The Role of Surgical Management in Recurrent Thymic Tumors

Analysis of different surgical approaches to the treatment of thymoma

BACKGROUND

Surgical approach in the treatment of thymoma is varied. This retrospective study aimed to evaluate the outcomes of different surgical approaches in the treatment of thymoma.

METHODS

From January 2020 to December 2023, a total of 208 patients underwent thoracoscopic surgical treatment and were diagnosed with thymoma by postoperative pathological result in our institution. We collected and then analysed potential factors including general conditions, surgical approaches, preoperative clinical symptoms, surgical procedures, postoperative hospital stay, postoperative drainge, postoperative pain score, postoperative complications and postoperative follow-up.

RESULTS

Of the 208 patients, 98 patients underwent surgery via subxiphoid approach (47.1%) and 110 patients via lateral intercostal approach (52.8%). The duration of the surgical procedure (P = 0.02), intraoperative blood loss (P = 0.045), total postoperative drainage (P = 0.021), postoperative drainage per day (P = 0.004) and Postoperative pain score (Day1 P = 0.010 and Day2 P = 0.002)showed a significant difference between these two groups. 31 patients (14.9%) received postoperative radiotherapy. One patient died due to postoperative radiotherapy. No recurrence occurred in one-year follow-up.

CONCLUSIONS

The present study not only showed that subxiphoid approach was a safe and feasible technique for thymoma, with a potentially faster postoperative recovery and less postoperative pain.

Survival Outcome After Surgery in Patients With Thymoma Distant Recurrence

OBJECTIVE

The aim of this study is to describe characteristics and survival outcome of patients who underwent surgical treatment for distant thymoma relapse according to the definition of the International Thymic Malignancy Interest Group.

METHODS

Data of patients affected by thymoma recurrence from four different institutions were collected and retrospectively reviewed. Patients with locoregional metastases who underwent nonsurgical therapies and with incomplete data on follow-up were excluded. According to the International Thymic Malignancy Interest Group distant recurrence definition, patients with recurrence due to hematogenic localization were included. Clinical and pathologic characteristics were described using descriptive statistics, whereas survival outcome was calculated using Kaplan-Meier curves and Cox regression analysis.

RESULTS

The analysis was conducted on 40 patients. A single localization was present in 13 patients, the relapse was intrathoracic in 28 cases (70%), and lung involvement was found in 26 cases. The liver was operated in seven cases, whereas other kinds of abdominal involvement were detected in eight cases. Adjuvant treatment was administered in 22 cases (55%).Five- and 10-year overall survival (OS) were 67% and 30%, respectively. Univariable analysis identified as significant favorable factor a low-grade histology (A, B1, B2): five-year OS at 92.3% versus 53.3% in high-grade (B3-C) (p = 0.035). Site of recurrence and number of localization did not influence the prognosis, but in patients with adjuvant therapy administration, there was a survival advantage also if not statistically significant: five-year OS 84.8% versus 54.5% in patients without adjuvant therapy (p = 0.101).Multivariable analysis confirmed as independent prognostic factor low-grade histology: hazard ratio = 0.176, 95% confidence interval 0.042-0.744, p = 0.018.

CONCLUSIONS

Our study revealed a good survival outcome in patients who underwent surgery for distant thymoma recurrence, independently from the number and site of the relapse localization. Patients with A, B1, or B2 histology presented a significantly better survival than patients with B3-C.

The Prognostic Role of the Number of Involved Structures in Thymic Epithelial Tumors: Results from the ESTS Database

BACKGROUND

The role of the number of involved structures (NIS) in thymic epithelial tumors (TETs) has been investigated for inclusion in future staging systems, but large cohort results still are missing. This study aimed to analyze the prognostic role of NIS for patients included in the European Society of Thoracic Surgeons (ESTS) thymic database who underwent surgical resection.

METHODS

Clinical and pathologic data of patients from the ESTS thymic database who underwent surgery for TET from January 2000 to July 2019 with infiltration of surrounding structures were reviewed and analyzed. Patients' clinical data, tumor characteristics, and NIS were collected and correlated with CSS using Kaplan-Meier curves. The log-rank test was used to assess differences between subgroups. A multivariable model was built using logistic regression analysis.

RESULTS

The final analysis was performed on 303 patients. Histology showed thymoma for 216 patients (71.3%) and NET/thymic carcinoma [TC]) for 87 patients (28.7%). The most frequently infiltrated structures were the pleura (198 cases, 65.3%) and the pericardium in (185 cases, 61.1%), whereas lung was involved in 96 cases (31.7%), great vessels in 74 cases (24.4%), and the phrenic nerve in 31 cases (10.2%). Multiple structures (range, 2-7) were involved in 183 cases (60.4%). Recurrence resulted in the death of 46 patients. The CSS mortality rate was 89% at 5 years and 82% at 10 years. In the univariable analysis, the favorable prognostic factors were neoadjuvant therapy, Masaoka stage 3, absence of metastases, absence of myasthenia gravis, complete resection, thymoma histology, and no more than two NIS. Patients with more than two NIS presented with a significantly worse CSS than patients with no more than two NIS (CSS 5- and 10-year rates: 9.5% and 83.5% vs 93.2% and 91.2%, respectively; p = 0.04). The negative independent prognostic factors confirmed by the multivariable analysis were incomplete resection (hazard ratio [HR] 2.543; 95% confidence interval [CI] 1.010-6.407; p = 0.048) and more than two NIS (HR 1.395; 95% CI 1.021-1.905; p = 0.036).

CONCLUSIONS

The study showed that more than two involved structures are a negative independent prognostic factor in infiltrative thymic epithelial tumors that could be used for prognostic stratification.

Updated outcomes of surgical treatment for recurrent thymic tumour: a report from the Japanese nationwide database

OBJECTIVES

This study aimed to analyse the surgical outcomes for recurrent thymic epithelial tumours and identify the factors associated with post-recurrence survival, using an updated Japanese nationwide database.

METHODS

The cohort that developed recurrence after the initial resection was extracted from an updated database of patients whose thymic epithelial tumours were treated surgically between 1991 and 2010. Furthermore, we reviewed clinicopathological and prognostic factors of re-resected cases. Post-recurrence survival outcomes and cause-specific deaths in non-re-resected cases were also reviewed.

RESULTS

We enrolled 191 patients who underwent re-resection and 259 patients who did not. In the surgery group, more patients with early stage disease, less aggressive World Health Organization (WHO) histological classification, initial complete resection and shorter recurrence-free intervals were included. Non-thymic carcinoma, absence of preoperative treatment, longer recurrent-free interval, single-site recurrence and R0-1 re-resection were all significantly favourable prognostic factors for post-recurrence survival in the surgery group, according to univariable analyses. Non-thymic carcinoma histology, longer recurrence-free interval and R0-1 re-resection were identified as independent prognostic factors according to multivariable analysis. The post-recurrence survival of the entire cohort with R2 re-resection was significantly better than that of the non-surgery group, although it was not demonstrated that patients with thymoma who underwent R2 re-resection had significantly better post-recurrence and lower cause-specific death.

