Standard Outcome Measures for Thymic Malignancies

Recommendations for Post-Operative RadioTherapy After Complete Resection of Thymoma-a French DELPHI Consensus Initiative

INTRODUCTION

Thymomas are rare intrathoracic malignancies that can relapse after surgery. Whether or not Post-Operative RadioTherapy (PORT) should be delivered after surgery remains a major issue. RADIORYTHMIC is an ongoing, multicenter, randomized phase 3 trial addressing this question in patients with completely R0 resected Masaoka-Koga stage IIb/III thymoma. Experts in the field met to develop recommendations for PORT.

METHODS

A scientific committee from the RYTHMIC network identified key issues regarding the modalities of PORT in completely resected thymoma. A DELPHI method was used to question 24 national experts, with 115 questions regarding the following: (1) imaging techniques, (2) clinical target volume (CTV) and margins, (3) dose constraints to organs at risk, (4) dose and fractionation, and (5) follow-up and records. Consensus was defined when opinions reached more than or equal to 80% agreement.

RESULTS

We established the following recommendations: preoperative contrast-enhanced computed tomography (CT) scan is recommended (94% agreement); optimization of radiation delivery includes either a four-dimensional CT-based planning (82% agreement), a breath-holding inspiration breath-hold-based planning, or daily control CT imaging (81% agreement); imaging fusion based on cardiovascular structures of preoperative and planning CT scan is recommended (82% agreement); right coronary and left anterior descending coronary arteries should be delineated as cardiac substructures (88% agreement); rotational RCMI/volumetric modulated arc therapy is recommended (88% agreement); total dose is 50 Gy (81% agreement) with 1.8 to 2 Gy per fraction (94% agreement); cardiac evaluation and follow-up for patients with history of cardiovascular disease are recommended (88% agreement) with electrocardiogram and evaluation of left ventricular ejection fraction at 5 years and 10 years.

CONCLUSION

This is the first consensus for PORT in thymoma. Implementation will help to harmonize practices.

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.

Perioperative outcomes and survival of modified subxiphoid video-assisted thoracoscopic surgery thymectomy for T2-3 thymic malignancies: A retrospective comparison study

OBJECTIVE

Our previous study demonstrated that modified subxiphoid video-assisted thoracic surgery thymectomy with an auxiliary sternal retractor is feasible for locally invasive thymic malignancies. This study aimed to compare perioperative and oncological outcomes of modified subxiphoid video-assisted thoracoscopic surgery thymectomy versus median sternotomy thymectomy for locally advanced thymic malignancies.

METHODS

In total, 221 patients with T2-3 thymic malignancies who underwent modified subxiphoid video-assisted thoracoscopic surgery thymectomy or median sternotomy thymectomy between 2015 and 2020 were enrolled in our prospectively maintained database. A 1:1 propensity score-matching analysis was performed to balance the bias. Surgical difficulty was evaluated with a modified resection index. Perioperative and oncological results were compared between the modified subxiphoid video-assisted thoracoscopic surgery thymectomy group and the median sternotomy thymectomy group.

RESULTS

There were 72 patients in each group in the final analysis. Our results showed that the modified subxiphoid video-assisted thoracoscopic surgery thymectomy group had a shorter operative duration (98 vs 129 minutes, P < .001), less blood loss (40 vs 100 mL, P < .001), shorter drainage duration (3 vs 5 days, P < .001), shorter length of hospital stay (5 vs 6 days, P < .001), and fewer postoperative complications (5.6% vs 23.6%; P = .005). No significant difference was detected in complete resection (98.6% vs 98.6%, P = 1.000) between the 2 groups. Conversion occurred in 5 of 106 patients (4.7%). Survival analyses indicated similar recurrence-free survival (hazard ratio, 0.94; 95% CI, 0.40-2.20; P = .883) and overall survival (hazard ratio, 0.52; 95% CI, 0.05-5.02; P = .590) between the 2 groups.

CONCLUSIONS

Modified subxiphoid video-assisted thoracoscopic surgery thymectomy was safe and effective for T2-3 thymic malignancies and could be an alternative for selected patients with locally advanced thymic diseases. Further prospective studies are needed to evaluate the long-term survival of those undergoing modified subxiphoid approach thoracoscopic thymectomy.

Effect of complete mesocolic excision (cme) on long-term survival after right colectomy for cancer: multivariate meta-analysis and restricted mean survival time estimation

INTRODUCTION

Debate exists concerning the impact of complete mesocolic excision (CME) on long-term oncological outcomes. The aim of this review was to condense the updated literature and assess the effect of CME on long-term survival after right colectomy for cancer.

METHODS

PubMed, MEDLINE, Scopus, and Web of Science were searched through July 2023. The included studies evaluated the effect of CME on survival. The primary outcome was long-term overall survival. Restricted mean survival time difference (RMSTD), hazard ratio (HR), and 95% confidence intervals (CI) were used as pooled effect size measures. GRADE methodology was used to summarize the certainty of evidence.

RESULTS

Ten studies (3665 patients) were included. Overall, 1443 (39.4%) underwent CME. The RMSTD analysis shows that at 60-month follow-up, stage I-III CME patients lived 2.5 months (95% CI 1.1-4.1) more on average compared with noCME patients. Similarly, stage III patients that underwent CME lived longer compared to noCME patients at 55-month follow-up (6.1 months; 95% CI 3.4-8.5). The time-dependent HRs analysis for CME vs. noCME (stage I-III disease) shows a higher mortality hazard in patients with noCME at 6 months (HR 0.46, 95% CI 0.29-0.71), 12 months (HR 0.57, 95% CI 0.43-0.73), and 24 months (HR 0.73, 95% CI 0.57-0.92) up to 27 months.

