Multimodal management of stages III–IVa malignant thymoma

A Re-Examination of Neoadjuvant Therapy for Thymic Tumors: A Long and Winding Road

For most patients with advanced thymic epithelial tumors (TETs), a complete resection is a strong indicator of a better prognosis. But sometimes, primary surgery is unsatisfactory, and preoperative therapy is needed to facilitate complete resection. Neoadjuvant chemotherapy is the most used form of preoperative therapy. But studies on neoadjuvant chemotherapy have included mainly patients with thymoma; its efficacy in patients with thymic carcinoma is less known. Neoadjuvant chemoradiation has also been explored in a few studies. Novel therapies such as immunotherapy and targeted therapy have shown efficacy in patients with recurrent/metastatic TETs as a second-line option; their role as preoperative therapy is still under investigation. In this review, we discuss the existing evidence on preoperative therapy and the insight it provides for current clinical practice and future studies.

Locally advanced thymoma; does neoadjuvant chemotherapy make a difference?

BACKGROUND

Regardless of its rare occurrence, Thymoma remains the most frequently encountered primary tumor of the anterior mediastinum comprising about 50% of all masses in the region. Surgical resection, via thymectomy, remains the mainstay treatment modality. In locally advanced and borderline resectable tumors, neoadjuvant chemotherapy (NACT) may be utilized to increase the chance of R0 resection, raising the question of its efficacy and safety.

METHODS

Demographic and clinical data from patients who presented to a tertiary cancer center between January 2015-October 2021 with a diagnosis of thymoma and underwent curative surgical resection was collected. Computed tomography scan was used to delineate clinical staging, tumor size and to detect post-therapeutic variations in tumor burden. The response evaluation criteria in solid tumors (RECIST) was used to classify the effect of NACT on tumor burden. The pathological response was determined by measuring the percentage of necrotic tissue.

RESULTS

A total of 23 patients were diagnosed with thymoma. Most patients were male with a mean age 46 (± 15) years at diagnosis. The most common clinical stage was stage II with 5 patients (22%). A total of 12 patients had NACT as compared to 11 patients who had upfront surgery. The mean change in tumor volume was 165 cm3 (p = 0.079) and the change in and maximum diameter was 1.53 ± 1.49 cm (p < 0.01). The effect of NACT on tumor burden based on RECIST criteria was minimal as 8 patients had stable disease. Based on pathological findings, the average necrotic portion of the tumor was 39.5% (p = 0.152). The overall survival rate is 95.65%, mean survival was 115 months (4-125). Recurrence occurred in 5 patients. The NACT group had a higher risk for recurrence (4; 33.3%) with a mean survival of 43.8 months compared to 59.6 months in those who did not receive induction therapy.

CONCLUSIONS

The exact role of induction chemotherapy in locally advanced thymoma patients remains controversial. NACT effect after utilizing radiological and pathological assessment tools was not found to significantly improve oncological outcomes compared to upfront surgery in locally advanced disease, with minimal radiologic and pathologic effect. To further demonstrate the impact of induction chemotherapy, we recommend multicentric collaborative studies.

Risk factor analysis of thymoma resection and its value in guiding clinical treatment

BACKGROUND

In this study, relationships between clinicopathologic characteristics and progression-free survival (PFS) of patients after thymomectomy were analyzed to provide valuable suggestions regarding the treatment of thymoma.

METHODS

Data from 187 thymoma patients undergoing surgery at Beijing Tongren Hospital between January 1, 2006, and December 31, 2015, were retrospectively reviewed. We explored the risk factors for PFS among sex, age, thymoma-associated MG, completeness of resection, histologic type and TNM stage, and investigated their interrelationship.

RESULTS

Among the 187 patients, 18 patients (9.63%) had tumor recurrence/metastasis, and all of whom had in situ recurrence or pleural metastasis, and most of them (10 of 18 patients) had MG symptoms that reappeared or were aggravated. Fifteen patients (8.02%) died, and myasthenic crisis was a leading cause. Based on Cox regression analysis, only age (HR = 3.16; 95% CI: 1.44-6.91; p = 0.004) and the completeness of resection (HR = 9.03; 95% CI: 2.58-31.55; p = 0.001) were independent risk factors for PFS. Furthermore, we found that the completeness of resection was related to the histologic type (p = 0.009) and TNM stage (p < 0.001) by Fisher's exact test.

CONCLUSIONS

The results of this cohort study remind us that we should pay attention to the reappearance or aggravation of MG after thymoma resection, because it is the leading cause of death and may indicate tumor progression. Furthermore, completeness of resection was related to the histologic type and TNM stage, but it was the independent risk factors of thymoma. Therefore, R0 resection is critical to the prognosis of thymoma.

Outcomes of Extended Resection for Locally Advanced Thymic Malignancies

BACKGROUND

Thymic malignancies are rare tumors about which data are limited. Our objective here was to evaluate the outcomes and risk factors for complications and death in patients who underwent extended surgery to remove thymic malignancies.

METHODS

We retrospectively included patients who underwent extended resection of locally advanced, nonmetastatic thymic malignancies at our institution. Patients were deemed eligible for resection by a multidisciplinary team. During surgery, priority was given to achieving complete resection rather than to sparing organs.

RESULTS

The 108 patients had a mean age of 53 ± 15 years (range, 9-83); among them, 91 had thymoma, 12 thymic carcinoma, and 5 neuroendocrine tumor. The Masaoka stage was III or higher in 86 patients; examination of operative specimens resulted in downstaging of 22 patients. Tumor-free resection margins were achieved in 98 patients. Overall 5- and 10-year survival rates were 80% and 68%, respectively. Myasthenia gravis, present in 36 patients, was the only independent significant risk factor for major postoperative complications. Age older than 70 years, thymic carcinoma or neuroendocrine tumor, pT3 or pT4 stage, and R1 or R2 resection margins independently predicted death. The number of resected structures was not associated with survival. Thymic carcinoma or neuroendocrine tumor was independently associated with shorter disease-free survival.

