Long-term follow-up and exploratory analysis of lenvatinib in patients with metastatic or recurrent thymic carcinoma: Results from the multicenter, phase 2 REMORA trial

OBJECTIVES

The main objective of this report was to detail the long-term follow-up data from the REMORA study, which investigated the safety and efficacy of lenvatinib in patients with thymic carcinoma. In addition, an exploratory analysis of the association between relative dose intensity (RDI) and the efficacy of lenvatinib is presented.

MATERIALS AND METHODS

The single-arm, open-label, phase 2 REMORA study was conducted at eight Japanese institutions. Forty-two patients received oral lenvatinib 24 mg once daily in 4-week cycles until the occurrence of intolerable adverse events or disease progression. The REMORA long-term follow-up data were evaluated, including overall survival (OS). RDI was calculated by dividing the actual dose administered to the patient by the standard recommended dose. This trial is registered on JMACCT (JMA-IIA00285) and on UMIN-CTR (UMIN000026777).

RESULTS

The updated median OS was 28.3 months (95 % confidence interval [CI]: 17.1-34.0 months), and the OS rate at 36 months was 35.7 % (95 % CI: 21.7 %-49.9 %). When grouped by RDI of lenvatinib, the median OS was 38.5 months (95 % CI: 31.2-not estimable) in patients with ≥ 75 % RDI and 17.3 months (95 % CI: 13.4-26.2 months) in patients with < 75 % RDI (hazard ratio 0.46 [95 % CI: 0.22-0.98]; P = 0.0406) at 8 weeks. Patients who maintained their lenvatinib dose over 8 weeks had a higher objective response rate than patients whose doses were reduced (75.0 % vs 29.4 %; P = 0.0379). No new safety concerns or treatment-related deaths were reported, and lenvatinib had a tolerable safety profile.

CONCLUSION

This follow-up report updated OS in patients with metastatic or recurrent thymic carcinoma. A higher RDI of lenvatinib at 8 weeks could be associated with improved outcomes.

Long-term outcomes following surgical treatment for thymic epithelial tumor in Japan and an analysis of prognostic factors based on the Japanese Association for Research on the Thymus nationwide database

PURPOSE

Patients with a thymic epithelial tumor (TET), comprising thymoma, thymic carcinoma (TC), and thymic neuroendocrine neoplasm (TNEN), are rarely encountered. The present study was conducted to determine the recent outcomes of surgical treatment for TET in Japan and clarify the significance of prognostic factors by analyzing a nationwide database created by the Japanese Association for Research on the Thymus (JART).

METHODS

The JART database includes records of 2471 thymoma, 285 TC, and 56 TNEN cases surgically treated between 1991 and 2010. At the time of the final follow-up examination, 439 patients had died, with tumor the cause of death in 188. The disease-specific survival was examined using the Kaplan-Meier method, with Cox's proportional hazards model utilized to determine independent prognostic factors.

RESULTS

The 10-year survival rate according to TNM-based Stage I, II, IIIA, IIIB, IVA, and IVB classification was 98.7%, 76.8%, 85.0%, 68.9%, 66.2%, and 59.8%, respectively. The T factor, M factor, and tumor size were independent prognostic factors in both thymoma and thymic carcinoma cases, while the N factor had tendency to be a prognostic factor in thymoma but not in thymic carcinoma cases. The WHO histological type was an independent factor in thymoma cases.

CONCLUSION

The significance of pathology and TNM classification as prognostic factors was confirmed.

The incidence and prognosis of thymic squamous cell carcinoma: A Surveillance, Epidemiology, and End Results Program population-based study

BACKGROUND

Thymic carcinoma represents a rare type of malignant mediastinal tumor and has been the subject of controversy. Although independent prognostic factors related to thymic carcinoma have been investigated previously, few studies have focused specifically on the survival outcomes associated with thymic squamous cell carcinoma (TSCC). This study aims at presenting a survival analysis in this rare malignant disease at population level.

METHODS

We extracted the data of 216 patients with TSCC recorded from 1973 to 2015 from the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. The patients' demographic features, clinical traits, and treatment factors were analyzed in order to identify prognostic factors, which correlate overall survival using the Kaplan-Meier method as well as a multivariate Cox regression model, for TSCC.

