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 important factor to increase survival after breast cancer surgery is adjuvant systemic therapy, such as Tamoxifen or chemotherapy, which offers the greatest survival benefit by targeting potential micrometastatic disease throughout the body. For a female patient who has undergone breast cancer surgery with axillary dissection, the choice of adjuvant therapy depends on the specific characteristics of the patient's cancer, including hormone receptor status, HER2 status, and stage of disease.

• Tamoxifen is particularly beneficial for hormone receptor-positive breast cancers, providing significant reduction in recurrence risk and mortality when taken for 5-10 years at a standard dose of 20mg daily 1.
• Postoperative chemotherapy is crucial for higher-risk cancers, especially those that are hormone receptor-negative or HER2-positive.
• Radiotherapy primarily reduces local recurrence risk rather than significantly impacting overall survival in most cases, although it may be beneficial in certain high-risk patients, such as those with four or more positive axillary lymph nodes 1.
• Axillary dissection provides important staging information and local control, but it doesn't directly increase survival rates compared to systemic therapies. The optimal approach involves multimodal treatment tailored to the patient's specific cancer biology, stage, and receptor status, with systemic therapies generally providing the greatest survival advantage by targeting potential micrometastatic disease throughout the body.
• The use of radiotherapy should be individualized based on the patient's risk factors, with careful consideration of the potential benefits and risks, including the risk of long-term cardiovascular mortality if an inappropriate technique is used 1.
• The choice of immediate breast reconstruction should not jeopardize the optimal use of locoregional radiotherapy and systemic treatment 1.
• The panel suggests that axillary radiotherapy not be given routinely to patients undergoing complete or level I/II axillary dissection, due to the increased risk of lymphedema 1.
• The incidence of clinical supraclavicular failure is sufficiently great in patients with four or more positive axillary nodes that supraclavicular irradiation should be given to all such patients 1.
• There is insufficient evidence to suggest or recommend whether internal mammary nodal irradiation should or should not be used routinely 1.
• The optimal sequencing of chemotherapy, tamoxifen, and PMRT cannot be determined from the available evidence, but the expert consensus is that chemotherapy should be started soon after surgery, and the start of chemotherapy should not be delayed until after PMRT 1.
• Doxorubicin should not be administered concurrently with PMRT 1.
• A meta-analysis using published data from only those trials in which all patients were treated with mastectomy plus axillary dissection and also received systemic therapy showed that PMRT reduced overall mortality, with an odds ratio of 0.83 (95% confidence interval, 0.74 to 0.94; P 5 .004) 1. Therefore, adjuvant systemic therapy, such as Tamoxifen or chemotherapy, is the most important factor to increase survival after breast cancer surgery, and should be tailored to the individual patient's cancer biology, stage, and receptor 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 Treatment Options for Breast Cancer Survival

To increase survival after breast surgery, several treatment options are considered, including:

• Tamoxifen: a hormone therapy used to treat breast cancer, particularly in patients with estrogen receptor-positive tumors 3
• Postoperative chemotherapy: a treatment used to eliminate any remaining cancer cells after surgery, reducing the risk of recurrence 4
• Radiotherapy: a treatment that uses high-energy rays to kill cancer cells, often used after surgery to reduce the risk of local recurrence 5, 6
• Axillary dissection: a surgical procedure to remove lymph nodes in the axilla, which can help determine the stage of cancer and guide further treatment 3, 4, 6

Comparison of Treatment Options

Studies have compared the effectiveness of these treatment options:

• A study published in 1999 found that lumpectomy alone without axillary dissection, followed by radiation therapy and tamoxifen, resulted in excellent survival rates and good cosmetic results for patients with early breast cancer 3
• A meta-analysis published in 2016 found no significant difference in disease-free survival and overall survival between axillary radiotherapy and axillary dissection, but noted that axillary relapse rates were higher in the radiation group 5
• A study published in 2021 found that neoadjuvant chemotherapy resulted in lower axillary lymph node dissection rates and fewer positive lymph nodes compared to neoadjuvant endocrine therapy, with no significant difference in survival rates 4

Long-Term Effects of Treatment

It is essential to consider the long-term effects of breast cancer treatment, including:

• Physical changes, such as chronic pain, lymphedema, and decreased strength 7
• Emotional and psychosocial changes, such as depression, anxiety, and concerns about body image 7
• The importance of a holistic approach to assessment, treatment, and referral to optimize health and quality of life for breast cancer survivors 7