CONCLUSION

In an expert center, extended resection targeting complete resection rather than organ preservation provided good outcomes in patients with locally advanced thymic malignancies. The risk/benefit ratio of surgery should be assessed with special care in patients who are elderly or have myasthenia gravis.

Neoadjuvant radiotherapy plus single-incision thoracoscopic surgery in the treatment of type B3 thymomas

Background

Although minimally invasive surgery is the standard treatment for thymomas, minimally invasive thymectomy is difficult for patients with type B3 thymomas, especially for giant or aggressive lesions. These tumors are frequently treated with radical radiation therapy or surgery plus adjuvant radiotherapy. Few studies, however, have tested the efficacy of neoadjuvant radiotherapy prior to thoracoscopic surgery.

Methods

Patients with type B3 thymomas >5 cm or with infiltrates into vital organs on CT-guided puncture biopsy who underwent neoadjuvant radiotherapy followed by single-incision minimally invasive thymectomy from March 2016 to July 2020 were retrospectively evaluated. Reduction ratios, TNM stage changes according to WHO stage criteria, resectability, long-term survival, and the response in terms of RECIST v1.1 criteria achieved by preoperative RT were analyzed.

Results

The 11 patients who underwent neoadjuvant radiotherapy plus minimally invasive thymectomy included five men and six women, of mean age 49.5 years. Four patients had myasthenia gravis. Neoadjuvant radiotherapy consisted of 50 Gy in 25 fractions, with all patients showing varying degrees of lesion reduction after radiotherapy. Surgery was performed about 1 month after neoadjuvant radiotherapy, with none of these patients having severe radiation pneumonitis. All patients underwent radical resection of the tumor and adjacent tissue, with none experiencing tumor seeding or rupture during surgery. The median postoperative hospital stay was 3 days (range: 2-6 days) and the frequency of additional regular analgesics (including those for wound pain and neuralgia) was 2.5 times per person. On follow-up, one patient experienced pleural metastasis and one experienced pulmonary metastasis, with the other nine patients showing no evidence of tumor recurrence.

Conclusion

Neoadjuvant radiotherapy followed by minimally invasive surgery was a safe and efficacious procedure for the treatment of type B3 thymomas, with less postoperative pain and faster recovery. This strategy, of tumor shrinkage prior to surgery, may make possible the easier removal of type B3 thymomas by single-incision thoracoscopy.

Hypofractionated Radiation Therapy Combined With Weekly Chemotherapy in Patients With Unresectable or Recurrent Thymic Epithelial Tumor: A Prospective, Single-Arm Phase 2 Study (GASTO-1042)

PURPOSE

This prospective phase 2 study aimed to evaluate the efficacy and safety of hypofractionated radiation therapy (HRT) combined with concurrent weekly chemotherapy in patients with unresectable or recurrent thymic epithelial tumors (TETs).

METHODS AND MATERIALS

Patients with unresectable or recurrent intrathoracic TETs that could be encompassed within the radiation fields were enrolled. HRT using intensity modulated radiation therapy (IMRT) technique was administered with 3 different levels of radiation doses (51 Gy/17 fractions (fx), 48 Gy/12 fx, and 45 Gy/9 fx; biologically effective dose of 66.3-67.5Gy), combined with weekly docetaxel (25 mg/m²) and nedaplatin (25 mg/m²). Weekly thymosin α1 (1.6 mg) was administered from the start to 2 months after radiation therapy. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), health-related quality of life (QOL), and toxicity were recorded.

RESULTS

Fifty eligible patients enrolled from August 1, 2018, to July 1, 2020, were analyzed. Most patients (82.0%) had stage IVB tumors. Patients had IMRT-HRT (36-51 Gy in 9-17 fx, median biologically effective dose of 67.2 Gy) and concurrent weekly docetaxel/nedaplatin (2-4 cycles). During a median follow-up of 25.0 months (14.0-40.0), the ORR was 83.7%, the 2-year PFS was 59.1%, and the 2-year OS was 90.0%. There was 1 (2.0%) in-field recurrence while 19 (38.0%) patients developed out-of-field recurrence. Grade 3 pneumonitis was observed in 1 patient (2.0%). The ORR, 2-year PFS, 2-year OS, and toxicity were similar among 3 dose levels. Fourteen (28.0%) patients had 2 to 4 courses of radiation therapy because of recurrent diseases. Only 1 suffered from grade 1 pulmonary fibrosis during follow-up. Most patients (88%) maintained a stable QOL within 1 year after radiation therapy.

CONCLUSIONS

IMRT-HRT and concurrent weekly docetaxel/nedaplatin was effective and well tolerated in unresectable or recurrent TETs. Considering the common out-of-field recurrence, this combined regimen could be an option for repeated radiation therapy. Thymosin α1 might help lower the incidence of pneumonitis and maintain the QOL.

Phase II study of S‐1 plus cisplatin with concurrent radiotherapy for locally advanced thymic carcinoma: Results of the LOGIK1605 / JART ‐1501 study

Background

Combination chemotherapy is used to treat advanced thymic carcinoma; however, the effects are insufficient.

Methods

Previously untreated patients with unresectable locally advanced thymic carcinoma received two cycles of 80 mg/m²/day S‐1 orally on days 1–14 plus 60 mg/m²/day cisplatin intravenously on day 1, and concurrent radiotherapy (60 Gy).

Results

Three patients were enrolled into the study. Toxicity and survival were assessable in all patients, but the treatment response was only assessable in one patient. The study was terminated because of poor case recruitment. The patients' characteristics were as follows: male/female = 2/1; PS 0/1 = 2/1; median age (range) = 59 (55–72); and stage III/IV = 2/1. The patient in which the treatment response was assessed exhibited SD (response rate: 0%). In both nonevaluable cases, the second course of chemotherapy was judged to be post‐protocol treatment because it was delayed by ≥14 days, but a CR and PR were achieved after the end of the study, respectively. G4 leukopenia/neutropenia and G3 febrile neutropenia occurred in one patient each (33%). The median time to tumor progression was 17.6 months, and the 1‐, 2‐, 3‐, and 4‐year survival rates were 67, 33, 33, and 33%, respectively. The median overall survival time was not reached, and the 1‐, 2‐, 3‐, and 4‐year survival rates were 100, 67, 67, and 67%, respectively.

