Limited thymectomy as a potential alternative treatment option for early-stage thymoma: A multi-institutional propensity-matched study

Early stage thymoma and the surgical extent paradigm

The recommended treatment for early stage thymoma without myasthenia gravis is complete thymectomy (CT). Limited thymectomy (LT) (simply resecting the thymoma with safe surgical margins) is gaining popularity. In this study, we compared the surgical and oncological results of complete and limited thymectomy in non-myasthenic patients with early stage thymoma. Non-myasthenic, Masaoka stage I-II, 86 patients who underwent surgical resection for thymoma were included in the study. Complete thymectomy (n:44) included patients who had resection of the thymoma together with the entire thymus and limited thymectomy (n:42) included patients who had resection of the thymoma without remaining thymus. The surgical approach, tumor size, histological type, pathological stage, adjuvant therapy, complications, postop myasthenia gravis, recurrence and death were recorded and compared between groups. Complete thymectomy group had more WHO type B1-3 tumors, more complications and more deaths than patients in the limited thymectomy group (p = 0.03, 0.018 and 0.023 respectively). Although statistically not significant CT group had more recurrences than LT group (11.4%/4.8%, p = 0.43). The 10-year freedom from recurrence (FFR) rate in the CT group was 84.8% and in the LT group ıt was 97.6%, the difference was not statistically significant (p = 0.15). None of the factors including surgical extent analysed with univariate and multivariate analysis had a significant effect on FFR. Limited thymectomy may be a good treatment option for non-myasthenic early stage thymoma patients but randomized controlled trials with long follow-up periods, ideally comparing patients operated with minimally invasive surgery are necessary.

Perioperative outcomes comparison of robotic and video-assisted thoracoscopic thymectomy for thymic epithelial tumor: a single-center experience

BACKGROUND

The advent of robot-assisted thoracoscopic surgery (RATS) has completely revolutionized the modality of thymectomy, which could reportedly achieve equivalent efficacy compared with a minimally invasive approach. This study was conducted to further compare the perioperative outcomes between these two modalities.

METHODS

A retrospective single-center study that included patients receiving either a robotic or video-assisted thoracoscopic (VAT) thymectomy between February 2021 and January 2023 was conducted. All the patients were pathologically confirmed with thymic epithelial tumors. Clinical and pathological characteristics and perioperative outcomes were collected and compared between these two cohorts.

RESULTS

A total of 190 patients were included in this study, with 61 (32.1%) and 129 (67.9%) receiving robotic and video-assisted thymectomy, respectively. The clinicopathological characteristics were not significantly different between these 2 groups. The size of the resected specimens in the RATS cohort was larger than the VATS cohort [median (IQR), 13.0 (8.0-16.0) vs. 9.0 (6.7-12.0) cm, p < 0.001], while the procedural duration was longer for the RATS group than its counterpart [median (IQR), 105 (85-143) vs. 85 (69-115) min, p = 0.001]. Moreover, no other significant difference was observed between these two groups. Since more than half of the robotic thymectomy was performed using a subxiphoid approach, a subgroup analysis was further conducted. Similarly, the robotic group through a subxiphoid approach harbored a longer procedural duration, and the size of the specimens obtained was larger than the VATS group [median (IQR), 14.0 (11.0-16.5) vs. 12.5 (8.5-15.0) cm, p = 0.061].

CONCLUSIONS

The early clinical efficacy of robotic thymectomy was proven comparable to the established VATS approach, and such a modality might have strength when obtaining larger specimens, which could contribute to improving long-term efficacy. Despite the longer procedural duration recorded in the early stage of conducting robotic thymectomy, further accumulation would help decrease the time.

Prognosis and surgical outcomes of the total thymectomy versus thymomectomy in non-myasthenic patients with early-stage thymoma: A systematic review and meta-analysis

Whether thymectomy (TM) or thymomectomy (TMM) is better for non-myasthenic patients with early-stage thymoma. We conducted a meta-analysis to compare the clinical outcomes and prognoses of non-myasthenic patients with early-stage thymoma treated using thymectomy versus thymomectomy. PubMed, Embase, Cochrane Library and CNKI databases were systematically searched for relevant studies on the surgical treatment (TM and TMM) of non-myasthenic patients with early-stage thymoma published before March 2022. The Newcastle-Ottawa scale was used to evaluate the quality of the studies, and the data were analyzed using RevMan version 5.30. Fixed or random effect models were used for the meta-analysis depending on heterogeneity. Subgroup analyses were performed to compare short-term perioperative and long-term tumor outcomes. A total of 15 eligible studies, including 3023 patients, were identified in the electronic databases. Our analysis indicated that TMM patients might benefit from a shorter duration of surgery (p = 0.006), lower blood loss volume (p < 0.001), less postoperative drainage (p = 0.03), and a shorter hospital stay (p = 0.009). There were no significant differences in the overall survival rate (p = 0.47) or disease-free survival rate (p = 0.66) between the two surgery treatment groups. Likewise, TM and TMM were similar in the administration of adjuvant therapy (p = 0.29), resection completeness (p = 0.38), and postoperative thymoma recurrence (p = 0.99). Our study revealed that TMM might be a more appropriate option in treating non-myasthenic patients with early-stage thymoma.