CONCLUSIONS

This study suggests that CME is associated with unclear OS benefit in stage I-III disease. Caution is recommended to avoid overestimation of the effect of CME in stage III disease since the marginal benefit of a more extended resection may have been influenced by tumor biology/molecular profile and multimodal adjuvant treatments.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumors Staging Project: Proposal for a Stage Classification for the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors

INTRODUCTION

A TNM-based system for all types of thymic epithelial tumors was introduced in the eighth edition of the TNM classification of thoracic malignancies. The Thymic Domain of the Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer, composed of multispecialty international experts, was charged to develop proposals for the ninth edition. This article outlines the proposed definitions for the T, the N, and the M components and their combination into stage groups.

METHODS

A large central database of 11,347 patients with thymic epithelial tumors was assembled thanks to the contribution of the major thymic organizations worldwide and analyses were carried out for the T, the N, and the M components and the stage groups. Overall survival was the outcome measure for patients with completely and incompletely resected tumors, and recurrence for those with complete resection. When the number of patients was sufficient, analyses were performed separately for thymomas, thymic carcinomas, and neuroendocrine thymic tumors.

RESULTS

Tumor size is included in the T1 category as T1a (≤5cm) and T1b (>5 cm); the mediastinal pleura is dropped as a T descriptor; invasion of the lung or phrenic nerve is reclassified as T2 (instead of T3). No changes are proposed for the N and the M components from the eighth edition. The stage groups remain the same.

CONCLUSIONS

The proposed changes for the ninth edition of the TNM classification set the stage for further progress in the future for these rare tumors.

Clinical characteristics, prognostic factors, and long-term outcomes associated with epithelial malignancies of the thymus: A 20-year single-institution experience

BACKGROUND

Thymic epithelial tumors are rare and include thymomas and thymic carcinomas. There is scarce literature characterizing prognostic factors and long-term outcomes in these tumors.

AIMS

This review aims to describe disease features of thymomas and thymic carcinomas and to report clinical differences among thymoma histological subtypes.

METHODS AND RESULTS

A retrospective chart review was performed at the University of Florida Shands Hospital, a tertiary care academic medical center in Gainesville, Florida, USA. The review included clinical data of adults with thymic epithelial tumors diagnosed between 2001 and 2021. Significant associations among demographics, histology, stage, and outcomes were investigated. Thymoma subgroup analysis was performed using histological subtype and sex. Forty patients with thymoma and seven patients with thymic carcinoma were included in the final analysis. Among those with thymomas, patients with subtype B1, B2, or B3 tumors were younger, had larger tumors, and presented with higher stage disease when compared to those with subtypes A or AB. Tumor recurrence was most common in subtype B2 and B3 tumors (50.0% and 16.7% vs. 0%; p < .01). However, there was no significant difference in overall survival between histologic subtypes. Compared to females, males with thymomas had superior overall survival (103.0 vs. 62.9 months; p = .021) despite presenting with larger tumors (9.8 vs. 5.8 cm; p = .041). Concomitant myasthenia gravis was associated with increased recurrence but not worsened mortality. Compared to thymomas, patients with thymic carcinoma presented with higher-stage disease and had poorer 5-year survival (50.0% vs. 93.1%; p < .01).

CONCLUSION

This study affirmed pathologic stage and resectability as prognostic factors for thymic epithelial tumors. New findings include inferior overall survival in female patients and higher recurrence rates in those with thymomas and concomitant myasthenia gravis.

The Value of Postoperative Radiotherapy in Thymoma Patients with Myasthenia Gravis

INTRODUCTION

Surgery is the first-line treatment for patients with thymoma associated with myasthenia gravis (MG); however, the value of radiotherapy among these patients remains debatable. Herein, we examined the impact of postoperative radiotherapy (PORT) on the efficacy and prognosis of patients with thymoma and MG.

METHODS

This retrospective cohort study included 126 patients with thymoma and MG who were enrolled in the Xiangya Hospital clinical database between 2011 and 2021. Demographic and clinical data were collected including sex, age, histologic subtype, Masaoka-Koga staging, primary tumor, lymph node, metastasis (TNM) staging, and therapeutic modalities. To evaluate short-term MG symptom improvement following PORT, we examined changes in the quantitative myasthenia gravis (QMG) scores within 3 months post-treatment. Minimal manifestation status (MMS) was the main endpoint for assessing long-term improvement in MG symptoms. Overall survival (OS) and disease-free survival (DFS) were primary endpoints to determine the impact of PORT on prognosis.

RESULTS

Effects of PORT on MG symptoms: QMG scores significantly differed between the non-PORT and PORT groups (χ2= 6.300, p = 0.012). The median time to achieve MMS was significantly shorter in the PORT group than that in the non-PORT group (2.0 years vs. 4.4 years; p = 0.031). Multivariate analysis revealed that radiotherapy was associated with a reduced time to achieve MMS (hazard ratio [HR] 1.971, 95% confidence interval [CI]:1.102-3.525, p = 0.022). Effects of PORT on DFS and OS: The 10-year OS rate of the entire cohort was 90.5%, whereas OS rates for the PORT and non-PORT groups were 94.4 and 85.1%, respectively. The 5-year DFS rates for the whole cohort, PORT group, and non-PORT group were 89.7, 95.8, and 81.5%, respectively. PORT was associated with improved DFS (HR 0.139, 95% CI: 0.037-0.533, p = 0.004). In the high-risk histologic subgroup (type B2, B3), patients who received PORT had better OS (p = 0.015) and DFS (p = 0.0053) than those who did not receive PORT. PORT was associated with improved DFS (HR 0.232, 95% CI: 0.069-0.782, p = 0.018) in Masaoka-Koga stages II, III, and IV disease.