RESULTS

The majority of patients were male, Caucasian, married, and insured. Furthermore, 58.3%, 54.6%, and 59.7% of patients TSCC underwent surgery, radiotherapy, and chemotherapy respectively. In a multivariate analysis, age of diagnosis (hazard ratio [HR]: 1.022, 95% confidence interval [CI]: 1.003-1.040, P = .020), surgical treatment (HR: 0.282, 95% CI: 0.164-0.484, P = .000), and stage (regional vs distant HR: 0.532, 95% CI: 0.324-0.872, P = .013; localized vs distant HR: 0.297, 95% CI: 0.133-0.664, P = .003) correlated with increased overall survival, whereas adjuvant therapy, including chemotherapy and radiotherapy, did not correlate with survival. Among surgically treated patients, age of diagnosis and stage were associated with better overall survival, while chemotherapy and radiotherapy did not contribute significantly to overall survival.

CONCLUSION

Surgery, age of diagnosis, and stage were associated with better overall survival among TSCC.

Primary thymus tumors: retrospective case analysis at a reference center in Latin America, 2011-2019

BACKGROUND

Thymic tumors are unusual neoplasms, representing 0.2 to 1.5% of tumors in humans, but correspond to 20% of mediastinal tumors and 50% of those that occur in the anterior mediastinum. They tend to appear around the fourth and fifth decades of life without gender predilection. Up to 30% of patients are asymptomatic, therefore many are incidentally diagnosed. Radical thymectomy is the treatment of choice with high survival rates when detected in the early stages.

METHODS

This was a retrospective descriptive study, including 18 adult patients' diagnosis of thymic neoplasm, who were managed with surgical resection from 2011 to 2019. Information about demographics, clinical characteristics, imaging findings, surgical and medical management, plus histological findings was obtained and reported.

RESULTS

18 patients with thymic tumors were included, of which specific histologic studies reveled thymomas, carcinomas, neuroendocrine tumors, thymolipoma and thymic cyst. Mean age was 52.7 years, with a predominance of male population. The main symptom was dyspnea, followed by cough and chest pain. Paraneoplastic syndromes such as myasthenia gravis, aplastic anemia and Cushing syndrome were reported. 89% of cases were treated by radical thymectomy alone, while only 2 cases required chemotherapy and radiotherapy. There were no surgical complications. Mean hospital stay length was 11. 9 days, with only 1 mortality during hospital admission. 5-year survival rate was 81%.

CONCLUSIONS

The treatment of choice is radical thymectomy, which has been shown to positively impact patient mortality. Early detection is key to improve patient outcomes.

Lenvatinib in patients with advanced or metastatic thymic carcinoma (REMORA): a multicentre, phase 2 trial

BACKGROUND

Thymic carcinoma is a rare malignant disease and standard treatment for advanced or metastatic thymic carcinoma previously treated with platinum-based chemotherapy has not been established. Lenvatinib is a novel multi-targeted inhibitor of VEGFR, FGFR, RET, c-Kit, and other kinases. The aim of this trial was to assess the activity and safety of lenvatinib as a second-line treatment in thymic carcinoma.

METHODS

This single-arm, phase 2 trial done in eight institutions in Japan (five cancer centres, two medical university hospitals, and one public hospital) enrolled patients with pathologically confirmed unresectable advanced or metastatic thymic carcinoma that progressed following at least one platinum-based chemotherapy. Key inclusion criteria were age 20 years or older, at least one measurable lesion as defined by the Response Evaluation Criteria in Solid Tumors version 1.1, and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received 24 mg of lenvatinib orally once daily in 4-week cycles until disease progression or occurrence of unacceptable adverse events. The primary endpoint was objective response rate evaluated at the data cutoff date (Feb 22, 2019), by independent central review in the intention-to-treat population. This trial is registered on JMACCT, JMA-IIA00285, and on UMIN-CTR, UMIN000026777.