Surgical, Radiation, and Systemic Treatments of Patients With Thymic Epithelial Tumors: A Systematic Review

INTRODUCTION

Thymic epithelial tumors are rare and are classified as thymoma, thymic carcinoma, and thymic neuroendocrine tumors. The objective of this systematic review was to evaluate the treatment options for patients with thymic epithelial tumors.

METHODS

This systematic review was developed by Ontario Health (Cancer Care Ontario)'s Program in Evidence-Based Care and by the Lung Cancer Disease Site Group. MEDLINE, EMBASE, and the Cochrane Library were searched for studies comparing surgical, radiotherapy, or systemic treatments against any combination of these treatments in patients with thymic epithelial tumors. Meta-analyses were conducted with clinically homogenous studies.

RESULTS

A total of 106 studies were included, mainly from observational studies. There was an overall survival benefit with postoperative radiotherapy for patients with thymic carcinoma (hazard ratio = 0.65, 95% confidence interval: 0.47-0.89) and for patients with thymoma (hazard ratio = 0.70, 95% confidence interval: 0.59-0.82), especially for those with a high risk for mortality. Patients with thymic carcinoma or thymoma had a response to chemotherapy. Selection bias affected the results for studies that evaluated neoadjuvant chemotherapy or minimally invasive surgical techniques. Furthermore, the overall survival benefit found for adjuvant chemotherapy may have been confounded by the administration of postoperative radiotherapy.

CONCLUSIONS

For patients with thymoma or thymic carcinoma, the literature is of low quality and subject to bias. There were overall survival benefits with postoperative radiotherapy. The results of this systematic review were used to inform treatment recommendations in a clinical practice guideline. Future large-scale prospective studies that control for confounders are needed.

Unilateral video-assisted thoracoscopic thymoma resection – Indications, early and mid-term results

Introduction. Thymoma is the most common tumour of the anterior mediastinum. Video-Assisted Thoracic Surgery technique of thymoma resection is spreading world-wide, but the thoracoscopic method is still contentious in many ways. Authors evaluate the early and mid-term results of a 17 years period of VATS unilateral approach at 2 Hungarian thoracic surgical centers. Method. Depending on the anatomical situation of the thymoma, we performed thymectomy, or partial thymectomy (thymomectomy) for the Masaoka–Koga I–II–III stage thymoma from the right or left side through 2 or 3 intercostal ports. We managed the operations with ultrasonic dissector and electrocauter. By using international standards we evaluated perioperative morbidity, mid-term oncological results and clinical symptoms of myasthenia. Results. 23 of the 54 patients were man, 31 were woman, the average age was 58 (26–79) years, 23 of them had myasthenia. The conversion rate was 11,5% (7/61). The average operation time was 84 (39–150) minutes. The average hospitalisation time was 5.5 (3–19) days. The average size of the thymomas was 46 (18–90) mm. The histology resulted thymoma type A in 2 cases, AB in 19 cases, B1/2/3 in 11/11/1 cases, mixed B in 10 cases. The examination of the resection line was R0/1/2 in 42/11/1 cases. The Masaoka–Koga stages were: I (17), IIA (28), IIB (2), III (7). There was 25 thymomectomies, and 29 thymectomies. In seven cases there were extension of the operation to the pericardium (2), to the lung (2), to the phrenic nerve (6), and to innominate vein (1). The in-hospital mortality over 30 day was in 1 case (1.85%). The morbidity was 11/54 (20.4%). The average follow-up time was 62.56 (5–198) months. In the group with myasthenia the effectivity of the operation was 18/21 (85.7%), including complete remission of 5/21 (23.8%). Post-thymectomy myasthenia gravis developed in 2/31 cases (6.5%). The average 5 years survival was 100%, tumour-free 5 years survival was 96%. Conclusions. The higher proportion of the thymomectomy in the early results, higher conversion rate and lower R0 proportion might be in connection with the attitude of the surgeons, with the learning curve and with the limitations of the unilateral method. After a longer follow-up time late results may become more real and comparable. Instead of unilateral VATS technique we have changed to the subxyphoideal approach of VATS because of its better visualisation.