CONCLUSIONS

Overall, our findings indicate that PORT positively impacts thymoma patients with MG, particularly those with a higher histologic subtype and Masaoka-Koga staging.

Postoperative clinical outcomes of patients with thymic epithelial tumors after over-3-year follow-up at a single-center

BACKGROUND

To evaluate postoperative clinical outcomes and analyze influencing factors for patients with thymic epithelial tumors over 3 years after operation.

METHODS

Patients with thymic epithelial tumors (TETs) who underwent surgical treatment in the Department of Thoracic Surgery at Beijing Hospital from January 2011 to May 2019 were retrospectively enrolled in the study. Basic patient information, clinical, pathological, and perioperative data were collected. Patients were followed up by telephone interviews and outpatient records. Statistical analyses were performed using SPSS version 26.0.

RESULTS

A total of 242 patients (129 men, 113 women) with TETs were included in this study, of which 150 patients (62.0%) were combined with myasthenia gravis (MG) and 92 patients (38.0%) were not. 216 patients were successfully followed up and their complete information was available. The median follow-up period was 70.5 months (range, 2-137 months). The 3-year overall survival (OS) rate of the whole group was 93.9%, and the 5-year OS rate was 91.1%. The 3-year relapse-free survival (RFS) rate of the whole group was 92.2%, and the 5-year relapse-free survival rate was 89.8%. Multivariable COX regression analysis indicated that recurrence of thymoma was an independent risk factor for OS. Younger age, Masaoka-Koga stage III + IV, and TNM stage III + IV were independent risk factors for RFS. Multivariable COX regression analysis indicated that Masaoka-Koga staging III + IV, WHO type B + C were independent risk factors for postoperative improvement of MG. For patients with MG, the postoperative complete stable remission (CSR) rate was 30.5%. And the result of multivariable COX regression analysis showed that thymoma patients with MG with Osserman staging IIA + IIB + III + IV were not prone to achieving CSR. Compared with patients without MG, MG was more likely to develop in patients with WHO classification type B, and patients with myasthenia gravis were younger, with longer operative duration, and more likely to develop perioperative complications.

CONCLUSIONS

The 5-year overall survival rate of patients with TETs was 91.1% in this study. Younger age and advanced stage were independent risk factors for RFS of patients with TETs, and recurrence of thymoma were independent risk factors for OS. In patients with MG, WHO classification type B and advanced stage were independent predictors of poor outcomes of MG treatment after thymectomy.

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

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.

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.

The Early Perioperative Outcomes of Subxiphoid Approach Versus Lateral Intercostal Approach Thoracoscopic Thymectomy for Thymic Tumors: A Meta-Analysis

Objectives: To systematically evaluate the early perioperative outcomes regarding the safety and efficacy of subxiphoid thoracoscopic thymectomy (STT) versus lateral intercostal thoracoscopic thymectomy (LITT) for patients with thymic tumors. Methods: A thorough literature search of the following online databases was performed: Web of Science, PubMed, Embase, Cochrane Library, Google Scholar, and ClinicalTrials.gov. Original research articles published before December 30, 2020, that compared STT with LITT were included. Meta-analysis was performed for early perioperative outcomes, including blood loss, pain score, duration of hospital stay, operative time, chest tube drainage time, and incidence of postoperative complications. Results: Six studies that included 604 patients were finally selected for our analysis, with 296 cases of STT and 308 cases of LITT. Our results showed that compared with LITT, STT was associated with less blood loss (standardized mean difference = -0.81, 95% confidence interval [CI] = -1.49 to -0.14, P = .02), a lower pain score (weighted mean difference [WMD] = -2.55, 95% CI = -3.52 to -1.59; P < .00001), and a shorter hospital stay (WMD = -1.37, 95% CI = -2.37 to -0.36; P = .008), whereas there were no significant differences with regard to the operative time (WMD = -10.04, 95% CI = -22.29 to 2.21, P = .11), chest tube drainage time (WMD = -0.58, 95% CI = -1.17 to 0.02, P = .06), and the incidence of postoperative complications (odds ratio = 0.75, 95% CI = 0.39 to 1.44, P = .38). Conclusions: The current analysis suggests that STT is superior to LITT with respect to the early perioperative outcomes, and STT is a safe and effective surgical method for patients with thymic tumors.

Surgical outcomes of 215 patients with thymic epithelial tumors: A single-center experience

Objectives

To evaluate the oncological prognosis and neurological outcomes for patients with thymic epithelial tumors (TETs) after thymectomy.

Methods

Consecutive patients with TETs who underwent thymectomy at Beijing Hospital from January 2011 to December 2018 were retrospectively enrolled into the study. Clinical, pathological, and perioperative data was collected. Patients were followed‐up by telephone interview and outpatient records. Statistical analyses were performed using SPSS version 19.0.

Results

A total of 215 patients (115 men and 100 women) were included in this study of which 133 patients (61.9%) had TETs associated with myasthenia gravis (MG), and 82 patients (38.1%) had thymic tumors without MG. A total of 194 (90.2%) patients were successfully followed‐up. The median follow‐up period was 42 months. The five‐year overall survival (OS) rate was 88.6%. MG was the first cause of death for patients with MG (6/10). Prognosis in MG patients was similar to those without MG. Multivariate Cox regression analysis demonstrated that TNM stage III + IV was an independent risk factor for OS. Incomplete resection and younger age were risk factors for tumor recurrence. For patients with MG, the cumulative complete stable remission (CSR) rate increased with the postoperative follow‐up period, and the five‐year CSR rate was 44.7%. Univariate Cox analysis indicated that age, preoperative MG duration and preoperative medication might correlate with CSR. Multivariate Cox analysis only indicated older age as a negative factor of achieving CSR.

