Long-term survival and prognostic factors in thymic epithelial tumours☆

Rising Threat: Long-Term Trends in the Incidence and Mortality of Thymic Epithelial Tumor

INTRODUCTION

An upward trend in the incidence of thymic epithelial tumors (TETs) has been reported over the past few decades, but because of its rarity, little is currently known about its epidemiological trends. This study examined temporal trends in the incidence and mortality of TETs in the US and explored these trends in population subgroups while investigating important factors that influence their prognosis.

METHODS

A retrospective, population-based study was conducted using nationally representative data from the Surveillance, Epidemiology, and End Results program, and 4979 patients diagnosed with TETs from 2000 to 2020 were evaluated. Associated population data were used to determine age-adjusted incidence and mortality, and 5-year TET-specific mortality (SM). Trends were assessed for the entire cohort, as well as for particular subgroups, including thymoma and thymic carcinoma.

RESULTS

From 2000 to 2020, the overall incidence and mortality of TETs were 2.769 and 1.203 per million person-years, respectively. Both the age-adjusted incidence and mortality of TETs increased over the study period, with increases occurring across almost all ethnic groups, histological subtypes, and stages. Multivariate analysis revealed that age, World Health Organization histological type (B1, B2, and B3 thymoma and thymic carcinoma), Masaoka-Koga stage (IIB and III/IV), maximum tumor diameter (5-10 and > 10 cm), surgery, and chemotherapy were independently associated with TET-SM.

CONCLUSIONS

The incidence and mortality of TETs have steadily increased over time, and these trends might be related to the widespread use of computed tomography for lung cancer screening and the increasing number of TETs found incidentally. The study also identified several important factors independently associated with TET-SM, suggesting that early diagnosis and surgical intervention are critical to achieving good prognoses.

Risk factors and prognostic factors of pleural metastases in thymic epithelial tumors: A narrative review

INTRODUCTION

Pleural metastases are common in thymic epithelial tumors (TET), which include pleural recurrence and stage IVa at initial diagnosis. However, the specific risk factors predicting its recurrence (i.e., pleural recurrence group) and prognostic factors for pleural metastasis (i.e., stage IVa) remain unclear. This review aims to identify and discuss the predictors associated with pleural metastases in patients with TET.

METHODS

A systematic literature search was conducted on PubMed, MEDLINE, Embase, and Cochrane for articles published between 1/1/1990 and 3/11/2023. The selection process was independently carried out by three researchers, and the quality of the selected papers was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Out of the 4932 papers reviewed, 22 were included in the final analysis: 15 papers on risk factors of pleural recurrence after primary treatment(i.e., recurrence group) and 7 papers on the prognostic factors of patients with stage IVa at diagnosis(i.e., stage IVa group). Of the 15 former articles, 5 identified pleural invasion and invasion of other tissues as significant risk factors for pleural recurrence. Four of 15 papers identified the Masaoka-Koga stage as a significant risk factor, while two of 15 papers identified the contact length between the tumor contour and the lung as a contributing factor for pleural recurrence. Additionally, two papers suggested that tumor size may be a risk factor for pleural recurrence. Six other papers discussed various factors, including a lobulated tumor contour, WHO histologic classifications B2 and B3, radiotherapy doses of≤50Gy, incomplete resection, and Entire hemithorax radio therapy, as potential risk factors. Furthermore, one paper specifically addressed the decreased risk for pleural dissemination associated with Video-Assisted Thoracoscopic Surgery (VATS) thymectomy. In patients with stage IVa at diagnosis group, three of 7 papers mentioned that resection influenced the prognosis. Two papers discussed the number of nodules in the pleura but arrived at different conclusions. One paper suggested that patients older than 50 years might have worse outcomes, while another analyzed the invasion of structures but did not find any significant results.

CONCLUSION

For pleural recurrence patients, the most commonly discussed risk factor is pleural invasion. Other identified risk factors include the Masaoka-Koga stage, contact length between the tumor contour and the lung, tumor size, lobulated tumor contour, WHO histologic classifications B2 and B3, radiotherapy doses of≤50Gy, and incomplete resection. For patients with stage IVa at diagnosis, non--extrapleural pneumonectomy, incomplete or no resection, and histological subtype may contribute to a poorer prognosis in patients diagnosed with pleural dissemination. The number of disseminated pleural nodules remains controversial and may be correlated with resectability.

The clinical significance of open vs. minimally invasive surgical approaches in the management of thymic epithelial tumors and myasthenia gravis

Though advancements have been made in the pharmacologic treatment of myasthenia gravis (MG), surgical resection is not only an option as a last line of defense for those patients who do not respond to medical therapy but also remains vital for those with thymic epithelial tumors (TET). While prior studies have shown the potential superiority of minimally invasive approaches via robotic- and video-assisted thoracoscopic surgery (RATS/VATS) for thymectomy compared to open surgery, in the setting of malignancies, this outcome delineation is controversial. As RATS/VATS may be associated with less post-operative complications in the treatment of TET, some surgeons argue that the open approach is necessary for complete resection (R0 resection) and to prevent potential seeding of the malignancy. In this review article, we will compare the efficacy and implications of the different surgical approaches and techniques themselves in performing a thymectomy for autoimmune and oncologic pathologies.

Three different surgical methods for large-sized anterior mediastinal tumors in real-world practice

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) for a relatively large mediastinal tumor (5.0-10.0 cm) remains controversial. In addition, few studies have focused on comparing different surgical approaches for large mediastinal tumors. Therefore, this study aimed to compare the short-term outcomes between subxiphoid approach VATS, intercostal approach VATS, and traditional sternotomy for large-sized anterior mediastinal tumors.

METHODS

The study consecutively enrolled 159 patients with large-sized anterior mediastinal tumors (5.0-10.0 cm) who received surgery in our hospital between January 2018 and July 2022 (subxiphoid approach VATS: 52 patients, intercostal approach VATS: 70 patients, traditional sternotomy: 37 patients). We analyzed the clinical baseline data, intraoperative and postoperative outcomes, and postoperative complications of all patients. Then the patients were further divided into two groups according to whether there was a peripheral organ (such as pericardium, lung, or left innominate vein) invasion: group A, invasion of the surrounding organ, and group B, no invasion of the surrounding organ. Intraoperative and postoperative outcomes and postoperative complications were also analyzed in group A and group B, respectively.

RESULTS

In all patients, there were significant differences in blood loss (subxiphoid approach: 33.1 ± 46.0 ml, intercostal approach: 36.9 ± 44.1 ml, sternotomy: 113.0 ± 84.9 ml, P < 0.001) and duration of postoperative oral analgesics (subxiphoid approach: 3.4 ± 0.9 d, intercostal approach: 3.7 ± 1.4 d, sternotomy: 4.5 ± 1.5 d, P = 0.002) among the three methods. In group A, there was a significant difference in blood loss (subxiphoid approach: 50.0 ± 67.7 ml, intercostal approach: 90.0 ± 66.6 ml, sternotomy: 157.9 ± 90.2 ml, P < 0.001) among the three methods. In group B, there were significant differences in the duration of postoperative oral analgesics (subxiphoid approach: 3.2 ± 0.8 d, intercostal approach: 3.7 ± 1.4 d, sternotomy: 4.2 ± 1.1 d, P < 0.05) and blood loss (subxiphoid approach: 22.5 ± 19.3 ml, intercostal approach: 31.9 ± 38.5 ml, sternotomy: 65.6 ± 44.9 ml, P < 0.001) between the three methods. There were no significant differences in the postoperative complications.

CONCLUSIONS

VATS is an effective, minimally invasive, and safe procedure for large-sized anterior mediastinal tumors (5.0-10.0 cm) without an invasion of the surrounding organs, and maybe a feasible and secure method for large-sized anterior mediastinal tumors with an invasion of the surrounding organ (such as the pericardium, lung, or left innominate vein). Subxiphoid approach VATS is a less invasive procedure than intercostal approach VATS and traditional sternotomy due to its reduced blood loss and postoperative pain.

