How does anatomic stage and receptor status of a patient's breast cancer inform that individual's risk of having a cancer recurrence? That's the question researchers set out to answer in a new analysis published in the journal Cancer (2023; https://doi.org/10.1002/cncr.34656).
"We hope that this data can inform conversations between oncologists and their patients regarding risk. These data provide key insight into the absolute recurrence risk and timing of risk," noted Heather B. Neuman, MD, MS, FACS, Associate Professor in the Division of Surgical Oncology at the University of Wisconsin School of Medicine and Public Health, as well as the study's lead author.
Researchers administered a secondary analysis of 8,007 patients with Stage I-III breast cancer enrolled in nine Alliance legacy clinical trials from 1997 to 2013. The dataset involved patients receiving standard-of-care therapy, while individuals missing stage or receptor status were excluded. The primary outcome was days from the earliest treatment start date to the date of first recurrence. The researchers then looked at the relationship to anatomic stage and stratified the results by receptor type.
According to the research data, time to first recurrence did indeed vary significantly for cancers of different anatomic stage and receptor types: "1) The risk of recurrence was highest and occurred earliest for estrogen receptor (ER)-negative/progesterone receptor (PR)-negative/HER2neu-negative tumors (Stage III; 5-year probability of recurrence: 45.5%), and 2) the risk of recurrence was lower for ER-positive/PR-positive/HER2neu-positive tumors (Stage III; 5-year probability of recurrence: 15.3%), with recurrences distributed over time."
Neuman said the team hopes the data will be used to inform future guidelines for breast cancer survivorship care and appropriate surveillance for patients. "This data can be used to better align patients' expectations with anticipated outcomes, in many cases providing reassurance." She shared her thoughts on what is important for oncologists and cancer care providers to know about the work.
1 Why did you and your colleagues decide to pursue this research now on anatomic stage and receptor status of a patient's breast cancer?
"Breast cancer care has evolved to the point that we are able to personalize treatment decisions based on information such as anatomic stage and receptor status. However, our follow-up care recommendations have remained one-size-fits-all.
"Inevitably, this means some patients receive more, and some patients less, follow-up than they really need. Monitoring for recurrence is one significant reason why oncology teams follow their survivors. We felt that this study was an important first step in defining what risk looks like for survivors with different cancer types so that we could rationally plan follow-up care.
There have been prior studies that have examined this question [about the relationship of anatomic stage and receptor status with timing of the first recurrence for patients with local-regional breast cancer]. However, the data in the prior studies were older with either no or limited data on HER2 status.
"The small sample size of patients with known HER2 status who received standard-of-care HER2neu-directed therapy limits the utility of these older studies to inform follow-up recommendations. Our study addressed these limitations and was able to affirm the importance of both anatomic stage and receptor status on individual breast cancer survivors' risk."
2 How could this research inform future guidelines and patient care?
"This study confirmed the importance of both anatomic stage and receptor type on both the absolute risk of recurrence, but also the timing. Risk of recurrence was highest for patients with triple-negative cancer. However, those patients with HER2-positive disease have a very low risk of recurrence, especially if hormone-positive. We were able to model the timing and risk of recurrence to generate follow-up recommendations by stage and receptor type.
"Our data establish that significant differences in absolute risk and timing of recurrence exist based on anatomic stage and receptor subtype. This data can be translated into risk-stratified follow-up recommendations that can improve both the efficiency and the quality of breast cancer follow-up care.
"The most commonly used guidelines for follow-up care are developed by the National Comprehensive Cancer Network. We hope that this data will be used to inform future iterations of their work."
3 Are there any limitations that should be noted from this research study?
"One of the limitations is that we weren't able to incorporate some of the additional data that is relevant for patients who receive neoadjuvant therapy. For these patients, their response to systemic therapy is highly prognostic. Follow-up may be able to be tailored further for patients who have a complete pathologic response to neoadjuvant therapy. However, this was not something we were able to explore in this study."