Establishment of multi-center database on thymic epithelial tumors (TETs) and current situation in Korea

The Korean Association for Research on the Thymus (KART) was established in January 2014 with the following members: Asan Medical Center, Samsung Seoul hospital, Seoul national university hospital and Severance hospital, known to be the top four hospitals with the most amount of surgical cases on thymic epithelial tumor (TET). The aim of KART is to establish a multi-center TET database and present the clinical features and treatment outcomes in Korea. The KART database which was based on the International Thymic Malignancy Interest Group (ITMIG) database system included 1,462 cases of retrospectively collected thymoma and thymic carcinoma from Jan 2000 to Dec 2013. Masaoka-Koga stage I consisted of 34%, stage IIA 22% and stage IIB 17%. The overall 5- and 10-year survival rates were 90% and 76% respectively. As the Masaoka-Koga stage progressed, the survival rates decreased. Through the collaboration of ITIMG, 1,327 cases from KART were registered in the database of Cancer Research And Biostatistics (CRAB) in 2019. The Korean Association for Thoracic Surgical Oncology (KATSO) is the only organization in which all thoracic surgeons in South Korea are registered. Because KART was established with the purpose of collecting data on a national scale, KART is in collaboration to produce a nationwide database system with KATSO. The new database system is planning to collaborate with the ITMIG CRAB database and will adopt a TNM staging system developed in parallel to the Masaoka-Koga system. Data is planned on being collected retrospectively and prospectively and KART data will be the foundation of the retrospective data. Once the KATSO database is fully established, the national data of TET will be used to establish a guideline and standard of the treatment for TET in South Korea and KATSO will collaborate with ITMIG.

Thymomectomy plus total thymectomy versus simple thymomectomy for early-stage thymoma without myasthenia gravis: a European Society of Thoracic Surgeons Thymic Working Group Study

OBJECTIVES

Resection of thymic tumours including the removal of both the tumour and the thymus gland (thymothymectomy; TT) is the procedure of choice and is recommended in most relevant articles in the literature. Nevertheless, in recent years, some authors have suggested that resection of the tumour (simple thymomectomy; ST) may suffice from an oncological standpoint in patients with early-stage thymoma who do not have myasthenia gravis (MG) (non-MG). The goal of our study was to compare the short- and long-term outcomes of ST versus TT in non-MG early-stage thymomas using the European Society of Thoracic Surgeons thymic database.

METHODS

A total of 498 non-MG patients with pathological stage I thymoma were included in the study. TT was performed in 466 (93.6%) of 498 patients who had surgery with curative intent; ST was done in 32 (6.4%). The completeness of resection, the rate of complications, the 30-day mortality, the overall recurrence and the freedom from recurrence were compared. We performed crude and propensity score-adjusted comparisons by surgical approach (ST vs TT).

RESULTS

TT showed the same rate of postoperative complications, 30-day mortality and postoperative length of stay as ST. The 5-year overall survival rate was 89% in the TT group and 55% in the ST group. The 5-year freedom from recurrence was 96% in the TT group and 79% in the ST group.

CONCLUSION

Patients with early-stage thymoma without MG who have a TT show significantly better freedom from recurrence than those who have an ST, without an increase in postoperative morbidity rate.

Partial Versus Complete Thymectomy in Non-Myasthenic Patients With Thymoma: A Systematic Review and Meta-Analysis of Clinical Outcomes

The optimal extent of surgical resection for non-myasthenic patients with thymoma is controversial. The objective of this meta-analysis was to compare complete to partial thymectomy in non-myasthenic patients for oncological and postoperative clinical outcomes. We performed a PubMed and EMBASE search (from inception to January 2020) for English-language studies directly comparing partial to complete thymectomy for thymoma resection. Clinical endpoints studied included overall and disease-free survival, Masaoka and World Health Organization staging, adjuvant therapy, postoperative complications, postoperative drainage, length of hospital stay, thymoma-related deaths, postresection development of myasthenia gravis, incomplete resection, and recurrence. Random effects meta-analyses across all clinical endpoints was done. There was no statistically significant difference between the two approaches with regard to recurrence (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.78-1.92), completeness of resection (OR, 1.17; 95% CI, 0.66-2.10), adjuvant therapy (OR, 0.71; 95% CI, 0.40-1.26), or thymoma-related deaths (OR, 0.76; 95% CI, 0.12-4.66). There was a statistically significant decrease in postoperative complications (OR, 0.61; 95% CI, 0.39-0.97), drainage (mean difference [MD], -0.99; 95% CI, -1.98 to -0.01), and length of hospital length (MD, -1.88; 95% CI, -3.39 to -0.36) with partial thymectomy. The evidence appeared to suggest that partial thymectomy is oncologically equivalent to complete thymectomy for non-myasthenic patients with early-stage thymoma. There is an additional advantage of reduced postoperative complications and decreased length of hospital stay with partial thymectomy.

Video-Assisted Thoracic Surgery Thymectomy: Transpleural Approach

There are several types of minimally invasive approaches for thymectomy, of which the transpleural approach by video-assisted thoracoscopic surgery is particularly useful. In this approach, thymectomy is performed from either side of the thoracic cage. Thoracic surgeons should be familiar with the principles of the procedure, the anatomy of the region, and surgical strategies for successful thymectomy. The details of transpleural thymectomy are discussed herein.

