Key points
- Breast cancer surgery is the most common primary treatment for invasive breast cancer and ductal carcinoma in situ (DCIS) in NZ.
- Surgical options include breast-conserving surgery (also known as lumpectomy, partial mastectomy, wide local excision) and mastectomy.
- Most patients with invasive breast cancer will have a sentinel node biopsy to detect spread of disease to the axilla, followed by axillary node dissection if cancer cells are detected in axillary lymph nodes.
- A sentinel lymph node biopsy is also recommended when a mastectomy is being performed for DCIS.
- Breast reconstruction can be performed at the time of tumour excision or may be delayed, depending on the recommendation with expected treatment plan.
Content:
Surgery to excise the tumour remains the most common and effective treatment for breast cancer. Tumour size and number of foci help to determine the type of surgery recommended; patient preferences are also taken into consideration following a thorough explanation regarding their viable options. The goals of surgery are to remove the tumour/s with a margin of healthy tissue surrounding this to reduce the risk of recurrence. The tumour and breast tissue is examined by a pathologist to obtain a final diagnosis and report including the size, grade, type, hormone receptor and HER2 status.
Surgical options are:
- Breast-conserving surgery (BCS), also called partial mastectomy, lumpectomy and wide local excision (WLE)
- Mastectomy (unilateral or bilateral).
International and New Zealand studies suggest a survival advantage for BCS + radiation therapy (RT) over mastectomy, even after adjusting for clinical and socioeconomic confounders. Therefore, when both procedures are valid, BCS + RT is the preferred option.
Generally, if surgery is the primary treatment it should be performed within 31 days of diagnosis. Surgeons may aim to treat higher risk cases more quickly.
Surgery may not be the first treatment if the cancer is high risk (e.g. large tumours, locally advanced disease, aggressive subtypes, BRCA mutation) and better treated with neo-adjuvant chemotherapy to shrink the tumour prior to surgery. Surgery also may not be an option for patients diagnosed with de novo metastatic breast cancer.
Fact sheet for patients - "Preparing for your hospital stay"
After surgery, adjuvant treatment is given to reduce the risk of locoregional recurrence (radiation therapy) and distant/metastatic recurrence (chemotherapy, endocrine therapy).
Breast reconstruction can be performed at the time of tumour excision or delayed for clinical or personal reasons.
In larger centres, breast cancer surgery is performed by a specialist breast surgeon or oncoplastic breast surgeon. In some centres, general surgeons will perform BCS and mastectomy. Reconstructive surgery may be performed by a breast surgeon or reconstructive plastic surgeon.
Timing of axillary surgery
Unless metastases have already been clinically (palpation) or radiologically detected in axillary lymph nodes, most patients with invasive carcinoma will have a sentinel lymph node biopsy (SLNB/SNB) during primary surgery; the aim is to detect spread of disease to the axilla. Detection of tumour in the lymph nodes may lead to axillary node dissection in a separate procedure. If a frozen section is performed at time of surgery, and the result is positive, this would allow for immediate axillary lymph node dissection if the result of the frozen section is positive.
