Minimally invasive approaches to breast surgical oncology: narrative review

Introduction

Breast cancer remains the most common cancer in women and the second most common cause of cancer-related mortality (1). Surgical techniques have evolved from the practice of radical mastectomy to modified radical mastectomy. In the 1980s, breast-conservation therapy with radiation was introduced (1). Nipple-sparing mastectomy became an option for patients in the late 1990s (1). The current standard of care in surgical management of breast cancer involves mastectomy or breast-conserving surgery (BCS) followed by radiation therapy (2).

While these approaches have been successful in treating breast cancer, they can still result in cosmetic deformities and functional impairments. This can significantly impact the quality of life of patients. Recently, minimally invasive techniques have been explored to improve cosmetic outcomes and reduce morbidity associated with traditional surgical techniques (1). These novel techniques include robotic mastectomy and endoscopic mastectomy (2).

These new minimally invasive approaches may provide patients with improved cosmesis, psychosocial, physical, and sexual well-being. High powered validated studies are required to ensure the safety and efficacy of these techniques. We present this review in accordance with the Narrative Review reporting checklist (available at https://ales.amegroups.com/article/view/10.21037/ales-23-25/rc).

Methods

A comprehensive literature search was employed using the following search strategy on PubMed: ((“Robotic Surgical Procedures”[MeSH]) OR (“Laparoscopy”[MeSH]) OR (“Minimally Invasive Surgical Procedures”[MeSH])) AND ((“Mastectomy, Segmental”[MeSH]) OR (“Breast Neoplasms”[MeSH]) OR (“Unilateral Breast Neoplasms”[MeSH]) OR (“Triple Negative Breast Neoplasms”[MeSH]) OR (“Inflammatory Breast Neoplasms”[MeSH]) OR (“Breast Neoplasms, Male”[MeSH])). Filters applied from 2000–2023, clinical trial, meta-analysis, randomized controlled trial, review, systematic review. A total of 466 articles were obtained and screened for applicability, with a total of 15 ultimately applied to the chapter review below. All articles were first screened manually, and then final selection was determined by the primary authors. The articles were specifically selected on the basis of their ability to provide insight into breast oncologic surgery and robotics platforms. Exclusion criteria were open or exploratory surgery and non-general surgery (see Table 1).

Endoscopic mastectomy

Overview

Endoscopy is a minimally invasive technique through a small incision that uses camera assistance for guidance. Endoscopy has gained acceptance in multiple surgical subspecialties, especially intra-abdominal surgery. Endoscopic mastectomy was first recognized in 2002 (3,4). It has recently evolved as a minimally invasive approach to performing an oncologically safe and cosmetically favorable surgery in Asia over the past decade. It was first introduced and performed through either axillary or peri-areolar incisions as a method for breast augmentation (5,6). It has recently evolved as a method for resection of benign and malignant breast lesions.

Techniques

There are several methods to how endoscopic mastectomy is performed. Hung et al. explain an approach they used in patients with ductal carcinoma in situ (DCIS) and early-stage breast cancer. The patient is positioned supine with the ipsilateral arm abducted to 90 degrees (7). There are variations in how incision technique can be performed depending on the size and location of the breast lesion. Lai et al. contrarily describe a dual incision technique with both peri-areolar and axillary incision (6). The axillary incision is used for nodal dissection and to posteriorly dissect the breast tissue off the pectoralis major fascia. The peri-areolar incision is used to develop the skin flap. The dual incision technique described is how endoscopic mastectomy is typically performed (8). A modification of this technique has been adapted to now involve a single incision. Hung et al. describe endoscopic mastectomy performed through a small 2–3 cm incision in the axilla (9).

Advantages

The advantage of a single axillary incision is that this avoids the risk of necrosis to the nipple areolar complex involved with peri-areolar dissection. Using either technique, the sentinel lymph node biopsy is performed first. There are two techniques using two dissection plans: subcutaneous and sub-mammary. Tunneling and hydrodissection can be used to interrogate and open up these planes. For example, lidocaine with saline can be instilled into breast parenchyma to assist with posterior dissection of the breast off of the underlying pectoralis major fascia. The mastectomy dissection is continued using a skin lift system using wires that are fixed by a frame. Dissection is continued under endoscopic visualization using an oblique-ended 30 degree 5- or 10-mm rigid endoscope (6).