CONCLUSIONS

R0-1 re-resection was newly identified as a prognostic factor after re-resection, in addition to non-thymic carcinoma histological classification and longer recurrence-free intervals, as documented in the initial report.

Impact of adjuvant radiotherapy and chemotherapy on thymoma

PURPOSE

Thymoma is a rare tumour. The most common treatment for thymoma is surgical resection, while the use of radiotherapy and chemotherapy remains controversial.

PATIENTS AND METHODS

We conducted a monocentric observational study of 31 patients diagnosed with thymoma from June 2004 to July 2020 at cancer centre in Strasbourg, France. We analysed the outcomes of the patients.

RESULTS

The 2- and 5- year locoregional relapse-free survival rates were 96.3% (95% confidence interval [CI]: 76.5-99.5%) and 68.0% (95% CI: 43.8-83.5%), respectively. Radiotherapy and chemotherapy significantly improved local tumour control (P=0.0008 and 0.04, respectively), while a larger initial tumour size significantly worsened local control rates (P=0.04). The 5- and 10-year overall survival rates were 87.1% (95% CI: 69.2-95%) and 81.7% (95% CI: 60.3-92.2%), respectively. The median overall survival was not reached, and no favourable factor was retrieved. For relapsed patients, the median overall survival after relapse was 115 months.

CONCLUSION

Despite the inherent limitations of retrospective studies with a limited patient sample size, we demonstrated that chemotherapy and radiotherapy in addition to surgery were effective in achieving local control and contributed to improving patient outcomes in thymoma. Notably, an aggressive treatment strategy at the time of relapse resulted in favourable outcomes for retreated patients.

Acute myeloid leukemia post‑cytotoxic therapy following chemotherapy for thymoma: A case report

The present study reports the case of a patient with acute myeloid leukemia post-cytotoxic therapy (AML-pCT) that developed following chemotherapy for thymoma. A 64-year-old female patient underwent surgical resection for a mediastinal tumor and was diagnosed with stage IVa thymoma. She received chemotherapy, including carboplatin/etoposide, carboplatin/paclitaxel and amrubicin monotherapy. At 56 months following surgery, she developed blastosis and was diagnosed with AML-pCT. As demonstrated herein, although treatment for thymoma is associated with a markedly lower frequency of myeloid neoplasms post-cytotoxic therapy (MN-pCT) than treatment for other malignancies, such as breast carcinoma, it is important to be aware that MN-pCT may occur as a late complication of thymoma treatment.

Atypical type A thymoma component identified by pulmonary metastasectomy 11 years after surgery of type AB thymoma

Atypical type A thymomas exhibit more aggressive features than conventional type A thymomas. Type AB thymomas rarely have atypical type A components. We report a rare case of type AB thymoma with an atypical type A component, that was identified after pulmonary metastasectomy 11 years after the primary surgery and long-term follow-up after recurrence. A 61-year-old female underwent extended thymectomy for an anterior mediastinal tumor 11 years prior and was diagnosed with type AB thymoma (Masaoka stage II). Five years ago, follow-up computed tomography showed well-circumscribed pulmonary nodules up to 1.0 cm in both lungs. All the pulmonary nodules grew slowly; however, one of the nodules grew to 1.6 cm, and thoracoscopic wedge resection was performed for diagnosis. Pathologically, the pulmonary nodule was consisted of type A thymoma component. Conventional type AB thymomas are usually locally aggressive neoplasms; thus, we reviewed the tissue slides of primary thymomas. Histologically, cytological atypia, hypercellularity, and increased mitosis are observed in the type A component. Consequently, the diagnosis was revised to a type AB thymoma with an atypical type A component. The pulmonary nodule exhibited the same atypical type A features. Pulmonary metastasectomy was performed two more times as volume-reduction surgery. The residual metastasis was located only in the lung with slow growth, 4 years after the first pulmonary resection; therefore, we followed up as an outpatient without treatment.

Thymoma and Thymic Carcinoma: Surgical Resection and Multidisciplinary Treatment

Thymoma and thymic carcinoma are the most common tumors of the anterior mediastinum and a relatively rare type of thoracic cancer. The prerequisite for surgery is clinical staging and operative evaluation, both of which are based on medical imaging. The best strategy for treating a thymic epithelial tumor is surgical resection of the organ and surrounding tissue. Thymectomy modalities vary, including open surgery and minimally invasive surgery, and surgeons have used various innovations to better meet the needs of the procedure; therefore, it is critical to select the appropriate procedure based on the patient's characteristics. Evaluation of resectability is the first step of surgical resection for thymic tumors without distant metastasis. The decision regarding unresectability should be made carefully. During subsequent chemotherapy or chemoradiotherapy, reevaluation of whether an area is resectable or not remains essential. Despite numerous technological advances in the surgical treatment of thymic tumors, several contentious issues remain, including the selection of surgical approaches for difficult cases, the selection of video-assisted thoracoscopic approaches, the evaluation of resectability, minimally invasive surgery for locally advanced thymic tumors, lymphadenectomy in thymic tumors, neoadjuvant therapy for thymic tumors, debulking surgery, and salvage surgery. In solving these problems, the surgeon's judgment, surgical experience, and surgical skills are especially important.

Open redo thymectomy for a large recurrent thymoma in a patient with myasthenia gravis: a case report

Thoracoscopic and robotic approaches are becoming increasingly popular for thymoma surgery. Yet open thymectomy must still be mastered today, as it may be the only viable option in challenging cases. In this study, we report a case of an extended local recurrence of myasthenia gravis associated thymoma and a history of previous sternotomy. The mediastinal mass infiltrated the left upper lobe of the lung, the pericardium, and presumably the aortic arch. Although the standard for thymoma resection at our institution is the robotic approach, we performed primary open redo thymectomy in standby of cardiopulmonary bypass in this case. Intraoperatively, bleeding from the aortic arch occurred, which was promptly controlled due to the open approach and due to immediate availability of cardiopulmonary bypass. The patient was transferred to the normal ward on the first postoperative day, was treated according to fast-track principles and recovered well. The pathology revealed a WHO B2:B1 thymoma with negative resection margins. Thymectomy is recommended as the principal treatment for thymoma and is also advised in the case of recurrence. However, there is no evidence regarding the optimal surgical approach. Our case indicates that in the era of minimally invasive thymectomy, the decision to conduct open surgery is wise when the risk of serious bleeding is anticipated or adherence to oncologic principles is challenged by tumor size or growth pattern.