Conclusions

Although it was difficult to recruit patients, there was a long‐term survivor >4 years who appeared to have achieved a CR, indicating that such chemoradiotherapy may be effective against locally advanced thymic carcinoma.

Induction Strategy for Locally Advanced Thymoma

Surgery remains cornerstone for the management of thymoma. Complete surgical resection (R0), is recognized as the constant and significant factor for prognosis. However, in locally advanced (Masaoka-Koga stages III-IVa) thymomas, achieving R0 resection remains challenging due to local-regional invasion of the disease. Induction treatment, with the aim of reducing bulky tumor mass, offers new strategy to facilitate totally surgical resection. Herein, we reviewed recent progress and provided a comprehensive overview of induction strategy in locally advance thymoma.

The safety and efficacy of Cyberknife® for thymic malignancy

PURPOSE

To evaluate the safety and efficacy of Cyberknife® (CK) for the treatment of primary or recurring thymic tumours.

MATERIALS AND METHODS

We retrospectively reviewed 12 patients (16 tumour lesions) with primary or recurring thymic tumours who were treated with CK between March 2008 and October 2017. Their data was stored in prospectively collected database. Kaplan-Meier method was used to calculate survival curves.

RESULTS

Five patients (41.7%), who had inoperable disease or refused surgery, were treated with CK initially, and 7 patients (58.3%) were treated with CK when they had recurrence diseases. The disease sites treated with CK were primary tumour site (5), regional lymph nodes (4), tumour bed (3), chest wall (2), pleura (1), and bone (1). The median target volume was 43.8 cm³ (range, 13.1-302.5cm³) for the 16 tumour lesions. The median follow-up time was 69.3 months (range, 9.7-124.8 months). The median survival time was 48.2 months, and the 5-year and 10-year OS rates were 68.2% and 45.5%, respectively. A high response rate for the tumour lesions irradiated with CK was obtained. Only one patient (8%) experienced in-field recurrence, and the 5-year local recurrence free survival was 90.9%. A case indicated that CK may induce the abscopal effect, which provides the potential to combine CK and immunotherapy. No severe radiation related toxicities were observed, and no treatment related death occurred.

CONCLUSION

CK treatment resulted in good outcomes, particularly local control, with minimal side effects, in highly selected patients with primary and recurring thymic tumours. More studies with larger sample are needed.

Surgical feasibility and long-term outcome of superior vena cava replacement for advanced thymoma in patients undergoing preoperative chemotherapy or chemoradiotherapy

Background

The aim of this study was to investigate the long‐term outcome of superior vena cava (SVC) replacement after chemotherapy or chemoradiotherapy for advanced thymoma.

Methods

The medical information of patients with advanced thymoma who underwent thymoma resection and SVC replacement in Beijing Tongren Hospital from 2002 to 2017 were reviewed. We compared surgical outcomes, postoperative complications and long‐term prognosis in the chemoradiotherapy + surgery group (CRT + surgery group, 19 cases) and the surgery group (26 cases).

Results

The operation time (486.05 ± 148.01 vs. 370.77 ± 124.32 min; p = 0.007) and intraoperative blood loss (1400 ml [IQR 1125–2105 ml] vs. 855 ml [IQR 555–1682.5 ml], p = 0.036), poor wound healing (three cases [15.79%] vs. zero cases [0.0%], p = 0.036) in the CRT + surgery group were significantly higher than those of the surgery group. There was no significant difference between the CRT + surgery group and the surgery group in postoperative chest tube drainage time, hospitalization time, postoperative arrhythmia and incidence of pneumonia. Kaplan Meier analysis showed that the recurrence‐free survival (RFS) curves of the CRT + surgery group patients were better than those of the surgery group (p = 0.031). However, overall survival (OS) between the two groups was not significantly different (p = 0.069).

Conclusions

Thymoma resection and SVC replacement is feasible for patients undergoing preoperative induction chemotherapy or chemoradiotherapy for advanced thymoma. Although patients in the CRT + surgery group had a longer operation time and increased intraoperative bleeding, the RFS rate seemed to be better than that in the surgery group.

Multimodality approach in treatment of thymic tumors

Thymic tumors are rare neoplasms showing important clinical and pathologic polymorphisms ranging from low-mitotic encapsulated tumors to a highly aggressive and disseminating one. Complete resection of the tumor with surrounding fatty and mediastinal tissue is of paramount importance and provides good prognosis. Diagnosis of the tumor, radiologic evaluation and implementation of multimodal treatment including preoperative chemotherapy, radiotherapy, postoperative radiotherapy, adjuvant chemotherapy or radiotherapy are important components of the treatment strategy. Some of the stage III tumors can be resected without additional treatment, however, there is a good evidence to support administering preoperative and postoperative chemotherapy and postoperative radiotherapy in these patients providing higher complete resection rate and better survival. For stage IVA thymomas, surgery alone should not be considered as an effective approach and these tumors are considered as unresectable. Chemo/radiotherapy can be administered to those patients. Of those, postoperative chemotherapy and radiotherapy should be considered if these patients who were deemed to be previously unresectable become resectable. The combined modality treatment should provide prevention of locoregional and intrathoracic recurrence and eventually long-term survival with cure. New targeted therapies including agents against PI3K, CDK, and immune checkpoint PD-1/PD-L1 may lead to higher response rates with less toxicity.

Role of modern neoadjuvant chemoradiotherapy in locally advanced thymic epithelial neoplasms

PURPOSE

To improve resectability in patients with stage III-IVA thymic epithelial neoplasms, neoadjuvant chemotherapy and radiotherapy are considered. This retrospective study aimed to investigate the efficacy and safety of neoadjuvant therapies using modern techniques in thymic epithelial neoplasms.