Limited resection for early-stage thymoma: minimally invasive resection does not mean limited resection

Standard resection for patients with thymoma is resection of thymoma with total thymectomy (TTx) via median sternotomy. Hence, limited resection for thymoma means a lesser extent of resection of normal thymus compared with a standard procedure, i.e. resection of thymoma with partial thymectomy (PTx). In contrast, minimally invasive resection has been defined as resection of thymoma with TTx via a less-invasive approach. However, to date, few studies have precisely evaluated the differences in surgical and oncological outcomes among these three procedures. This report summarizes the differences among these three procedures with a review of studies (January 2000 to December 2020) focusing on the difference in surgical and oncological outcomes and presents current issues in the surgical management of thymoma. In this report, 16 studies were identified; 5 compared standard resection to limited resection, 9 compared standard resection to minimally invasive resection and 2 compared limited resection to minimally invasive resection. Most studies reported that the surgical and oncological outcomes of limited resection or minimally invasive resection were similar to those of standard resection in patients with early-stage thymoma. However, they did not include a sufficient follow-up period. Both limited resection and minimally invasive resection for early-stage thymoma might be reasonable treatment options. However, they are still promising modes of resection. Further studies with a long follow-up period are needed.

Meta-Analysis of Limited Thymectomy versus Total Thymectomy for Masaoka Stage I and II Thymoma

Background

This meta-analysis aimed to evaluate the incidence of tumor recurrence, postoperative myasthenia gravis, postoperative complications, and overall survival after limited versus total thymectomy for Masaoka stage I and II thymoma.

Methods

A systematic search of the literature was conducted using the PubMed, Embase, MEDLINE, and Cochrane databases to identify relevant studies that compared limited and total thymectomy in Masaoka stage I-II patients. The quality of the included observational studies was assessed using the Newcastle-Ottawa Scale. The results of the meta- analysis were expressed as log-transformed odds ratios (log ORs), with 95% confidence intervals (CIs).

Results

Seven observational studies with a total of 2,310 patients were included in the meta-analysis. There was an overall non-significant difference in favor of total thymectomy in terms of tumor recurrence (pooled log OR, 0.40; 95% CI, -0.07 to 0.87; p=0.10; I²=0%) and postoperative myasthenia gravis (pooled log OR, 0.12; 95% CI, -1.08 to 1.32; p=0.85; I²=22.6%). However, an overall non-significant difference was found in favor of limited thymectomy with respect to postoperative complications (pooled log OR, -0.21; 95% CI, -1.08 to 0.66; p=0.64; I²=36.1%) and overall survival (pooled log OR, -0.01; 95% CI, -0.68 to 0.66; p=0.98; I²=47.8%).

Conclusion

Based on the results of this systematic review and meta-analysis, limited thymectomy as a treatment for stage I and II thymoma shows similar oncologic outcomes to total thymectomy.

Long-Term Outcomes of Robotic Thymectomy in Patients With Thymic Epithelial Tumors

BACKGROUND

The long-term outcomes of robotic thymectomy for thymic epithelial tumors (TETs) are not well known, even though the early postoperative outcomes have improved. This study aimed to report the long-term survival and recurrence in patients with TETs who underwent robotic thymectomies.

METHODS

A total of 158 patients who underwent robotic thymectomy for TET and who were followed-up for more than 1 year were included in the study. The median follow-up time was 43 (interquartile range, 40) months, and 156 (98%) patients were followed completely until the end of the study period.

RESULTS

The mean age of the patients was 55.7 ± 12.7 years, and the mean size of the tumor was 4.6 ± 2.1 cm. There was no postoperative mortality and postoperative complications occurred in 7 (4.4%) patients. The median length of the postoperative hospital stay was 2 (interquartile range, 1-20) days. Thymoma was the most common cell type (n = 132, 84%), and thymic carcinoma (n = 24, 15%) and neuroendocrine tumors (n = 2, 1%) were the next most common types. Advanced stages more than stage III were identified in 15 patients (stage IIIA: n = 7, 4%; stage IVA: n = 5, 3%; and stage IVB: n = 3, 2%). The 5-year disease-specific survival was 100% in thymoma and 95% in thymic carcinoma. The 5-year recurrence-free survival was 94% in thymoma and 79% in thymic carcinoma.

CONCLUSIONS

Robotic thymectomy could achieve favorable long-term survival and recurrence rates, comparable to open or thoracoscopic thymectomy.

Perioperative risk factors for occurrence of myasthenia gravis after thymectomy in patients with thymoma

OBJECTIVES

The goal of this study was to identify the relationship between clinical characteristics and the occurrence of postoperative myasthenia gravis (PMG) in patients with thymomas and to further identify the relationship between PMG and prognosis.

METHODS

Thymoma patients who had surgery at the First Affiliated Hospital of Sun Yat-sen University between July 2004 and July 2016 were reviewed and those who had no previous symptoms of myasthenia gravis were selected for further investigation. In total, 229 patients were included in the study; their clinical characteristics were gathered and analysed.

