Therapy for locally recurrent breast cancer
Approximately 30% of patients experienced recurrence of breast cancer, but most patients with metastases may lose their chance of surgery [14]. The incidence of locally recurrent breast cancer was 4% (2–20%), and can occur as an isolated cancer or in combination with distant metastasis in other organ systems [15]. That’s why we reported a small number of surgical cases within 5 years. Whenever possible, isolated local recurrence should be treated with a curative intent. If feasible, it was recommended to pathologically confirm the margin of negative tissue and completely remove the recurrent tumor [16]. The resection area must contain at least 2 cm of normal tissue around lesion [17, 18]. Then, the chest wall defect coverage should be performed immediately instead of breast reconstruction. This was due to limited tissue, limited surgical tolerance, and poor patient willingness to perform breast reconstruction immediately. Adjuvant treatments for recurrent breast cancer were radiotherapy, endocrine therapy in patients with estrogen or progesterone receptor-positive cancer, and chemotherapy in patients with receptor-negative cancer [19–21].
Reconstruction Materials for the chest wall bone
Local recurrence of breast cancer in the deep chest wall will lead to thoracic defects after surgery. If the diameter of full-thickness defect was greater than 6 cm, or if there were more than three defected ribs, especially in the anterior and lateral chest wall, it is recommended to reconstruct the chest wall bone in order to maintain proper cardio-pulmonary function [22]. Ideally, materials used for chest wall reconstruction should have good tensile strength, elasticity, stable physical and chemical properties, ease of use, ready availability, and high biocompatibility as well as characteristics that do not affect chest inspections [23]. Various materials for chest wall reconstruction were classified into autologous tissue, allogeneic tissue, and artificial materials [24–27].
Although autologous tissue and allogeneic tissue are considered to be the most suitable repair materials for human physiology, the disadvantages of autologous and allogeneic tissues are limited materials, increased trauma, increased difficulty in surgery, poor satisfaction in shaping, poor aesthetics, and insufficient hardness. These disadvantages often lead to postoperative abnormal breathing, thus it is more suitable for smaller defect repair and difficult to repair larger defect area, especially in the case of local infection or radioactive necrosis. Compared with autologous tissue, artificial materials have better bone support for the chest wall, simplifying the operation process, shortening the operation time, and reducing the surgical trauma. Therefore, for larger chest wall defects, artificial materials are currently the preferred materials for bone reconstruction [28].
Although many artificial repair materials were used clinically, none of them can meet all the above requirements at the same time. Polytetrafluoroethylene (PTFE) patch may injury intrathoracic organs due to thermal reaction. Insufficient rigidity of repair materials such as Marlex mesh, Prolene mesh, Vicryl mesh, Gare-Tex patch may cause abnormal breathing. Autologous tissue and allogeneic tissue are not suitable for bone reconstruction of large chest wall defects. Moreover, titanium mesh has become a better option, originally created for craniofacial reconstruction [29, 30]. Thus, we applied titanium mesh to stabilize the chest wall in two cases because titanium mesh has the following characteristics: rigid enough to prevent paradoxical respiration movement; malleability can be shaped into appropriate shape, inertness can avoid immune rejection, radiolucency can be used for radiographic tracking of potential problems, and porosity can allow in-growth of fibrous tissue [31]. Although it affects X-ray inspection, CT and MRI are now more common and accurate for chest examination. Therefore, we recommend titanium mesh for bone reconstruction of large chest wall defects (Fig. 1G,H).
Selection of flaps for the chest wall reconstruction
As a prerequisite for stabilizing the chest wall, care should be taken to cover the soft tissue coverage, not only to cover the artificial material that reconstructs the chest wall, but also restore the integrity of the chest wall, maintain the function of normal breathing and circulation, and improve the appearance and quality of life of the patients [11, 12]. The soft tissue characteristics of recurrent breast cancer are often quite different from those of the primary cancer. There may be no donor vessels in the lesion available for free flaps because of resection and radiotherapy. Meantime, for recurrent breast cancer patients, the simpler the surgery, the less invasive. Hence, free flaps are not preferred. Especially for closure of large defects, they are not the first choice for increasing the time of surgery and the incidence of complications. In addition to the local flap, the pedicle flap, or both flaps fail to repair [32, 33]. Myocutaneous flaps are more suitable for the repair of breast cancer patients [33].
The selection of flaps depends primarily on the location and area of the defect. On the vertical axis, the latissimus dorsi musculocutaneous flap and the pectoralis major myocutaneous flaps are generally recommended for use in the upper 1/3 of the chest wall. It is recommended to use the latissimus dorsi musculocutaneous flap, rectus abdominis myocutaneous flap, pectoralis major myocutaneous flap, and omentum in the middle 1/3 of the chest wall. For the lower 1/3 of chest wall, it is recommended to use the rectus abdominis myocutaneous flap and omentum flap. On the horizontal axis, if the defect is located in the center of the chest wall, the latissimus dorsi musculocutaneous flap [34], the rectus abdominis myocutaneous flap [35] and the pectoralis major myocutaneous flap [36, 37] can be repaired. In addition, in the lateral chest wall, the latissimus dorsi musculocutaneous flap is more commonly used.
However, the pectoralis major is usually resected in the locally recurrent breast cancer patients. Although the omentum flap has abundant blood supply, strong anti-infection ability, and strong plasticity, there is still a high risk of complicated operation, prolonged operation time, hemorrhage, abdominal hernia, and gastrointestinal complications after surgery. This is why they are not the first choice for repairing chest wall defects. Although the latissimus dorsi myocutaneous flap may affect the ability of arm to lift, and the rectus abdominis myocutaneous flap may cause a weakness of the abdominal wall, they are still recommended as we did[1, 2, 10, 11]. In addition, they not only provide enough volume to cover a large soft tissue defect, but also are simple to operate and can achieve good outcome.
Radical mastectomy and subsequent radiation may result in the loss of many important tissues, such as vessels, which may result in some of those flaps being unstable for reconstruction as the above typical patient. Therefore, it is an important process to detect adjacent vessels by Doppler ultrasound before the operation.
In summary, for locally recurrent breast cancer, complete tumor resection is a crucial step and ensures that there is no recurrence. After surgery, the appropriate material should be selected to reconstruct the chest wall to restore the integrity of the thorax. Finally, according to the location and size of the defect, the blood-rich flap or myocutaneous flap is used to cover the wound, eliminate the dead space, and repair the soft tissue defect of the chest wall. Our therapy in chest wall resection and reconstruction of patients with locally recurrent breast cancer, that using a pedicled latissimus dorsi musculocutaneous flap or a pedicled rectus abdominis musculocutaneous flap, and a piece of titanium mesh if necessary, is reasonable and practical. We will furtherly make a larger sample size analysis for more robust evidence.