METHODS

We included 32 patients with Masaoka stage III-IV disease treated at our institution from January 2010 to December 2017. Data regarding clinicopathologic characteristics, treatment protocols, toxicities, and survival were collected. Response was evaluated according to the Response Evaluation Criteria in Solid Tumours 1.1. Survival was assessed using the Kaplan-Meier method. Adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

Neoadjuvant radiotherapy alone, chemotherapy alone, sequence chemoradiotherapy, and concurrent chemoradiotherapy were administered to 10 (31.3%), 9 (28.1%), 3 (9.4%), and 10 (31.3%) patients, respectively. Twenty-nine patients (90.6%) underwent R0 resection. The median follow-up time was 38.0 months (3.3-109.5 months). After neoadjuvant therapy, 18 patients (56.3%) achieved partial response and 14 (43.8%) had stable disease. Pathologic complete response was achieved in 6 patients (18.8%), all of whom had thymic carcinoma. The 5-year overall and progression-free survival rates were 90.9% and 67.5%, respectively. For patients with thymic carcinoma, the 5-year overall and progression-free survival rates were 80.0% and 66.2%, respectively. Grade 3 toxicities were observed in only 1 patient (leukopenia).

CONCLUSIONS

For patients with primary unresectable thymic neoplasms, neoadjuvant chemoradiotherapy is an efficient and safe choice, with favorable response and survival and moderate toxicities. Patients with thymic carcinoma might benefit more from neoadjuvant therapies.

Thymic Malignancy-Updates in Staging and Management

Thymomas are relatively indolent tumors that present with locally advanced disease in 30% of the patients. Thymic carcinoma is a more aggressive histology with shorter disease-free and overall survival. Early-stage tumors are managed best with complete resection. Multimodal therapy is the standard of care for locally advanced tumors and neoadjuvant therapy may help improve respectability. Stage and complete resection are the strongest prognostic factors for long-term survival. Based on early experience, targeted and immunotherapies have shown limited promise in advanced disease.

Heart rupture repair during huge mediastinal mass resection - case report

BACKGROUND

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

CASE PRESENTATION

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

CONCLUSION

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

Does size matter? A national analysis of the utility of induction therapy for large thymomas

Background

Tumor size of 8 cm or greater is a risk factor for recurrence after thymoma resection, but the role of induction therapy for large thymomas is not well defined. This study tested the hypothesis that induction therapy for thymomas 8 cm and larger improves survival.

Methods

The use of induction therapy for patients treated with surgical resection for Masaoka stage I–III thymomas in the National Cancer Database between 2006–2013 was evaluated using logistic regression, Kaplan-Meier analysis, and Cox-proportional hazards methods.

Results

Of the 1,849 patients who met inclusion criteria, 582 (31.5%) had tumors ≥8 cm. Five-year survival was worse in patients with tumors ≥8 cm compared to smaller tumors [84.6% (95% CI: 81.2–88.1%) vs. 89.4% (95% CI: 87.2–91.7%), P=0.003]. Induction therapy was used in 166 (9.0%) patients overall and was more likely in patients with tumors ≥8 cm [adjusted odds ratio (AOR) 3.257, P<0.001]. Induction therapy was not associated with improved survival in the subset of patients with tumors ≥8 cm in either univariate [80.9% (95% CI: 72.6–90.1%) vs. 85.4% (95% CI: 81.8–89.3%), P=0.27] or multivariable analysis [hazard ratio (HR) 1.54, P=0.10]. Increasing age (HR 1.56/decade, P<0.001) and Masaoka stage III (HR 1.76, P=0.04) were associated with worse survival in patients with tumors ≥8 cm.

Conclusions

Survival after thymoma resection is worse for tumors 8 cm or larger compared to smaller tumors and is not improved by induction therapy. Size alone should not be a criterion for using induction therapy prior to thymoma resection.

Thymic epithelial tumor treatment in Japan: analysis of hospital cancer registry and insurance claims data, 2012-2014

INTRODUCTION

Thymic epithelial tumors are a rare type of neoplasm. Accordingly, it is difficult to perform phase III trials in patients with thymic epithelial tumors, and thus, no standard treatment has been established for these tumors. In this study, we aimed to investigate the current status of thymic epithelial tumor treatment in Japan.

METHODS

This retrospective observational study enrolled patients with thymic epithelial tumor whose data were recorded in a nationwide Hospital-based Cancer Registry that was linked with health insurance claims data for the registered patients between 2012 and 2014. The patients' treatment details were obtained from a health insurance claims database.

RESULTS

A total of 813 patients with thymoma and 547 with thymic carcinoma were included in the analysis. Overall, 549 (67.5%) thymoma patients underwent surgical resection alone. Among patients with thymic carcinoma, 230 (42.0%) underwent initial surgery, and 124 (53.9%) received subsequent radiotherapy and chemotherapy. Chemotherapy regimens varied across the hospitals; overall, 21 and 22 regimens were used to treat thymoma and thymic carcinoma, respectively. Platinum-based combination regimens were predominantly selected for both diseases.

CONCLUSIONS

This study revealed the real-world patterns of thymic epithelial tumor treatment in Japan. Although the nature of this study did not enable the determination of optimal treatment strategies, the simultaneous analysis of nationwide registry, insurance, efficacy and prognostic data may contribute to the establishment of a standard treatment strategy for rarely occurring cancers such as thymic epithelial tumor.

S-1 plus cisplatin with concurrent radiotherapy for locally advanced thymic carcinoma: Study protocol of LOGIK1605/JART-1501

Thymic carcinoma is a rare epithelial tumor of the thymus with a poor prognosis, and multimodal approaches are important for its treatment. Recently, a number of studies have indicated that S-1 treatment is effective against thymic carcinoma. S-1 plus cisplatin with concurrent radiotherapy is a commonly used treatment for other malignancies, including non-small cell lung cancer (NSCLC). In addition, its safety has been confirmed, and it has been reported to have a marked effect against thymic carcinoma. Therefore, we conducted a phase II study of S-1 plus cisplatin with concurrent thoracic radiotherapy for locally advanced thymic carcinoma, in which the overall response rate was employed as the primary endpoint. The secondary endpoints were overall survival, progression-free survival, and safety.

Clinical Outcomes of Up-front Surgery Versus Surgery After Induction Chemotherapy for Thymoma and Thymic Carcinoma: A Retrospective Study

INTRODUCTION

Although induction chemotherapy improves the resectability of thymic neoplasms, it is unclear whether surgery after induction chemotherapy can improve outcomes. We compared long-term outcomes of surgery with and without induction chemotherapy in patients with thymic neoplasms.