Conclusions

MG had little influence on OS and tumor recurrence of thymic tumors. The new TNM staging system was an independent prognostic factor. Incomplete resection and younger age were risk factors for tumor recurrence. Older age was a negative factor of achieving CSR for thymoma patients with MG after extended thymectomy.

Key points

Surgical effect and prognostic factors of myasthenia gravis with thymomas

Background

To evaluate the surgical effect and prognostic factors of extended thymectomy for myasthenia gravis (MG) patients with thymomas.

Methods

Patients with MG with thymomas who underwent extended thymectomy at Peking University People's Hospital and Beijing Hospital between January 2010 and December 2018 were retrospectively enrolled. Patients were followed up by telephone or outpatient record review . Statistical analyses were performed using SPSS version 19.0.

Results

A total of 194 patients were included in this study. According to the Osserman classification, there were 56 type I, 52 type IIa, 67 type IIb, 14 type III, and five type IV. Video‐assisted thoracoscopic surgery (VATS) thymectomies were performed in 137 patients, and transthymectomies in 57 patients. The average operation time was 136.6 ± 46.5 minutes, average blood loss was 129.3 ± 287.4 mL, and average postoperative stay was 8.3 ± 7.4 days. A total of 170 patients (87.6%) were successfully followed up. The median follow‐up period was 45 months, and the five‐year overall survival (OS) rate was 81.9%. Cox regression analysis demonstrated that age, Masaoka stage, and recurrence were prognostic factors of OS. Tumor recurrence tended to occur in patients with Masaoka stage III + IV, and age was a protective factor. A total of 20 patients experienced postoperative myasthenic crisis (POMC). Univariate analysis indicated that presence of bulbar symptoms, surgical procedure, and blood loss were risk factors for POMC, but multivariate analysis only indicated the presence of bulbar symptoms as an independent risk factor. A total of 162 patients were evaluated for post intervention MG status. A total of 55 patients achieved complete stable remission; the overall effective rate was 84.5%. Older patients and those with B‐type thymomas had a lower probability of achieving complete stable remission. Efficacy was similar in patients who underwent VATS or the transsternal procedure.

Conclusions

Age, Masaoka stage, and recurrence were prognostic factors of OS. Presence of bulbar symptoms was an independent risk factor for POMC. Age and World Health Organization classification influence the postoperative effect of MG.

Key points

Significant findings of the study

Age, Masaoka stage, and recurrence were prognostic factors of OS for MG with thymomas. The presence of bulbar symptoms was an independent risk factor for POMC. Age and World Health Organization classification may influence the postoperative effect of MG.

What this study adds

Our study had a relatively large sample size of MG patients with thymomas only. We emphasize the analysis of the postoperative effect of MG and overall survival for these patients, which is a complement to previous studies.

Clinical prognostic scores for patients with thymic epithelial tumors

Several inflammation-based prognostic scores emerged in various types of cancer to predict clinical outcomes. So far, no accurate pre-treatment scoring systems exist for patients with thymic epithelial tumors (TETs), comprising thymomas and thymic carcinomas (TCs). Therefore, we sought to test the prognostic value of different clinical composite scores and their components, identify optimal cut-off values for TETs as well as combine predictive components to new suitable prognostic scores. One hundred eighty-four patients with TETs undergoing surgical tumor resection were analyzed. A significant advantage in Freedom-from-Recurrence and/or Cause-specific survival (CSS) was evident for patients with high Advanced-Lung- Cancer-Inflammation-Index, low CRP-Fibrinogen-Score (CFS), low Glasgow-Prognostic-Score (GPS), low high-sensitivity-modified GPS, low TET-adapted GPS (TET-aGPS) and low Systemic-Immune-Inflammation Index. On multivariable analysis high TET-aGPS (HR = 14.9;p = 0.001), incomplete resection status (HR = 13.5;p = 0.001) and TC (HR = 26.0;p = 0.001) were significant independent prognostic factors for worse CSS. The CFS had the highest coefficient of determination (R² = 0.188) to predict tumor recurrence of all composite scores, comprising CRP (R² = 0.141) and fibrinogen (R² = 0.158), the best single factor predictors. Inflammation-based prognostic scores and selected components are suitable to predict survival and/or tumor recurrence in TET patients undergoing primary surgery. Due to excellent long-term survival and frequent tumor recurrence, cut-off values were tailored to increase prognostic power.

A Recurrence Predictive Model for Thymic Tumors and Its Implication for Postoperative Management: a Chinese Alliance for Research in Thymomas Database Study

OBJECTIVE

Our aim was to investigate appropriate postoperative management based on the risk of disease recurrence in thymic epithelial tumors after complete resection.

METHODS

The Chinese Alliance for Research in Thymomas retrospective database was reviewed. Patients having stage I to IIIa tumors without pretreatment and with complete resection were included. Clinicopathologic variables with statistical significance in the multivariate Cox regression were incorporated into a nomogram for building a recurrence predictive model.

RESULTS

A total of 907 cases, including 802 thymomas, 88 thymic carcinomas, and 17 neuroendocrine tumors, were retrieved between 1994 and 2012. With a median follow-up of 52 months, the 10-year overall survival rate was 89.5%. Distant and/or locoregional recurrences were noted in 53 patients (5.8%). The nomogram model revealed histologic type and T stage as independent predictive factors for recurrence, with a bootstrap-corrected C-index of 0.86. On the basis of this model, patients with T1 thymomas or T2 or T3 type A, AB, or B1 thymomas had a significantly lower incidence of recurrence (low-risk group) than those with T2 or T3 type B2 or B3 thymomas and all thymic carcinomas and neuroendocrine tumors (high-risk group) (2.7% versus 20.1% [p < 0.001]). In the high-risk group, more than half of the recurrences (55.2% [16 of 29]) were seen within the first 3 postoperative years, whereas all recurrences but one were recorded within 6 years after surgery. Recurrence occurred quite evenly over 10 postoperative years in the low-risk group.