Postoperative radiotherapy for completely resected thymoma and thymic carcinoma: A systematic review and meta-analysis

BACKGROUND

The role of postoperative radiotherapy (PORT) after complete tumor resection in patients with thymoma or thymic carcinoma remains controversial. We performed a meta-analysis to identify groups that would benefit from PORT.

METHODS

Multiple scientific databases were systematically searched for studies comparing overall survival (OS) and/or disease-free survival (DFS) between PORT and surgery alone in patients with completely resected thymomas or thymic carcinomas until April 10, 2024. A random-effects model was used for the statistical analysis.

RESULTS

A total of 31 studies with 10543 patients were included (17 studies involving 4763 patients with thymoma, seven studies involving 1045 patients with thymic carcinoma, and seven studies involving 4735 patients with mixed histological types). Notably, PORT significantly prolonged OS (hazard ratio [HR] = 0.73, 95% confidence interval [CI]: 0.59-0.91) and DFS (HR = 0.62, 95% CI: 0.43-0.89). Similar results were also observed when the multivariate-adjusted HRs were used as the measure of effect (OS: HR = 0.60, 95% CI: 0.43-0.83; DFS: HR = 0.48, 95% CI: 0.29-0.79). In subgroup analyses, PORT was associated with a longer OS and DFS for thymoma (HR = 0.73, 95% CI: 0.56-0.96 and HR = 0.65, 95% CI: 0.46-0.93), thymic carcinoma (HR = 0.72, 95% CI: 0.49-1.07 and HR = 0.38, 95% CI: 0.19-0.77), and stage 3-4 disease (HR = 0.50, 95% CI: 0.34-0.74 and HR = 0.44, 95% CI: 0.27-0.70), but not for stage 2 disease (HR = 0.81, 95% CI: 0.55-1.19 and HR = 0.97, 95% CI: 0.51-1.83).

CONCLUSIONS

PORT is likely to improve OS and DFS in patients with completely resected stage 3-4 thymoma or thymic carcinoma; however, the value of PORT for stage 2 disease requires further evaluation in large-scale studies.

Clinical evaluation of the impact of mediastinal tumour size on the subxiphoid approach video-assisted thoracoscopic surgery

OBJECTIVES

The application of video-assisted thoracoscopic surgery (VATS) for relatively large mediastinal tumours (≥5.0 cm) has been a subject of debate, and few studies have investigated the subxiphoid approach VATS in different tumour size categories. The study aims to compare the efficacy of the subxiphoid approach VATS for achieving curative outcomes based on tumour size categories (<3.0, 3.0-4.9 and 5.0-10.0 cm).

METHODS

A total of 165 patients with anterior mediastinal tumours who underwent surgery at our hospital between January 2018 and July 2022 were consecutively enrolled, categorized according to tumour size-group A (<3.0 cm): 58, group B (3.0-4.9 cm): 70 and group C (5.0-10.0 cm): 37. Clinical baseline data, intraoperative and postoperative outcomes, and postoperative complications were analysed.

RESULTS

The study revealed significant differences in operation time among the 3 groups (group A: 103.4 ± 36.1, group B: 106.4 ± 35.2, group C: 127.4 ± 44.8; P < 0.05) as well as in the volume of drainage (group A: 273.3 ± 162.0, group B: 411.9 ± 342.6, group C: 509.7 ± 543.7; P < 0.05). However, no differences were seen in blood loss, drainage duration, postoperative hospital stay and duration of postoperative oral analgesics. Additionally, the incidence of postoperative complications did not exhibit significant differences across these groups.

CONCLUSIONS

Subxiphoid approach VATS is considered a feasible and safe surgical method for large-sized anterior mediastinal tumours (5.0-10.0 cm) with no invasion to the surrounding tissues and organs.

Prognostic factors and outcome in cats with thymic epithelial tumours: 64 cases (1999-2021)

OBJECTIVES

To describe the clinical presentation, treatment and outcomes of cats diagnosed with thymic epithelial tumours and to determine prognostic factors for survival and recurrence.

MATERIALS AND METHODS

Clinical records of cats diagnosed with a thymic epithelial tumour between 1999 and 2021 at three referral institutions were retrospectively reviewed.

RESULTS

Sixty-four cats were included. Paraneoplastic syndromes were present in nine cats and metastatic disease was seen in two cats, one at diagnosis and one at the time of recurrence. Median tumour diameter was 6 cm (range, 2 to 15) and a cystic appearance was described on imaging in 25 cats. Surgical excision was attempted in 54 cats with a perioperative mortality rate of 11%. Median survival time for cats surviving to hospital discharge was 897 days (range, 21 to 3322). The 1-, 2- and 5-year survival rates for surgically treated thymic epithelial tumour were 86%, 70% and 66%, respectively. Survival was longer for cats with Masaoka-Koga stage I and II tumours compared to stages III and IV (1366 days versus 454 days; P=0.002). Masaoka-Koga stage was the only significant prognostic factor detected on multi-variable analysis, with stage III and IV tumours associated with increased risk of death (hazard ratio: 5.67, 95% confidence interval: 1.29 to 24.91, P=.021). Tumour recurrence occurred in 11 cats at a median of 564 days (range, 93 to 1095); no significant prognostic factors for recurrence were identified.

CLINICAL SIGNIFICANCE

Cats with thymic epithelial tumours had a good long-term prognosis following surgery. Tumour recurrence can occur late in the disease course and ongoing monitoring should therefore be considered. Masaoka-Koga stage may influence survival time and could be used to predict outcome.

Survival nomogram for patients with thymic squamous cell carcinoma, based on the SEER database and an external validation cohort

OBJECTIVE

This study aimed to construct a nomogram to effectively predict the 3 years and 5 years overall survival of patients with thymic squamous cell carcinoma (TSCC).

METHOD

From 2000 to 2019, a total of 355 patients with TSCC were enrolled in our research from the Surveillance, Epidemiology, and End Results (SEER) database and used as the training cohort. 106 patients were included from the Zhejiang Cancer Hospital, for the external validation cohort. A nomogram was constructed based on the risk factors affecting prognosis using a Cox proportional hazards regression model. The discrimination and calibration of the nomogram were evaluated by C-index and curve of calibration. The two cohorts were divided into low-risk and high-risk subgroups based on the median risk score.

RESULTS

Age (p = 0.002), stage (p = 0.003), surgery therapy (p < 0.001), and radiotherapy (p = 0.030) were the independent prognostic factors for overall survival and were incorporated in the prognostic model. The discrimination of the nomogram revealed a good prognostic accuracy and clinical applicability as indicated by C-index values of 0.696 (95% confidence interval [CI] 0.676-0.716) and 0.717 (95% CI 0.640-0.794) for the training cohort and external validation cohort, respectively. In addition, the two cohorts were divided into a high-risk group and a low-risk group according to the median risk score. Significant differences in overall survival were observed between the high-risk and low-risk groups in the training (p < 0.0001) and external validation cohort (p < 0.0001).

CONCLUSION

We developed a nomogram to predict 3- and 5 year survival rate for TSCC. This nomogram provides a convenient and reliable tool for assessing the condition of patients with TSCC and assisting clinicians in making decisions.

Prognostic factors and role of postoperative radiotherapy in surgically resected thymomas

Objective

To investigate the prognostic factors in and role of postoperative radiotherapy (PORT) for surgically resected thymomas.

Methods

A total of 1540 patients with pathologically confirmed thymomas undergoing resection between 2000 and 2018 were identified retrospectively from the SEER (Surveillance, Epidemiology, and End Results) database. Tumors were restaged as local (limited to thymus), regional (invasion to mediastinal fat and other neighboring structures), or distant stage. Disease-specific survival (DSS) and overall survival (OS) were estimated by the Kaplan-Meier method and the log-rank test. Adjusted hazard ratios (HRs) with 95% CIs were calculated by Cox proportional hazards modeling.