Outcomes of extended surgical resections for locally advanced thymic malignancies: a narrative review

BACKGROUND AND OBJECTIVE

Thymic malignancies represent the most common anterior mediastinal neoplasms, as well as rare and challenging tumors. Surgery is the cornerstone in the treatment of thymic malignancies, although a multidisciplinary approach is mandatory, for both, locally advanced or metastatic disease. In our narrative review, we explored the recent literature to investigate clinical and radiological assessment, multimodality approach and outcomes of locally advanced thymic tumors. More than one-third of patients affected by an anterior mediastinal mass are asymptomatic at diagnosis. In case of locally advanced thymoma, symptoms are related to compression or invasion of adjacent structures, such as the superior vena cava (SVC), innominate veins and pericardium. Paraneoplastic syndromes, such as myasthenia gravis (MG), are related to release of antibodies, hormones and cytokines.

METHODS

Diagnostic methods must be chosen accurately to avoid unnecessary surgical resections, to define the best strategy of care, and to plan the surgical strategy. Therefore, each case must be evaluated in a multidisciplinary context, where surgery plays an essential role.

KEY CONTENT AND FINDINGS

In this narrative review, we describe indications and surgical techniques for the treatment of locally advanced thymoma; focusing on oncological outcomes after different approaches.

CONCLUSIONS

In conclusion, aggressive surgery is always indicated, when possible, and when a complete resection can be planned, yet, the multidisciplinary approach is mandatory, in case of both locally or metastatic advanced disease.

Thymic tumours and their special features

Thymic tumours are rare thoracic malignancies, that may be aggressive and difficult to treat. The pillars of the management include pathological review, consideration of differential diagnoses, staging and multidisciplinary discussion. Assessment of resectability is key to drive the treatment sequencing. Association with autoimmune diseases, especially myasthenia gravis, is observed, which impacts the oncological management. Networks are being built at the national and international levels. This article provides an overview of the most recent findings in the diagnosis, staging, histology, and management strategies of thymic tumours.

Thymic tumours are rare and heterogeneous tumours. Management is based on multidisciplinary discussion and networking.https://bit.ly/3kYAZ7u

Long-term survival in thymic carcinoma with postoperative pleural dissemination

BACKGROUND

We report a patient with thymic squamous cell carcinoma who underwent multiple rounds of surgical resection and definitive radiotherapy for both primary tumor and postoperative recurrence. However, the patient remains well and healthy 18 years after initial diagnosis. Since long-term survival after postoperative recurrence of thymic carcinoma is extremely rare, we also present her immunohistochemical staining results, which suggested indolent disease.

CASE PRESENTATION

A 42-year-old woman with thymic squamous cell carcinoma underwent en bloc resection of the tumor and thymus gland. Pleural dissemination was noted in the right thoracic cavity 3, 10, and 16 years postoperatively. Where possible, the nodules were resected surgically: during the postoperative 3rd and 16th years. Definitive radiotherapy was administered for all nodules that could not be excised during the postoperative 3rd and 10th years. Disease-free survival is 25 months.

CONCLUSIONS

Local control of pleural dissemination may be beneficial in the treatment of postoperative recurrence of thymic carcinoma in limited cases of indolent disease.

Potential Prognostic Value of Preoperative Leukocyte Count, Lactate Dehydrogenase and C-Reactive Protein in Thymic Epithelial Tumors

Thymic epithelial tumors are the most common mediastinal tumors. Surgery is the mainstay of treatment and complete resection provides the best survival rate. However, advanced tumors often require multimodality treatment and thus we analyzed the prognostic potential of routine circulating biomarkers that might help to risk-stratify patients beyond tumor stage and histology. Preoperative values for white blood cell count (WBC), C-reactive protein (CRP) and lactate dehydrogenase (LDH) were analyzed in 220 thymic epithelial tumor patients operated between 1999 and 2018. Increased CRP levels (>1 mg/dl) were significantly more often measured in thymic carcinoma and neuroendocrine tumors when compared to thymoma. LDH serum activity was higher in thymic neuroendocrine tumors when compared to thymoma or thymic carcinoma. The median disease specific survival was significantly longer in thymoma cases than in thymic carcinoma and neuroendocrine tumors. Increased preoperative LDH level (>240 U/L) associated with shorter survival in thymus carcinoma (HR 4.76, p = 0.0299). In summary, higher CRP associated with carcinoma and neuroendocrine tumors, while LDH increased primarily in neuroendocrine tumors suggesting that biomarker analysis should be performed in a histology specific manner. Importantly, preoperative serum LDH might be a prognosticator in thymic carcinoma and may help to risk stratify surgically treated patients in multimodal treatment regimens.

Which Is the Best Treatment in Recurrent Thymoma? A Systematic Review and Meta-Analysis

BACKGROUND

Optimal recurrent thymoma management remains arguable because of limited patient numbers, and relatively late and variable recurrence patterns. Given the absence of high-quality evidence and relatively small study cohorts, we performed a quantitative meta-analysis to determine the outcome of surgical and non-surgical approaches assessing the five-year overall survival (5y overall survival (OS)) in patients with recurrent thymoma.

METHODS

We performed a comprehensive literature search and analysis according to PRISMA guidelines of studies published from 1 January 1980 until 18 June 2020 from PubMed/MEDLINE, EMBASE, and Scopus. We included studies with the cohorts' superior to 30 patients describing recurrent thymoma treatment, comparing surgical and non-surgical approaches reporting survival data.

RESULTS

Literature search revealed 3017 articles. Nine studies met all inclusion criteria and were selected for the meta-analysis. The recurrences were local/regional in 73-98% of cases and multiple in 49-72%. After treatment, 5y OS ranged from 48-77% and 10y OS from 37-51%. The quantitative meta-analysis showed a better outcome comparing surgical vs other treatments. Two studies showed statistically significant risk differences in the 5y OS favoring complete resection. After pooling results of seven studies using the random model, the combined 5y OS risk difference was 0.39, with lower and upper limits of 0.16 and 0.62, respectively (p = 0.001), and a moderate heterogeneity among studies (p = 0.098, I2 = 43.9%). Definitive conclusions could not be drawn regarding the prognostic impact of myasthenia gravis, histology, and patterns of relapse reported in literature.

CONCLUSIONS

Surgical treatment after thymoma recurrence is associated with a significant better 5y OS; therefore, surgical resection should be preferred in all technically feasible cases.

Surgical treatment strategies for invasive thymoma

A thymoma is a common anterior thymus mediastinal tumor composed of atypical epithelial tumor cells, though the morbidity rate is lower as compared to other types of thoracic malignancy such as lung cancer and lung metastasis from another primary cancer. As a result, clinical data regarding thymomas have not been well discussed as compared to those of other carcinomas. Also, because of the low morbidity rate and insufficient clinical experience, oncological characteristics and clinical treatment options are poorly understood. Surgical complete resection is the most reliable option for clinical treatment of a thymoma. This tumor can easily develop adjacent to several different structures and nearby organs, such as the pericardium, lungs, and great vessels, which are easily invaded when the size is large, and a combined resection is then needed. When en bloc resection is considered to be difficult based on evaluation with preoperative modalities, induction chemotherapy followed by surgery is recommended. Moreover, when pleural dissemination is revealed during pre- or peri-operative procedures, volume reduction surgery has been reported by several groups to extend prognosis. On the other hand, in cases with a small-sized tumor, a minimally invasive surgical procedure, such as video-assisted thoracic surgery (VATS) or robotic-assisted thoracic surgery (RATS), is usually selected. Because of the wide variety of cases with thymoma, a deliberate strategy and skillful techniques are necessary for effectual surgical treatment. In this review, we discuss strategies that have been shown to be effective for treating patients with early and advanced thymoma, including those with involved adjacent organs.