RESULTS

Among the 229 patients, 19 (8.3%) had PMG. The time between the operation and the onset of myasthenia gravis was 134 days on average (range 2-730 days). Patients experiencing PMG showed a lower rate of complete thymoma resection (73.7% vs 91.4%; P = 0.014) and total thymectomy (63.2% vs 82.9%; P = 0.035) compared with those who did not. Univariable and multivariable logistic regression revealed that thymomectomy [odds ratio (OR) 2.81, 95% confidence interval (CI) 1.02-7.77; P = 0.047] and incomplete tumour resection (OR 3.79, 95% CI 1.20-11.98; P = 0.023) were associated with the occurrence of PMG. Multivariable Cox regression showed that the PMG was not related to overall survival (P = 0.087).

CONCLUSIONS

This study revealed that incomplete tumour resection and thymomectomy were independent risk factors for PMG in thymoma patients with no previous history of myasthenia gravis.

Extended thymectomy with blood vessel resection and reconstruction improves therapeutic outcome for clinical stage III thymic carcinoma patients: a real-world research

OBJECTIVES

We examine the therapeutic efficacy of extended thymectomy with blood vessel resection and reconstruction in thymic carcinoma patients with great vessel invasion.

METHODS

In total 26 patients diagnosed as clinical stage III thymic carcinoma with severe great vessel invasion were enrolled in this retrospective study. Among these patients, 14 cases received adjuvant chemo- and radiotherapy (non-operation subgroup, NOG), the other 12 patients received extended thymectomy with vessel resection and reconstruction followed by the adjuvant treatment (operation subgroup, OG).

RESULTS

All surgical procedures went smoothly with no perioperative death. R0 resection was obtained in all surgical cases, and we also observed a lymph node metastasis rate of 38.8%. The overall survival (OS) was 34 months for the whole cohort, 48 and 26 months for the OG and NOG respectively (p = 0.013). The median disease metastasis free survival (DMFS) was 47 months for the OG and 18 months for the NOG (p = 0.019).

CONCLUSION

Extended thymectomy with vessel resection is feasible for patients with clinical stage III thymic carcinoma. Surgery significantly improves the overall survival and the prognosis of clinical stage III thymic carcinoma.

Report from the European Society of Thoracic Surgeons prospective thymic database 2017: a powerful resource for a collaborative global effort to manage thymic tumours

OBJECTIVES

We queried the European Society of Thoracic Surgeons (ESTS) prospective thymic database for descriptive analysis and for comparison with the ESTS retrospective thymic database (1990-2010).

METHODS

Data were retrieved (January 2007-November 2017) for 1122 patients from 75 ESTS institutions.

RESULTS

There were 484 (65%) thymomas, 207 (28%) thymic carcinomas and 49 (7%) neuroendocrine thymic tumours. Staging (Masaoka) included 483 (67%) stage I and II, 100 (14%) stage III and 70 (10%) stage IV tumours. The new International Association for the Study of Lung Cancer/International Thymic Malignancies Interest Group tumour, node and metastasis (TNM) classification was available for 224 patients and including 177 (85%) stage I-II, 37 (16%) stage IIIA and 10 (4%) stage IIIB tumours. Chemotherapy as induction and adjuvant treatment was used in 14% and 15% of the patients. Radiotherapy was almost exclusively used postoperatively (24%). A minimally invasive surgical approach (video-assisted thoracic surgery/robotic-assisted thoracic surgery) was used in 276 (33%) patients. The overall recurrence rate was 10.8% (N = 38). Compared to the ESTS retrospective database, the increased prevalence of thymic carcinomas (from 9% to 28%) and neuroendocrine thymic tumours (from 2% to 7%), an increase in the use of minimally invasive techniques (from 6% to 34%) and a wider use of chemotherapy as induction (from 9% to 15%) and adjuvant (from 2% to 16%) treatment were observed in the prospective database. The introduction of a set of variables considered essential for the data use ('minimum dataset') resulted in an increased average completeness rate.

CONCLUSIONS

The reported data from the ESTS prospective thymic database confirm the recent trends in the management of thymic tumours. The ESTS prospective thymic database represents a powerful resource open to all ESTS members for the global effort to manage these rare tumours.

Minimal Access Surgery for Thymoma

Thymoma is a rare epithelial tumor of the thymus gland. Despite rarity, it is the most common tumor of the anterior mediastinum. Surgical resection in the form of extended thymectomy is the gold standard operation. Conventionally and even in the current era of significant advances in the minimally invasive surgery, open transsternal extended thymectomy is considered the gold standard, particularly for advanced-stage tumors. There is however significant evidence now available for the use of minimally invasive approaches for early-stage thymomas. This article aims to discuss the various minimally invasive approaches currently being employed for thymomas.

Heart rupture repair during huge mediastinal mass resection - case report

BACKGROUND

Ventricular rupture is rarely described in the literature outside the context of myocardial infarction, infection or neoplasm. It is associated with a high mortality rate due to late presentation and delayed surgical intervention, which involves sutureless or sutured techniques. Comprehensive literature review failed to identify any case of intra-operative right ventricular heart rupture followed by myocardial repair and a complete recovery after a prolonged intensive care unit (ICU) stay.

