Enlarged axillary lymph nodes are not necessarily metastatic, so the staging of invasive breast cancer with slightly enlarged axillary lymph nodes is uncertain, and it may be stage II to III, and it needs to be staged according to the specific conditions of the lesion, lymph nodes and distant metastasis.
Since axillary lymph node enlargement may not be caused by metastasis of invasive breast cancer, it is impossible to fully determine the specific staging of invasive breast cancer with slightly enlarged axillary lymph nodes. However, if the axillary lymph node enlargement is caused by invasive breast cancer metastasis, it may be stage II to III.
The “N” in TNM staging classifies lymph node metastasis. Patients with invasive breast cancer who have enlarged lymph nodes in the axilla on the same side of the breast cancer lesion that can be pushed are classified as N1; those with enlarged lymph nodes in the axilla on the same side that are fused or adherent to the surrounding tissues that cannot be pushed are classified as N2; and those who have metastases to the parietal sternum or supraclavicular lymph nodes on the same side are classified as N3.
T1N1M0 is stage I; T0~1N1M0, T2N0~1M0, T3N0M0 are stage II of TNM staging; T0~2N2M0, T3N1~2M0, T4 any NM, any TN3M0 are stage III; and those with distant metastases are stage IV.
Therefore, if axillary lymph node enlargement is caused by metastasis of invasive breast cancer, the presence of axillary lymph node enlargement belongs to at least N1 grade, which is at least stage II or above in TNM staging.
Patients are advised to seek timely medical treatment and choose the appropriate treatment plan according to the lesion as well as their physical condition.