CONCLUSIONS

A 6-year active surveillance should be considered in high-risk patients regardless of adjuvant therapy. For low-risk patients, annual follow-up may be sufficient. Studies examining postoperative adjuvant therapies would be plausible in high-risk patients.

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.

Best practices for the management of thymic epithelial tumors: A position paper by the Italian collaborative group for ThYmic MalignanciEs (TYME)

Thymic epithelial tumors (TETs) are a heterogenous group of rare tumors, with a complex histopatological classification. Furthermore, the recent introduction of the first TNM staging system, that is scheduled to replace the Masaoka-Koga system, may create further difficulties in TET management, that remains challenging. Several guidelines for treatment of TETs are available and provide recommendations based mainly on non randomized trials and retrospective or limited series. Often the lack of evidence leads to formulation of indications based on expert opinions. As for other rare cancers it is crucial to create networks to coordinate the work among centres involved in treatment of these diseases in order to offer the best diagnostic and therapeutic tools. For this purpose, in 2014 a network named TYME (ThYmic MalignanciEs), was founded in Italy with the aim of improving care and research in TETs. In September 2017 a panel of multidisciplinary experts from TYME network and from other Italian centres strongly involved in TET diagnosis and treatment convened a first Italian Expert meeting together with representatives of association for patients affected by rare thoracic cancers Tu.To.R, to explore how these tumors are managed in the different centres of Italy compared to ESMO guidelines. In this paper we summarize the issues discussed during that meeting and we propose recommandations based on Masaoka Koga and the new TNM staging system.

Elective Nodal Irradiation as Adjuvant Radiotherapy for Advanced Thymomas and Thymic Carcinomas

INTRODUCTION

We evaluated the clinical outcome of patients with stage III to IV thymomas (Ts) or stage II to IV thymic carcinomas (TCs) treated with complete thymectomy and local radiation therapy (LRT, targeting the tumor bed and anterior mediastinal areas only) or elective nodal irradiation (ENI, targeting the entire mediastinal and supraclavicular regions).

MATERIALS AND METHODS

Data from 47 patients diagnosed with Ts or TCs and treated with surgery and adjuvant RT from May 2002 to May 2015 were analyzed. The standard RT dose was 50.4 Gy in 28 fractions; patients with a positive resection margin received a further 4 to 10 Gy. Survival outcomes determined at 5 years included local recurrence-free survival, regional recurrence-free survival, distant metastasis-free survival, and overall survival.

RESULTS

Five-year local recurrence-free survival was similar in both groups (LRT, 94.7% vs. ENI, 96.2%; P = .849). Significant differences were seen in 5-year regional recurrence-free survival (LRT, 55.1% vs. ENI, 83.7%; P = .006); however, tumor size was seen to be a significant factor (< 7 cm, 95.2% vs. ≥ 7 cm, 48.9%; P < .001), and the LRT group contained a greater proportion of patients with ≥ 7-cm tumors (70% vs. 33%). Multivariate analysis demonstrated that tumor size was the only significant prognostic factor (P < .001). No differences in 5-year overall survival were seen (LRT, 91.7% vs. ENI, 100%; P = .106).

CONCLUSION

ENI may not be indicated in all cases, as additional benefit in reducing recurrence or improving survival was not predominant. LRT seems to be a feasible option with favorable patient outcomes.

Systemic Therapy in Advanced Thymic Epithelial Tumors: Insights from the RYTHMIC Prospective Cohort

INTRODUCTION

Thymic epithelial tumors (TETs) are rare malignancies that may be aggressive and difficult to treat. In the advanced setting, systemic treatments may be delivered as primary therapy before surgery or definitive radiotherapy, as exclusive treatment when no focal treatment is feasible, or in the setting of recurrences. Réseau tumeurs THYMIques et Cancer (RYTHMIC) is the nationwide network for TETs in France. The objective of the study was to describe the modalities and analyze the efficacy of systemic treatments for patients with advanced TETs included in the RYTHMIC prospective database hosted by the French Thoracic Cancer Intergroup.

METHODS

All consecutive patients for whom systemic treatment was discussed at the RYTHMIC multidisciplinary tumor board from 2012 to 2015 and who received at least one cycle of treatment were included. The main end points were objective response and progression-free survival (PFS).

RESULTS

A total of 236 patients were included in this analysis. Of those 236 patients, 91 received primary chemotherapy, leading to response rates of 83% for thymomas and 75% for thymic carcinomas and a median PFS of 23.2 months. A strong predictor of longer PFS was histologic type of thymoma (p < 0.001). Exclusive chemotherapy was delivered to 54 patients. The response rates were 31% for thymomas and 37% for thymic carcinomas. The median PFS was 6.2 months, and it was correlated to response rate (p = 0.001). Systemic therapy for a first, second, third, and fourth recurrence was delivered to 114, 81, 51, and 27 patients, respectively. The response rates ranged between 15% and 39% for thymomas and 4% to 21% for thymic carcinomas. The median PFS times were 7.7, 6.2, 5.9, and 6.5 months, respectively.

CONCLUSION

Patients with advanced thymic malignancies may receive multiple lines of systemic therapy, with an opportunity for clinically relevant PFS rates for which objective response may be a surrogate. Our real-life study provides landmark efficacy data that are needed when designing clinical trials to assess innovative agents.

