En bloc extended total thymectomy and extrapleural pneumonectomy in Masaoka stage IVA thymomas

Surgical outcomes of patients with locally advanced thymic epithelial tumor undergoing induction therapy followed by surgery: a narrative review

Background and Objective

Thymic epithelial tumors (TETs), including thymomas and thymic cancers, are relatively rare malignancies originating from the thymus. Although complete surgical resection is the cornerstone of treatment for these tumors, the optimal management strategy for locally advanced cases remains uncertain. Neoadjuvant therapies, with their potential to improve the likelihood of complete resection, are promising, particularly in marginally operable cases. However, the current evidence supporting this approach is lacking. This review of the existing literature on the efficacy of induction therapy followed by surgical resection for stage III or IV locally advanced TETs aimed to provide an up-to-date perspective and highlighting directions for future clinical research.

Methods

PubMed was searched using the keywords "surgery," "survival", "thymoma", "thymic cancer", and "induction therapy". Relevant articles including case series, retrospective studies, prospective studies, and review articles were reviewed and selected for this comprehensive narrative review.

Key Content and Findings

This review included primarily revealed retrospective studies and a limited number of prospective phase II trials on induction therapy followed by surgery for stage III or IV locally advanced TETs. No randomized phase III studies were identified, indicating that a comprehensive evaluation of the benefits of induction therapy on overall survival (OS) has not yet been conducted. Induction therapies for both invasive thymoma and thymic cancer included chemotherapy, radiotherapy, and chemoradiotherapy, with anthracycline-based combination chemotherapies being the primary option. For exclusively invasive thymomas, the median rate of complete surgical resection and the 5-year OS rate were reported as 76% and 85%, respectively. Literature focusing on induction therapy for TETs, which includes both thymoma and thymic cancers, indicates that the rates of complete resection and 5-year OS are 76% and 70%, respectively.

Conclusions

Our narrative review of retrospective and prospective studies highlighted promising long-term OS rates in patients with advanced TETs who underwent induction therapy followed by surgical resection. These findings support this multimodal treatment strategy in selected patients with stage III and IV TETs.

Surgical treatment of thymic epithelial tumors: a narrative review

Background and Objective

Thymic epithelial tumors (TETs) are scarce neoplasms of the prevascular mediastinum. Included in this diverse category of lesions are thymomas and thymic carcinomas (TCs). Surgery is the mainstay of treatment of tumors that are deemed resectable. However, up till now, optimal surgical access has been a subject of debate. The advent of new techniques, such as video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracoscopic surgery (RATS), challenged the median sternotomy which was traditionally considered the access of choice. This review aims to demonstrate the current evidence concerning the surgical treatment of TET and to enlighten other controversial issues about surgery.

Methods

PubMed research was conducted using the terms [surgery] AND [thymic epithelial tumors] OR [thymomas] and [surgical treatment] AND [thymic epithelial tumors] OR [thymomas]. Papers concerning pediatric cases and non-English literature papers were excluded. Individual case reports were also excluded.

Key Content and Findings

Minimally invasive surgical techniques (MIST) such as VATS and RATS are increasingly applied in early-stage TET. Although numerous published studies have demonstrated better perioperative outcomes in early-stage TET, long-term follow-up data are still required to demonstrate the oncological equivalent of MIST to open surgery. Resection of stage III TET is more challenging. Thymectomy can be expanded en bloc to include the major vascular structures, lung, pleura, phrenic, or vagus nerve in these individuals. There is no agreement on the ideal surgical access and traditionally these patients underwent open sternotomy, sometimes combined with a thoracic access. Evidence concerning the treatment of stage IVA disease is mainly derived from retrospective case series which are highly heterogeneous in terms of the number of enrolled patients, histology, degree of pleural involvement, and timing of presentation.

Conclusions

New techniques in the field of minimally invasive surgery are gaining acceptance for early-stage TET but longer follow-up periods are warranted to prove their oncological outcomes. On the contrary, these techniques should be used cautiously in case of locally advanced tumors. Surgeons must not forget that the main objective is the complete resection of the lesion, which is one major predictive factor for increased survival.

