When you had your surgery, your doctor may have removed some of the lymph nodes under the arm next to the breast that developed cancer. But breast cancer can come back in:
- some of the remaining underarm (axillary) lymph nodes
- lymph nodes at the base of the neck (supraclavicular)
- lymph nodes just bellow the collarbone (infraclavicular)
- lymph nodes under the chest wall, along the breastbone (internal mammary)
- lymph nodes under the armpit on your other side (rarely)
In about 40% of women who develop a recurrence, the breast cancer has spread to the lymph nodes. If you or your doctor notices hard, round lumps forming in any of these areas near the breast that had cancer, it could be a regional recurrence. Sometimes such enlarged lymph nodes are found in a routine mammogram.
It is uncommon to have a regional recurrence in only the lymph nodes under the arm. Fewer than 5% of women treated for breast cancer have recurrence that happens this way. Instead, the cancer generally comes back in both the lymph nodes and inside the breast or in the tissues of the chest wall.
Your doctor will probably recommend a biopsy of an enlarged lymph node to see if there is a regional recurrence. It is possible that the lymph node is not a sign of recurrence, and close follow-up will be recommended.
Most women know when they have a recurrence, especially a metastatic recurrence. I can count on just a few fingers the number of times I have discovered recurrence when the woman didn't know she had it. If you are feeling good when you go to see your physician, it is very unlikely that you have metastatic disease. This differs from local recurrence, in which the skill and experience of your health care provider may lead to detection of a cancer coming back that you did not suspect.
Jennifer Griggs, M.D., M.P.H.