Results

Tumor stage and histology were independent predictors of both DSS (regional: HR, 3.711; 95% CI, 2.006-6.864; distant: HR, 7.920; 95% CI, 4.061-15.446; type B2/B3: HR, 1.435; 95% CI, 1.008-2.044) and OS (regional: HR, 1.461; 95% CI, 1.139-1.875; distant: HR, 2.551; 95% CI, 1.855-3.509; type B2/B3: HR, 1.409; 95% CI, 1.153-1.723). For patients with regional stage and type B2/B3 thymomas, PORT was associated with better DSS after thymectomy/thymomectomy (HR, 0.268; 95% CI, 0.099-0.727), but the association was not significant after extended thymectomy (HR, 1.514; 95% CI, 0.516-4.44). Among patients with lymph node metastases, those who received PORT (HR, 0.372; 95% CI, 0.146-0.949), chemotherapy (HR, 0.843; 95% CI, 0.303-2.346), or both (HR, 0.296, 95% CI, 0.071-1.236) had a better OS.

Conclusions

The extent of invasion and tumor histology were independent predictors of worse survival following surgical resection of thymoma. Patients with regional invasion and type B2/B3 thymoma who undergo thymectomy/thymomectomy may benefit from PORT, while patients with nodal metastases may benefit from multimodal therapy, including PORT and chemotherapy.

Unradical Surgery for Locally-Advanced Thymoma: Is it time to evolve Perspectives?

OBJECTIVES

Nearly-one-third of thymomas are locally-advanced at diagnosis. The traditional dogma that surgery is justified in case a complete resection can be achieved has remained unmovable until today. This study aimed to investigate feasibility and oncologic efficacy of incomplete resection for locally-advanced thymomas in a contest of multimodality therapy.

MATERIALS AND METHODS

A retrospective analysis was conducted using data of prospectively maintained thymomas database in a single high-volume centre. Data on 285 consecutive patients undergoing surgery for stage III and IVa thymomas between 1995 and 2019 were reviewed. Patients who underwent incomplete resection with curative-intent (removal of at least 90% of tumour burden) were included. Long-term outcomes and predictors of cancer-specific survival (CSS) and progression-free survival (PFS) were analyzed. Secondary endpoint was to assess adjuvant therapy efficacy.

RESULTS

The study included 79 patients, 60 with microscopic residual tumour (76%, R1) and 19 with macroscopic residual disease (24%, R2). Masaoka-Koga stage was: III in 41 patients (52%) and IVa in 38 (48%). Histology was B2-thymomas (n = 31, 39.2%) followed by B3 (n = 27, 34.2%). Five- and 10-years CSS was 88% and 80%. Seventy patients (90%) underwent adjuvant treatment; they showed CSS comparable to radical resected patients (5-years: 89.1% vs 98.9%, respectively; 10-years: 81.8% vs 92.7%, respectively, p = 0.43). The site of residual disease, Masaoka-Koga stage and WHO histology did not affect prognosis. Stepwise multivariable analysis confirmed adjuvant therapy as a favourable CSS prognostic factor (HR, 0.51; 95% CI, 0.33-0.79, p = 0.003). Stratifying by subgroups, R2-patients who received postoperative chemo(radio)therapy (pCRT) showed a significantly better prognosis than R2-patients treated by consolidation radiotherapy alone (10-years CSS: 60%, p < 0.001).

CONCLUSION

In locally-advanced thymomas, whenever a radical surgery cannot be achieved, incomplete resection has proved to be effective in a contest of multimodality strategy, independently of WHO histology, Masaoka-Koga stage and site of residual disease.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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 role of surgery in advanced thymic tumors: A retrospective cohort study

Background

There is no definitive and detailed treatment guideline for advanced thymic tumors, thus when lymph node and other organ metastasis are present, clinical guidelines recommend chemotherapy-based multidisciplinary treatment. A consensus has been reached that surgery has beneficial effects on partial patients with stage IVA whose metastatic lesions were isolated and resectable, but because of few cases of advanced thymic tumor s and the scarcity of reports, the role of surgery in stage IVB is still unknown. The current study aimed to systematically analyze the role of surgery in advanced thymic tumors based on the Surveillance, Epidemiology, and End Results (SEER) database, with a sufficient number of cases. A secondary aim was to clarify the prognostic value of surgery in advanced thymic tumors.

Method

Data derived from a total of 979 patients with advanced thymoma or advanced thymic carcinoma were collected from the SEER database. Propensity score matching was performed to eliminate confounding factors, and Cox regression analyses were conducted to assess prognoses.

Results

Patients were assigned to four groups based on pathology and whether surgery was performed; thymoma (surgery), thymoma (no surgery), thymic carcinom a (surgery), and thymic carcinoma (no surgery). Disease-specific survival differed significantly in the thymoma (surgery) and thymoma (no surgery) groups, both before and after propensity score matching (both p < 0.001). Similarly, disease-specific survival differed significantly in the thymic carcinoma (surgery) and the thymic carcinoma (no surgery) groups (p < 0.001 before and p = 0.003 after). No total resection, distant metastasis, and thymic carcinoma were all unfavorable prognostic factors.

Conclusions

In the present study surgery had positive effects on advanced thymoma and advanced thymic carcinoma patients who could undergo surgical resection, significantly improving survival times. Total resection of the primary site was the most advantageous form of surgery. The study provides a reference for the clinical treatment of advanced thymic tumors.

Prognostic factors and genetic markers in thymic epithelial tumors: A narrative review

Thymic epithelial tumors (TET) are a group of rare neoplasms of the anterior mediastinum comprising thymomas and thymic carcinomas. The carcinogenesis of TET is mostly unknown. Many studies, mostly retrospective case series, have tried to establish prognostic factors in TET. TET is a very heterogeneous group of tumors with many subtypes for which diagnosis and treatment remains a very challenging task. Despite the disparities among retrospective studies, there are some prognostic factors that are more pertinent such as the completeness of resection, TNM stage and the Masaoka-Koga classification. On the other hand, the identification of different genetic pathways that result in the pathogenesis of TET represents a fascinating field of study that could possibly lead to the development of new targeted therapies. The aim of this review is to discuss the different prognostic factors and genetic markers of TET. The meticulous use of national and international databases could provide sufficient number of patients in order to draw more valid conclusions.

Prognostic value of preoperative C-reactive protein to albumin ratio in patients with thymic epithelial tumors: a retrospective study

Background

The C-reactive protein to albumin ratio (CAR) is associated with poor prognosis in various cancers. However, its value in thymic epithelial tumors remains to be elucidated, we aimed to evaluate the prognostic significance of preoperative CAR in patients with surgically resected thymic epithelial tumors (TETs).

Methods

We retrospectively collected data from 125 patients with TETs who underwent thymoma resection at our center. The best cutoff values ​​for the continuous variable, CAR, were obtained using X-tile software. Univariate and multivariate Cox regression analyses were used to evaluate CAR as an independent predictor of overall survival (OS) and recurrence-free survival (RFS). Kaplan–Meier analysis and log-rank tests were used to present risk stratification of patients based on CAR and the Glasgow-prognostic-score (GPS). The prognostic effect of CAR was assessed using a receiver operating characteristic curve.

Results

Patients were categorized into high (≥ 0.17) and low (< 0.17) CAR groups according to the optimal cutoff value of 0.17. Univariate and multivariate analyses showed that CAR was an independent predictor of prognosis. World health organization stage, CAR level, GPS score, and drinking history were important independent prognostic factors for OS (p < 0.05). T stage, CAR level, and drinking history were important independent prognostic factors for RFS (p < 0.05). The area under the curve value of CAR to predict prognosis was 0.734 for OS and 0.680 for RFS.

Conclusions

Elevated preoperative CAR was independently associated with poor OS and RFS after thymectomy. Therefore, CAR may be a valuable biomarker for the postoperative prognosis of TETs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10234-x.