FINDINGS

Between April 21, 2017, and Feb 22, 2018, 42 patients were enrolled and all patients were included in the activity and safety analysis. The median follow-up period was 15·5 months (IQR 13·1-17·5). The objective response rate was 38% (90% CI 25·6-52·0, p<0·0001). 16 (38%) of 42 patients had a partial response and 24 (57%) had stable disease. The most frequent grade 3 treatment-related adverse events were hypertension (27 [64%]) and palmar-plantar erythrodysaesthesia syndrome (three [7%]). No patient died from adverse events.

INTERPRETATION

The activity and safety of lenvatinib in patients with advanced or metastatic thymic carcinoma was confirmed. These results suggest that lenvatinib could become a standard treatment option for patients with previously treated advanced or metastatic thymic carcinoma.

FUNDING

Center for Clinical Trials, Japan Medical Association.

A national analysis of open versus minimally invasive thymectomy for stage I to III thymoma

OBJECTIVE

The oncologic efficacy of minimally invasive thymectomy for thymoma is not well characterized. We compared short-term outcomes and overall survival between open and minimally invasive (video-assisted thoracoscopic and robotic) approaches using the National Cancer Data Base.

METHODS

Perioperative outcomes and survival of patients who underwent open versus minimally invasive thymectomy for clinical stage I to III thymoma from 2010 to 2014 in the National Cancer Data Base were evaluated using multivariable Cox proportional hazards modeling and propensity score-matched analysis. Predictors of minimally invasive use were evaluated using multivariable logistic regression. Outcomes of surgical approach were evaluated using an intent-to-treat analysis.

RESULTS

Of the 1223 thymectomies that were evaluated, 317 (26%) were performed minimally invasively (141 video-assisted thoracoscopic and 176 robotic). The minimally invasive group had a shorter median length of stay when compared with the open group (3 [2-4] days vs 4 [3-6] days, P < .001). In a propensity score-matched analysis of 185 open and 185 minimally invasive (video-assisted thoracoscopic + robotic) thymectomy, the minimally invasive group continued to have a shorter median length of stay (3 vs 4 days, P < .01) but did not have significant differences in margin positivity (P = .84), 30-day readmission (P = .28), 30-day mortality (P = .60), and 5-year survival (89.4% vs 81.6%, P = .20) when compared with the open group.

CONCLUSIONS

In this national analysis, minimally invasive thymectomy was associated with shorter length of stay and was not associated with increased margin positivity, perioperative mortality, 30-day readmission rate, or reduced overall survival when compared with open thymectomy.

Neoadjuvant therapy for thymic neoplasms reduces tumor volume per 3D-reconstructed images but does not improve the complete resection rate

Objectives

Complete resection of thymic neoplasms is important for achieving a favorable prognosis; however, the efficacy of neoadjuvant therapy remains controversial. We investigated the effect of induction therapy on complete resection and survival using 3-dimensionally reconstructed images to measure tumor volume.

Methods

Eighty-nine patients who underwent surgical resection for Masaoka-Koga stage III–IV thymic neoplasms between January 2000 and December 2013 were enrolled, including 71 and 18 in the primary surgery and neoadjuvant therapy groups, respectively. Baseline characteristics, postoperative outcomes, and survival rates were analyzed. Moreover, baseline and post-neoadjuvant therapy tumor volumes were compared among patients in the neoadjuvant group.

Results

Adjacent mediastinal structure invasion was significantly rarer in the primary surgery group than in the neoadjuvant group (1.27±1.09 vs. 2.61±1.42, p<0.001). On subgroup analysis of patients who underwent neoadjuvant therapy, tumor volumes decreased significantly from 206.08±132.32 cm³ to 81.25±71.24 cm³ post-therapy (p = 0.001). Interestingly, only the pre-neoadjuvant tumor volume was significantly associated with complete resection, while the post-neoadjuvant volume was not (p = 0.012 and p = 0.458, respectively). Moreover, despite significantly reduced tumor volumes, patients in the neoadjuvant therapy group did not exhibit significantly different R0 resection rates (odds ratio 1.490, p = 0.581) or overall survival (p = 0.285) compared to those in the primary surgery group.