CASE PRESENTATION

A 57-year-old previously healthy gentleman presented complaining of a new onset shortness of breath for 2 months. A large mediastinal mass was found on chest imaging and biopsy revealed a thymoma. Patient received a neoadjuvant Cisplatin/Doxorubicin/Cyclophosphamide (CAP) regimen chemotherapy then sternotomy and thymectomy en bloc with anterior pericardium. Post-thymectomy, the patient continued to be hypotensive in recovery despite aggressive fluid resuscitation. He was sent back to theatre, aggressive fluid resuscitation continued, surgical site exploration was done by reopening the sternum, and the bleeding source was identified and controlled, but intraoperative asystole developed. During internal cardiac massage, the right ventricle ruptured with a 3 cm defect which was successfully repaired using a pericardial patch without a bypass machine due to unavailability at our cancer center. The patient remained dependent on mechanical ventilation through tracheostomy for a total of 2 months due to bilateral phrenic nerve paralysis, was discharged from ICU to the surgical floor 66 days after the operation and weaned off ventilator support after 85 days, adequate respiratory and physical rehabilitation followed. Patient is doing very well now with excellent performance, and free of tumor recurrence 30 months after surgery.

CONCLUSION

Right ventricular rupture is rarely described outside the context of myocardial infarction and valvular heart disease. Tumor proximity to the heart and neoadjuvant cardiotoxic chemotherapy are the proposed causes for precipitating the cardiac rupture in our case. Post-surgical patients who receive early physical rehabilitation and respiratory physiotherapy have improved survival and outcome.

Comparison between thoracoscopic and open approaches in thymoma resection

Background

To investigate the feasibility and indications of video-assisted thoracic surgery (VATS) in thymoma resection.

Methods

The clinical data of 103 patients undergoing thymoma resection via different approaches [including conventional lateral thoracotomy approach (LTA) in 41 cases, median sternotomy approach (MSA) in 40 cases, and right-sided VATS in 22 cases] were analyzed. Among them, 59, 13, 25, and 6 patients were in Masaoka stage I, II, III, and IV, respectively. Myasthenia gravis (MG) was also found in 54 cases. The patients were followed up for postoperative survival and the improvement in MG. The prognostic indicators of patients undergoing thymoma resection via different surgical approaches (i.e., LTA, MSA, and VATS) were statistically analyzed.

Results

Eight of 103 patients died. Six patients underwent unilateral sacral nerve resection, among whom 4 patients developed respiratory dysfunction, and 3 died. Two patients died of MG after surgery, 1 patient died of tumor recurrence and metastasis, 1 patient died of heart disease, and the cause of death was unknown in the remaining patient. The drainage time was shorter in VATS group than in open groups, along with smaller tumor size. The VATS group also had shorter hospital stay in the whole series and the subgroup without accompanying MG. The improvement in MG showed no significant difference among the three surgical groups. Both 5- and 10-year survival rates were 91% in the entire cohort.

Conclusions

VATS is like a conventional surgeries for improving MG in thymoma patients with accompanying MG. VATS resection can still be considered for thymoma that only invades the mediastinal pleura. For thymomas that have intact capsules and have not invaded mediastinal pleura, MSA surgery shall be performed to ensure patient safety if the anteroposterior diameters of the tumors are large and the masses have produced severe compression of the innominate vein, even if the tumors are still in the Masaoka stage II. For thymomas with large left-to-right diameters and with most parts of the tumors located in the left thoracic cavity, a left-sided approach (either VATS or an open approach) may be used in the absence of MG; if MG accompanies the condition, an MT approach or a bilateral VATS may be considered. In patients with unilateral pericardial phrenic nerve and/or local pericardial involvement, right-sided VATS thymectomy may be considered for thymomas located at the right side and bilateral VATS surgery can be performed for tumors located at the left side. In summary, VATS is feasible for the treatment of thymoma complicated by MG. VATS can be performed in patients with Masaoka stage I, II and (a certain portion of) III thymoma; for some patients with Masaoka stage II thymoma, especially those with compression of the innominate vein, the use of VATS should be cautious.

Optimal management of thymic malignancies: current perspectives

Thymic epithelial tumors (TETs) belong to orphan oncology. The incidence of TETs is about 1.3–3.2 cases per million worldwide. Following pathology, evolution and prognosis are variable. The World Health Organization classification distinguishes thymomas and thymic carcinomas. TETs are composed of thymic epithelial tumoral cells and normal lymphocytes. The mean age at diagnosis is 50–60 years-old. There are no identified risk factors. TETs are frequently associated with paraneoplastic syndromes as myasthenia gravis. The complete R₀ surgical resection is the most significant prognosis factor on survival. In 2010, the French National Institute of Cancer labeled the RYTHMIC network as a specific tumor board including thoracic surgeons, oncologist, and radiation therapist to define standard of care for the management of TETs. The aim of the review was to update knowledge to optimize the standard of care.