The role of surgery in the management of locally advanced and metastatic thymoma: a narrative review

Thymic epithelial tumors (TETs) are rare neoplasms. While treatment guidelines for early stage TETs are well established, treatment for advanced and locally invasive and metastatic TETs (Masaoka stage IVa/IVb) is varied. Many studies examining outcomes in this patient population are single institution, retrospective studies with small sample sizes. Further complicating study of advanced TETs is that Masaoka stage IVa/IVb describes a wide variety of disease heterogeneity, and includes both thymoma and thymic carcinoma. Thus, recommendations for treatment strategies vary widely. Surgical resection with an R0 resection is a key component of treatment for early stage TETs, however the utility of surgery and appropriate surgical approach for patients with locally invasive disease is debated and ranges from local metastasectomy to extrapleural pneumonectomy (EPP). The use of multimodal therapies, including adjuvant and neoadjuvant radiation and chemoradiation, are important for patients with locally advanced disease, however identifying patients who would most benefit from each strategy has been challenging. In this review we examined the literature to provide treatment strategies for advanced TETs. Surgery with an R0 resection should be attempted in all risk appropriate patients. Multimodal therapies are likely beneficial to patients particularly with locally advanced disease, and neoadjuvant therapies may increase likelihood of R0 resection. Further investigation is necessary to identify optimal treatment strategies for patients with locally advanced TETs.

Long-Term Outcomes After Surgical Resection for Pleural Dissemination of Thymoma

BACKGROUND

Cases of thymoma with pleural dissemination are occasionally encountered, and their management is difficult. Some reports have noted that surgical treatment for dissemination is effective, although the long-term results and clinical course details remain unclear. The current study investigated the short- and long-term outcomes of surgical resection of pleural dissemination.

METHODS

A retrospective review examined the medical records for 38 patients who underwent surgical resection for pleural dissemination occurring synchronously with a primary thymoma or metachronously after complete surgical resection of a primary thymoma between 1996 and 2017 at the authors' institution. Clinical characteristics and prognostic factors were analyzed.

RESULTS

The patients were classified into synchronous (n = 21) and metachronous (n = 17) groups. The 10-year overall survival rate was 59% for the synchronous group and 88% for the metachronous group. The median follow-up period for all the patients was 61 months (range 4-225 months). No perioperative deaths occurred. For all the patients, the 5- and 10-year overall survival rates were respectively 91% and 82%, and the 5- and 10-year relapse-free survival rates were respectively 29% and 19%. A significantly worse prognosis was observed for patients 50 years of age or older than for those younger than 50 years (p = 0.02). For 13 patients who underwent repeat resection for pleural dissemination, the prognosis was better than for those without repeat resection (p < 0.01).

CONCLUSION

Surgical resection of thymoma with pleural disseminated nodules can be safely performed and provides a favorable long-term outcome. Repeat resection is considered to be effective for achieving a good prognosis.

Multimodality therapy for thymoma patients with pleural dissemination

BACKGROUND

Although multidisciplinary treatment is recommended for patients with advanced stage and recurrent thymoma, a detailed treatment strategy remains controversial. We have performed a multimodality therapy of induction chemotherapy (CAMP therapy: cisplatin, doxorubicin, and methylprednisolone) combined with surgery for those patients. We now conducted a retrospective study for investigating the results of this multimodality therapy for thymoma patients with pleural dissemination.

PATIENTS AND METHODS

Between 2003 and 2017, 201 patients underwent surgical resection for thymomas. Twenty-six of them received induction CAMP therapy followed by surgery, and 19 of them with pleural dissemination were enrolled in this study. Those cohort were divided into 2 groups by employing surgical procedures: extrapleural pneumonectomy (EPP) group (n = 10) and resection of plural dissemination (RPD) group (n = 9).

RESULTS

The median age of all patients was 49 years. Based on the WHO classification, the histological diagnoses of those thymomas were as follows: Type B1 (n = 1), Type B2 (n = 13), and Type B3 (n = 5). Seven patients were complicated with myasthenia gravis (MG). Clinical stage of the 13 primary cases based on the Masaoka classification were stage IV, and the remaining six cases had recurrent pleural dissemination after surgery. Partial response in induction CAMP therapy was obtained in 78.9% (n = 15) of the patients. Adverse events (Grade 4) occurred in 2 patients (10.5%). Postoperative complications (Grade 4) were observed in 2 patients (10.5%). In all of the enrolled patients, the five-year overall survival rate (5Y-OS) and 5-year progression-free survival rate (5Y-PFS) were 76.7% and 55.1%, respectively. In the EPP group, 5Y-OS and 5Y-PFS were 83.3% and 83.3%, respectively, and in the RPD group, 70.0% and 29.6%, respectively.

