What is the most important factor to increase survival after breast cancer surgery, specifically in a female patient who underwent axillary (axilla) lymph node dissection?

From the Guidelines

The most critical factor to increase survival after breast cancer surgery is adjuvant systemic therapy, such as Tamoxifen or postoperative chemotherapy, as it targets microscopic disease throughout the body and addresses the primary cause of breast cancer mortality: distant metastasis. When considering the options provided, while radiotherapy is crucial for reducing locoregional recurrences and breast cancer mortality, especially in patients with ≥4 positive nodes or 1 to 3 positive nodes, as seen in the EBCTCG’s analysis of 22 randomized trials 1, the overall impact of systemic therapy on survival cannot be overstated. Key points to consider include:

• The role of Tamoxifen in hormone receptor-positive breast cancers, providing a significant reduction in recurrence risk and mortality 1.
• The importance of postoperative chemotherapy for higher-risk cancers, especially those that are hormone receptor-negative, HER2-positive, or have significant nodal involvement.
• The benefit of radiotherapy in reducing locoregional recurrences and breast cancer mortality, with an absolute difference in breast cancer mortality of 7.9% at 20 years for patients with ≥4 positive nodes or 1 to 3 positive nodes 1.
• Axillary dissection, while important for staging, does not directly contribute to the survival benefit in the same way that systemic therapies do. Given the patient's scenario of having undergone axillary dissection, the focus should be on the systemic treatment approach that best matches the tumor's biology and the patient's overall health status.

From the FDA Drug Label

The corresponding reductions in breast cancer recurrence were 21%, 29% and 47% (trend significant at 2p < 0.00001). Benefit is less clear for women with ER poor breast cancer in whom the proportional reduction in recurrence was 10% (2p = 0.007) for all durations taken together, or 9% (2p = 0. 02) if contralateral breast cancers are excluded. The corresponding reduction in mortality was 6% (NS). The effects of about 5 years of tamoxifen on recurrence and mortality were similar regardless of age and concurrent chemotherapy.

The most important thing to increase survival after breast surgery is postoperative chemotherapy and/or hormone therapy like Tamoxifen, as it reduces the risk of recurrence and mortality.

• Tamoxifen has been shown to reduce the risk of breast cancer recurrence by 21-47% and mortality by 6% (although not statistically significant).
• The benefits of Tamoxifen are more pronounced in women with estrogen receptor-positive breast cancer.
• Postoperative chemotherapy has also been shown to improve disease-free survival in women with positive axillary nodes. 2

From the Research

Importance of Axillary Dissection in Breast Cancer Survival

• The role of axillary dissection in breast cancer surgery has evolved, with a shift towards less invasive local treatment 3.
• Studies have shown that axillary lymph node dissection (ALND) may not be necessary for patients with limited clinically node-positive breast cancer who receive axillary radiation and systemic therapy 4.
• The use of sentinel lymph node biopsy (SLNB) has increased, and ALND is often avoided in patients with negative SLNs or those with one or two positive SLNs receiving breast and/or axillary radiation 3, 5.

Factors Influencing Survival After Breast Surgery

• The extent of axillary surgery has decreased with increased use of systemic and radiation therapy 3.
• Neoadjuvant chemotherapy (NAC) has been shown to downstage axillary disease in node-positive breast cancer, reducing the need for ALND 6, 5.
• The presence of two positive macro-metastatic sentinel lymph nodes significantly predicts additional nodal involvement, especially in patients without a pathologic complete response 7.

Increasing Survival After Breast Surgery

• Postoperative chemotherapy and radiation therapy are important factors in increasing survival after breast surgery 3, 4.
• De-escalation of axillary surgery to SLNB alone may be safely considered in neoadjuvant-treated clinical node-positive patients with <2 positive sentinel lymph nodes 7.
• The decision to perform ALND should be based on individual patient factors, including tumor size, nodal status, and response to NAC 4, 5, 7.