Model may help identify breast cancer survivors at risk for lymphedema
Key takeaways:
- A five-factor model effectively stratified patients with breast cancer based on lymphedema risk.
- Researchers believe this tool could be useful in clinical practice and in future research.
A five-factor risk model effectively predicted 2-year lymphedema-free survival among a cohort of patients with breast cancer, according to findings published in JAMA Network Open.
Researchers evaluated data from a longitudinal cohort of 101 women (median age, 54.8 years; interquartile range, 48.8-62.3) treated for breast cancer at Princess Margaret Cancer Centre between February 2010 and July 2014. Most women had early-stage disease.
Investigators used a regression-based model that accounted for five factors — age, BMI, breast density, nodal burden and receipt of axillary lymph node dissection — to stratify patients as high risk or low risk for lymphedema.
Lymphedema-free survival served as the primary endpoint.
Kaplan Meier analysis showed 2-year lymphedema-free survival rates of 97.5 (95% CI, 94-100) in the low-risk group vs. 65% (95% CI, 47.1-89.7) in the high-risk group (P<.001).
The model showed a sensitivity of 0.83 (95% CI, 0.52-0.98), specificity of 0.89 (95% CI, 0.8-0.94) and accuracy of 0.88 (95% CI, 0.8-0.94) for predicting breast cancer-related lymphedema outcomes.
“In our breast radiation oncology clinical practice, we can input these five factors, which are easily accessible, and then provide personalized counseling to patients about their exact risk for lymphedema,” researcher Jennifer Kwan, MD, PhD, FRCPC, breast radiation oncologist and clinician scientist at Princess Margaret Cancer Centre, told Healio. “We can discuss preventive as well as personalized surveillance strategies to help improve outcomes for these patients."
Healio spoke with Kwan about the need for this model, the model’s performance and her team’s next steps to implement the tool more widely.
Healio: Can you provide brief context about the impact of breast cancer-related lymphedema on quality of life?
Kwan: Breast cancer-related lymphedema can impact medical, physical, social and financial domains of life. First, individuals are at higher risk for developing an infection in the affected arm and for developing another cancer. Physical symptoms like swelling, heaviness of the arm, decreased arm mobility and pain can also occur. Beyond that, these patients may have psychosocial changes related to body image. They also have to pay for ongoing therapies to manage lymphedema, so there can be a financial burden.
Healio: What motivated your team to develop this risk model?
Kwan: The risk for breast cancer-related lymphedema can range from close to 0% to 40% for some patients, depending on personal risk factors, as well as cancer- and treatment-related risk factors. This model incorporates personal risk factors, cancer-related risk factors and treatment-related risk factors to predict risk more accurately. It allows physicians to advise their patients about their individual risk.
Healio: What did you find?
Kwan: The model was able to stratify patients well into high-and low-risk groups. We found that only 65% of those in the high-risk group would be lymphedema-free 2 years after cancer treatment versus 97.5% of those in the low-risk group.
Healio: What are your next steps in research?
Kwan: The next step is to help facilitate implementation into clinical practice more widely. Additionally, this tool can be used to identify high-risk patients for potential new clinical trials looking at interventions to benefit patients at high risk for lymphedema. Continued reassessment of these risk factors for predicting breast cancer-related lymphedema will be very important. As treatment of breast cancer changes and advances, we will need to reassess which factors go into the model in the future.
References:
For more information:
Jennifer Kwan, MD, PhD, FRCPC, can be reached at jennifer.kwan@uhn.ca.
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