Breast conservation surgery

Breast conservation surgery (BCS) denotes the removal of a breast cancer with clear surgical margins and is variously called a “lumpectomy,” “wide local excision,” “partial mastectomy,” “segmental resection,”“tylectomy,” or “quadrantectomy.”

Current indications for BCS are (1):

• a. A biopsy-proven diagnosis of DCIS or invasive breast cancer clinically assessed as resectable with clear margins and with an acceptable cosmetic result.

Current contraindications for BCS include (1):

• a. Early pregnancy
• b. Multicentric tumor involving 2 or more quadrants of the breast
• c. Diffuse malignant/indeterminate microcalcifications
• d. Inflammatory breast cancer
• e. Persistently positive margins of excision

Stated relative contraindications for BCS include contraindications to RT (radiotherapy) (prior breast RT, collagen-vascular disease, morbid obesity, and unavailability), very large breast size (sufficient to posetechnical difficulty with breast RT), and very large tumor size relative to breast volume. Of note, neoadjuvant chemotherapy may allow BCS for some patients in whom it would nototherwise be possible, including those with second- or third-trimester pregnancy.

A study investigated in the context of breast cancer, recurrence and survival outcomes between breast-conserving surgery (BCS) and mastectomy after neoadjuvant chemotherapy (NACT) (2):

• recurrence and survival outcomes are comparable with BCS and mastectomy
  • thus, BCS is a safe treatment option for selected breast cancer patients after NACT

NICE state with respect to further surgery after breast-conserving surgery (3):

• Further surgery (re-excision or mastectomy, as appropriate) after breast-conserving surgery should be considered for invasive cancer with or without DCIS if tumour cells are present within 1 mm of, but not at, the radial margins (greater than 0 mm and less than 1 mm). As part of the decision making the clinician should:
  • discuss the benefits and risks with the person
  • take into account:
    • the person's circumstances, needs and preferences
    • any comorbidities
    • tumour characteristics and potential treatments, including the use of radiotherapy (also see radiotherapy after breast-conserving surgery and other adjuvant therapies

Further surgery (re-excision or mastectomy, as appropriate) after breast-conserving surgery should be considered for DCIS without invasive cancer if tumour cells are present within 2 mm of, but not at, the radial margins (greater than 0 mm and less than 2 mm). As part of the decision making the clinician should:

• discuss the benefits and risks with the person
• take into account:
  • the person's circumstances, needs and preferences
  • any comorbidities
• tumour characteristics and potential treatments, including the use of radiotherapy (also see radiotherapy after breast-conserving surgery and other adjuvant therapies

Reference:

1. American Society of Breast Surgeons (2018). Resource Guide - Breast-Conserving Surgery/Partial Mastectomy
2. Song YC et al. Breast-conserving surgery versus mastectomy for treatment of breast cancer after neoadjuvant chemotherapy. Front Oncol. 2023 Jul 11;13:1178230.
3. NICE (February 2025). Early and locally advanced breast cancer: diagnosis and management