Fibrous bands associated with higher Masaoka stage and poor recurrence-free survival in patients with thymoma

Background

Fibrous bands (FBs) are one of the histological features in tumors which can be confirmed by hematoxylin and eosin (H&E)‐stained slides. FBs have been reported to correlate with malignancy in various tumors. This study aimed to investigate whether the presence of FBs is associated with malignancy in thymoma.

Methods

A total of 123 consecutive patients with thymoma who underwent microscopically complete resections from January 2000 to December 2018 were enrolled into this study. H&E‐stained slides of all thymoma patients were re‐examined. Study patients were classified into two groups: with FBs (n = 36) and without FBs (n = 87). Clinicopathological characteristics, overall survival (OS), and recurrence‐free survival (RFS) were compared between the two groups. Furthermore, multivariate analyses were performed to identify whether the presence of FBs was associated with higher Masaoka stage and poor prognosis in patients with thymoma.

Results

The Masaoka stage was found to be higher and recurrence more likely in thymoma patients with FBs than in those without. RFS was significantly poorer in thymoma patients with FBs than in those without, although no significant difference was observed in OS between them. The presence of FBs was significantly associated with higher Masaoka stage in the multivariate analysis using logistic regression. Additionally, the presence of FBs was an independent prognostic factor for poor RFS in multivariate analysis using Cox's proportional hazards model.

Conclusions

The presence of FBs in patients with thymoma was associated with higher Masaoka stage, higher recurrence rate, and poorer RFS.

Key points

Significant findings of the study

Fibrous bands (FBs) are bands of fibrosis dividing tumors into different‐sized irregular islands. The presence of FBs is associated with higher Masaoka stage and poor recurrence‐free survival in patients with thymoma.

What this study adds

The presence of fibrous bands might be associated with the malignant behavior of thymoma. Confirming the presence or absence of FBs may result in personalized medication for patients with thymoma.

Surgical treatment of pleural recurrence of thymoma: is hyperthermic intrathoracic chemotherapy worthwhile?

OBJECTIVES

Recurrence of thymoma is described in 10-30% of cases after surgical resection. Iterative surgery for thymoma pleural relapses (TPRs) is often part of a multimodal treatment. Hyperthermic intrathoracic chemotherapy (HITHOC) following macroscopic radical surgery is an option that combines the effects of mild hyperthermia with those of chemotherapeutic agents. We evaluated the effectiveness of surgery + HITHOC, compared with surgery alone, in the treatment of TPR.

METHODS

We retrospectively collected data of all patients who underwent surgery for TPR in our centre from 2005 to 2017. Relapses were treated by partial pleurectomy with radical intent, followed by HITHOC when not contraindicated. Patients were divided into 2 groups: surgery + HITHOC and surgery alone. We collected demographic and clinical data and analysed postoperative results together with oncological outcomes.

RESULTS

Forty patients (27: surgery + HITHOC, 13: surgery alone), mean age 49.8 (±13.7) years, were included in this study. There were no perioperative deaths. We experienced 33.3% perioperative morbidity in the surgery + HITHOC group compared with 23.1% in the surgery alone group (P = 0.71). The overall survival rate was comparable between the 2 groups (P = 0.139), whereas the local disease-free interval was 88.0 ± 15 months in the surgery + HITHOC group and 57 ± 19.5 months in the surgery alone group (P = 0.046). The analysis of factors affecting the outcomes revealed that radical surgery is related with a better survival rate whereas the local disease-free interval was significantly influenced by HITHOC.

CONCLUSIONS

The safety and feasibility of HITHOC in the treatment of TPR are already known, even if it should be reserved for selected patients. Surgery + HITHOC seems to be associated with a longer local disease-free time compared to surgery alone.

The treatment and survival of patients with postoperative recurrent thymic carcinoma and neuroendocrine carcinoma: a multicenter retrospective study

PURPOSE

There are few data available on the outcomes of postoperative recurrent thymic carcinoma (TC) and thymic neuroendocrine carcinoma (TNEC). The aim of this study is to evaluate the treatment and survival in patients with recurrent TC and TNEC after undergoing surgical resection.

METHODS

A retrospective chart review was performed using our multicenter database to identify patients with a postoperative recurrence of TC and TNEC from 1995 to 2018. The clinicopathological factors were reviewed and the survival outcomes were analyzed.

RESULTS

Sixty patients were identified among 152 patients who underwent resection of TC and TNEC. The median follow-up period from the first recurrence was 14.8 months (range 0-144). The 5-year post-recurrence survival was 23% for the whole cohort. According to a univariable analysis, advanced stage [hazard ratio (HR) 2.81, 95% confidence interval (CI) 1.09-9.54], interval between primary surgery and recurrence (HR 0.97, 95% CI 0.95-0.99), any treatment for recurrence (HR: 0.27, 95% CI 0.13-0.58) and chemotherapy for recurrence (HR: 0.46, 95% CI 0.22-0.95) were significant factors related to post-recurrence survival.

CONCLUSIONS

Chemotherapy rather than surgery appears to be the mainstay treatment for managing patients with postoperative recurrent TC and TNEC and it may also be considered in multidisciplinary management. Further studies with a larger sample size are required to confirm our findings.

Tumor size as a prognostic factor in limited-stage thymic epithelial tumors: A multicenter analysis

OBJECTIVE

The prognostic significance of tumor size in thymic epithelial tumors (TETs) has not been fully evaluated. We aimed to clarify the prognostic value of tumor size in limited-stage and advanced-stage TETs.

METHODS

Clinical records of patients with completely resected TETs were retrospectively collected from 4 tertiary centers between January 2000 and February 2013. Information on the Masaoka-Koga stage was available for 1215 patients (M-K group), and 433 patients were classified according to the eighth edition of the Tumor-Node-Metastasis staging system (TNM group). Limited-stage and advanced-stage TETs were defined according to whether they were confined within the surrounding fatty tissues without invasion. The optimal cutoff value was selected using a maximally selected log-rank statistic.

RESULTS

The median tumor size was 6.0 ± 2.8 cm in the M-K group and 6.5 ± 3.0 cm in the TNM group. In the multivariable analysis, tumor size had a significant effect on both overall survival (P = .003) and recurrence-free survival (P < .001) for limited-stage tumors (M-K stage I or II or TNM stage I), but not for advanced-stage tumors (M-K stage III or IV or TNM stage II-IV; P = .349 for overall survival and P = .439 for recurrence-free survival). The optimal cutoff value for tumor size was >5.5 cm for both overall survival and recurrence-free survival in limited-stage TETs.