Prognostic factors for overall survival after surgical resection in patients with thymic epithelial tumors: A systematic review and meta-analysis

BACKGROUND

Thymic epithelial tumors (TETs) originate in the thymic epithelial cell, including thymoma and thymic carcinoma. Surgical resection is the first choice for most patients. However, some studies have shown that the factors affecting the prognosis of these patients are not consistent. To evaluate prognostic factors in patients with surgically resected thymic epithelial tumors, we performed a meta-analysis.

METHODS

We searched the Chinese biomedical literature database, Pubmed, Embase, Cochrane Library and other electronic databases. Studies including postoperative overall survival (OS) and predictors of TETs were included. We made a comprehensive analysis the hazard ratios (HRs) through a single proportional combination. HRs were combined using single proportion combinations.

RESULTS

The meta-analysis included 11,695 patients from 26 studies. The pooled OS was 84% at 5 years and 73% at 10 years after TETs operation. The age as continuous-year (HR 1.04, 95% confidence interval (CI) 1.02-1.04), incomplete resection (HR 4.41, 95% CI 3.32-5.85), WHO histologic classification (B2/B3 vs A/AB/B1 HR 2.76, 95% CI 1.25-6.21), Masaoka Stage (stage III/IV vs I/II HR 2.74, 95% CI 2.12-3.55,) were the poor prognostic factors.

CONCLUSIONS

For patients with TETs after surgical resection, advanced age, incomplete resection, WHO classification B2/B3, and higher Masaoka stage are risk factors for poor prognosis.

Thymic epithelial tumors: examining the GTF2I mutation and developing a novel prognostic signature with LncRNA pairs to predict tumor recurrence

Background

General transcription factor IIi (GTF2I) mutations are very common in thymic epithelial tumors (TETs) and are related to a more favorable prognosis in TET patients. However, limited research has been conducted on the role of GTF2I in the tumor immune microenvironment (TIME). Further, long non-coding RNAs (lncRNAs) have been associated with the survival of patients with TETs. Therefore, this study aimed to explore the relationship between GTF2I mutations and TIME and build a new potential signature for predicting tumor recurrence in the TETs. Research data was downloaded from The Cancer Genome Atlas database and the CIBERSORT algorithm was used to evaluate TIME differences between GTF2I mutant and wild-type TETs. Relevant differentially expressed lncRNAs based on differentially expressed immune-related genes were identified to establish lncRNA pairs. We constructed a signature using univariate and multivariate Cox regression analyses.

Results

GTF2I is the most commonly mutated gene in TETs, and is associated with an increased number of early-stage pathological types, as well as no history of myasthenia gravis or radiotherapy treatment. In the GTF2I wild-type group, immune score and immune cell infiltrations with M2 macrophages, activated mast cells, neutrophils, plasma, T helper follicular cells, and activated memory CD4 T cells were higher than the GTF2I mutant group. A risk model was built using five lncRNA pairs, and the 1-, 3-, and 5-year area under the curves were 0.782, 0.873, and 0.895, respectively. A higher risk score was related to more advanced histologic type.

Conclusion

We can define the GTF2I mutant-type TET as an immune stable type and the GTF2I wild-type as an immune stressed type. A signature based on lncRNA pairs was also constructed to effectively predict tumor recurrence.

Maximal Thymectomy via Mini Sternotomy with Pleural Preservation

Gaurav PatelBackground  There are different surgical techniques used for maximal thymectomy. Each technique has its own advantages and disadvantages. We propose a mini sternotomy with pleural preservation approach for complete maximal thymectomy. Methods  Over time range of 5 years, 32 patients with diagnosis of thymoma with or without myasthenia gravis (MG) underwent maximal thymectomy by mini sternotomy in our institute. Patient records were examined for the following parameters: age, sex, preoperative medication, symptoms of MG as per Myasthenia Gravis Foundation of America grading system, operating time, duration of postoperative ventilation, length of stay in the intensive care unit, overall length of hospitalization, and postoperative complications. Results  The mean age of patients in our study was 43.66. Sex ratio in this study was almost equal. Sixty-nine percent of patients were stage I thymoma according to Masaoka staging. Size of the tumor ranged from 3 to 8 cm with mean size being 4.54 cm. Complete resection with negative tumor margins was possible in all the cases. Four patients had intraoperative pleural injury out of which two patients required intercostal tube insertion. We did not have any serious postoperative complications with no perioperative mortality. Conclusions  Mini sternotomy allows maximal removal of thymus through a less invasive approach and is associated with a significantly smoother postoperative course, less overall complications, and good clinical outcome. It is a simple technique that can be performed by any thoracic and surgical oncologists especially in Indian subcontinent where facilities of video-assisted thoracoscopic surgery and robotic video-assisted thoracoscopic surgery are not available in all areas and are expensive.

Development of a competing risk nomogram for the prediction of cause-specific mortality in patients with thymoma: a population-based analysis

Background

This study was developed to assess the odds of cause-specific mortality and other types of mortality in thymoma patients. In addition, these analyses were leveraged to develop a comprehensive competing risk model-based nomogram capable of predicting cause-specific mortality as a result of thymoma.

Methods

Thymoma patients included within the Surveillance, Epidemiology, and End Results (SEER) database from 2004–2016 were identified, and the odds of cause-specific mortality due to thymoma and other forms of mortality for these patients were estimated. In addition, Fine and Gray’s proportional subdistribution hazard model was constructed, and a competing risk nomogram was developed using this model that was capable of predicting the odds of 3-, 5-, and 10-year cause-specific mortality in thymoma patients.

Results

In total, 1,591 relevant cases in the SEER database were selected for analysis. In this patient cohort, the respective 5-year cumulative incidence rates for cause-specific mortality and mortality attributable to other causes were 12.4% and 8.2%. Variables significantly associated with cause-specific mortality included age, chemotherapy, surgery, and Masaoka stage. Additionally, the odds of other-cause-specific mortality rose with increasing patient age, and chemotherapy was correlated with other-cause-specific mortality. The competing risk nomogram that was developed exhibited good discriminative ability as a means of predicting cause-specific mortality, as evidenced by a concordance index (C-index) value of 0.84. Calibration curves further revealed excellent consistency between predicted and actual mortality when using this nomogram.

Conclusions

In summary, we herein assessed the odds of cause-specific and other-cause-specific mortality among thymoma patients, and we designed a novel nomogram capable of predicting cause-specific mortality for thymoma, providing a promising tool that may be of value in the context of individualized patient prognostic evaluation.

The Prognostic Value of Preoperative Serum D-dimer Levels After Surgical Resection of Thymic Epithelial Tumors

Introduction

Thymic epithelial tumors are the most common mediastinal tumors. Despite the high survival rate after surgery, some patients still require postoperative adjuvant therapy and closer follow-up. Hematological indicators such as biochemical routines and coagulation indicators have been reported to be independently associated with the prognosis of various malignancies. Therefore, we included hematological indicators in the analysis.

Methods

The data of 105 patients with thymic epithelial tumors were retrospectively collected from Sun Yat-sen University Cancer Center, and the patients with missing preoperative hematological indicators were excluded. X-tile software was used to obtain the best cutoff value of each preoperative hematological indicator, and COX regression analysis and Kaplan-Meier survival curves were used to demonstrate statistically significant results.

Results

COX univariate regression analysis of all patients showed that Masaoka stage, T stage, WHO histologic types, D-dimer, albumin-fibrinogen ratio (AFR), Fibrinogen (Fbg) were associated with postoperative overall survival ( P < .05). T stage, WHO histologic types, D-dimer, and AFR were associated with postoperative recurrence-free survival ( P < .05). Finally, multivariate regression analysis showed that T stage, D-dimer levels were independently associated with postoperative overall survival (OS) and recurrence-free survival (RFS) in patients with thymic epithelial tumors.

Conclusions

For thymic epithelial tumors, higher preoperative D-dimer levels predict poorer survival and shorter recurrence-free survival. This may help guide postoperative adjuvant therapy and follow-up patterns in patients with thymic epithelial tumors.

Thymic tumours: a single center surgical experience and literature review on the current diagnosis and management of thymic malignancies

OBJECTIVE

This study aimed to provide an extensive overview of clinical and pathological findings along with various therapeutic options analyzing in addiction, retrospectively, the surgical outcomes of a single center cohort.