Several small-scale studies have recently evaluated this technique. Lai et al. performed a single institution retrospective study evaluating 100 consecutive endoscopic-assisted breast conserving surgery (E-BCS). This study revealed that E-BCS is an oncologically safe procedure with a margin involvement rate of 4%, consistent with what is reported in literature ranging from 0–20% (6). They had compared this to a margin involvement rate of 11.3% in 2,050 patients who received BCS. This study also suggests the small incision and scar placement in inconspicuous areas improve cosmesis according to patient-reported outcomes. A total of 98% of patients were satisfied with the scar appearance (6). In a retrospective review, 11 patients (2.6%) presented with local recurrence after endoscopic nipple-sparing mastectomy (3). Recurrence occurred in younger patients <40 years of age and those with advanced stage 3 disease or inadequate surgical margins (3). This may suggest that endoscopic nipple-sparing mastectomy can be oncologically safe in select patients. More data are needed to confirm this.

Disadvantages and controversy

Endoscopic surgery in the breast though does not remain standard of care in the United States (5). Though preliminary data have suggested that endoscopic mastectomy is a viable option, there lacks large scale high quality data to validate this. Endoscopic surgery also has some limitations. For example, one technical complication is the inconsistency in field visualization around the curvature of the breast, which may lead to potential limitations in tumor margin assessment (5). Endoscopic mastectomy technique has a steep learning curve and can be challenging (5). In addition, different patients have various anatomical considerations that may limit the reach of endoscopy utilization for all cases. Endoscopic mastectomy involves longer operative time and requires more instruments and devices (3). This includes a trocar, handle light retractor, bipolar scissors, bipolar forceps, endoscope 3 mm and retractor with ring connection (5). In a multi-center Taiwanese retrospective cohort study, learning curves for endoscopic total mastectomy were evaluated in 134 patients (6). The endoscopic approach required more operative time (275.3 minutes) when compared to traditional mastectomy (228.9 minutes) (6). However, this difference in operative time has been shown to decrease significantly after 15 cases (6). The amount of time decreased after 15 cases though is not reported (6).

There are a lack of data to assess if longer operative time is due to a learning curve. This may be difficult to evaluate at this time given this is a new technique. Although oncologic safety is suggested, there are not enough high quality data to validate this. More data are required on the standardization, practice guidelines, and outcome assessments for endoscopic mastectomy (5). See Table 2 for summary of endoscopic mastectomy.

Robotic mastectomy

Overview

An alternative minimally invasive technique to endoscopy involves the use of robotics to perform mastectomies. Robotic nipple-sparing mastectomy was initially introduced by Toesca et al. in 2015 (7). It has progressively become a more popular technique in Europe and Asia, specifically Italy, France, Taiwan and Korea (6). It provides improved visualization of breast tissue at the time of dissection and decreases scar size compared to non-robotic mastectomy. This technique is not currently widely adapted in the United States although ongoing clinical trials do exist.

Techniques

A recent consensus statement in 2019 provided by robotic nipple sparing mastectomy (R-NSM) experts evaluated R-NSM through multiple domains (6). These domains include: indication, contraindications, technical considerations, patient counseling, outcome measures and indicators, training and learning curve assessment (6). This statement reported that patients eligible for R-NSM are those with up to 5 cm of the tumor with at least 3 mm between the tumor and the skin, no involvement of the nipple areola complex and up to clinical stage IIIA (6). Absolute contraindications include patients with nipple areola complex involvement, inflammatory breast cancer or T4d disease with involvement of skin or chest wall. Relative contraindications to R-NSM include breast size of D cup or larger and ptotic breasts to minimize technical difficulty and suboptimal cosmesis (6).

Robotic nipple-sparing mastectomy begins with the patient in the supine position. A shoulder pad is placed with the ipsilateral arm straightened and abducted towards the head to about 90 degrees. A small incision averaging 3.5 cm is made. Several studies describe between one to three incisions averaging about 3–6 cm in length with the main port site located laterally at the anterior axillary line (7).

Toesca et al. describe an additional incision about 8 cm caudal to the main port site for the camera. The sentinel lymph nodes are removed under direct visualization prior to the mastectomy (7). A skin flap is created and extended towards the nipple areola complex. Indigo carmine is injected into the borders of the breast to assist with visualization. The da Vinci robotic system is then docked either at the head or on the contralateral side of the patient. Gas insufflation can be used through an additional port to allow dissection of the skin flap and detachment of the breast tissue from the fascia. The breast is insufflated to a pressure of 7–8 mmHg. An anterior plane is created between the breast parenchyma and subcutaneous tissue using a combination of sharp dissection and monopolar electrocautery. If indicated a subareolar biopsy can be performed for frozen section analysis at this time to determine if the nipple areola complex needs to be resected. Posterior dissection of the breast parenchyma off the pectoralis major fascia is performed. Once dissection is completed, the specimen is removed. After the breast tissue is removed, the patient can undergo breast reconstruction.