PATIENTS AND METHODS

We retrospectively investigated the clinical information of patients with thymic neoplasms at the National Taiwan University Hospital between 2005 and 2013.

RESULTS

Of 204 patients, 119 underwent direct surgery (group 1), 45 underwent surgery after induction chemotherapy (group 2), and 40 underwent no surgery (group 3). The 5-year overall survival rates of groups 1, 2, and 3 were as follows: for 204 patients, 96.3%, 76.4%, and 35.5% (P < .001); for 119 thymoma patients, 96.6%, 88.9%, and 100.0% (P = .835); for 85 thymic carcinoma patients, 94.7%, 69.7%, and 17.7% (P < .001); for 36 American Joint Committee on Cancer (AJCC) stage III-IVA thymoma patients, 92.9%, 83.3%, and 100% (P = .833); and for 28 stage III-IVA thymic carcinoma patients, 75.0%, 76.2%, and 62.5%, (P = .160). Univariate analysis showed that for group 2 (P = .0208) and group 3 (P < .0001), thymic carcinoma pathology type (P = .0010) and stage IVB disease (P < .0001) were poor prognostic factors. Multivariate analysis found thymic carcinoma (P = .0026) and stage IVB disease (P = .0449) to be poor prognostic factors.

CONCLUSION

Up-front surgery leads to best overall survival, and induction chemotherapy followed by surgery may improve resectability and outcomes. Only thymic carcinoma and stage IVB disease were poor prognostic factors in multivariate analysis.

Diagnosis of thymic epithelial tumor subtypes by a quantitative proteomic approach

This study shows the first depth proteomic profiling of all TET subtypes and six candidate biomarkers were identified and validated.

[Application of Postoperative Chemotherapy on Thymomas and Its Prognostic Effect]

背景与目的

探讨术后化疗在胸腺肿瘤中的应用及术后化疗对Masaoka Ⅲ期/Ⅳ期预后的影响。

方法

1994年3月至2012年12月, 中国胸腺瘤研究协作组(Chinese Alliance of Research for Thymomas, ChART)数据库共纳入2, 306例胸腺肿瘤病例, 资料相对完整1, 700例患者纳入本研究, 对其中Masaoka Ⅲ期/Ⅳ期665例患者进行进一步分析, 初步评估术后化疗的临床价值, 采用Kaplan-Meier法绘制不同亚组患者生存曲线, Cox回归进行多因素分析影响预后的因素。采用倾向值匹配研究(propensity-matched study, PSM), 评估化疗的临床价值。

结果

1, 700例患者中未行术后化疗1, 406例(82.7%), 术后化疗294例(17.3%), 随着Masaoka分期的增加, 术后化疗患者的比例也随之增高, 差异有统计学意义(P<0.001)。对Masaoka Ⅲ期/Ⅳ期患者665例进行进一步分析, 其中未术后化疗组444例, 术后化疗组221例。两组患者在有无重症肌无力、WHO病理类型、病理分期、手术根治性、有无术后放疗等方面分布有差异(P<0.05)。其中C型胸腺瘤、不完全切除和术后放疗明显影响患者术后复发和生存(P<0.05)。术后化疗组5年和10年无病生存率分别为51%、30%, 5年和10年复发率分别为46%、68%, 而未术后化疗组5年和10年无病生存率分别为73%、58%。5年和10年复发率分别为26%、40%, 两组无病生存率和复发率均有明显统计学差异(P=0.001, P=0.001)。对有无重症肌无力, 病理类型, 病理分期, 手术根治性状态, 术后放疗等因素进行倾向值匹配筛选出其中158例未术后化疗和158例术后化疗共316例患者, 生存分析显示:未术后化疗组和术后化疗组两组5年生存率并无明显统计学差异(P=0.332)。

结论

病理学类型、手术的根治性和术后放疗是影响进展期胸腺肿瘤患者术后生存和复发的主要因素。术后化疗并未给Masaoka-Koga Ⅲ期/Ⅳ期胸腺瘤患者带来生存获益。

[Preoperative Induction Therapy for Locally Advanced Thymic Tumors: A Retrospective Analysis Using the ChART Database]

背景与目的

探讨术前诱导治疗在胸腺瘤中的应用及其对局部进展期胸腺瘤预后的影响。

方法

收集中国胸腺肿瘤协作组（Chinese Alliance of Research for Thymomas, ChART）1994年1月1日至2012年12月31日回顾性数据库中局部进展期胸腺瘤（Masaoka-Koga分期为Ⅲ期-Ⅳa期）病例。分为诱导治疗组和直接手术组，对比分析两组的R0切除率、5年复发率及5年生存率等指标。诱导治疗组术后分期为Masaoka-Koga Ⅰ期-Ⅱ期的病例视为诱导治疗后降期。为更加精确评估诱导治疗效果，在剔除术后Ⅳ期病例的基础上，再次将诱导治疗组术后Masaoka-Koga Ⅰ期-Ⅲ期的病例与直接手术组Masaoka-Koga Ⅲ期的病例进行对比分析。

结果

ChART回顾性数据库1, 713例有效病例中，局部进展期胸腺瘤706例，仅68例（4%）作了术前诱导治疗，R0切除率为67.6%，5年复发率为44.9%，5年与10年生存率分别为49.7%和19.9%。其中17例诱导治疗后达到降期，降期亚组中胸腺瘤的比例高于胸腺癌（38.7% vs 13.9%, P=0.02）；与未降期亚组相比，降期亚组获得更高的5年生存率（93.8% vs 35.6%, P=0.013）。剔除术后Ⅳ期的病例后，直接手术组和诱导治疗组R0切除率接近（76.4% vs 73.3%, P=0.63），但5年生存率差异明显（85.2% vs 68.1%, P < 0.001），对于降期亚组，5年生存率优于直接手术组（93.8% vs 85.2%, P=0.438），未降期亚组5年生存率仅35.6%，明显差于降期亚组和直接手术组（P < 0.001）。

结论

术前诱导治疗目前尚未在局部进展期胸腺瘤中广泛应用，但ChART的回顾性数据研究显示通过有效的术前诱导治疗可以使难以彻底切除的病例降期后增加R0切除的机会，从而延长生存，特别是胸腺瘤的病例。这一初步结果将有助于未来的研究。

Induction Therapy for Thymoma

Thymomas are uncommon tumors that can present as locally advanced tumors in approximately 30% of the patients. Stage and complete resection are the strongest prognostic factors. For locally advanced tumors, induction treatment may improve the ability to achieve a complete resection. Combination treatment with cisplatin, doxorubicin, and cyclophosphamide is the most commonly used induction regimen. Similar rates of resectability are noted with the use of induction chemotherapy and chemoradiation therapy; however, more tumor necrosis is noted with the addition of radiation.

