Necessary conditions to carry out breast-conserving treatment
Close collaboration of surgery, pathology, diagnostic imaging, radiotherapy, and internal medicine. (Each of the above mentioned departments can be distributed in different medical units)
The patient has the subjective will to conserve breast after fully understanding the characteristics and differences between mastectomy treatment and breast-conserving treatment.
Patients are objectively qualified to receive post-mastectomy radiotherapy, systemic therapy and related imaging follow-up, such as mammography or MRI, after breast-conserving surgery. (The patient’s economic conditions, access to medical care where he/she lives, and general health status must be fully considered)
The medical unit should have the relevant technical and equipment conditions
Appropriate population for breast-conserving treatment
Breast-conserving treatment is generally suitable for patients with clinical stage I and II breast cancer; stage III patients can also be considered carefully after preoperative chemotherapy to lower the stage. (See Appendix VIII for details of breast cancer staging)
Adequate breast volume and ability to maintain cosmetic results after surgery
Absolute contraindications to breast-conserving treatment
Prior radiation therapy to the affected breast or chest wall
Active connective tissue disease, with particular attention to the risk of scleroderma and systemic lupus erythematosus
Pregnant, lactating patients (but lactation may be considered after termination of breastfeeding)
Multicentric or multifocal lesions distributed in more than two quadrants.
Positive cut margins after extensive local excision of the tumor, with no guarantee of negative pathological cut margins even after re-excision.
Relative contraindications of breast-conserving treatment
Tumors located in the central region of the breast, i.e., within a 2-cm ring around the areola and areola, including nipple Paget’s disease.
Diameter >3cm (but it is recommended to measure according to the proportion of tumor to the breast, some patients with large breasts and tumor ≤5cm still have a chance to receive breast-conserving treatment; for those with masses >5cm, preoperative chemotherapy to reduce to less than 3cm can also be carefully considered)
Mammogram showing diffuse malignant or suspected malignant microcalcifications
Talk before breast-conserving treatment
It has been confirmed in numerous clinical trials (over 10,000 patients) that patients with early-stage breast cancer have comparable survival rates and the chance of developing distant metastases after breast-conserving treatment and total mastectomy.
Breast-conserving treatment includes extensive local excision of the cancer plus axillary lymph node dissection, postoperative whole-breast radiotherapy, and necessary systemic therapy, such as chemotherapy or endocrine therapy.
Postoperative treatment is basically the same as mastectomy, but requires additional whole-breast radiotherapy, which may incur additional costs.
The chance of recurrence of the affected breast after breast-conserving treatment is low, with a 5-year recurrence rate of 3%-5% for radical surgery and 5%-7% for breast-conserving treatment (including the second primary). Patients presenting with a recurrence in the affected breast may undergo a complementary total mastectomy and still have a good outcome.
Breast-conserving treatment may affect the appearance of the original breast, but the degree of impact varies depending on the size and location of the mass.
Although breast-conserving surgery has been chosen, it is possible to change to a total mastectomy style intraoperatively to ensure efficacy.
Breast-conserving surgery
Pre-operative preparation
Imaging evaluation of the breast: bilateral mammograms, breast ultrasound (MRI of the affected breast if available)
Sign the informed consent form.
Pre-operative histological diagnosis of the breast mass can be clarified by hollow-core needle biopsy, which will help to remove sufficient area at one time and allow better pre-operative conversation.
General anesthesia or epidural anesthesia is preferred.
The rest of the preoperative preparation is the same as for conventional surgery.
Surgical procedure
Recommended incision: Generally, it is recommended to make one incision in the breast and one in the axilla, but if the tumor is located in the caudal part of the breast, one incision can be used. The direction and size of the incision can be curved or radial according to the convenience of the operation and to ensure the postoperative cosmetic effect. Skin excision is not recommended.
The primary breast site should be excised to include the tumor, 1-2 cm of tissue surrounding the tumor, and the deep pectoralis major fascia of the tumor. Preoperative puncture or surgical biopsy should include the puncture needle tract, biopsy residual cavity, and skin scars on the surface of the breast.
Marking of the specimen for surgical excision of the primary breast is performed in the upper and lower, inner and outer, and anterior and posterior directions.