Conclusions

Neoadjuvant therapy does not significantly influence the R0 resection rate or overall survival relative to primary surgery. Nevertheless, it may by useful for patients planning surgical resection because it significantly reduces the presurgical tumor volume and extent of invasion.

Capecitabine and Temozolomide as a Promising Therapy for Advanced Thymic Atypical Carcinoid

BACKGROUND

Thymic atypical carcinoid (TAC) is a rare thymic neuroendocrine tumor that originates in the neuroendocrine system and lacks a standardized treatment. The combination of capecitabine (CAP) and temozolomide (TEM) is associated with an extremely high and long-lasting response rate in patients with metastatic pancreatic neuroendocrine tumors. However, there is little evidence showing that the CAPTEM regimen is effective for TAC. For patients with unresectable or metastatic atypical carcinoid of the thymus, few treatment options are available, and the treatment efficacy is not satisfactory. To explore the efficacy and safety of the CAPTEM regimen against TAC, we conducted a retrospective review.

PATIENTS AND METHODS

A total of nine patients with advanced atypical carcinoid of the thymus in the China-Japan Friendship Hospital were treated with capecitabine (750 mg/m² twice daily, days 1-14) and temozolomide (200 mg/m² once daily, days 10-14) every 28 days between 2014 and 2018. The disease control rate (DCR), progression-free survival (PFS), and adverse effects after treatment were analyzed. The DCR was calculated by RECIST version 1.1. Progression-free survival was calculated by the Kaplan-Meier survival method.

RESULTS

A total of nine patients (six male and three female) were included. The median age at CAPTEM initiation was 50 years (range, 26-58). The median number of CAPTEM cycles was 8 (range, 3-23). The DCR was 89% (8/9), with eight patients achieving stable disease. Only one patient (11%) showed progressive disease. The median PFS was 8 months. Because we applied vitamin B6 and ondansetron before administering the drugs, the side effects of this regimen were very small. Adverse reactions were all below grade 3 and included myelosuppression and digestive tract reaction.

CONCLUSION

Our results suggest that the CAPTEM regimen may be effective and well tolerated for the treatment of TAC. More evidence is needed to validate the effectiveness of this regimen.

IMPLICATIONS FOR PRACTICE

Capecitabine and temozolomide regimen is effective and well tolerated in patients with advanced thymic atypical carcinoid.

Isonicotinic Acid Hydrazide and Urethan Carcinogenesis in suckling SWR Mice

Five i.p. injections of 1 mg urethan/g body weight on alternate days administered to 10-day old SWR mice resulted in the development of thymic lymphosarcomas in 60 % and of lung adenomas in nearly 100 % of the animals, irrespective of sex. Concurrent treatment with isonicotinic acid hydrazide (INH), 0.1 mg/g body weight, administered five times on alternate days starting at 9 days of age, did not modify the carcinogenic effect of urethan. The treatment with INH alone did not induce a higher tumor incidence than in untreated controls.

Pembrolizumab in patients with thymic carcinoma: a single-arm, single-centre, phase 2 study

BACKGROUND

Treatment options are limited for patients with thymic carcinoma. These aggressive tumours are not typically associated with paraneoplastic autoimmune disorders, and strong PD-L1 expression has been reported in thymic epithelial tumours. We aimed to assess the activity of pembrolizumab, a monoclonal antibody that targets PD-1, in patients with advanced thymic carcinoma.

METHODS

We completed a single-arm phase 2 study of pembrolizumab in patients with recurrent thymic carcinoma who had progressed after at least one line of chemotherapy. This was a single-centre study performed at Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA. Key inclusion criteria were an Eastern Cooperative Oncology Group performance status of 0-2, no history of autoimmune disease or other malignancy requiring treatment or laboratory abnormality, and adequate organ function. Patients received 200 mg of pembrolizumab every 3 weeks for up to 2 years. The primary objective of the study was the proportion of patients who had achieved a response assessed with Response Evaluation Criteria in Solid Tumors version 1.1. Analysis was per protocol, in all eligible patients. The study is registered with ClinicalTrials.gov, number NCT02364076, and is closed to accrual; we report the final analysis.