CONCLUSIONS

Tumor size is an independent prognostic factor in patients with completely resected limited-stage TETs and a cutoff value >5.5 cm might help clinicians enact proper treatment strategies and surveillance.

[Treatment of Recurrent Thymoma]

胸腺瘤是一种具有恶性潜能的疾病，完整切除后的复发率为10%-30%。复发性胸腺瘤的治疗策略及标准未达成一致，治疗方式包括再次手术治疗、化疗、放疗、靶向治疗及免疫治疗等，至今存在着争议。在这篇综述中，通过回顾既往的文献，总结了复发性胸腺瘤的不同治疗方法的适应证、疗效以及预后，以期给复发性胸腺瘤治疗标准的制定提供一些参考。

Tumor location may affect the clinicopathological features and prognosis of thymomas

BACKGROUND

The current staging systems do not consider the tumor location of thymomas, and its clinical relevance is poorly understood. This study aimed to evaluate the impact of tumor location on the clinicopathological features and prognosis of thymomas.

METHODS

We performed a retrospective review of patients at our institution who underwent an extended thymectomy for a thymoma from 1976 to 2015. The tumor location was classified as either the superior or inferior mediastinum based on the maximum tumor diameter. The clinicopathological characteristics of the thymoma were also evaluated. Kaplan-Meier estimates and Cox proportional hazards models were used to analyze the survival outcomes and risk factors for recurrence.

RESULTS

A total of 194 patients with thymoma were eligible for this study. Compared with the inferior mediastinum group (n = 167), the superior mediastinum group (n = 27) had a higher frequency of myasthenia gravis (MG), advanced Masaoka-Koga staging, disease progression and recurrence (P < 0.05). The Kaplan-Meier analysis demonstrated thymomas in the superior mediastinum had worse survival outcomes that included overall survival, progression-free survival and disease-free survival (P < 0.05). The multivariate analysis showed tumor location was an independent prognostic factor for all the survival outcomes (P < 0.05). Furthermore, the tumor location (P = 0.004) and Masaoka-Koga stage (P < 0.001) were the only two independent risk factors for recurrence in the multivariate analysis.

CONCLUSIONS

The clinicopathological features of thymomas on MG, Masaoka-Koga staging, disease progression, and recurrence were different between locations of superior and inferior mediastinum locations. Thymomas in the superior mediastinum tended to be associated with worse survival and increased recurrence.

Favourable health-related quality of life reported in survivors of thymic malignancies

OBJECTIVES

The management of patients with locally advanced thymic malignancies remains controversial. Differing combinations of surgical resection, chemotherapy and radiation are used in the management of initial and relapsed disease. Treatment-related toxicities and quality of life could inform therapeutic options. This study describes health utility scores (HUS) in survivors with locally advanced thymic malignancies and investigates the impact of multimodality regimens on HUS.

METHODS

In a cross-sectional study (2014-2017), patients with Masaoka Stage II-IVa thymic malignancies completed various self-reported questionnaires, including EuroQol-5-Dimensions with visual analogue scale (VAS), Eastern Cooperative Oncology Group (ECOG) and Edmonton Symptom Assessment Scale tools. Trimodality versus uni- or bimodality regimens and aggressive versus non-aggressive management of recurrent disease were compared using regression analyses.

RESULTS

Of the 72 patients, 43 (60%) were male with a median age of 58 years, 65 (90%) had thymoma while 7 (10%) had thymic carcinomas; and median time since diagnosis was 50.5 months (range: 3-266). Median HUS and VAS did not differ between groups (trimodality n = 24 vs uni- or bimodality n = 48: HUS = 0.77 vs 0.80, P = 0.29; VAS = 80 vs 75, P = 0.79, respectively). The distributions of patient-reported ECOG were also similar (P = 0.86). Edmonton Symptom Assessment Scale scores for every assessed symptom were similar for different modalities of therapy. Median scores on these tools were also similar regardless of recurrence status or management of relapsed disease (aggressive versus non-aggressive).

CONCLUSION

Survivors with Stage II-IVa thymic malignancies report favourable HUS, VAS and self-reported ECOG with minimal symptom burden. These outcomes may be independent of number and type of initial treatment modalities or management of recurrence.

Elevated CRP levels predict poor outcome and tumor recurrence in patients with thymic epithelial tumors: A pro- and retrospective analysis

Objective

Scarce information exists on the pathogenesis of thymic epithelial tumors (TETs), comprising thymomas, thymic carcinomas (TCs) and neuroendocrine tumors. C-reactive protein (CRP) increases during certain malignancies. We aimed to investigate the clinical relevance of CRP in patients with TETs.

Results

Pretreatment CRP serum concentrations were significantly elevated in patients with TETs, particularly TCs and metastatic TETs. After complete tumor resection CRP serum concentrations were decreased (p = 0.135) but increased significantly in case of tumor recurrence (p = 0.001). High pretreatment CRP was associated with significantly worse 5- and 10-year freedom-from recurrence (FFR) (p = 0.010) and was a negative prognostic factor for FFR (HR 3.30; p = 0.015). IL-6 (not IL-1β) serum concentrations were significantly elevated in patients with TETs but we did not detect CRP tissue expression in TETs.

Materials and Methods

Pretreatment CRP serum concentrations were retrospectively analyzed from 128 surgical patients (1990–2015). In a subset of 68 patients longitudinal analysis of CRP was performed. Additionally, immunohistochemical tumor CRP expression and serum concentrations of interleukin (IL)-6 and IL-1β were measured.

Conclusions

Hence, diagnostic measurement of serum CRP might be useful to indicate highly aggressive TETs and to make doctors consider tumor recurrences during oncological follow-up.

Video-assisted thoracic surgery for thymoma: long-term follow-up results and prognostic factors-single-center experience of 150 cases

Background

The use of video-assisted thoracic surgery (VATS) in the treatment of thymoma is becoming more and more common. The aim of this study was to evaluate safety and effectiveness of thoracoscopic treatment of thymoma and, more importantly, to report long-term follow-up results of a large single-center cohort.

Methods

A retrospective review of a prospective database was performed. In total, 150 patients who underwent VATS resection for thymoma at Peking University People's Hospital from April 2001 to November 2014 were retrospectively reviewed.