A nomogram for predicting recurrence after complete resection for thymic epithelial tumors based on the TNM classification: A multi-institutional retrospective analysis

OBJECTIVES

This study aimed to compare the predictive ability between the Masaoka-Koga (M-K) staging system and the 8th TNM staging system for the recurrence of thymic epithelial tumors (TETs). In addition, a nomogram was developed on the basis of the proposed TNM classification to predict individual recurrence rate.

METHODS

A retrospective study was performed on 445 patients who underwent complete resection (R0) of TETs between January 2000 and February 2013. Concordance index (C-index) was used as a statistical indicator to quantify the prediction power of the prediction models.

RESULTS

In multivariate analysis, tumor stage and WHO classification were independent recurrence factors in a predictive model on the basis of M-K and TNM stage. The TNM model showed higher C-index than the M-K model (0.837 vs 0.817). The nomogram, on the basis of the TNM model, revealed a highly predictive performance, with a bootstrap-corrected C-index of 0.85 (95% CI, 0.76 to 0.93).

CONCLUSIONS

A predictive model based on the 8th TNM stage was slightly better than that based on M-K stage with respect to recurrence after R0 of TETs. The proposed nomogram could be applied to estimate the individual recurrence rate and make decisions for proper surveillance.

Paraneoplastic Syndromes and Thymic Malignancies: An Examination of the International Thymic Malignancy Interest Group Retrospective Database

INTRODUCTION

Thymic epithelial tumors (TETs) are associated with paraneoplastic/autoimmune (PN/AI) syndromes. Myasthenia gravis is the most common PN/AI syndrome associated with TETs.

METHODS

The International Thymic Malignancy Interest Group retrospective database was examined to determine (1) baseline and treatment characteristics associated with PN/AI syndromes and (2) the prognostic role of PN/AI syndromes for patients with TETs. The competing risks model was used to estimate cumulative incidence of recurrence (CIR) and the Kaplan-Meier method was used to calculate overall survival (OS). A Cox proportional hazards model was used for multivariate analysis.

RESULTS

A total of 6670 patients with known PN/AI syndrome status from 1951 to 2012 were identified. PN/AI syndromes were associated with younger age, female sex, thymoma histologic type, earlier stage, and an increased rate of total thymectomy and complete resection status. There was a statistically significant lower CIR in the group with a PN/AI syndrome than in the group without a PN/AI syndrome (10-year CIR 17.3% versus 21.2%, respectively [p = 0.0003]). The OS was improved in the group with a PN/AI syndrome compared to the group without a PN/AI syndrome (median OS 21.6 years versus 17.0 years, respectively [hazard ratio = 0.63, 95% confidence interval: 0.54-0.74, p < 0.0001]). However, in the multivariate model for recurrence-free survival and OS, PN/AI syndrome was not an independent prognostic factor.

DISCUSSION

Previously, there have been mixed data regarding the prognostic role of PN/AI syndromes for patients with TETs. Here, using the largest data set in the world for TETs, PN/AI syndromes were associated with favorable features (i.e., earlier stage and complete resection status) but were not an independent prognostic factor for patients with TETs.

Thymoma size significantly affects the survival, metastasis and effectiveness of adjuvant therapies: a population based study

Background

Thymoma, though a rare tumor disease, is the most common tumor of the anterior mediastinum. However, tumor size, as a critical factor, has been underestimated.

Results

Age, advanced tumor stage, and preoperative radiotherapy were poor prognostic factors of overall survival (OS) and disease specific survival (DSS) (P < 0.05 for all). Besides, tumor size was significantly related to survival. The larger tumor size indicated the less OS and DSS (P < 0.001 for all). Multivariate analysis revealed elder age, advanced stage, larger size were independent adverse predictors for survival (P < 0.05 for all). Logistic analysis revealed larger tumor size had greater rate of metastasis (P < 0.001). In the group with tumors smaller than 90mm, chemotherapy was a negative predictive factor of DSS (P < 0.05 for all), and it significantly decreased OS especially with tumor sizes between 50 and 90 mm (P < 0.001).

Materials and Methods

A total of 1,272 thymoma patients were enrolled from the Surveillance, Epidemiology, and End Results (SEER) database. Survival based on thymoma size and other characteristics of tumors were analyzed by univariate and multivariate analysis. Correlation between thymoma size and thymoma metastatic status was contributed by logistic regression analysis. The efficiency of adjuvant therapy was analysis by stratification analysis.

Conclusions

Thymoma size could predict postoperative survival and guide chemotherapeutic regimens of patients. Larger tumor size indicated worse survival and higher metastatic rate. If thymoma is smaller than 90mm, traditional chemotherapy should be prohibited. While chemotherapy could be performed moderately when thymoma larger than 90 mm.

Could thymomectomy be a reasonable option for non-myasthenic thymoma patients?