Octreotide LAR and Prednisone as Neoadjuvant Treatment in Patients with Primary or Locally Recurrent Unresectable Thymic Tumors: A Phase II Study

Therapeutic options to cure advanced, recurrent, and unresectable thymomas are limited. The most important factor for long-term survival of thymoma patients is complete resection (R0) of the tumor. We therefore evaluated the response to and the induction of resectability of primarily or locally recurrent unresectable thymomas and thymic carcinomas by octreotide Long-Acting Release (LAR) plus prednisone therapy in patients with positive octreotide scans. In this open label, single-arm phase II study, 17 patients with thymomas considered unresectable or locally recurrent thymoma (n = 15) and thymic carcinoma (n = 2) at Masaoka stage III were enrolled. Octreotide LAR (30 mg once every 2 weeks) was administered in combination with prednisone (0.6 mg/kg per day) for a maximum of 24 weeks (study design according to Fleming´s one sample multiple testing procedure for phase II clinical trials). Tumor size was evaluated by volumetric CT measurements, and a decrease in tumor volume of at least 20% at week 12 compared to baseline was considered as a response. We found that octreotide LAR plus prednisone elicited response in 15 of 17 patients (88%). Median reduction of tumor volume after 12 weeks of treatment was 51% (range 20%-86%). Subsequently, complete surgical resection was achieved in five (29%) and four patients (23%) after 12 and 24 weeks, respectively. Octreotide LAR plus prednisone treatment was discontinued in two patients before week 12 due to unsatisfactory therapeutic effects or adverse events. The most frequent adverse events were gastrointestinal (71%), infectious (65%), and hematological (41%) complications. In conclusion, octreotide LAR plus prednisone is efficacious in patients with primary or recurrent unresectable thymoma with respect to tumor regression. Octreotide LAR plus prednisone was well tolerated and adverse events were in line with the known safety profile of both agents.

Preoperative induction therapy for locally advanced thymic tumors: a retrospective analysis using the ChART database

BACKGROUND

To evaluate the role of preoperative induction therapy on prognosis of locally advanced thymic malignancies.

METHODS

Between 1994 and 2012, patients received preoperative induction therapies (IT group) in the Chinese Alliance for Research in Thymomas (ChART) database, were compared with those having surgery directly after preoperative evaluation (DS group). All tumors receiving induction therapies were locally advanced (clinically stage III-IV) before treatment and those turned out to be in pathological stage I and II were considered downstaged by induction. Clinical pathological characteristics were retrospectively analyzed. To more accurately study the effect of induction therapies, stage IV patients were then excluded. Only stage I-III tumors in the IT group and stage III cases in the DS group were selected for further comparison in a subgroup analysis.

RESULTS

Only 68 (4%) out of 1,713 patients had induction therapies, with a R0 resection of 67.6%, 5-year recurrence of 44.9%, and 5- and 10-year overall survivals (OS) of 49.7% and 19.9%. Seventeen patients (25%) were downstaged after induction. Significantly more thymomas were downstaged than thymic carcinomas (38.7% vs. 13.9%, P=0.02). Tumors downstaged after induction had significantly higher 5-year OS than those not downstaged (93.8% vs. 35.6%, P=0.013). For the subgroup analysis when stage IV patients were excluded, 5-year OS was 85.2% in the DS group and 68.1% in the IT group (P=0.000), although R0 resection were similar (76.4% vs. 73.3%, P=0.63). However, 5-year OS in tumors downstaged after induction (93.8%) was similar to those in the DS group (85.2%, P=0.438), both significantly higher than those not downstaged after induction (35.6%, P=0.000).

CONCLUSIONS

Preoperative neoadjuvant therapy have been used only occasionally in locally advanced thymic malignances. Effective induction therapy leading to tumor downstaging may be beneficial for potentially unresectable diseases, especially in patients with thymomas. These findings would be helpful to related studies in the future.

The application of postoperative chemotherapy in thymic tumors and its prognostic effect

BACKGROUND

To study the role of postoperative chemotherapy and its prognostic effect in Masaoka-Koga stage III and IV thymic tumors.

METHODS

Between 1994 and 2012, 1,700 patients with thymic tumors who underwent surgery without neoadjuvant therapy were enrolled for the study. Among them, 665 patients in Masaoka-Koga stage III and IV were further analyzed to evaluate the clinical value of postoperative chemotherapy. The Kaplan-Meier method was used to obtain the survival curve of the patients divided into different subgroups, and the Cox regression analysis was used to make multivariate analysis on the factors affecting prognosis. A Propensity-Matched Study was used to evaluate the clinical value of chemotherapy.

RESULTS

Two-hundred and twenty-one patients were treated with postoperative chemotherapy, while the rest 444 cases were not. The two groups showed significant differences (P<0.05) regarding the incidence of myasthenia gravis, World Health Organization (WHO) histological subtypes, pathological staging, resection status and the use of postoperative radiotherapy. WHO type C tumors, incomplete resection, and postoperative radiotherapy were significantly related to increased recurrence and worse survival (P<0.05). Five-year and 10-year disease free survivals (DFS) and recurrence rates in patients who underwent surgery followed by postoperative chemotherapy were 51% and 30%, 46% and 68%, comparing with 73% and 58%, 26% and 40% in patients who had no adjuvant chemotherapy after surgery (P=0.001, P=0.001, respectively). In propensity-matched study, 158 pairs of patients with or without postoperative chemotherapy (316 patients in total) were selected and compared accordingly. Similar 5-year survival rates were detected between the two groups (P=0.332).

