Overview
Neoadjuvant chemotherapy is treatment given before surgery. In breast cancer, it is often used to shrink the tumor, improve the chance of breast-conserving surgery, and reduce the disease burden in the axillary lymph nodes. Its value is well established in triple-negative breast cancer and HER2-positive disease, where tumors are more likely to respond dramatically. However, in hormone receptor-positive, HER2-negative breast cancer, the benefit has been less certain because these tumors are often less sensitive to chemotherapy.
This study used a large U.S. national cancer registry to compare survival outcomes in women with node-positive, hormone receptor-positive, HER2-negative breast cancer who received neoadjuvant chemotherapy versus those who went directly to surgery. The analysis also examined which patients were more likely to achieve nodal pathologic complete response, meaning no cancer was found in the lymph nodes at surgery after preoperative treatment.
Why this question matters
Patients with cancer in the lymph nodes are generally considered to have higher-risk disease. For many of these patients, chemotherapy before surgery can be helpful if it meaningfully shrinks the cancer or clears the nodes. That can influence both surgical planning and prognosis. Still, treatment decisions are not based only on response rates; they must also consider overall survival, tumor biology, and whether chemotherapy is truly improving long-term outcomes.
In hormone receptor-positive breast cancer, treatment often relies heavily on endocrine therapy, and many tumors grow more slowly than other breast cancer subtypes. Because of that biology, some patients may not gain much from chemotherapy before surgery, especially if their nodal burden is limited. This makes it important to identify which patients are likely to benefit and which may do just as well, or better, with upfront surgery followed by tailored postoperative therapy.
How the study was done
The investigators performed a retrospective analysis using the National Cancer Database, which captures a very large share of cancer diagnoses in the United States. They identified female patients diagnosed between 2010 and 2022 with clinically node-positive, hormone receptor-positive, HER2-negative breast cancer, specifically cN1 to cN3 disease, who underwent definitive surgery.
Patients were grouped according to whether they received neoadjuvant chemotherapy or did not receive neoadjuvant treatment before surgery. The main outcome was overall survival. To reduce bias between groups, the authors used inverse probability of treatment weighting, a statistical method that helps balance baseline differences such as age, tumor features, and nodal stage. They then compared survival using weighted Kaplan-Meier analysis and Cox proportional hazards models.
The study also used multivariable logistic regression to identify factors associated with nodal pathologic complete response, or ypN0, which is when lymph nodes are free of residual cancer after preoperative chemotherapy.
Key findings
A total of 146,842 patients met the study criteria. Of these, 44,046 patients, or 30.0%, received neoadjuvant chemotherapy, while 102,796 patients, or 70.0%, did not.
Among those who received neoadjuvant chemotherapy, 10.2% achieved ypN0. That means only about 1 in 10 patients had complete clearance of nodal disease after treatment, reflecting the generally modest chemosensitivity of this breast cancer subtype.
After adjustment for baseline differences, neoadjuvant chemotherapy was associated with inferior overall survival compared with non-neoadjuvant therapy. The reported 80% survival time was 67.2 months in the neoadjuvant chemotherapy group versus 71.2 months in the group that did not receive neoadjuvant therapy, and this difference was statistically significant.
The survival disadvantage appeared most pronounced in patients with N1 disease, which represents limited nodal involvement. In contrast, patients who achieved ypN0 had the most favorable survival outcomes, with an 80% survival time of 93.1 months. In other words, when chemotherapy successfully cleared the nodes, the long-term outlook was excellent.
What predicts nodal complete response?
The study identified several factors associated with a higher chance of achieving ypN0 after neoadjuvant chemotherapy. These included:
High tumor grade
High Oncotype DX score
Ductal histology
Younger age
Lower progesterone receptor expression
Absence of lymphovascular invasion
Smaller tumor size
These findings are clinically meaningful. They suggest that tumors with more aggressive biological behavior, or those that appear less strongly hormone-driven, may be somewhat more likely to respond to chemotherapy. Conversely, strongly hormone-sensitive, larger, or lymphovascular-invasive tumors may be less likely to clear the lymph nodes with preoperative chemotherapy.
