This week, our research article is focusing on the potential risk of lymphedema after undergoing a sentinel lymph node biopsy (SLNB) in the axilla, or armpit, of the side affected by breast cancer.
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The article nicely details how there is already a known difference between the risk of developing lymphedema after an axillary lymph node dissection (ALND). During this type of procedure, many, if not all, lymph nodes in the armpit are removed due to the concern for or actual presence of cancer that has spread to these lymph nodes. While ALND used to be the common go-to during surgery, as more patients were observed to develop post-operative lymphedema, many surgeons are now opting for an initial SLNB, if appropriate.
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If the SLNB does not show concern for spread of the breast cancer to the axillary lymph nodes, then a dissection can be avoided. If there is concern for spread of the cancer, then an ALND may still be necessary. It has been found though, that the SLNB has been able to reduce the occurrence of lymphedema onset in patients with breast cancer.
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While the occurrence of lymphedema has been able to be reduced with a SLNB, the risk is not completely eliminated. This article aims to dive into how much of a risk there actually is in developing lymphedema after a SLNB.
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Let’s dive into things a bit further!
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Research Methods
The article describes how they refined their search to a database of women diagnosed with breast cancer, who underwent surgical removal at Seoul National University Hospital. Data was retrieved during the time frame of 1/1/2014-12/31/2020 only for those who underwent a SLNB. For the purposes of the study, this was called the development group.
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The data pulled from the development group was used to find and acknowledge possible risk factors for lymphedema onset and create a prediction model. These models were then appropriately validated from information retrieved from surgical patients between January 2014-December 2016.
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Information that was gathered included the following:
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Age
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BMI
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Type of surgery performed
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If chemotherapy was implemented before or after surgery
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If radiation therapy was performed
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Number of harvested lymph nodes (narrowed down to those with > 3 lymph nodes harvested)
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The specific criteria for correctly identifying and diagnosing lymphedema was also established. The diagnostic criteria included the following:
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A difference of > 200mL volume in comparison to the opposite arm
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A 10% increase in limb volume
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Or a difference of > 2.0cm circumference in the upper arm or forearm of the affected limb
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The research primarily focused on those who used perometry for diagnosing lymphedema. This focuses on using an infrared light to scan and measure limb volume, in comparison to circumferential measurements using a tape measure; however, if patients were unable to assume the necessary positioning for the perometry measurements, then circumferential measurements using a tape measure were used instead.
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Specific software and models were used to break down the collected data and create the final predictive model and criteria for risk of developing lymphedema after a SLNB. Four groups, with varying levels of risk, were created:
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Low
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Intermediate-low
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Intermediate-high
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High
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The final model was then further analyzed using specifical statistical date, which is specifically detailed in the research article.
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Research Results
Results time!
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Here’s what the research found:
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In the development group, the low risk and intermediate–low risk groups had < 1.0% risk of developing lymphedema; whereas, the high risk group had a > 3.3% chance of developing lymphedema.
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In the validation group, the low risk and intermediate–low risk groups also had a < 1.0% risk of developing lymphedema; whereas, the high risk group had a > 1.7% chance of developing lymphedema.
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The overall incidence of lymphedema onset in the data analyzed was 0.9%.
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The following factors were the largest contributors for onset of lymphedema:
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Both neoadjuvant and adjuvant chemotherapy
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Radiation therapy
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BMI > 30 kg/m2
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If > 3 lymph nodes were harvested during the biopsy
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Out of the above factors, chemotherapy and the number of lymph nodes harvested (>3) were found to be the most important and determining factors for risk of lymphedema developing.
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Take-Home Message
All in all, a SLNB creates a much lower risk for development of lymphedema versus an ALND.
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When the choice and necessity of a SLNB is made by you and your surgical team, factors to consider for potential lymphedema risk include if you are also receiving or will need chemotherapy, radiation therapy, if you have a higher BMI, and if > 3 lymph nodes will be removed (which often may not be able to be determined until the surgeon is performing the surgery).
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It’s always important to be open with your medical team regarding any concerns you have about developing lymphedema.
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It can be beneficial, if you know you have even a small risk for lymphedema onset, to request a referral to a Certified Lymphedema Therapist (CLT). They will be able to teach you preventative strategies, look for signs and symptoms consistent with lymphedema, as well as address any active swelling if it presents.
Resource
1.  Jinyoung Byeon, Kang E, Jung JJ, et al. Risk of Lymphedema After Sentinel Node Biopsy in Patients With Breast Cancer. Journal of Breast Cancer. 2024;27(5):323-323. doi:https://doi.org/10.4048/jbc.2024.0180.