BACKGROUND

Thymic neoplasms are rare thoracic tumors which commonly are located in the anterior mediastinum and are associated with a wide spectrum of clinical presentations. They may run an indolent course or could present a very aggressive biologic progression with infiltration of mediastinal structures and presence of distant metastases. The pathogenesis of these tumors is so far not completely clear. Several treatment modalities in a multidisciplinary setting have to be considered in order to provide the best treatment for patients affected by thymic tumors.

METHODS

We conducted a retrospective cohort analysis of all patients who underwent surgery due to thymic tumor in a university hospital located in Switzerland (Bern University Hospital) and then we performed a narrative review of the English literature using PubMed, Embase, Cochrane Database of Systematic Reviews and Scopus.

CONCLUSIONS

Minimally invasive techniques play an important role in the treatment of thymic tumors. A careful patients selection in a multidisciplinary setting is mandatory in order to offer the best treatment for patients affected by thymic tumors.

Future Perspective of Chemotherapy and Pharmacotherapy in Thymic Carcinoma

Simple Summary

Thymic carcinoma is a rare cancer, and its biology remains largely unknown. Although complete surgical resection is a standard treatment for thymic carcinoma, systemic chemotherapy is frequently administered in metastatic or recurrent cases. Given the rarity, therapeutic agents are often confirmed on the basis of the results of phase II trials or retrospective studies. Platinum-based combination chemotherapy has long been employed for treating thymic carcinoma. Recently, biomarkers have been explored, and molecular profiles and major oncogenic pathways have gradually been revealed by next-generation sequencing, resulting in the development of targeted therapies. Moreover, clinical trials assessing combination therapy with immune checkpoint inhibitors are ongoing and are expected to be efficacious for treating thymic epithelial tumors. We reviewed the current role of systemic chemotherapy, including targeted therapies and immune checkpoint inhibitors, considering recent findings regarding its biology.

Abstract

Thymic carcinoma is a rare cancer that arises from thymic epithelial cells. Its nature and pathology differ from that of benign thymoma, presenting a poorer prognosis. If surgically resectable, surgery alone or surgery followed by chemoradiotherapy or radiotherapy is recommended by the National Comprehensive Cancer Network Guidelines. Metastatic and refractory thymic carcinomas require systemic pharmacotherapy. Combined carboplatin and paclitaxel, and cisplatin and anthracycline-based regimens have been shown a fair response rate and survival to provide a de facto standard of care when compared with other drugs employed as first-line chemotherapy. Cytotoxic agents have been pivotal for treating thymic carcinoma, as little is known regarding its tumorigenesis. In addition, genetic alterations, including driver mutations, which play an important role in treatments, have not yet been discovered. However, molecular pathways and biomarker studies assessing thymic epithelial tumors have been reported recently, resulting in the development of new agents, such as molecular targeted agents and immune checkpoint inhibitors. As treatment options are currently limited and the prognosis remains poor in metastases and recurrent thymic carcinoma, genetic alterations need to be assessed. In the present review, we focused on the current role of targeted therapies and immune checkpoint inhibitors in treating thymic carcinoma.

A rare case of hepatic metastasis 20 years after surgical resection of a thymoma: A case report

INTRODUCTION

Thymoma is the most common solid, primary mediastinal tumour, accounting for 20% of mediastinal neoplasms. Malignant thymus tumours (thymomas and thymic carcinomas) metastasize primarily locally. Distant metastases, especially to liver are very rare.

PRESENTATION OF CASE

We review the case of a 59 year-old female patient, who underwent resection of the thymus with a diagnosed type B2 thymoma 20 years ago. The patient was referred to our hospital with a newly discovered space-occupying lesion in the liver, which had been detected in a routine follow-up magnetic resonance imaging scan. Since a malignant tumour of the liver could not be excluded, a conventional left hemihepatectomy was performed. Histological examination revealed a liver metastasis of the type B2 thymoma, which had been removed 20 years ago.

CLINICAL DISCUSSION

The case was discussed in the interdisciplinary tumour board. Based on the very long history of the primary removal of the thymoma as well as the R0 resection of the liver metastasis, a follow-up regimen with CT scans on a regular basis was recommended.

CONCLUSIONS

Newly discovered lesions of the liver in patients even with a long history of a thymoma should raise the suspicion of a liver metastasis that should be surgically resected as the therapy of choice. Further, this case indicates the importance for long-term radiographic follow-up.

[Long-term outcomes of thoracoscopic thymectomy for thymoma stage i-ii]

OBJECTIVE

To compare long-term outcomes of video-assisted thoracoscopic (VATS) and conventional open surgery in patients with early-stage (Masaoka stage I-II) thymic malignancies.

MATERIAL AND METHODS. A

Retrospective study included patients after VATS and open thymectomy for the period 2000-2019. Long-term outcomes were analyzed.

RESULTS

VATS thymectomy was performed in 53 (54.1%) patients, open thymectomy - in 45 (45.9%) cases. Median follow-up period was 66.9 months. Overall 5-year survival was 89.8% and 97% in the Open and VATS groups, respectively (p=0.076). Disease-free survival rates were 79.6% and 86.6% (p=0.279), respectively. There was no significant difference in cumulative incidence of recurrence (13.3% vs 7.5%, p=0.505). Age <50 years and tumor size >5 cm were the independent risk factors of recurrence.

CONCLUSION

VATS thymectomy is an effective approach ensuring similar long-term outcomes in patients with early stages of thymic malignancies.

Characteristics and outcomes of thymomas in Latin America: Results from over 10 years of experience (CLICaP-LATimus)

BACKGROUND

Thymomas are a group of rare neoplasms of the anterior mediastinum. The objective of this study was to describe the demographics, clinical characteristics and treatment approaches in Latin America.

METHODS

This was a retrospective multicenter cohort study including patients with histologically proven thymomas diagnosed between 1997 and 2018. Demographics, clinicopathological characteristics and therapeutic outcomes were collected locally and analyzed in a centralized manner.

RESULTS

A total of 135 patients were included. Median age at diagnosis was 53 years old (19-84), 53.3% (n = 72) of patients were female and 87.4% had an ECOG performance score ranging from 0-1. A total of 47 patients (34.8%) had metastatic disease at diagnosis. Concurrent myasthenia gravis occurred in 21.5% of patients. Surgery was performed in 74 patients (54.8%), comprising 27 (20%) tumorectomies and 47 (34.8%) thymectomies. According to the Masaoka-Koga system, overall survival (OS) at five-years was 73.4%, 63.8% and 51%, at stages I-II, III-IVA and IVB, respectively (p = 0.005). Furthermore, patients with low lactate dehydrogenase (LDH) (≤373 IU/L) at baseline and myasthenia gravis concurrence showed significantly better OS (p = 0.001 and p = 0.008, respectively). In multivariate analysis, high LDH levels (HR 2.8 [95% confidence interval [CI]: 1.1-7.8]; p = 0.036) at baseline and not performing a surgical resection (HR 4.1 [95% CI: 1.3-12.7]; p = 0.016) were significantly associated with increased risk of death.

CONCLUSIONS

Our data provides the largest insight into the clinical characteristics and outcomes of patients with thymomas in Latin America. Survival in patients with thymomas continues to be very favorable, especially when subjected to adequate local control.

Epidemiology of thymic epithelial tumors: 22-years experience from a single-institution

Background

To assess the correlation of WHO histological classification and Masaoka–Koga staging system of thymic epithelial tumors (TETs) with prognosis.

Methods

We retrospectively analyzed 83 patients with TETs in the Instituto Nacional de Enfermedades Neoplasicas between 1996 to 2018. We analyzed the clinical stages, histological types and treatment modalities and attempted to determine the impact on overall survival. The data was retrieved from clinical files and reviewed by a pathologist who reclassificated according to the 2004 WHO classification system. The staging was performed with the Masaoka–Koga staging system. Survival curves were constructed with Kaplan‐Meir method.