CONCLUSIONS

Pathologically higher grade histology, incomplete resection, and postoperative radiotherapy were found to be associated with worse outcomes in advanced stage thymic tumors. At present, there is no evidence to show that postoperative chemotherapy may help improve prognosis in patients with Masaoka-Koga stage III and IV thymic tumors.

[Thymus cancers: A clinical observation]

INTRODUCTION

Thymic tumors including thymomas, thymic carcinomas, and thymic carcinoid tumors are rare tumors with an incidence of 0.13/100,000.

MATERIALS AND METHODS

A literature search was performed to identify recent findings on epidemiology, classification, and various therapeutic approaches.

RESULTS

These tumors with a wide spectrum of histologic and biologic features may be clinically unapparent for a long time or show a very aggressive behavior with local invasion and distant metastases. Surgical resection is the mainstay in stage I and II thymomas, whereas in stage III thymomas and in thymomas with pleural dissemination surgery in context of a multimodal treatment should be discussed. Thymic tumors are chemoreactive. Targeted therapies show poor results and should only be considered in the palliative situation after failure of chemotherapy.

CONCLUSION

The new TNM (T: tumor, N: node, M: metastasis) classification of thymic tumors will help to identify the best treatment options.

Management of metastatic malignant thymoma with advanced radiation and chemotherapy techniques: report of a rare case

Malignant thymomas are rare epithelial neoplasms of the anterior superior mediastinum that are typically invasive in nature and have a higher risk of relapse that may ultimately lead to death. Here we report a case of an advanced malignant thymoma that was successfully treated with neoadjuvant chemotherapy followed by surgical resection and subsequently with advanced and novel radiation therapy techniques. A 65-year-old male was diagnosed with a stage IV malignant thymoma with multiple metastatic lesions involving the left peripheral lung and pericardium. Initial neoadjuvant chemotherapy with a cisplatin-based regimen resulted in a partial response allowing the inoperable tumor to become operable. Following surgical resection of the residual disease, the tumor recurred within a year. The patient then underwent a course of targeted three-dimensional intensity modulated radiation therapy (IMRT) and image-guided radiation therapy (IGRT). Five years after radiation therapy, the localized soft tissue thickening at the left upper lung anterior pleural space had resolved. Seven years after radiation therapy the tumor mass had completely resolved. No recurrences were seen and the patient is well even 8 years after IMRT/IGRT with a favorable outcome. Chemotherapy with targeted three-dimensional IMRT/IGRT should be considered the primary modality for the management of advanced malignant thymoma patients.

Thymic epithelial tumors: analysis of prognostic factors with emphasis on the role of adjuvant radiation therapy

BACKGROUND

The prognostic impacts of histopathological classification, Masaoka staging system, extent of surgery, and adjuvant treatment approaches in thymic epithelial tumors (TETs) were investigated.

MATERIAL AND METHODS

Records of 22 patients were retrospectively reviewed. Total thymectomy was performed on 5 patients and thymectomy on 17. Complete resection was achieved for 14 patients. Radiation therapy (RT) was considered for all patients with stage III or IV disease and all patients undergoing incomplete resections.

RESULTS

Local control had been achieved in all patients and all were alive with no evidence of disease (ANED) at 0.2-7.8 years (median, 2.3 years). Of 4 patients with stage II disease, 2 (favorable group) had undergone complete resections and 2 (intermediate group) had undergone incomplete resections. Those undergoing incomplete resections had received RT. Of these 4 patients, all were ANED. All 4 patients with Masaoka stage III disease that were involved in the study had undergone incomplete resections and had received RT. Also, these patients were ANED.

CONCLUSIONS

Patients with TETs undergoing less than complete resections might be referred for RT in the postoperative setting, while the role of RT in patients undergoing complete resections remains unclear.

Therapy for thymic epithelial tumors

Thymoma is the most common tumor of the anterior mediastinum. This tumor is associated with unique paraneoplastic syndromes. The rarity of this tumor has somewhat obscured the optimal treatment for this disease. The World Health Organization classification system, which published in 1999, appears to be an advance in our understanding of thymoma. The Masaoka classification is now the most widely accepted and is an excellent predictor of the prognosis of thymoma. Now the International Thymic Malignancy Interest Group is currently engaged in the development of a validated formal TNM classification system for thymic malignancies. The optimal treatment of thymoma is performed according to its clinical stage. Surgery remains the mainstay of treatment for thymic epithelial tumors. Minimally invasive surgery including thoracoscopic surgery and robotic surgery for stage I and II thymomas is increasing now. The value of postoperative radiotherapy in completely resected stage II or III tumors is questionable. As thymomas have a moderate response rate to chemotherapy or radiotherapy, multimodality therapy involving surgery, chemotherapy and radiotherapy appears to increase the rate of complete resection and survival in the advanced (stage III and IV) thymomas.

Thymic neoplasms: an update on the use of chemotherapy and new targeted therapies. A literature review

Thymic malignancies represent a wide range of clinical, histological and molecular entities, with probably considerable heterogeneity even among tumors of the same histotype. Systemic chemotherapy with cisplatin-based regimens continues to represent the standard of care in metastatic or inoperable refractory/recurrent diseases and ADOC regimen (including cisplatin, doxorubicin, vincristine and cyclophosphamide) demonstrated the longer overall response rate and median survival in the first line setting, although no randomized trial is available; and there is still a lack of standard treatment after first-line failure. To date research efforts are focused on translational studies on molecular pathways involved in thymic tumors carcinogenesis, aimed to better understand and predict the efficacy of chemotherapy and targeted therapy. Recent molecular characterization includes identification of a number of oncogenes, tumor suppressor genes, chromosomal aberrations, angiogenic factors, and tumor invasion factors involved in cellular survival and proliferation and in tumor growth. The use of biologic drugs is currently not recommended in a routine practice because there are limited data on their therapeutic role in thymic epitelial tumors. Because of the lack of data from adequate-sized, prospective trials are required for validation and the enrolment of patients with advanced disease into available clinical trials has to be encouraged.