The expanding role of radiation therapy for thymic malignancies

The role of radiation therapy (RT) in thymic malignancies has long been subject to considerable controversy. The main role for RT is in the setting of adjuvant therapy after surgical tumor resection, especially in advanced or incompletely resected cases. However, recent studies with larger patient numbers and cleaner study populations than previous studies have indicated a potentially clearer than previously assumed benefit after post-operative RT (PORT) even for completely resected patients with earlier stages of thymoma. In marginally resectable patients RT may be used in combination with neoadjuvant chemotherapy to shrink tumors and thereby potentially enable resection. In unresectable patients concurrent or sequential chemotherapy and RT can be employed as the definitive nonsurgical approach. The tendency of thymic tumors to recur in the pleural space highlights the necessity for more effective approaches to identify and treat high risk patients. Experiences in other pleural malignancies may pave the way to novel treatment modalities, for example pleural IMRT. The role of these techniques in thymic malignancies has yet to be determined and is not advisable at the current time outside of a clinical study. As the disease often takes an indolent course with excellent long-term local control (LC) and survival, late toxicities related to radiation of the mediastinum and adjacent organs at risk (OARs) have to be taken into consideration and may jeopardize the benefit patients experience from RT, especially in younger patients with a long-anticipated life expectancy. Radiation techniques, such as intensity modulated RT (IMRT) and proton beam therapy (PBT), have substantially reduced the exposure of OARs to ionizing radiation which is expected to translate into reduced long-term toxicities. Hence, the risk-benefit ratio of RT in early stage thymoma patients may be shifted favorably.

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.

Neuroendocrine tumors of the thymus: the oncologist point of view

Thymic malignancies represent a heterogeneous group of rare thoracic cancers, which are classified according to the World Health Organization (WHO) histopathologic classification that distinguishes thymomas from thymic carcinomas and neuroendocrine tumors; neuroendocrine thymic tumors (NETTs) exhibit the same histological spectrum as in other anatomical locations, although with different frequencies. NETTs represent around 2% of all neuroendocrine tumors, and about 5% of all thymic malignancies. Overall, the management of patients with NETTs tumors requires continuous multidisciplinary expertise at any step of the disease progression. Systemic treatment relies on cytotoxic chemotherapy, as well as on somatostatin analogues and everolimus. Systemic treatment may be delivered in a curative-intent approach, for patients presenting with locally-advanced tumor at the time of diagnosis, with invasion of intra-thoracic neighboring structures. In such cases, chemotherapy has been used in an induction setting, to reduce the tumor burden-possibly allowing subsequent surgery and/or radiotherapy-or as a postoperative treatment if the tumor was resectable upfront, to reduce the risk of recurrence and achieve prolonged disease control. Systemic therapies are also a palliative-intent treatment of unresectable, metastatic, and recurrent NETTs. Chemotherapy may then be an option for aggressive disease, but somatostatin analogues and everolimus are suitable as well. Alternative options are emerging through clinical trials. As no dedicated study has ever been conducted, recommendations for systemic treatment in NETTs have been mostly based on retrospective cohorts of limited numbers patients, especially in the advanced disease setting, and expert opinion based on experience from primary pulmonary, as well as gastro-intestinal neuroendocrine tumors, for which clinical trials have been conducted.

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.

Sclerosing thymoma-like thymic amyloidoma with nephrotic syndrome: a case report

Background

Primary localized amyloidosis presenting as an isolated mediastinal mass is extremely rare, especially in the thymus. Sclerosing thymoma is also an extremely rare anterior mediastinal tumor, pathologically characterized by extensive sclerotic lesions with hyalinization and calcification. Only 14 cases of sclerosing thymoma and five cases of thymic amyloidosis have been reported to date.

Case presentation

A 78-year-old Japanese woman was diagnosed as having sclerosing thymoma (Masaoka stage IVa pericardial dissemination)-like thymic amyloidoma. She was diagnosed as having either lung cancer or mediastinal tumor with pericardial dissemination, and received palliative treatment. Three years later, she was readmitted with a complaint of general malaise. Since minimal change nephrotic syndrome was suspected based on the disease onset and selectivity index of urinary protein, steroid pulse therapy was started. Subsequently, because a marked reduction in tumor size was observed during maintenance treatment with prednisolone, a thoracoscopic needle biopsy was performed for a definitive diagnosis. According to the pathological findings and clinical investigations, a final diagnosis of sclerosing thymoma (Masaoka stage IVa pericardial dissemination)-like thymic amyloidoma was made.

Conclusions

This is a case report of sclerosing thymoma-like thymic amyloidoma. Both sclerosing thymoma and thymic amyloidoma are extremely rare diseases: only 14 cases of sclerosing thymoma and five cases of thymic amyloidosis have been reported to date. In either diagnosis, our case is the first case in which marked reduction in tumor size was observed with steroid therapy. All reported cases of sclerosing thymomas underwent surgical resection, but steroid therapy to sclerosing thymoma has not been reported. It is still unknown whether steroid therapy is effective or not. The hyalinized components of sclerosing thymoma possibly contain amyloid deposits. The marked reduction in tumor size with steroid therapy may result in amyloid deposits. The association between sclerosing thymoma and thymic amyloidoma remains uncertain. Sclerosing thymoma should be stained with Congo red.

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.

Value of volume-based early metabolic response in patients with unresectable thymic epithelial tumor

OBJECTIVE

We conducted this study to investigate the value of early metabolic responses assessed by (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in predicting prognosis and monitoring treatment response in patients with unresectable thymic epithelial tumors (TETs).

PATIENTS AND METHODS

Study subjects were selected from the prospective dataset of a phase II clinical trial for cisplatin plus Cremorphor EL-free paclitaxel. A total of thirty patients with unresectable TETs who underwent baseline and early post treatment scan after two cycles of chemotherapy were enrolled (22 Male; mean age 55.0±15.0years). Metabolic parameters including metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the tumor lesions were measured.