Results

There was a total of 83 patients with a median age of 55 years old included in the study. The histological type corresponded to thymoma (T) in 63.8% (n = 53) and to thymic carcinoma (TC) in 36.1%. T were type A, AB, B1, B2 and B3 in 14.4%, 18%, 12%, 3.6%, 7.4% of cases, respectively. The proportion of advanced disease (Masaoka stage III–IV) was high (65%). With a median follow‐up of 88.4 months, median overall survival (OS) was 81.6 months for T and 12.3 months for TC (P = 0.01). Univariate analysis showed that sex, histological type, clinical stage and surgery (P = 0.01) were significant independent prognostic factors. On multivariate analysis, histology type and Masaoka–Koga staging had an effect on survival.

Conclusions

The results indicates a clear association between the WHO histological classification and Masaoka–Koga staging system with survival. We found a higher proportion of TETs with advanced disease at diagnosis. Further research are required and collaboration is important to foster knowledge focused on classification and treatment.

Key points

Significant findings of the study

The WHO histological classification, the Masaoka–Koga system and surgery treatment were associated with overall survival.

What this study adds

To determine prognosis factors in TETs.

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.

Video-assisted thoracoscopic thymectomy is feasible for large thymomas: a propensity-matched comparison

OBJECTIVES

Video-assisted thoracoscopic thymectomy is becoming the preferable approach for early-stage thymoma. However, large thymomas are still recognized as a relative contraindication due to the possible risk of incomplete resection or capsular disruption. Thus, the aim of this study is to evaluate the feasibility of video-assisted thoracoscopic thymectomy for large thymomas.

METHODS

Patients diagnosed with Masaoka stage I-IV thymoma between April 2001 and December 2018 were retrospectively reviewed. All patients were divided into 2 groups: thymoma <5.0 cm (group A) and thymoma ≥5.0 cm (group B). Propensity score matching analysis was performed to compare postoperative results. Recurrence-free survival and overall survival were compared for oncological evaluation.

RESULTS

A total of 346 patients were included in this study. In the propensity score matching analysis, 126 patients were included both in group A and group B. There was no significant difference between these 2 groups in terms of the R0 resection rate (95.2% vs 94.4%, P = 1.000), conversion rate (1.6% vs 3.2%, P = 0.684), operation time (119.4 ± 48.4 vs 139.1 ± 46.6 min, P = 0.955), blood loss (93.2 ± 231.7 vs 100.5 ± 149.3 ml, P = 0.649), duration of chest drainage (2.7 ± 1.6 vs 2.8 ± 2.0 days, P = 0.184), length of hospitalization (5.0 ± 3.9 vs 5.2 ± 2.9 days, P = 0.628) or postoperative complications (5.9% vs 8.5%, P = 0.068). There was no significant difference between these 2 groups in terms of the overall survival (P = 0.271) and recurrence-free survival (P = 0.288).

CONCLUSIONS

Video-assisted thoracoscopic thymectomy is a safe and effective approach for large thymomas (≥5 cm) with comparable surgical and oncological results.

Tumor Maximum Area May Determine the Survival Outcomes of Patients with Thymic Epithelial Tumors

BACKGROUND

The tumor maximum area (TMA) of thymic epithelial tumors (TETs) is not mentioned in current staging systems. This study aimed to assess whether TMA is of prognostic significance in TETs.

METHODS

Patients who underwent extended thymectomy for TETs from 2001 to 2019 at our institute were retrospectively reviewed. TMA was examined by computed tomography imaging prior to surgery. Time-dependent receiver operating characteristic (ROC) curves were used to divide the cohort into two groups. The relationships between the TMA and clinicopathological characteristics or survival outcomes were assessed. Cox proportional hazards models were used to identify independent prognostic factors.

RESULTS

A total of 122 TET patients were included for evaluation, with a median age of 61 years (range 27-83). The time-dependent ROC curve indicated that the difference in 10-year overall survival (OS) was most significant for a TMA of 1392 mm² (area under the curve 0.793); therefore, the two groups of larger (n = 40) and smaller (n = 82) TMAs were divided. The differences in adjuvant therapy, TNM stage, and disease progression between the two groups were significant (p < 0.05). Kaplan-Meier curves indicated that TET patients with a larger TMA had worse survival outcomes, including OS, progression-free survival (PFS) and disease-free survival (DFS) [p < 0.05]. TMA was demonstrated to be an independent prognostic factor of all of the above survival outcomes in multivariate analysis (p < 0.05).

CONCLUSIONS

A larger TMA is associated with a more advanced TNM stage and disease progression in TET patients and may indicate worse survival outcomes, even if more patients receive adjuvant therapy.

Midterm Results for Robotic Thymectomy for Malignant Disease

BACKGROUND

There are limited reports on robotic thymectomy for malignant disease. Our objectives are to review our experience and midterm outcomes.

METHODS

We reviewed a single-surgeon prospective database for patients who underwent planned robotic resection for malignancy from January 2010 to June 2019.

RESULTS

Two hundred thirteen patients underwent resection of an anterior mediastinal mass, all of which were planned for a robotic approach. Of these, 84 (39%) underwent robotic thymectomy for malignant disease. Thymoma was the most common pathology resected (68%). Median tumor size was 4.7 cm (interquartile range, 2.9-6.3), and median operative time was 81.5 minutes (interquartile range, 64-104). All except 1 patient had a complete (R0) resection (98.8%). There were 2 (2.3%) unplanned but elective conversions to open surgery, 1 of which required cardiopulmonary bypass. Median length of stay was 1 day (range, 0-9) with 1 readmission (1.2%). Major morbidity occurred in 3 patients (3.5%), and there were no 30- or 90-day mortalities. In patients with thymoma, follow-up was complete at a median of 32 months (range, 1-98), and 1 patient (1.8%) had an ipsilateral chest recurrence. To date there have been no patient deaths.

CONCLUSIONS

Robotic thymectomy for patients with malignant disease is safe with excellent perioperative outcomes. A robotic approach achieves a high rate of complete R0 resection, even for larger tumors. For patients with thymoma local recurrence is low after midterm follow-up, but longer-term analysis is needed to determine oncologic durability.

Phase II trial of S-1 treatment as palliative-intent chemotherapy for previously treated advanced thymic carcinoma

Thymic carcinoma (TC) is a rare cancer with minimal evidence of survival following palliative-intent chemotherapy. Sunitinib, everolimus, and pembrolizumab have been proposed as active agents based on previous phase II trials. In this phase II study, TC patients previously treated with platinum-based chemotherapy were enrolled. The patients received S-1 orally twice daily at a dose of 40-60 mg/m² for 4 weeks, followed by 2 weeks off until the progression of the disease or the presence of unacceptable toxicities. The primary endpoint was the objective response rate (ORR), and secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. The sample size of 26 patients was planned to reject the ORR of 10% under the expectation of 30% with a power of 0.80 and a type I error of 0.05 (one-sided). Twenty-six patients were recruited between 2013 and 2016; 23 patients had squamous cell carcinoma and 10 had an ECOG performance status of 0. One patient showed complete response and seven patients showed partial responses, resulting in a 30.8% response rate (90% confidence interval [CI], 18.3-46.9) and an 80.8% disease control rate (90% CI, 65.4-90.3). The median PFS was 4.3 months (95% CI, 2.3-10.3 months) and median OS was 27.4 months (95% CI, 16.6-34.3). Adverse events of grade ≥ 3 included neutropenia (12%), skin rash (8%), elevated alanine aminotransferase, and fatigue (4%). No treatment-related death was observed. S-1 confirmed clinical activity with tolerability in patients with previously treated TC. (UMIN000010736).

Management and Long-Term Outcomes of Advanced Stage Thymoma in the United States

BACKGROUND

Thymomas are rare tumors, with limited data regarding treatment of advanced stage disease. Although surgical resection is the mainstay of treatment, the role of additional therapy remains controversial. Our objectives were to describe treatment strategies for stage III/IV thymoma in the United States and compare survival outcomes among treatment approaches.