Clinical interpretation
The central message of this study is that neoadjuvant chemotherapy should not automatically be the preferred option for every patient with node-positive hormone receptor-positive, HER2-negative breast cancer. In this large registry analysis, patients who received chemotherapy before surgery had worse overall survival than those who underwent upfront surgery, especially when nodal disease was limited.
This does not necessarily prove that neoadjuvant chemotherapy causes worse outcomes. Registry studies cannot fully eliminate selection bias, and patients selected for neoadjuvant treatment may have had more concerning disease features that were not completely captured in the database. However, even after robust statistical adjustment, the survival results raise an important caution: preoperative chemotherapy may not provide a net benefit for many patients in this subtype.
At the same time, the study also shows that patients who do achieve nodal complete response do very well. That supports a more selective approach, reserving neoadjuvant chemotherapy for patients in whom downstaging is particularly valuable or where the chance of meaningful response appears higher.
How this fits into breast cancer care
For hormone receptor-positive, HER2-negative breast cancer, treatment usually includes surgery, endocrine therapy, and sometimes radiation and chemotherapy. The decision to use chemotherapy before or after surgery depends on many factors, including tumor size, number of involved nodes, grade, menopausal status, genomic testing, and patient preferences.
This study adds to the growing evidence that upfront surgery remains a reasonable and often preferred strategy for many patients with limited node-positive disease, followed by adjuvant therapy guided by final pathology and tumor biology. Neoadjuvant chemotherapy may still be appropriate in selected cases, such as when tumor downstaging is needed to facilitate surgery or when the likelihood of response is judged to be higher.
The findings also highlight the importance of individualized care. A patient with a small number of involved nodes and strongly hormone receptor-positive disease may not gain much from chemotherapy before surgery. By contrast, a younger patient with high-grade disease, a high Oncotype DX score, and other high-risk features may be a better candidate for neoadjuvant treatment if the goal is to attempt nodal clearance.
Practical implications for patients and clinicians
For patients, the study reinforces that more treatment is not always better. The timing of chemotherapy matters, and in some breast cancers, surgery first may be the wiser path. It is important to discuss not only whether chemotherapy is needed, but also when it should be given and what the goals are.
For clinicians, the study suggests a careful risk-benefit discussion before recommending neoadjuvant chemotherapy in node-positive hormone receptor-positive, HER2-negative disease. Useful considerations include:
The extent of nodal involvement
Tumor grade and size
Hormone receptor expression, especially progesterone receptor levels
Lymphovascular invasion
Genomic risk results, such as Oncotype DX when appropriate
Whether surgical downstaging would truly change management
The presence of multiple favorable biological features and limited nodal disease may argue against neoadjuvant chemotherapy unless there is a clear surgical advantage.
Study limitations
As with all retrospective registry studies, this analysis has limitations. Treatment was not randomly assigned, so unmeasured differences between groups may have influenced outcomes. The database does not capture every detail of systemic therapy, such as specific chemotherapy regimens, adherence to endocrine therapy, or recurrence patterns. It also cannot fully account for the reasoning behind treatment selection by physicians.
Overall survival, while important, is influenced by many factors beyond breast cancer itself, including comorbid conditions and subsequent treatments. In addition, the relatively low pathologic complete response rate in this subtype means the study is less about whether neoadjuvant chemotherapy can work at all, and more about which patients are likely to derive enough benefit to justify the approach.
Bottom line
In this large national analysis of node-positive hormone receptor-positive, HER2-negative breast cancer, neoadjuvant chemotherapy was associated with inferior overall survival compared with upfront surgery, especially in patients with N1 disease. Only a minority achieved nodal complete response, but those who did had excellent long-term outcomes.
The results support a selective, individualized approach rather than routine use of neoadjuvant chemotherapy in this breast cancer subtype. Upfront surgery remains an important option for many patients with limited nodal disease, while preoperative chemotherapy may be best reserved for carefully chosen cases where the potential for downstaging is meaningful and the biology suggests a higher chance of response.