FINDINGS

41 patients were enrolled from March 12, 2015, to Dec 16, 2016, of whom 40 were eligible and evaluable and one was excluded because of elevated liver enzymes at screening. The median follow-up was 20 months (IQR 14-26). The proportion of patients who achieved a response was 22·5% (95% CI 10·8-38·5); one (3%) patient achieved a complete response, eight (20%) patients achieved partial responses, and 21 (53%) patients achieved stable disease. The most common grade 3 or 4 adverse events were increased aspartate aminotransferase and alanine aminotransferase (five [13%] patients each). Six (15%) patients developed severe autoimmune toxicity, including two (5%) patients with myocarditis. There were 17 deaths at the time of analysis, but no deaths due to toxicity.

INTERPRETATION

Pembrolizumab is a promising treatment option in patients with thymic carcinoma. Because severe autoimmune disorders are more frequent in thymic carcinoma than in other tumour types, careful monitoring is essential.

FUNDING

Merck & Co.

Treatment, prognostic markers, and survival in thymic neuroendocrine tumors: A single center experience of 41 patients

Neuroendocrine tumors of the thymus (NETTs) are rare but aggressive, and lead to poor overall survival. This retrospective study was designed to analyze factors that correlate with the prognosis of patients with NETTs.From 1999 to 2015, 41 ongoing patients with NETTs were enrolled in this study. The clinical data and outcome were compiled. Overall survival (OS) rate was analyzed using the Kaplan-Meier method in univariate analysis and the Cox-model was used in multivariate analysis.Of the 41 NETTs patients analyzed (31 male and 10 female), 12 were typical carcinoma, 14 were atypical carcinoma, 14 were small-cell carcinoma and, 1 was large-cell carcinoma. The median follow-up time was 29 months (range, 9.0-69.0). In total, 25 patients died of cancer-related disease by the last follow-up. The 3- and 5-year survival rates for all patients were 42.7% and 23.4%, respectively. Among the prognostic factors analyzed by multivariate analysis, low tumor grade, complete resection, and a negative chromogranin A (CgA) expression were positively correlated with survival.The surgical treatment of NETTs, CgA negative, and low grade of NETTs were associated with a statistically significant better prognosis. However, large, multicenter studies are required to fully validate these prognostic factors.

Long term oncological outcome of thymoma and thymic carcinoma - an analysis of 235 cases from a single institution

BACKGROUND AND OBJECTIVES

Thymoma has a variable long-term oncological outcome after surgical resection. Survival and tumor recurrence were analyzed to determine the predisposing factors for tumor recurrence.

METHODS

A total of 235 patients who underwent surgery for thymoma or thymic carcinoma from December 1997 to March 2013 were analyzed using Masaoka staging system and World Health Organization (WHO) histological classification. Surgical intervention included extended thymothymectomy via median sternotomy and thymomectomy via thoracotomy/ video-assisted thoracoscopic surgery (VATS).

RESULTS

The median duration of follow-up was 105 months (12-198 months). Among these 235 patients, recurrence was observed in 25 patients (10.7%). according to Masaoka stage I, IIA, IIB, III, IVA, IVB, recurrence rates were 1/65(1.5%), 8/106(7.5%), 1/32(3.1%), 6/20(30.0%), 8/10(80.0%), 1/1(100.0%), respectively. Disease or treatment-related mortality was observed in 13 patients. Overall survival rate was 94.4%. After univariate analysis, predisposing factors for tumor recurrence included Masaoka stage, WHO histologic type, tumor size, adjuvant therapy and margin status.

CONCLUSIONS

Due to the indolent behavior of thymoma, tumor recurrence appears to be a better assessment of oncological outcome rather than survival. Factors associated with tumor recurrence include Masaoka stage, WHO histologic type, tumor size, adjuvant therapy and margin status.

Single-center retrospective analysis of 162 cases with thymoma complicating myasthenia gravis

PURPOSE

We conducted this study to retrospectively analyze the clinical effects of surgical resection for patients with myasthenia gravis (MG) complicated with thymoma.