METHODS

We identified Masaoka stage III/IV thymoma reported in the National Cancer Database between 2004 and 2016. Frequencies of treatment with surgery, chemotherapy, radiation, and combinations were calculated. Five-year overall survival was compared using the Kaplan-Meier method and log-rank test. Risk-adjusted proportional hazards modeling compared mortality between treatment regimens.

RESULTS

A total of 1849 patients were identified (1108 stage III, 741 stage IV). Among stage III patients, 83.8% underwent resection (± other modalities) compared with 60.2% of stage IV. Surgery plus radiation was the most common regimen for stage III (32.6%), and nonsurgical treatment (definitive chemotherapy and/or radiation) was the most common for stage IV (36.4%). Overall 5-year survival was 70.3% for stage III and 58.5% for stage IV. In risk-adjusted analysis, surgery plus radiation had the lowest mortality (hazard ratio 0.41, 95% confidence interval 0.30-0.55). Patient age, tumor size, metastases, and non-academic treating hospital were associated with mortality.

CONCLUSIONS

Current treatment regimens for advanced stage thymoma vary significantly. Regimens that include surgical resection are most common and are associated with superior outcomes. Patients selected to have surgery as primary treatment had the best survival. Adjuvant radiation treatment is associated with better survival and should be considered in patients who undergo resection.

Clinical significance of age at diagnosis among patients with thymic epithelial tumors: a population-based study

Background: To investigate the clinicopathologic characteristics and survival outcomes of patients with thymic epithelial tumors (TET) according to age at diagnosis.

Results: A total of 4431 patients were analyzed. Gender, race, tumor histology and surgery were similar between different age groups. The 0-18 group was associated with a higher risk of distant metastasis. Compared to patients aged above 80, the hazard ratios (HR) for patients aged 0-18, 19-30, 31-40, 41-50, 51-60, 61-70, 71-80 were 1.079, 0.739, 0.614, 0.621, 0.633, 0.673, 0.861, respectively. From the subgroup analysis for the adult patients who were above 19 years old, we found that the 19-70 group had significant better cancer specific survival (CSS) and overall survival (OS) than the above 70 group.

Conclusions: Age is a strong independent prognostic factor for survival in TET. Pediatric TET has a higher risk of distant metastasis and an inferior CSS. For the adults who were above 19, patients older than 70-year-old were associated with a shorter CSS.

Methods: Information of 4431 TET patients was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Demographic features, clinicopathologic characteristics and survival outcomes were compared between patients diagnosed at different age groups (0-18, 19-30, 31-40, 41-50, 51-60, 61-70, 71-80, above 80).

Treatment Outcome and Prognostic Factors of Malignant Thymoma - A Single Institution Experience

Objective:

Our objectives are to investigate the clinicopathological features, treatment modalities, and prognostic and prognostic factors in order to estimate long-term outcomes for patients with thymoma and thymic carcinoma at our institution.

Methods:

We reviewed all patients diagnosed with thymic malignancies malignancies over a period of 38 years (from 1976 to 2014). Patients were identified using a single institution database at King Faisal Specialist Hospital and Research Center (KFSH and RC), Riyadh. Demographic data, clinical staging, histopathology classification, treatment approaches, and survival data were collected. Data Analysis was performed using both the Kaplan–Meier method and Cox proportional hazards modeling.

Results:

The fifty-six identified patients consists of 30 females (53.6%) and 26 males (46.4%). The median age at diagnosis was 39 years. About 37% of the patients were diagnosed with myasthenia gravis (MG). There was a significant association between the WHO histologic classification and the Masaoka stage (p= 0.018). The estimated 5-year overall survival rate was 88.6% for patients with thymic malignancies. The median survival time of thymoma and thymic carcinoma was 61 and 14 months, respectively. The univariate analysis suggested that histology (thymoma versus thymic carcinoma, p= 0.044) and Masaoka stage (II-III versus IV, p= 0.048) were independent prognostic factors affecting overall survival. Histology (p = 0.044) was found to be an independent predictor of overall survival.

Conclusion:

The findings of this study indicates that late Masaoka-Koga staging and histology types are significantly associated with extended overall survival. Similarly, surgical resection and multimodality treatments play a significant role in thymic malignancies neoplasms therapy strategies to prolong survival rates.

Impact of Definitive Radiotherapy and Surgical Debulking on Treatment Outcome and Prognosis for Locally Advanced Masaoka-Koga stage III Thymoma

The role of definitive radiotherapy (dRT) and debulking surgery (DS) for patients with locally advanced, unresectable, Masaoka-Koga stage III thymomas was not well studied. Unresectable tumor refers to tumor that could not be completely resected because of invasion of surrounding organs. Consecutive patients with unresectable stage III thymomas between 2000 and 2017 were reviewed. According to the treatment intent and radiation dose, patients were categorized into a dRT group and a non-dRT group. The former group included patients who received radiotherapy at doses ≥ 54 Gy after DS or biopsy. The latter group included patients who did not receive radiotherapy and those who received a radiation dose < 54 Gy. A total of 82 patients were included. Compared with non-dRT, dRT significantly improved 5-year overall survival (OS, P = 0.003), progression-free survival (PFS, P = 0.008), and freedom from locoregional failure (FFLF, P < 0.001). Compared with biopsy alone, DS did not improve OS, PFS, FFLF. On multivariate analysis, dRT was an independent prognostic factor for OS (hazard ratio [HR]: 2.37, P = 0.024), PFS (HR: 2.40, P = 0.004), and FFLF (HR: 3.83, P = 0.001). In conclusion, dRT was an effective and beneficial treatment for patients with unresectable Masaoka-Koga stage III thymoma.

Median sternotomy versus minimally invasive thymectomy for early-stage thymoma: A systematic review and meta-analysis protocol

BACKGROUND

The completeness of resection is an important prognostic factor for early resectable thymoma. Since its inception 2 decades ago, median sternotomy has been recognized as the gold standard method for the treatment of all types and stages of thyomas. Minimally invasive surgical techniques, including video-assisted and robot-assisted surgery, have been rapidly developed as an alternative to traditional open approach surgery. Compared with traditional open approach surgery, minimally invasive approach has better cosmetic effect, faster improvement of lung function, reduction of surgical trauma, length of stay, and complications. We believe that this is an appropriate time and there is a need for a systematic, comprehensive, and objective assessment of the 2 surgical modalities in order to provide reliable evidence for clinicians to determine the best treatment for patients with early resectable thymoma.

METHODS

Pubmed (Medline), Web of Science, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar will be searched for relevant randomized controlled trials (RCTs), quasi-RCTs, and Hi-Q (high quality) prospective cohort trials published or unpublished in any language before March 1, 2020. Subgroup analysis will be performed in tumor pathological stage and ethnicity. PROSPERO registration number: CRD42019133724.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

This study will be the first to assess the efficacy and safety of median sternotomy recognized as the gold standard method for the treatment of all types and stages of thyomas and minimally invasive thymectomy for patients with early-stage thymoma. This study will assess whether minimally invasive thoracoscopic and robotic assisted thymectomy can be used as an alternative to traditional median sternotomy for patients with early resectable thymoma and provide high-quality and reliable evidence for clinicians' decision-making.

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.

Uniportal video-assisted thoracoscopy approach to the management of non-pulmonary diseases of the chest

The use of uniportal video-assisted thoracoscopy (u-VATS) is becoming a commonly used surgical technique and can be an effective approach for the surgical treatment of many pulmonary and non-pulmonary conditions. This review article summarizes current medical evidence informing the practice of u-VATS for treating non-pulmonary conditions including hyperhidrosis, hemothorax, pleural effusion, and thymic disease.

Multilobulated thymoma with an acute angle: a new predictor of lung invasion

OBJECTIVE

Imaging features of thymomas such as lobulation, infiltration into lung, and adjacent lung abnormality have been associated with lung invasion but are unreliable. The goal of this study was to develop a more objective and reproducible method for predicting lung invasion by thymomas.