RESULTS

Multivariate analysis using Cox proportional hazards regression model showed that percent decrease of MTV (HR=0.995 by 1% decrease, P=0.037) and TLG (HR=0.996 by 1% decrease, P=0.044) were significant predictors of progression-free survival (PFS). Receiver operating characteristic curve identified an 88.0% decrease in MTV and a 92.0% decrease in TLG as the optimal cut-off value for disease progression. Responders with ≥88% of ΔMTV and ≥92% of Δ TLG had significantly longer PFS than non-responders (P=0.012, 0.026, respectively).

CONCLUSION

The percent decrease in MTV and TLG of tumor lesions measured by early post treatment FDG PET/CT significantly associated with disease progression in this study. Early metabolic response based on these volumetric parameters has the potential to monitor treatment response and predict prognosis in patients with unresectable TETs.

Patterns of metastasis and recurrence in thymic epithelial tumours: longitudinal imaging review in correlation with histological subtypes

AIM

To determine the patterns of metastasis and recurrence in thymic epithelial tumours based on longitudinal imaging studies, and to correlate the patterns with World Health Organization (WHO) histological classifications.

MATERIALS AND METHODS

Seventy-seven patients with histopathologically confirmed thymomas (n=62) and thymic carcinomas (n=15) who were followed with cross-sectional follow-up imaging after surgery were retrospectively studied. All cross-sectional imaging studies during the disease course were reviewed to identify metastasis or recurrence. The sites of involvement and the time of involvement measured from surgery were recorded.

RESULTS

Metastasis or recurrence was noted in 24 (31%) of the 77 patients. Patients with metastasis or recurrence were significantly younger than those without (median age: 46 versus 60, respectively; p=0.0005), and more commonly had thymic carcinomas than thymomas (p=0.002). The most common site of involvement was the pleura (17/24), followed by the lung (9/24), and thoracic nodes (9/24). Abdominopelvic involvement was noted in 12 patients, most frequently in the liver (n=8). Lung metastasis was more common in thymic carcinomas than thymomas (p=0.0005). Time from surgery to the development of metastasis or recurrence was shortest in thymic carcinoma, followed by high-risk thymomas, and was longest in low-risk thymoma (median time in months: 25.1, 68.8, and not reached, respectively; p=0.0015).

CONCLUSIONS

The patterns of metastasis and recurrence of thymic epithelial tumours differ significantly across histological subgroups, with thymic carcinomas more commonly having metastasis with shorter length of time after surgery. The knowledge of different patterns of tumour spread may contribute to further understanding of the biological and clinical behaviours of these tumours.

Thymoma and thymic carcinomas

Thymomas (Ts) and thymic carcinomas (TCs) are rare tumours of the mediastinum with an incidence rate of 1.7/million per year in Europe. Histological classification is based on rate of non-malignant-appearing thymic epithelial cells and proportions of lymphocytes (A, AB, B1, B2, B3, and C), while staging system concerns localisation of the involved areas. Surgery is the mainstay of treatment with a 10-year survival of 80%, 78%, 75%, and 42% for stages I, II, III and IV, respectively, with an R0 resection. Radiotherapy has a role in selected cases (stage III patients or R1-2 residual) and platinum-based chemotherapy remains the standard of care for patients with advanced disease. A multimodality approach would be advisable when surgery is not recommended. Since molecular aberrations are poorly understood and few responses are reported, targeted therapies are yet being studied. In this review, we describe key aspects of clinical management for Ts and TCs.

The ITMIG/IASLC Thymic Epithelial Tumors Staging Project: A Proposed Lymph Node Map for Thymic Epithelial Tumors in the Forthcoming 8th Edition of the TNM Classification of Malignant Tumors

Although the presence of nodal disease is prognostic in thymic malignancy, the significance of the extent of nodal disease has yet to be defined. Lymph node dissection has not been routinely performed, and there is currently no node map defined for thymic malignancy. To establish a universal language for reporting as well as characterize the staging of this disease more accurately, an empiric node map is proposed here. This was developed using prior classification systems, series reporting specifics of nodal involvement, anatomical studies of lymphatic drainage, and preexisting node maps of the chest as defined by the International Association for the Study of Lung Cancer and the neck as defined by the American Academy of Otolaryngology-Head and Neck Surgery and the American Society for Head and Neck Surgery. The development of this node map was a joint effort by the International Thymic Malignancy Interest Group and the Thymic Domain of the IASLC Staging and Prognostic Factors Committee. It was reviewed and subsequently approved by the members of ITMIG. This map will be used as an adjunct to define node staging as part of a universal stage classification for thymic malignancy. As more data are gathered using definitions set forth by this node map, a revision may be undertaken in the future.

Thymic carcinoma patients with myasthenia gravis exhibit better prognoses

BACKGROUND

Thymic carcinoma is an aggressive mediastinal neoplasm with a poor prognosis, but the factors that contribute to its prognosis are not completely understood. Myasthenia gravis (MG) can coexist with thymic carcinoma with low incidence, but the effect MG has on thymic carcinoma prognosis is unknown. Here, we investigated the prognostic factors of thymic carcinoma and the influence of MG on patients with this disease.

METHODS

Between January 1996 and December 2012, 49 patients were diagnosed with thymic carcinoma and surgically treated at our institution. Clinical data and survival information were recorded and systematically reviewed. Kaplan-Meier survival curves were generated, and independent prognostic factors were identified by Cox's proportional hazard model.

RESULTS

Complete resection was achieved in 30 patients (61.2 %), and incomplete resection was performed on the other 19 patients (38.8 %). Six of the 49 patients with thymic carcinoma also presented with MG (12.2 %). Interestingly, these 6 patients exhibited much better prognoses when compared to the other 43 patients. Patients with MG also had significantly smaller tumors (P = 0.045), earlier Masaoka stage (P = 0.048), and higher complete resection rates (P = 0.042). However, multivariate analysis demonstrated that complete resection was the only independent predictor for overall survival (OS) (P < 0.001).