Results

Average operation time was 140.1±54.2 min, median blood loss was 50 mL (range, 10-700 mL), median post-operative drainage time was 3 days (range, 1-11 days), and median length of post-op stay was 5 days (range, 2-20 days); 134 patients (89.3%) were followed up successfully. Median follow-up was 59.5 months (range, 2-187 months). Five- and 10-year recurrence free survival (RFS) rates of entire group were 96.5% and 94.4%, respectively; 5- and 10-year RFS rates for Masaoka stages I + II were 98.1% and 98.1%, respectively; 5- and 6-year RFS rates for Masaoka stage III were 90% and 60%, respectively. One case of recurrence in five Masaoka stage IV patients was observed, and 4-year RFS was 80%. Multivariable analysis indicated that recurrence tended to occur in Masaoka stages III + IV patients (P=0.037, HR =12.69, 95% CI: 1.17-138.22) and older patients had a lower risk of recurrence (P=0.029, HR =0.87, 95% CI: 0.77-0.99). Myasthenia gravis (MG) presented in 44 patients (29.3%), of which 36 patients (81.8%) were followed up. Nine patients achieved complete remission, and 19 patients had symptom improvement after surgery. Overall response rate of MG was 77.8% (28/36).

Conclusions

VATS was a safe and effective procedure for treatment of thymomas with satisfactory prognosis. MG with thymoma treated by VATS had comparable neurological outcome to that associated with the trans-sternal approach.

Treatment and prognostic factors of patients with thymic epithelial tumors at first recurrence or progression

AIM

The treatment of patients with recurrent or progressive thymic epithelial tumors remains uncertain due to limited data in this rare disease.

MATERIALS & METHODS

A retrospective 10-year monoinstitutional analysis was conducted on 25 patients with first recurrence or disease progression following primary treatment.

RESULTS

Twenty patients had thymoma, five thymic carcinomas. Ten patients (40%) received surgery, four (40%) following chemotherapy; 17 (68%) had chemotherapy, with a combination regimen in 16 of them (94%). Surgery had a significant effect both on overall survival and progression-free survival-2 by univariate analysis (p = 0.04), combination chemotherapy only on progression-free survival-2 (p = 0.03).

CONCLUSION

Combination chemotherapy and surgery at first recurrence/progression of thymic epithelial tumors were associated with improved survival.

DISCUSSION

Although several limitations may have affected this retrospective study on a relatively small number of patients with this rare entity of recurrent thymic malignancies, we suggest the use of combination chemotherapy and surgery at their first recurrence may have contributed to the high overall and progression-free survival observed with adequate follow-up and deserve further investigations in broader retrospective and comparative studies.

Intra-pericardial recurrent thymoma presenting with compression of the pulmonary trunk

A patient who had a second recurrent intra-pericardial thymoma is presented. The tumor was expanding in the pericardial space and compressed the pulmonary trunk. The obstruction of the pulmonary trunk could have resulted in a fatal outcome. Surgical management was required, and complete surgical resection and mediastinal adjuvant radiation therapy were effective in this patient’s management.

Long-term outcomes of 307 patients after complete thymoma resection

Background

Thymoma is an uncommon tumor without a widely accepted standard care to date. We aimed to investigate the clinicopathologic variables of patients with thymoma and identify possible predictors of survival and recurrence after initial resection.

Methods

We retrospectively selected 307 patients with thymoma who underwent complete resection at the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (Beijing, China) between January 2003 and December 2014. The associations of patients’ clinical characteristics with prognosis were estimated using Cox regression and Kaplan–Meier survival analyses.

Results

During follow-up (median, 86 months; range, 24–160 months), the 5- and 10-year disease-free survival (DFS) rates were 84.0% and 73.0%, respectively, and the 5- and 10-year overall survival (OS) rates were 91.0% and 74.0%, respectively. Masaoka stage (P < 0.001), World Health Organization (WHO) histological classification (P < 0.001), and postoperative radiotherapy after initial resection (P = 0.006) were associated with recurrence (52/307, 16.9%). Multivariate analysis revealed that, after initial resection, WHO histological classification and Masaoka stage were independent predictors of DFS and OS. The pleura (25/52, 48.0%) were the most common site of recurrence, and locoregional recurrence (41/52, 79.0%) was the most common recurrence pattern. The recurrence pattern was an independent predictor of post-recurrence survival. Patients with recurrent thymoma who underwent repeated resection had increased post-recurrence survival rates compared with those who underwent therapies other than surgery (P = 0.017).

Conclusions

Masaoka stage and WHO histological classification were independent prognostic factors of thymoma after initial complete resection. The recurrence pattern was an independent predictor of post-recurrence survival. Locoregional recurrence and repeated resection of the recurrent tumor were associated with favorable prognosis.

The clinical features, diagnosis and management of recurrent thymoma

Thymoma is a disease with malignant potential, which has a recurrence rate after complete resection ranging from 5 to 50 %. Multiple studies on the risk factors, treatment or prognosis have been reported. Many of them are controversial, however. In this review, we summarized some accepted risk factors, means of diagnosis and different treatments of recurrent thymoma. The risk factors of recurrent thymoma haven’t been well-studied, and its management remains controversial. We reviewed the literatures and found some key points which should be noticed during the surgery of initial thymoma. Although reoperation should be taken into account preferentially, multimodal treatments are also available. The prognosis are also been discussed.

The role of adjuvant chemotherapy following resection of early stage thymoma

BACKGROUND

There is a paucity of data regarding adjuvant chemotherapy for resected early stage thymoma. This systematic review was designed to investigate the effect of adjuvant chemotherapy on outcomes in patients with early stage thymomas.

METHODS

PubMed database was queried for studies containing information on adjuvant chemotherapy following surgery in patients with Masaoka stage I or II thymoma.

RESULTS

Eight retrospective observational studies were reviewed. The number of patients with stage I or II thymoma was not clearly reported in several studies. Five studies reported on 890 patients with stage I or II patients, including 140 patients (15.7%) who received adjuvant chemotherapy with or without radiotherapy. No study reported short-term mortality in patients undergoing adjuvant chemotherapy following thymectomy.

CONCLUSIONS

Adjuvant chemotherapy following resection of early thymomas appears to be a safe approach with favorable short-term outcomes. However, long-term outcomes remain unclear. There is no strong evidence to support adjuvant chemotherapy following resection of early-stage thymoma.

Minimally invasive thymectomy: the Mayo Clinic experience

BACKGROUND

The prevalence of minimally invasive thymectomy (MIT) is increasing and may have significant benefit to patients in terms of morbidity and post-operative recovery. Our aim was to review the Mayo Clinic experience of MIT.

METHODS

We reviewed data from all MIT cases collected in a prospectively maintained database from January 1995 to February 2015. Data were collected regarding patient demographics, perioperative management and patient outcomes.