SUBJECTS AND METHODS

Fifty-four thymomas resected from 2007 to 2017 were included for analysis. Pre-operative CT scans for these thymomas were reviewed, and multiple features were evaluated, including the interface of each thymoma with the adjacent lung. A multilobulated thymoma with at least one acute angle between lobulations was considered suspicious for lung invasion. Two blinded radiologists then tested this hypothesis by reviewing all 54 CT scans and using this single criterion to predict lung invasion.

RESULTS

Twelve thymomas invaded the lung. All lung-invasive thymomas were multilobulated. Twenty-nine thymomas had a multilobulated interface with the lung. Multilobulated thymomas were more likely to invade the lung than thymomas with a single lobulation or no lobulation (p = 0.0008). Using the criterion of multilobulation with at least one acute angle between lobulations to predict lung invasion, the two readers achieved a sensitivity of 67-83%, specificity of 93-98%, positive predictive value of 77-89%, and negative predicted value of 91-95%. Nine lung-invasive thymomas also invaded mediastinal structures or disseminated to the pleura.

CONCLUSIONS

A multilobulated thymoma with at least one acute angle between lobulations predicts lung invasion with a high degree of accuracy. When lung invasion is suspected, the findings are indicative of a locally aggressive tumor, and the pleura and mediastinal structures should also be closely inspected for invasion.

KEY POINTS

• A multilobulated thymoma with at least one acute angle between lobulations is predictive of lung invasion. • Coronal and sagittal reformations and thin sections are helpful in challenging cases. • Lung invasion indicates a locally aggressive tumor, and the pleura and other mediastinal structures should also be closely inspected for invasion.

Extended resections of large thymomas: importance of en bloc thymectomy

Background

Primary tumors of the thymus are rare; the most common histologic type is thymoma. Most important prognostic factors are anatomical extent of tumor and completeness of surgical resection. Large size has not been directly associated with survival, but is strongly associated with advanced disease and high rates of incomplete resections.

Methods

A retrospective cohort of patients who underwent thymectomy for thymomas of 5 cm or larger at the National Cancer Institute (INCan) of México from January 2005 to December 2016 was analyzed. Primary end-points were rate of complete resection, morbidity and mortality of thymectomy. Secondary end-points were overall survival (OS) and disease-free survival (DFS).

Results

A total of 25 patients were identified and included in the final analysis. Mean age was 56.6 years (27-82 years). Median size of thymoma was 8.3 cm (5-14 cm). Transesternal approach was used in 72% of cases, most of cases (68%) required an extended resection to achieve negative margins. Complete resection was achieved on 23 cases (92%). A 90-day morbidity of 24% and mortality of 8% was found, with a median follow-up of 34.5 months (1-113 months). The only factor associated with OS was completeness of surgical resection (P<0.0001).

Conclusions

Size of thymomas should not be considered as a contraindication for surgical treatment. Our data suggest that extended surgery is feasible even in advanced cases and provides the best chance for cure. Complete resection remains as one of the most important prognostic factor in thymomas and is associated with prolonged DFS and OS.

[Correlation between Serum Cytokeratin 19 Fragment and the Clinicopathological Features and Prognosis of Thymic Epithelial Tumors]

背景与目的

胸腺肿瘤中尚无肿瘤标志物的应用，本研究旨在评估血清细胞角蛋白19片段（cytokeratin 19 fragment, Cyfra 21-1）与胸腺肿瘤临床病理特征和预后的相关性。

方法

回顾性分析上海市胸科医院2012年11月-2016年9月收治的159例胸腺肿瘤病例的临床资料。比较术前血清Cyfra 21-1水平在不同分期及组织学类型间的差异，研究术前及术后血清Cyfra 21-1水平与复发的关系。

结果

在局部晚期（T4期）（P < 0.001）、胸腺癌（P < 0.001）患者中，术前血清Cyfra 21-1水平显著升高，且当术前Cyfra 21-1≥1.66 ng/mL时，其对术后复发有提示意义。分析患者随访的血清Cyfra 21-1，将2.66 ng/mL作为cut-off值时，提示胸腺肿瘤复发的敏感度为0.667，特异度为0.925，阳性预测值为0.462，阴性预测值为0.966。

结论

术前患者血清Cyfra 21-1水平较高，有助于提示肿瘤分期较晚、肿瘤恶性程度较高，或可提示术后复发的风险升高。在随访时结合血清Cyfra 21-1检测，将可能有助于提高复发患者的检出率，改善预后。

Radical thymectomy versus conservative thymomectomy in the surgical treatment of thymic malignancies

Background

Complete thymectomy is recommended for thymic malignancies to reduce local recurrence and the likelihood of the long-term development of myasthenia gravis (MG). Thymus-conserving surgery (thymomectomy) seems to yield similar results, but evidence is still limited. The objective of this study was to assess if the oncological outcome, in terms of overall survival (OS) and disease-free survival (DFS), are comparable between radical thymectomy vs. conservative thymomectomy patients, and to assess if the outcome of the video-assisted thoracoscopic surgery (VATS) approach was similar to open surgery approach.

Methods

We retrospectively analyzed 157 consecutive patients with either resectable thymoma or thymic carcinoma from two Italian centers (Humanitas Research Hospital, Milan, and Humanitas Gavazzeni, Bergamo) between 1997 and 2013 who underwent thymomectomy or extended thymectomy with the VATS or open approach; the patients with Miastenia Gravis underwent radical thymectomy. The patients were followed through physical examinations and phone interviews.

Results

Thymomectomy and thymectomy were performed on 86 (54.8%) and 71 (45.2%) patients, respectively. Prognostic factors and comorbidities were comparable in the two groups. The median follow-up was 77 months. Cox proportional hazards model revealed that Masaoka advanced stage and thymic carcinoma of WHO classification were independent predictive factors for overall survival, but that the extent of surgery and the approach used (minimally invasive versus open) were not. Notably, five- and ten-year survival rates were similar in the two groups.

Conclusions

In our experience, radical thymectomy and conservative thymomectomy did not differ in terms of disease-free and overall survival rates. In nonmyasthenic patients with early-stage resectable thymic malignancy, minimally invasive thymomectomy provided equivalent results to open thymectomy. Our results should be interpreted with caution due to the retrospective nature of the study. Well-designed, adequately-powered studies should be very welcome to increase the quantity and the quality of clinical evidence before incorporating this procedure in future guidelines.

[Surgical Treatment of Refractory Chest Tumors Assisted by Cardiopulmonary Bypass]

背景与目的

回顾性总结体外循环辅助下累及心脏或大血管的难治性胸部肿瘤外科治疗体会。

方法

总结我院2008年1月-2017年5月实施的体外循环下外科手术切除累及心脏或大血管的11例胸部肿瘤患者，分析所有患者的一般情况、临床特征、治疗方法、术后住院时间、并发症及随访结果。

结果

11例患者均在体外循环辅助下手术。肿瘤全部切除者8例，大部分切除者3例，其中1例先行左房内转移性肺平滑肌肉瘤切除，再行右肺中下叶切除术；1例经胸骨正中切口行左肺中央型肺癌切除术；2例同时行肺动脉修补术，3例同时行部分心包切除术，3例同时行肺楔形切除术。所有患者术后症状均得到有效缓解。无院内及术后30天死亡率。3例术后出现肺部感染，于抗生素治疗后恢复。1例淋巴瘤术后6个月复发，1年后死亡；1例心包内纤维肉瘤患者于术后13个月局部复发伴广泛转移，15个月死亡，1例肺平滑肌肉瘤患者于术后15个月发现局部复发灶，予以化疗后缓解。其余8例患者均存活，且计算机断层扫描（computed tomography, CT）检查均未发现明显复发及远处转移。

结论

对于累及心脏或大血管的难治性胸部肿瘤可以实施体外循环辅助下的外科手术治疗，可以提高难治性胸部肿瘤的手术切除率，有效缓解对呼吸、循环功能的影响，明显延长此类患者的生存期。