Advantages

Robotic nipple-sparing mastectomy provides the advantage of 10-fold magnification, three-dimensional (3D) optics and the 7 degrees of freedom. These benefits in addition to a smaller incision makes this technique appealing. Several studies comparing R-NSM to endoscopic nipple sparing mastectomy (E-NSM) or open nipple sparing mastectomy (NSM) showed no significant differences in complication rates.

Plastic and reconstructive surgeons are also exploring robotic nipple-sparing mastectomy. Filipe et al. published a highly powered systematic review and meta-analysis (1). It included 49 studies containing 13,886 cases (1). In this study, robotic nipple-sparing mastectomy had no statistically significant difference in rates of complication when compared to traditional nipple-sparing mastectomy (1). Wang et al. also published a systematic review where they evaluated robotic assisted tissue repair and reconstruction of the breast (10). They reviewed 33 studies that support the theory that robotic approaches enable better skin flap elevation, better microvascular anastomosis, fewer incisions, and improved cosmesis (10). Both of these reviews support the theory that the robotic approach is an option in select mastectomy patients.

Disadvantages and controversy

Robotic nipple-sparing mastectomy does present with some challenges. Robotic mastectomy is longer in operative time compared to open surgery by an average of 1 hour and 18 minutes. Cost is also presented as a significant issue for the robotic approach (8). Despite these challenges, Toesca et al. showed that complication rates after robotic versus classic open mastectomy are suggested to be similar (7,9). Quality of life including physical and sexual well-being have been shown to be improved with robotic mastectomy compared to open surgery (7). However, this study has been criticized for its lack of stratification of subjects, standardized surgical technique, and clarity in training between surgeons (10,11). Robotic nipple-sparing mastectomy can be an option for breast cancer patients. More data are needed to support its benefit over traditional mastectomy.

There are also a lack of data to support oncologic outcomes using R-NSM. This is primarily due to the fact that this technique is new and no long-term data exist. Another concern is whether it is economically justified. Training in robotics requires time and additional costs (12,13). Multiple studies have performed a comprehensive cost analysis for R-NSM (14,15). A multicenter nonrandomized trial from Taiwan performed a cost analysis comparing R-NSM, E-NSM, and open NSM (6). R-NSM was associated with a much higher overall cost per breast ($10,301,408) compared to open NSM ($6,254,499) and E-NSM ($7,699,738; P<0.01) (6). Much less of the cost of R-NSM is covered by health insurance (P=0.02). The overall out-of-pocket cost for R-NSM ranged from $7,667–$8,333 compared to open NSM at $3,667–$4,333 and E-NSM at $4,000–$5,667; P<0.01. This suggests that from a financial perspective R-NSM may not be as economically feasible for low-income and low-resource regions. See Table 3 for summary of robotic mastectomy.

Conclusions

Breast surgery has evolved greatly since its introduction by Halsted in the 1890s. The traditional surgical techniques such as mastectomy and breast-conservation therapy are now augmented by new technologies that have paved the way for minimally invasive techniques including endoscopic mastectomy and robotic nipple-sparing mastectomy. In this chapter, our review of the literature provides evidence that endoscopic and robotic nipple-sparing mastectomy have oncologic safety and low recurrence rates with the limitation of time and cost. From a cosmesis standpoint, these new techniques have shown benefits and improved psychosocial outcomes and satisfaction for the patients. With improved precision, reduced complications, patient satisfaction, and improved aesthetics, despite the short-term intra-operative costs incurred, long-term studies have identified robotic breast cancer surgery in the long-term as being cost-effective. Patients incur lower out-of-pocket costs because of the advantages offered by robotics and certain institutions are already identifying ways to improve robot introduction into health systems for breast cancer care (16,17). With further exploration of these techniques and collection of more data, these new techniques can be further implemented into everyday practice.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the Guest Editor (George Ferzli) for the series “Latest MIS Approaches and Data” published in Annals of Laparoscopic and Endoscopic Surgery. The article has undergone external peer review.

Reporting Checklist: The authors have completed the Narrative Review reporting checklist. Available at https://ales.amegroups.com/article/view/10.21037/ales-23-25/rc

Peer Review File: Available at https://ales.amegroups.com/article/view/10.21037/ales-23-25/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://ales.amegroups.com/article/view/10.21037/ales-23-25/coif). The series “Latest MIS Approaches and Data” was commissioned by the editorial office without any funding or sponsorship. The authors have no other conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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