RESULTS

A total of 510 thymectomies were performed in 20 years. Fifty-six patients underwent MIT (45 video-assisted thoracoscopy, 11 robotic-assisted). The median age was 55 years (range, 23-87 years) with male to female ratio of 25:31. Thymoma was the main pathologic diagnosis in 27/56 patients (48%), with 11/27 (41%) associated with myasthenia gravis (MG), and 16/27 (59%) non-MG. Other pathologies included 1/56 (2%) of each teratoma, lymphoma, lymphangioma, carcinoma and thymolipoma. There were 3/56 (5%) atrophic glands, 4/56 (7%) cysts, 6/56 (11%) benign glands and 11/56 (20%) hyperplastic. Mean blood loss (mL) and operative time (min) were significantly lower in the video-assisted thoracoscopic surgery (VATS) group compared to robotic (65±41 vs. 160±205 mL, P=0.04 and 102±39 vs. 178±53 min, P=0.001, respectively). There was no 30-day mortality. Post-operative morbidity occurred in 7/45 (16%) VATS patients (phrenic nerve palsy 7%, pericarditis 4%, atrial fibrillation 2%, pleural effusion 2%) and 1/11 (9%) robotic (urinary retention requiring self-catheterization). Reoperation was required in 1/3 of VATS patients with phrenic nerve palsy. There was no significant difference in length of hospital stay [VATS 1.5 days (range, 1-4 days) and robotic 2 days (range, 1-5 days) VATS; P=0.05]. Mean follow-up was 18.4 months (range, 1-50.4 months) with no tumor recurrences.

CONCLUSIONS

MIT can be performed with low morbidity and mortality. VATS is associated with reduced blood loss, operative times and earlier hospital discharge compared to robotic MIT.

Video assisted thoracic surgery (VATS) for recurrent thymoma

Between 10-30% of patients that undergo a radical operation for thymoma develop a recurrence in a variable range of time. The surgical treatment of thymoma relapses is an established and effective therapeutic approach, particularly for a single intrathoracic recurrence; however, no agreement has been reached on the best surgical approach and the extent of surgical resection, particularly in the most common event of pleural relapses. In the era of minimally invasive approach for most thoracic pathologies, the role of the video assisted thoracic surgery (VATS) approach for thymoma recurrence resection is still unclear and controversial: to date, only few authors have reported in their series a thoracoscopic resection of pleuro-pulmonary relapses, mostly when a single lesion was present. Furthermore, a thoracoscopic approach for mediastinal recurrence has been rarely reported after a previous sternotomy to resect the primary tumor. It is likely that in the future, the role of VATS for thymic recurrence resection will be better defined and extensively studied.

Behind and Beyond the Masaoka Staging: A 25-Year Follow-up Study of Tumor Recurrence in Completely Resected Thymic Epithelial Tumors in a Single Institution

We analyzed prognosticators for recurrence and post-recurrence survival in completely resected thymic epithelial tumors for the past 25 years in a single institution.Between June 1988 and December 2013, 238 patients undergoing intent-to-treat surgery for thymic epithelial tumors were reviewed. Sex, age, myasthenia gravis (MG), tumor histology, Masaoka staging, characteristic of locoregional invasion and recurrence, and the treatment for recurrence were collected. Comparison between groups was conducted using the Student t test and χ test. Survival analysis was performed using the Kaplan-Meier method and log-rank test. The Cox proportional hazards model was used for univariate and multivariate analyses of prognostic factors.One hundred sixteen of 135 patients with completely resected thymoma and 35 of 56 patients with thymic carcinoma remained free of recurrence. In patients with completely resected thymoma, Masaoka staging, MG, tumor invasion into the lung, pericardium, and innominate vein or superior vena cava (SVC) invasion were associated with recurrence-free survival in univariate analysis (P = 0.004, 0.003, 0.001, 0.007, and 0.039, respectively). In multivariate analysis, MG was the positive independent prognosticator (P = 0.039). In patients with completely resected thymic carcinoma, Masaoka staging and innominate vein or SVC invasion were associated with recurrence-free survival in univariate analysis (P = 0.045 and 0.005, respectively), whereas innominate vein or SVC invasion was the negative independent prognosticator (P = 0.012). In patients with recurrent thymoma, those treated with surgery followed by chemotherapy had a significantly better post-recurrence survival than those undergoing chemoradiotherapy (P = 0.029) and those without treatment (P = 0.007). Patients with recurrent thymic carcinoma undergoing surgery followed by chemotherapy had a significantly better post-recurrence survival than those without treatment (P = 0.004), but not significantly better than those undergoing chemoradiotherapy (P = 0.252).In patients with completely resected thymoma, MG was the positive independent prognosticators of recurrence-free survival. Surgery should be attempted for recurrent disease for better post-recurrence survival. In patients with completely resected thymic carcinoma, innominate vein or SVC invasion was the negative independent prognosticator. Surgery for recurrence could be considered since it provided benefit for post-recurrence survival as chemoradiotherapy did.

Surgical management of recurrent thymic epithelial tumors: a retrospective analysis based on the Japanese nationwide database

BACKGROUND

There is no standard treatment for recurrent thymic epithelial tumors. Although the efficacy has not been validated based on the large series studies, surgical resection is sometimes employed for patients with recurrent thymic tumors. The aim of this study is to evaluate the surgical outcomes for recurrent thymic epithelial tumors based on the Japanese nationwide database.

METHODS

From the database of patients whose thymic epithelial tumors were treated surgically from 1991 through 2010, the cohort who developed recurrence after the initial resection was extracted. Clinicopathological factors were reviewed, and the prognostic factors of re-resected cases were examined.

RESULTS

Twenty-eight hundred thirty-five patients who underwent surgical resection of thymic epithelial tumors were registered to the database. Among these patients, 420 (14.8%) experienced recurrence. One hundred sixty-two patients were treated surgically and 243 were treated nonsurgically for recurrent disease. The 5- and 10-year postrecurrence survival rates were 82.7% and 68.2%, respectively, in the surgery group and 43.5% and 25.4%, respectively, in the nonsurgery group (p < 0.001). According to univariate analyses, female sex and the pathological Masaoka I-II stage, nonthymic carcinoma, absence of preoperative treatment and longer recurrent-free interval (RFI) were significantly favorable factors for survival in the surgery group. According to the multivariate analysis, nonthymic carcinoma histology and longer RFI were identified to be independent prognostic factors.

CONCLUSIONS

The surgical outcomes of recurrent thymic epithelial tumors are favorable in selected patients. The role of re-resection may be limited in the setting of thymic carcinoma and/or a short RFI.

Stage-based treatment for thymoma in due consideration of thymectomy: a single-center experience and comparison with the literature

Background

Thymomas represent an uncommon and heterogeneous group of intrathoracic malignancies which require different treatments corresponding to their individual tumor stage. The objective of this study was to review the efficacy of our applied stage-based treatment for thymoma in due consideration of thymectomy.

Methods

This is a single-center, institutional review board-approved retrospective study of 50 consecutive patients with thymoma treated at our division within 10 years.

