed to be empowering or overwhelming.
Financial cost is a simple calculation – can the patient financially afford the measures to reduce the risk. If the modality requires the purchase of custom-made garments or visiting a therapist weekly for CDT out of pocket, it may be financially impossible for them to do so.
Finally, Lifestyle Cost is the cost-benefit analysis that each patient will have to make regarding the possible risk factors. Given the lack of evidence for these modalities, patients should be given the information as to what the risk is, why it may be a risk, and what can be done to possibly avoid the risk. They can assess what that change will mean to their lifestyle and if it is worth it for the avoidance of that risk.
In summary, the lack of any true evidence to what risk factors may be fact or fiction creates a difficult environment for both clinicians and patients. However, in today’s information-focused world, it is our belief that education and information is empowering and can ultimately lead to both happier patients and clinicians.