Breast-conserving Therapy in Breast Carcinoma

Breast-conserving therapy (synonym: BET) (synonym: breast-conserving surgery, BEO) is a surgical procedure for the treatment of breast carcinoma (breast cancer). In contrast to mastectomy (surgical removal of the breast), the surgical procedure is performed without complete removal of the pathologically altered breast. Both procedures primarily serve to achieve optimal tumor control in the breast area and in the area of the draining lymphatic ducts. For several years, the therapy of breast carcinoma has not been based solely on the use of one surgical procedure, but instead represents a therapeutic concept in which radiotherapy or chemotherapy play an important role in addition to surgical intervention.

Indications (areas of application)

  • Breast carcinoma – the use of breast-conserving therapy for breast carcinoma is indicated because various high-quality clinical trials have demonstrated that its use has the same effect on overall survival as mastectomy. Based on this, all patients should be adequately informed about the possibility of breast-conserving therapeutic intervention. However, if necessary, the use of a so-called modified radical mastectomy is indicated, since the neoplastic process can be treated more safely.
  • Ductal carcinoma in situ (DCIS) – in contrast to malignant breast carcinoma, ductal carcinoma in situ represents a localized pathological event. As a rule, carcinoma in situ affects only one mammary duct system. BET with a resection margin (removal in healthy tissue) of ten millimeters represents a safe control of the tumor. With the help of radiotherapy after surgery, the risk of recurrence (probability of recurrence of the tumor) can be reduced by about 50%.

Prerequisites for the use of BET are:

  • Demarcated tumor smaller than four centimeters.
  • Solitary tumor without skin involvement
  • The breast-tumor size ratio must be sufficient
  • On palpation, there must be no involvement of the axillary lymph nodes
  • Adherence to a tumor-free resection margin of at least 1 mm (R0) must be given in the presence of invasive breast carcinoma

Contraindications

According to the guidelines of the “Deutsche Krebsgesellschaft e. V.” and the “Deutsche Gesellschaft für Gynäkologie und Geburtshilfe”, BET is not indicated for the following:

  • Presence of multicentric carcinoma.
  • Breast carcinoma with inflammatory process
  • Unfavorable tumor-to-breast size ratio
  • In the case of non-feasibility of a post-irradiation

Before surgery

  • Preoperative diagnostics – the performance of the so-called triple diagnostics, consisting of mammography, clinical examination and sonography, is indicated before the surgical procedure.
  • Surgical planning – the planning of BET is of particular importance, because only through a systematic interdisciplinary case planning aesthetic and yet oncologically optimal results are achievable. Thus, depending on imaging and punch biopsy confirmed tumor histology, in addition to the expected tumor area and also the planned resection volume should be precisely defined in an interdisciplinary manner between radiologists, surgeons, and pathologists. As a result, the need for secondary interventions can be reduced.

The surgical procedures

Depending on the size and localization of the removed tissue, the individual surgical procedures are distinguished:

  • Segment resection – this surgical procedure of BET is based on the removal of the tumor together with part of the skin, nipple (breast) and fascia of the pectoralis major muscle.
  • Lumpectomy – in this procedure, which is also called wide excision, a circular skin incision is usually first made above the tumor area. Depending on the localization of the tumor, the volume to be removed during the procedure also varies. If the neoplasia is located directly under the skin, the skin spindle is often removed as well. After the skin incision, the tumor size is assessed by the surgeon using two fingers to locate the tumor by palpation and then using scissors to remove the tumor with a margin of healthy tissue.The removal of healthy tissue adjacent to the tumor, which must be removed with it, is usually between ten to twenty millimeters.
  • Quadrantectomy – the mamma can be divided into four quadrants. If the diagnostic findings are positive, the quadrant is removed along with the overlying skin spindle where the tumor is located. Removal of the laterocranial quadrant (upper lateral) may be accompanied by removal of the axillary lymph nodes or sentinel lymph node (guardian lymph node) if necessary. The use of quadrantectomy represents a combination procedure with other therapeutic methods. The combination of quadrantectomy, removal of axillary lymph nodes and radiotherapy is also known as QUART.

As a rule, after removal of the tumor, a histological (fine tissue) examination is performed immediately using the so-called frozen section to ensure complete removal “in healthy”. If necessary, resection is performed.If a calcified tumor had to be localized beforehand mammographically with dye or by means of a very delicate metal probe because of its only small, non-palpable size, an X-ray of the removed tissue is taken before the frozen section to check whether the finding has been optically removed. If necessary, resection must be performed.

After surgery

  • Follow-up therapy – as a rule, almost all patients receive adjuvant (supportive) therapy after the tumor has been operated on. In addition to radiotherapy (synonyms: radiation therapy; irradiation of breast tissue), systemic chemotherapy or antibody therapy may be used to eradicate (kill) any remaining tumor cells. If the breast carcinoma is a hormone-sensitive (hormone-dependent) tumor, anti-hormonal tumor therapy is usually used.
  • Aftercare – aftercare measures for a present breast carcinoma are carried out according to the guidelines of the German Cancer Society. In the first three years after diagnosis of the tumor, mammography should be performed every six months. In subsequent years, mammography should be performed annually. During follow-up examinations, in addition to tumor control, attention must be paid to adverse drug reactions or drug intolerances.

Possible complications

  • Inadequate tumor removal – should tumor cells remain in the breast, this represents a significant reduction in five-year survival.
  • Infections – inflammatory reactions can occur in the wound cavity as well as in the scar area.
  • Thrombosis – during surgery or postoperatively, thrombosis (blood clot) may occur, especially in the lower extremity. This can result, if necessary, in pulmonary embolism (settling of a dissolved clot in a pulmonary vessel), which is often fatal. However, this complication occurs very rarely.
  • Postoperative bleeding – bleeding vessels in the surgical area may cause postoperative bleeding. In rare cases, surgical hemostasis must be performed.

Other notes

  • In a study of nearly 130,000 patients with stage T1-2, N0-1, and T1-2, N2 tumors from the Erasmus Cancer Institute in Rotterdam, during the first study period (1999-2005; n = 60. 381), the probability of cancer-specific survival was 28 percent higher with breast-conserving therapy compared with mastectomy (hazard ratio [HR]: 0.72; 95% confidence interval: 0.69-0.76; p < 0.0001), and overall survival was 26 percent higher (HR: 0.74; 95% confidence interval: 0.71-0.76; p < 0.0001).In the second study period (2006-2015; n = 69,311), breast-conserving therapy also fared better than mastectomy for both survival parameters in stage T1-2, N0-1 tumors (HR: 0.75; 95% confidence interval: 0.70-0.80; p < 0.0001 and HR: 0.67; 95% confidence interval: 0.64-0.71; p < 0.0001, respectively); but not in T1-2, N1 tumors.