Results

There were 29 women (58 %) and 21 men (42 %), mean age 58.3 years. Twenty nine (58 %) had clinical symptoms and 14 (28 %) had myasthenia gravis. Forty-five patients (90 %) underwent thymectomy and complete resection was done in 42 cases (93.3 %). Histologic results were 6 subtype A, 5 AB, 8 B1, 12 B2, 12 B3, and 7 C. The Masaoka staging system revealed 20 stage I, 18 stage II, 6 stage III, and 6 stage IV. Two patients had neoadjuvant therapy and 25 received postoperative treatment. Five (11.1 %) had tumor recurrence, treated with re-resection. The 5-year disease-free survival was 91.5 %. Two patients died of tumor progression and three died of other causes (10 %). The 5-year overall survival was 82.3 % and the median survival time was 92.1 months. The 5-year survival rate after thymectomy was 87.2 % and the median survival was 92.1 months.

Conclusions

Complete resection still remains the mainstay in the treatment of non-metastatic thymoma and should be performed whenever feasible. Close multidisciplinary teamwork is mandatory to optimize the neurologic outcome and to prolong postoperative survival.

Is it valuable and safe to perform reoperation for recurrent thymoma?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether it is valuable and safe to perform reoperation for recurrent thymoma. Altogether, more than 500 papers were found using the reported search, of which 15 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. This paper includes 1 level 1a study and 15 level 2b studies. The operative mortality was reported in six studies, ranging from 0 to 13.3%, and the operative morbidity in five studies, ranging from 0 to 32.1%. Most patients suffering from operative mortality (5/5) and morbidity (16/19) had myasthenia gravis. One meta-analysis demonstrated improved rates of long-term overall survival in patients with recurrent thymoma who were treated surgically compared with those treated non-surgically. Ten studies showed better survival after surgical treatment than after non-surgical treatment with the difference being statistically significant in 4 of them. Two studies reported that the prognosis in patients with complete reresection was comparable with that of patients without recurrence. One study found that patients with a thymus-related syndrome improved after re-resection. Another two studies revealed that debulking surgery for recurrent thymoma was associated with poorer survival and worse outcomes than both complete resection and non-surgical therapy. From the papers identified in our search, we can conclude that reoperation can be performed with acceptable morbidity and low mortality in appropriately selected patients with locally and/or regionally recurrent thymoma. Both survival and thymus-related syndromes are improved if the recurrence is surgically resected when compared with other medical treatments. Debulking surgery should be limited to those few selected patients in whom other treatment options are not available. In addition, morbidity and mortality most commonly occur in association with myasthenia gravis, and hence medical control of this should be optimized prior to reoperation.

Patterns and predictors of recurrence after radical resection of thymoma

BACKGROUND

Recurrence of thymomas even after complete resection is common, but the relapse patterns remain controversial. This study aimed to define the patterns and predictors of relapse after complete resection of thymoma.

METHODS

A single-institution retrospective study was performed with 331 patients who underwent radical resection of thymoma between 1991 and 2012.

RESULTS

After a median follow-up of 59 months, the recurrence rate was 6.9% (23/331). Relapse occurred in 23 patients with the pleura (14) and tumor bed (6) as the most common sites of recurrence. According to the definitions of the International Thymic Malignancy Interest Group, 10 (43.5%) patients had local relapse, 15 (65.2%) had regional relapse, 10 (43.5%) had distant relapse. The difference in survival following relapse between lung and regional relapse was statistically significant (P=0.027) but that between lung and distant relapse was not (P=0.808). The recurrence rates correlated with the initial Masaoka stage. Further, recurrence also correlated with World Health Organization (WHO) tumor type. The recurrence-free survival rates in patients with tumor size ⩾8 cm were worse than those of patients with tumor size <8 cm (P=0.007). Tumor size was also correlated with stage (r=0.110). As tumor becomes larger, the stage is more advanced (P=0.023). Multivariate analysis showed that Masaoka stage (P=0.005), tumor size (P=0.033), and WHO histological type (P=0.046) were predictive factors of relapse.

CONCLUSION

Regional recurrence is the most common relapse pattern but local and distant relapse are also common. Advanced Masaoka stage, larger tumor size, and type B3 are risk factors of recurrence. Lung relapse should be considered distant relapse. Further, tumor size was correlated with Masaoka stage and therefore should be considered in the staging system.

Thoracic and duodenopancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1: natural history and function of menin in tumorigenesis

Mutations of the multiple endocrine neoplasia type 1 (MEN1) gene lead to loss of function of its protein product menin. In keeping with its tumor suppressor function in endocrine tissues, the majority of the MEN1-related neuroendocrine tumors (NETs) show loss of heterozygosity (LOH) on chromosome 11q13. In sporadic NETs, MEN1 mutations and LOH are also reported, indicating common pathways in tumor development. Prevalence of thymic NETs (thNETs) and pulmonary carcinoids in MEN1 patients is 2-8%. Pulmonary carcinoids may be underreported and research on natural history is limited, but disease-related mortality is low. thNETs have a high mortality rate. Duodenopancreatic NETs (dpNETs) are multiple, almost universally found at pathology, and associated with precursor lesions. Gastrinomas are usually located in the duodenal submucosa while other dpNETs are predominantly pancreatic. dpNETs are an important determinant of MEN1-related survival, with an estimated 10-year survival of 75%. Survival differs between subtypes and apart from tumor size there are no known prognostic factors. Natural history of nonfunctioning pancreatic NETs needs to be redefined because of increased detection of small tumors. MEN1-related gastrinomas seem to behave similar to their sporadic counterparts, while insulinomas seem to be more aggressive. Investigations into the molecular functions of menin have led to new insights into MEN1-related tumorigenesis. Menin is involved in gene transcription, both as an activator and repressor. It is part of chromatin-modifying protein complexes, indicating involvement of epigenetic pathways in MEN1-related NET development. Future basic and translational research aimed at NETs in large unbiased cohorts will clarify the role of menin in NET tumorigenesis and might lead to new therapeutic options.

Survival and treatments in patients with incompletely resected thymoma

Objectives

the objective of our study was to clarify survival and treatments in patients with incompletely resected thymoma.

Methods

between January 1991 and December 2012, 156 consecutive patients who underwent thymectomy with curative intent at Kyoto University Hospital, were evaluated retrospectively. Overall survival and progression-free survival were analyzed using the Kaplan-Meier method, comparing the complete resection group ( n = 141) with the incomplete resection group ( n = 15). Potentially relevant factors for overall survival and progression-free survival in patients with incompletely resected thymomas were analyzed using Cox proportional-hazard models.

Results

there was a significant difference in progression-free survival ( p = 0.0012) but not in overall survival ( p = 0.638) following thymectomy in the complete and incomplete resection groups. Adjuvant chemotherapy was performed in 6 (40%) patients and adjuvant radiotherapy in 6 (40%) in the incomplete resection group. In univariate analysis, younger age ( p = 0.073) showed a tendency for better overall survival, and adjuvant chemotherapy ( p = 0.071) showed a tendency for better progression-free survival.

Conclusion

our results suggest that patients with incompletely resected thymomas can achieve comparable overall survival to those with completely resected thymomas. Adjuvant chemotherapy for incompletely resected thymomas tends to improve progression-free survival.