In women with large tumors or with known metastasis to lymph nodes, a routine axillary dissection (AD) is performed without previous sentinel lymph node biopsy (SNB).
By AD, preferably a minimum of 10 lymph nodes are removed. The operation is most often performed together with breast conservative surgery or mastectomy.
- Part of the primary treatment if known lymph node metastases (pre-, per-, or postoperative).
- In the event the sentinel lymph node is not located during operation for invasive cancer.
Special conditions for breast conservative surgery (BCT)
There is no indication for AD for focus of metastasis ≤ 2 mm. AD is indicated when focus of metastasis is > 2mm, but may be omitted, when there are 1 or 2 positive sentinel nodes and if all the following criteria are met:
- Planned systemic adjuvant treatment
- T1/T2 tumor
- Clinical node-negative axilla
- Planned BCT with external radiation treatment of the breast
- No perinodal growth
- No preoperative chemotherapy
Patients with macroscopic tumor infiltration in the SN will anyway receive radiation therapy to regional lymph node stations (axilla, periclavicular area) in addition to the breast. The current criteria for radiation therapy of pN + status are used to evaluate the treatment of these patients. This means that the axillary level 1-2 also is included in the radiation field as <10 axillary lymph nodes are removed.
Locally advanced breast cancer
Most studies show that patients with locally advanced cancer including clinical N0 status in the axilla (US examination included) before start of preoperative systemic treatment may have SN diagnostics after preoperative chemotherapy with satisfactory detection rate and false negative results. For primary clinical N0 stage it is therefore recommended SN subsequent to neoadjuvant treatment if the conditions otherwise permit this. For SN negativity AD is not necessary. For SN positivity (<2mm) AD should be performed. For clinical N1-3 before neoadjuvant treatment there is still indication for AD without SNB, irrespective of tumor response. For T3/4 tumors locoregional irradiation should be performed irrespective of N status and AD. Thereby the axillary treatment wil be adequate even if there is a false negative SNB.
If the frozen section is false negative, but later investigation shows metastasis, AD should be performed later according to previous schedule mentiones above. Imprint can also be performed as a snap diagnostic.
Immunohistochemical examination of SN is not indicated (98). In some centres this is performed on frozen sections ,especially with regard to metastases from lobular carcinoma.
For parasternal uptake on scintigraphy AD should be performed first. The literature is ambiguous with regard to the indication for possible removal of parasternal SN. The major gain will be in the very few cases where positive parasternal lymph nodes will lead to other and more extensive adjuvant treatment as when the SN in the axilla is negative. There is no suggestion that removal of parasternal lymph nodes will influence the rate of recurrence.
- Remove lymph node metastases to cure the disease.