METHODS

162 patients with myasthenia gravis complicated with thymoma, that were admitted to our hospital and underwent surgical disease resection from Nov. 1993 to Nov. 2015, were selected for this study. Analyzed were the pathology (2004 WHO), Masaoka clinical stage, myasthenia gravis types (Osserman types), myasthenic crisis during the perioperative period, and the relationship between recurrence and survival rates during follow-up visits. Operational methods included thymusectomy by sternal incision or video-assisted thoracoscopic thymusectomy.

RESULTS

There were significant differences regarding distribution of clinical stages among different types of pathology. The operation time, efficacy rate, 5 and 10-year survival rates and complication rates during the perioperative period of video-assisted thoracoscopy were compared to those of the conventional surgery group. Among these groups, hemorrhage during operation, postoperative drainage and recurrence rate were significantly lower in the thoracoscopy group than in those of the conventional surgery group (p<0.05).

CONCLUSION

The pathology type and clinical stages of thymoma complicating myasthenia gravis are related to the types of myasthenia gravis and the myasthenic crisis during perioperative period. Therefore, our results indicate that the thoracoscope treatment is safe and effective.

Comparison of outcomes between neuroendocrine thymic tumours and other subtypes of thymic carcinomas: a joint analysis of the European Society of Thoracic Surgeons and the International Thymic Malignancy Interest Group

OBJECTIVES

The latest World Health Organization (WHO) histological classification divides thymic epithelial tumours in thymomas and thymic carcinomas (TCs), the latter also including the neuroendocrine thymic tumours (NETTs). NETTs and other TC histotypes have been described to have a significantly lower survival than thymomas, but these two groups of tumours have rarely been compared directly. Using the European Society of Thoracic Surgeons and the International Thymic Malignancy Interest Group datasets, we wanted to study this issue.

METHODS

This is a retrospective multicentre cohort study of patients operated for TC. Outcome measures were overall survival (OS) and recurrence-free survival (RFS). OS was analysed using the Kaplan-Meier method and RFS was assessed using competing risk analysis. The association with clinical and prognostic factors for OS and RFS was evaluated with log-rank test and Gray's test, respectively.

RESULTS

A total of 1247 tumours (1042 TCs) were collected between 1984 and 2012. A R0 resection was performed in 363 TCs and in 52 NETTs. The median follow-up was 4.4 years for TCs and 4.1 years for NETTs. Owing to the missing values for survival information, a total of 728 TC patients and 132 NETTs were included in the OS analysis. Among them, 262 TC and 39 NETT patients died. The median OS was 6.6 years for TC and 7.5 years for NETTs. The overall 5-year survival rates were 60% for TC and 68% for NETTs; 10-year survival rates were 40% for TCs and 39% for NETTs (P = 0.19). Five-year RFS was 0.35 and 0.34 for TCs and NETTs (P = 0.36). On multivariate analysis, histology did not influence either OS (P = 0.79) or RFS (P = 0.59).

CONCLUSIONS

This represents the largest clinical series of TCs and NETTs collected. Despite the biological aggressiveness of these rare neoplasms, the 5-year survival rate after resection is over 60% and TCs and NETT showed a similar rate of survival and recurrences after surgery.

KI-67 Antigen Expression Predicts Survival and Correlates with Histologic Subtype in the WHO Classification of Thymic Epithelial Tumors

We performed an immunohistochemical study with monoclonal antibodies to Ki-67 antigen and p53 protein on 45 cases of thymic epithelial tumors classified according to the recent World Health Organization (WHO) classification system to evaluate whether there is correlation between the expression of these markers and prognosis, histologic subtype, and myasthenia gravis (MG). We also correlated histologic subtype with sex, age, MG, and survival. Ki-67 and p53 labeling indices (LIs) were expressed as a percentage of positive nuclear immunostaining by counting 1,000 epithelial tumor cells. Statistically significant differences were found between Ki-67 LI and survival (p = 0.007), whereas the prognostic implication of p53 could not be demonstrated, although there appeared a trend that patients with tumors of higher LIs had worse survival. Significant correlations were also found between Ki-67 (p < 0.0005) and p53 (p < 0.0005) LIs and histologic subtypes. No correlation was found between these parameters and MG. Histologic subtypes of the WHO classification also correlated with survival (p = 0.01), whereas no correlation was found with sex, age, and MG. In conclusion, our results indicate that the proliferative activity, assessed by Ki-67 LI, and the histologic pattern, according to WHO classification system, seems to represent reliable parameters in the prognosis of thymic epithelial tumors.