CONCLUSIONS

The OS of patients with thymic carcinoma depends on complete resection, but patients with MG also demonstrate improved prognoses. MG patients have higher rates of complete surgical resection, which may account for their better prognoses. Patients with MG have unique features that may aid in the clinical management of these patients.

The impact of thymoma histotype on prognosis in a worldwide database

INTRODUCTION

The rarity of thymomas and lack of multi-institutional studies have hampered therapeutic progress for decades. To overcome this, the members of the International Thymic Malignancy Interest Group created a worldwide retrospective database. This database was analyzed regarding the demographic and geographic distribution of thymomas and the impact of different variables on survival and recurrence.

METHODS

This study analyzed 4221 thymomas diagnosed between 1983 and 2012 with World Health Organization histotype information from the International Thymic Malignancy Interest Group database. Associations to survival and recurrence were studied by univariate and multivariate analyses.

RESULTS

Type B2 thymoma is the most common (28%) and type A the least common (12%) histotypes. They are significantly more frequent in Europe and the United States than Asia. Type A and AB occur at significantly higher age than other thymomas (64 and 57 years, respectively). There are no differences in gender distribution. Stage is lower in type A (90% in stages I-II) and AB than B1 to B3 thymomas (38% of type B3 in stage III). In univariate analysis, recurrence is significantly less frequent among stage I/II tumors, in type A and AB (recurrence rates, 1-2%) than B1 to B3 thymomas (2-7%). Multivariate analysis reveals an impact of age, stage, and resection status on survival and recurrence, whereas for histology there is only a significant impact on recurrence.

CONCLUSION

New findings are (1) geographic differences such as a lower incidence of type A and B2 thymoma in Asia; and (2) impact of stage and histology, the latter partially limited to early stage disease, on recurrence.

Thymic epithelial tumors: prognostic determinants among clinical, histopathologic, and computed tomography findings

BACKGROUND

The Masaoka-Koga staging system has been known as the strongest prognostic factor for both survival and recurrence of thymic epithelial tumor (TET). The purpose of our study was to find prognostic determinants among computed tomography (CT), histopathologic, and clinical features of TET.

METHODS

Two radiologists reviewed retrospectively CT findings of 437 patients (male 242, female 195; mean age, 51 years) with TET. With medical record review, surgico-histopathologic results were subcategorized into Masaoka-Koga stages I through IV and World Health Organization histopathologic classifications A-B1, B2-B3, and carcinoma. Overall survival and progression-free survival were analyzed. Clinical, histopathologic, and CT features were correlated from each other.

RESULTS

In all, 437 tumors were in Masaoka-Koga stage I (n = 147, 33.6%), stage II (n = 121, 27.7%), stage III (n = 76, 17.4%), or stage IV (n = 93, 21.3%); A and B1 (n = 114, 26.1%) and B2 and B3 TET (n = 223, 51.0%); and thymic carcinoma (n = 100, 22.9%). In multivariable analyses, age, Masaoka-Koga stage IV, thymic carcinoma, and CT stages III and IV were significantly correlated with overall survival (p < 0.05), whereas adjuvant treatment, Masaoka-Koga stages III and IV, World Health Organization B2 and B3, thymic carcinoma, R2 resection, CT size, and CT stage IV were significantly associated with progression-free survival (p < 0.05). Computed tomography stages showed moderate association with Masaoka-Koga stages (K = 0.621).

CONCLUSIONS

For TET, CT staging is effective in distinguishing both overall survival and progression-free survival, and patients with Masaoka-Koga stage IV or thymic carcinoma or CT stage IV have the worst prognosis.

The correlation of morphological features of chest computed tomographic scans with clinical characteristics of thymoma

OBJECTIVES

Chest computed tomography (CT) scanning has been widely utilized in thymoma identification and staging as well as in follow-up monitoring for recurrence. However, the relationship between some CT imaging features and pathological types, clinical stage, completeness of resection, or prognosis in thymoma has not been well explored.

METHODS

We retrospectively reviewed preoperative CT imaging for 238 thymoma patients, who had undergone thymectomy from October 2007 to December 2011. All CT parameters were assessed in each case based on clinical and pathological data. Survival analysis was performed by using the Kaplan-Meier and log-rank tests.

RESULTS

Tumour contours (P = 0.008), homogeneity (P = 0.009), degree of enhancement (P = 0.013), fat plane obliteration with adjacent structures (P < 0.001), the presence of mediastinal lymphadenopathy (P = 0.010), irregular infiltration into the lung (P = 0.012) and tumour shape (P = 0.007) were associated with the World Health Organization (WHO) histological classification. Lobulated or irregular tumour contours (P < 0.001), presence of calcifications (P = 0.002), infiltration of surrounding fat (P < 0.001), irregular infiltration into the lung (P < 0.001), irregular infiltration into vascular (P < 0.001), more abutment of vessels (P < 0.001) and pulmonary changes adjacent to the tumour (P < 0.001) were associated with the more advanced Masaoka-Koga clinical stage. Tumour contours (P < 0.001), infiltration of surrounding fat (P = 0.008), irregular infiltration into the lung (P < 0.001) and degree of abutment of vessel circumference (P = 0.001) were associated with completeness of resection. With multivariate analysis, no CT image features could reliably predict on the overall or disease-free survival rate.

CONCLUSIONS

CT imaging does have some features, which are significantly correlated with the WHO classification, the Masaoka-Koga clinical staging and the completeness of resection, although it has no definite role to evaluate preoperatively the survival rate of thymoma patients.