Breast Conserving Surgery (BCS), frequently called a lumpectomy or partial mastectomy, is a surgical treatment for breast cancer designed to remove the malignancy while preserving the majority of the breast tissue. This procedure focuses on excising the cancerous tumor along with a small rim of surrounding healthy tissue. The goal is to achieve complete cancer removal with equivalent long-term survival outcomes to a full mastectomy, while maintaining the breast’s appearance.
How the Procedure is Performed
The operation begins with the surgeon making an incision, which is often planned to optimize cosmetic outcomes, such as following the natural lines of the breast. For tumors that cannot be felt, a radiologist localizes the precise area using a wire or a small marker like a radioactive seed before the surgery. The surgeon then carefully excises the tumor, ensuring the removal of a clear margin of healthy tissue around the growth.
Achieving a “clear margin” means that no cancer cells are found at the edges of the removed specimen when examined by a pathologist. If cancer cells are detected at the margin, a second surgery, known as a re-excision, may be required to remove additional tissue. The surgical site is often marked with small metal clips to guide subsequent radiation therapy treatments.
A sentinel lymph node biopsy is generally performed concurrently to determine if the cancer has spread to the armpit lymph nodes. This procedure involves injecting a tracer substance (radioactive material or blue dye) near the tumor site to identify the first one or two draining lymph nodes. If these sentinel nodes are clear of cancer, further lymph node removal is typically avoided, minimizing the risk of arm swelling.
Criteria for Patient Eligibility
Eligibility for breast conserving surgery depends on a combination of physical, biological, and practical factors. A central consideration is the ratio of tumor size to overall breast size, as the surgeon must be able to remove the tumor and clear margins while achieving an acceptable cosmetic result. Patients with very small breasts and a proportionally large tumor may not be suitable candidates, as the resulting defect would be significant.
The presence of multiple distinct tumors in different quadrants of the same breast, known as multicentric disease, is generally a contraindication for BCS. Similarly, extensive, malignant-appearing microcalcifications seen on mammography can indicate widespread disease that requires a full mastectomy to ensure complete clearance. Certain types of inflammatory breast cancer also disqualify a patient from this procedure.
The patient’s medical history and ability to commit to post-operative treatment are also considered. A prior history of radiation therapy to the chest or breast area usually precludes BCS because the breast tissue cannot safely tolerate a second course of high-dose radiation. Furthermore, the patient must be physically able and willing to undergo the mandatory course of follow-up radiation treatment, which is integral to the success of the surgery.
Mandatory Post-Surgical Care
Breast conserving surgery is rarely a standalone treatment and almost always requires follow-up whole-breast radiation therapy (WBRT) to maximize its effectiveness. This radiation is a fundamental component of the overall treatment plan, as it targets any microscopic cancer cells that may remain in the breast tissue after the tumor’s surgical removal. WBRT significantly reduces the risk of the cancer returning in the same breast, offering local control equivalent to that of a mastectomy.
The standard approach to radiation involves daily treatments over a period of three to five weeks, though accelerated or hypofractionated schedules using fewer, larger doses are increasingly common. Often, a supplemental boost dose of radiation is delivered directly to the area where the tumor was removed to further decrease the chance of local recurrence. This boost is particularly beneficial for younger patients or those with high-risk tumor features.
Depending on the biological characteristics of the tumor, such as hormone receptor status, patients will also likely require systemic therapies. These may include endocrine therapy, which is typically a pill taken for five to ten years, or chemotherapy, which may be given before or after surgery. While these systemic treatments address the risk of cancer spread throughout the body, the post-operative radiation therapy is the specific partner to the surgical procedure for local control.