Chemotherapy for thymic carcinoma and advanced thymoma in adults

BACKGROUND

Thymic carcinoma or advanced thymoma is a rare cancer of the thymus gland that tends to be aggressive and infiltrate neighbouring organs, making total resection very difficult. Induction or adjuvant chemotherapy, or both, are often used in a multimodality approach to treat people affected by this condition, but the effectiveness of chemotherapy for thymic carcinoma or advanced thymoma remains uncertain.

OBJECTIVES

To assess the role of chemotherapy in adults with thymic carcinoma or advanced thymoma.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 7), MEDLINE (accessed via Ovid from 1966 to July 2012), EMBASE (accessed via Ovid, from 1980 to July 2012), Latin American and Caribbean Literature on Health Sciences (LILACS), the Chinese Biological Medicine Database (CBM, 1978 to July 2012), China National Knowledge Infrastructure (CNKI, 1980 to July 2012) and the Chinese scientific periodical database VIP Information (VIP, 1989 to July 2012). There was no language restriction in searching for studies.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs) of  trials using chemotherapy (either single-agent or combination chemotherapy plus surgery, radiotherapy or not) for thymic carcinoma and/or advanced thymoma. We planned to include all adults (aged 18 years and over) diagnosed with thymic carcinoma and/or with Masaoka stage III or IV thymic tumours. The intended primary outcomes were overall survival (OS) and progression-free survival (PFS).

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated the search results according to the inclusion and exclusion criteria. There were no studies identified for inclusion and therefore no data extraction was completed.

MAIN RESULTS

No RCTs were eligible for inclusion in this review. We report details of excluded prospective studies in an additional table and try to provide some useful evidence regarding current practice.

AUTHORS' CONCLUSIONS

There were no RCTs eligible for inclusion in this review. In current practice the most common regimen for adult patients with thymic carcinoma or advanced thymoma is cisplatin-based chemotherapy. Considering the condition is rare, it is suggested that an international group is set up to organise and evaluate prospective collection of data from cohorts of patients to inform current clinical practice.

Thymoma: a population-based study of the management and outcomes for the province of British Columbia

INTRODUCTION

Thymomas are rare neoplasms with variable clinical behavior. Our primary study aim was to analyze treatment practices and outcomes in a population-based cohort of thymoma patients. We hypothesized that stage I and II thymomas would have high cure rates with resection and adjuvant radiation, whereas locally advanced cases would benefit from multimodality therapy.

METHODS

All patients, diagnosed with thymoma or thymic carcinoma in British Columbia between 1994 and 2009, were identified using the British Columbia Cancer Agency Registry. Chart review was used to collect demographic and treatment data. Detailed pathology review was performed using the World Health Organization classification.

RESULTS

One hundred and seventy-one patients were identified for analysis. The 5-year overall survival was 93.3%, 88.7%, 74.6%, 43.4% for stages I, II, III, and IV, respectively. Survival varied significantly among patients with thymoma compared with thymic carcinoma. In patients with stage II disease, adjuvant radiation did not confer an overall survival or recurrence-free survival benefit. Seventy-five patients had locally advanced disease. There was practice variation in treatment of these patients. Patients with thymoma undergoing trimodality treatment had a 5-year median overall survival of 80%, whereas patients with thymic carcinoma had poor outcomes despite aggressive treatment.

CONCLUSIONS

Survival rates in this population-based series were comparable to those in previously published reports. The ideal management of thymic tumors involves a multidisciplinary approach, particularly in locally advanced disease and selection of patients for adjuvant radiation therapy.

Thymoma: from chemotherapy to targeted therapy

Thymic malignancies are rare epithelial tumors that may be aggressive and difficult to treat. Thymomas are frequently eligible for upfront surgical resection. However, nearly 30% of patients present with locally advanced tumor at time of diagnosis, and chemotherapy is then used to reduce the tumor burden-possibly allowing subsequent surgery and/or radiotherapy. Metastatic and recurrent thymic malignancies may be similarly treated with chemotherapy. More recently, the molecular characterization of thymoma led to the identification of potentially druggable targets, laying the foundation to implement personalized medicine for patients.

Induction therapy for thymic malignancies

Thymic malignancies are rare tumors of the chest that express a broad range of biological behaviors. Surgery remains the mainstay of therapy, and complete surgical resection is the primary predictor of long-term survival. Although there is a paucity of clinical trials assessing the role of induction/adjuvant chemotherapy and/or radiation therapy in the treatment of thymic malignancies, existing data suggest that induction therapy should be offered for the treatment of advanced-stage disease, and postoperative radiation for specific stages.

Chemotherapy for thymic tumors: induction, consolidation, palliation

Although thymoma and thymic carcinoma are rare malignancies, they constitute a large proportion of tumors of the anterior mediastinum. Surgery forms the mainstay of therapy; however, thymic malignancies are sensitive to chemotherapy and radiation therapy also. Systemic chemotherapy is primarily used for treatment of metastatic or recurrent disease. Chemotherapy is also used as a component of multimodality treatment in the neoadjuvant setting with the aim of increasing the chances of achieving a complete surgical resection. In this article we outline various clinical trials that have been performed to evaluate the role of chemotherapy in the treatment of thymic malignancies.

Induction therapy for locally advanced thymoma

Thymomas are the most frequently encountered tumors of the mediastinum and often present with either localized or locally advanced disease. The prognosis in thymoma has been consistently shown to correspond to the invasiveness of the tumor (as represented by the Masaoka stage of the tumor) and the completeness of surgical resection. Because treatment with a variety of different chemotherapy regimens has demonstrated radiographic response rates greater than 50% in patients with advanced thymoma, a number of investigators have explored the use of preoperative (induction, neoadjuvant) therapy for patients with locally advanced thymoma. In this review, we summarize the published experience with preoperative therapy for thymoma and discuss ongoing clinical trials exploring multimodality therapy for treatment of locally advanced thymoma.