Intraoperative rapid frozen section examination or print cytology of the specimen cut margins is recommended, and postoperative verification of paraffin pathology section reports is required.
The residual cavity of the breast surgery is hemostatic, cleaned, and 4-6 titanium tongs are placed as localization markers for the radiation therapy tumor bed with additional irradiation. Subcutaneous tissue and skin were sutured layer by layer.
Axillary lymph node dissection, or biopsy of the anterior lymph nodes.
If the intraoperative or postoperative pathology reports positive cut margins, re-extension of the resection to achieve negative cut margins is possible. Although there is no limit to the number of re-excisions, it is recommended to switch to total mastectomy when an extended excision does not achieve a cosmetic result.
Postoperative pathological examination
Examination of the lesion margins and microscopic margin distance measurement.
Other pathological examinations are the same as the routine pathological examination.
Whole breast radiotherapy
Indications: Except for patients over 70 years of age with positive hormone receptors, negative axillary lymph nodes, local mass T1, and negative incision margins who can be treated with adjuvant endocrine therapy alone, all patients with breast conservation surgery should undergo whole breast radiotherapy, and the value of the application of partial breast irradiation is to be further confirmed by clinical trials.
Timing with combination therapy: postoperative radiotherapy should be started within 2-4 weeks after completion of adjuvant chemotherapy in patients with negative cut margins, and should be started within 24 weeks. Anthracycline- and paclitaxel-containing chemotherapy regimens are not recommended to be used concurrently with radiotherapy. Patients without an indication for adjuvant chemotherapy start radiotherapy within 8 weeks postoperatively. Adjuvant endocrine therapy and targeted therapy can be started during radiotherapy or after the end of radiotherapy. Concurrent use of Herceptin in left-sided patients requires close monitoring of the left heart ejection fraction.
Radiotherapy technique: The target area for breast irradiation includes intact postoperative breast tissue and chest wall lymphatic drainage tissue. The number of axillary lymph node metastases ≥ 4 or the proportion ≥ 20% need to be irradiated supraclavicular ± internal breast lymphatic drainage area (what is the level of evidence, please add by Jinming Yu, Prof. Chia-Yi Chen and other radiotherapy experts). X-rays of 4-6 MV are generally used. Patients with excessively wide body frame and the presence of high dose areas on both sides of the incidence of the tangential field can be considered for 8-10 MV X-rays.
The basic technique is a bilateral tangential field with an inner border at the inner edge of the breast tissue and an outer border at the outer edge of the breast tissue of 1 cm. the upper border is about 1-2 cm from the uppermost edge of the breast tissue (if there is a supraclavicular field, it needs to be articulated with it), the lower border is 1-2 cm below the breast fold, the posterior border includes 1-2 cm of lung tissue, and the anterior border is open, leaving a gap of 1.5-2 cm to prevent swelling of the breast during irradiation that would make the field appear The posterior border includes 1-2 cm of lung tissue, and the anterior border is open, leaving a gap of 1-5-2 cm to prevent the field from appearing restricted due to breast swelling during irradiation. Verify that the surgical scar is within the field coverage.
Dose of radiation: 50 Gy for the whole breast incision field and lymphatic drainage area, 1.8-2 Gy in divided doses, 5 times a week. The tumor bed is added to 60 Gy for negative cut margins and 65 Gy or more for positive cut margins. The tumor bed addition technique is performed by electronic wire or reduced tangential field, with the scope referring to intraoperative metal markers.
Adjuvant systemic therapy
The adjuvant systemic therapy includes postoperative adjuvant chemotherapy, endocrine therapy and molecular targeted therapy, see clinical guidelines for postoperative adjuvant systemic therapy for breast cancer.
Monitoring and management of recurrence in the affected breast after breast-conserving treatment
Clinical physical examination: every 3-4 months for 1-2 years after surgery; at least every 6 months for 3-5 years; and at least once a year for more than 5 years.
Breast imaging: Bilateral mammograms are recommended once a year starting within 6 months after the end of adjuvant radiotherapy/chemotherapy, combined with ultrasonography if necessary. Breast MRI can be performed if available.
For suspected recurrence or second primary lesions, hollow-core needle biopsy or surgical biopsy can be performed to clarify the diagnosis.
Total mastectomy remains the standard remedy for local recurrence after breast-conserving surgery.