CONCLUSIONS

Multidisciplinary treatment using induction CAMP therapy and surgical resection for thymoma patients with pleural dissemination was effective and feasible. Because of the low recurrent rate of disease, young patients with good cardiopulmonary function and well-controlled MG might be good candidates for EPP.

Pleuropneumonectomy for a large thymoma with multiple pleural dissemination using median sternotomy followed by posterolateral thoracotomy

We present 2 cases of a large thymoma with invasion to the hilum of the lung and pleural dissemination. Case 1: a 47-year-old woman was diagnosed with a type B3 thymoma with abundant left pleural effusion and multiple pleural masses, Masaoka stage IVa. A radical resection was planned after chemical pleurodesis and systemic chemotherapy. The left main pulmonary artery and left upper and inferior veins were dissected and resected in the pericardium, while the left main bronchus was cut behind the pericardium through a median sternotomy. Next, the median incision was closed and a left posterolateral thoracotomy was made, thus allowing the pleuropneumonectomy to be safely performed. Case 2: a 47-year-old woman was diagnosed with a type B3 thymoma with lymph node swelling and multiple pleural masses, indicating Masaoka stage IVb. Following induction chemotherapy, a thymothymectomy combined with a right pleuropneumonectomy was performed under a median sternotomy followed by a right posterolateral thoracotomy. The left brachiocephalic vein (BCV) was reconstructed with a ringed polytetrafluoroethylene (PTFE) graft, followed by resection of the right BCV. Next, the right main pulmonary artery and right upper and inferior veins were resected in the pericardium, and the right main bronchus was cut behind the pericardium, followed by reconstruction of the right BCV. Finally, the median incision was closed and a right posterolateral thoracotomy was made, thus allowing performance of a safe pleuropneumonectomy. The median sternotomy allowed safe dissection of pulmonary vessels surrounding the hilum of the lung and, in combination with a posterolateral thoracotomy, was required for performing a pleuropneumonectomy in patients with a huge thymoma with pleural dissemination.

Invasive thymoma disseminated into the pleural cavity: mid-term results of surgical resection

OBJECTIVES

The optimal strategy for pleural dissemination of advanced thymoma remains controversial, while a potential benefit from macroscopic clearance of disseminations has been reported. In this study, we review our mid-term results of surgical resection of pleural disseminations of invasive thymoma.

METHODS

Data from patients with pleural dissemination synchronously or metachronously to primary invasive thymoma who underwent surgical resection from 1991 to 2012 at our institute were retrospectively reviewed.

RESULTS

Of 136 thymoma patients who underwent surgery during the study period, 13 consecutive patients with pleural dissemination (synchronous: 7, metachronous: 6) with a median age of 49 years (range: 27-78 years) at the time of dissemination resection were identified. No patients presented with haematogenous metastases. Operative procedures included the thorough resection of visible disseminated nodules in 11 patients and extrapleural pneumonectomy (EPP) in 2 patients. The median number of resected nodules was 6 (range: 1-52). The median follow-up was 948 days (range: 38-4025 days). One patient died of postoperative bleeding, but there were no tumour-related deaths during the study period. Pleural recurrence was found in 9 cases, including 2 EPP cases, and among them, 3 underwent repeated resection. The overall survival and the recurrence-free survival ratio at 5 years was 92.3 and 33.3%, respectively. Five patients, including 2 repeated resection cases, remained tumour-free at the final observation.

CONCLUSIONS

Resection of pleural dissemination of invasive thymoma can be performed in selected patients and may offer optimal local control as part of a multimodal strategy.

[Intraoperative chemotherapy after radical pleurectomy or extrapleural pneumonectomy]

Trimodality treatment including induction and/or adjuvant chemotherapy, surgical resection and in some cases radiotherapy offers a curative intention in selected patients with pleural malignancies (malignant pleural mesothelioma, thymoma with pleural spread). Nevertheless, locoregional tumor recurrence mainly limits the outcome and the quality of life. A few years ago an additional intraoperative chemotherapy perfusion was developed in order to improve local tumor control and prognosis after surgical resection in a multimodality treatment setting. Cytoreductive surgery with the purpose of a macroscopic complete resection could be achieved by radical pleurectomy or extrapleural pneumonectomy. The concept, techniques and perioperative management of this additional treatment option are presented along with a detailed review of the recent literature.