Background

Complete resection is the mainstay of treatment for thymoma, but few studies have investigated the extent of resection on normal thymus. Extended thymectomy is considered the treatment of choice for myasthenic patients with thymoma, while the optimal therapy for non-myasthenic patients is still a matter of debate. The aim of this retrospective study was to compare extended thymectomy vs. thymomectomy in non-myasthenic thymoma patients for (I) oncological outcome, (II) multicentric thymoma occurrence and (III) postoperative myasthenia gravis (MG) development.

Methods

A retrospective comparative study was conducted on 92 non-myasthenic patients with completely resected thymoma, according to the extent of resection: extended thymectomy (70 patients) vs. R0-mediastinal thymomectomy (22 patients). Clinical and pathological characteristics, oncological outcome and postoperative MG occurrence were compared between the two study groups.

Results

We did not observe any significant differences in gender, age, symptomology, preoperative chemotherapy, histology, tumour size, adjuvant therapy or complications. There were no recorded postoperative mortalities. Stage distribution was different between the two groups: similar percentages of early stage thymoma for both groups were present, but there was a prevalence of stage III for extended thymectomy and stage IV for thymomectomy (P<0.01). At a median follow-up of 77.4 months (range 1-255 months), no statistically significant differences were recorded in local recurrence (P=0.396), thymoma related deaths (P=0.504), multicentric thymoma occurrence (P=0.742) and postoperative MG development (P=0.343). A high preoperative anti-acetylcholine receptor antibodies (ARAb) serum titer assay was statistically correlated with postoperative MG occurrence (r=0.49, P<0.05).

Conclusions

Thymomectomy appears to be a valid treatment option for non-myasthenic thymoma patients, as this procedure was associated to the same 5-year oncological results, compared to extended thymectomy, for both stage I-II small thymomas and patients with giant unilateral masses, as well as advanced diseases. Moreover, thymomectomy was not associated to an increased rate of postoperative MG.

Definitions and standard indications of minimally-invasive techniques in thymic surgery

BACKGROUND

The minimally invasive thoracic procedures are those performed through the intercostal, subxiphoid, subcostal or transcervical incisions. In most of these procedures (with exception of some transcervical procedures) the video-assisted thoracic surgery (VATS) technique is used for performance of an operation under guidance of a video monitor.

METHODS

According to the definition the minimally invasive procedures do not include the sternal manubriotomy (upper sternal split), transverse sternotomy and subcutaneous longitudinal sternotomy. Currently, a minimally invasive extended thymectomy became a widespread procedure advised for nonthymomatous myasthenia gravis (MG) and early-stage thymomas. The definition of an extended thymectomy is a removal of the whole thymus with the surrounding adipose tissue. Instead of the term "extended thymectomy" some authors recommended a term "complete thymectomy", which means total removal of the whole thymus, without the adjacent fatty tissue.

RESULTS

There are a lot of doubts about the definition of extended thymectomy. There have been no prospective randomized trials comparing the transsternal and minimally invasive approaches for MG or thymomas. Possible scenarios for such trials are analyzed in this paper.

CONCLUSIONS

There are several issues of a minimally invasive thymectomy for MG and thymomas necessitating further clarifications.

JOURNAL CLUB: Doubling Time of Thymic Epithelial Tumors Correlates With World Health Organization Histopathologic Classification

OBJECTIVE

Awareness of volume doubling times (VDTs) of different thymic epithelial tumors (TETs), including low- and high-grade thymomas and thymic carcinomas, is important for their management. The purpose of this study was to evaluate the VDTs of incidentally found TETs using 3D volumetry (3D-VDT) and longest diameter (LD-VDT).

MATERIALS AND METHODS

This retrospective study included 50 patients (30 men, 20 women) who had histologically proven TETs and who underwent at least two serial CT studies at greater than 2-month intervals. TETs were classified into World Health Organization subtypes and further divided into low-grade (group A [A-B1]) and high-grade (group B [B2, B3]) thymoma and thymic carcinoma (group C). Tumor volumetry was performed by either manual segmentation (3D-VDT) or longest diameter measurement (LD-VDT).

RESULTS

Groups A, B, and C accounted for 15, 26, and nine tumors. The median LDVDT in group A was 703.6 days (range, 286.7-1855.9 days); group B, 412.1 days (range, 130.9-716.9 days), and group C, 146.3 days (range, 68.9-448.3 days) (p < 0.01). The median 3D-VDTs were 1138.8 days (range, 350.1-3915.3 days), 711.0 days (range, 145.5-7209.5 days), and 203.1 days (range, 58.9-766.9 days) (p < 0.01). In ROC analysis, both LD-VDT (AUC, 0.873; p < 0.01; optimal cutoff value, 222.6 days; 90.2% sensitivity, 77.8% specificity) and 3DVDT (AUC, 0.859; p < 0.01; optimal cutoff value, 218.0 days; 92.7% sensitivity; 66.7% specificity) differentiated group C from groups A and B.

CONCLUSION

VDTs differ among TETs according to tumor grade. Measurement of either LD-VDT or 3D-VDT is sensitive for differentiating carcinomas from thymomas (cutoff value, ≈ 220 days).