Thoracoscopic thymectomy versus open thymectomy for the treatment of thymoma: A meta-analysis

BACKGROUND

Some studies compared the safety and efficacy of thoracoscopic thymectomy (OT) with open thymectomy (TT) in the treatment of thymoma, but the results remained controversial. This meta-analysis was designed to determine the safety and efficacy of thoracoscopic thymectomy in comparison with open thymectomy in the treatment of thymoma.

METHODS

Relevant studies were searched in databases of PubMed, EMBASE and Web of Science. Comparative studies of thoracoscopic thymectomy and open thymectomy in the treatment of thymoma were included. Both short-term perioperative and long-term oncologic outcomes were analyzed.

RESULTS

14 Eligible studies were identified through electronic databases. Our analysis suggested, when compared with open thymectomy, patients having thoracoscopy might benefit from less blood loss (p = 0.004), lower blood transfusion rate (p = 0.02), shorter mean duration of chest tube (p = 0.002), hospital stay (p < 0.001) and lower complication (p = 0.03). There was no statistical difference in 5-year OS rate (p = 0.14) and DFS/RFS rate (p = 0.07) between two groups.

CONCLUSION

Our study indicated that thoracoscopic thymectomy could become a valid alternative to open thymectomy in selected patients with thymoma.

Correlation between S-1 treatment outcome and expression of biomarkers for refractory thymic carcinoma

BACKGROUND

Thymic carcinoma is a rare cancer with minimal evidence of a survival benefit following chemotherapy. An oral fluoropyrimidine of S-1, however, is the recommended active cytotoxic chemotherapy agent for refractory thymic carcinoma based on a case series, whereas sunitinib or everolimus are recommended as molecular-targeted agents based on Phase II trials. We retrospectively investigated the efficacy of S-1 for refractory thymic carcinoma and performed a biomarker analysis.

METHODS

We assessed the clinicopathological variables of 14 consecutive patients who underwent S-1 for refractory thymic carcinoma and correlated the clinical outcomes with potential biomarkers using paraffin-embedded cancer tissues of eight patients in the cohort.

RESULTS

A total of 178 thymic malignancies were identified, of whom 14 patients included 12 cases of squamous cell carcinoma, one lymphoepithelioma-like carcinoma, and one undifferentiated carcinoma. Six patients exhibited a partial response (42.9 %: 95 % confidence interval [CI], 21.4-67.4) and the disease control rate was 85.7 % (60.0-96.0 %). After a median follow-up of 24.2 months, the median progression-free survival was 8.1 months (range, 2.6-12.2 months), and median overall survival was 30.0 months (range, 6.2-41.9 months). No significant correlation between biomarker expression and response was noted. However, thymidine synthase (TS)/dihydropyrimidine dehydrogenase and TS/orotate phosphoribosyltransferase were observed.

CONCLUSIONS

S-1 for refractory thymic carcinoma offered clinical activity and achieved an 85 % disease control rate. Although the biomarkers did not correlate with clinical outcome, the study results showed efficacy of S-1 as a cytotoxic chemotherapy for refractory thymic carcinoma, which warrants future investigation.

Clinicopathologic and prognostic factors of thymoma in Tunisia

BACKGROUND

although rare, thymomas are the most common tumors of the thymus in adults. They represent about 20% of all mediastinal tumors.

AIM

the aim of this study is to present clinicopathological features of thymomas in Tunisia and analyse the prognostic factors.

METHODS

From 1993 to 2004, clinical data of 40 cases of thymomas were compiled retrospectively. Microscopic slides were reviewed and reclassified according to the WHO classification of thymic tumors 2004. Clinical staging adopted was Masaoka system. Analysis of survival was determined by Kaplan-Meier method and log-rank test was used to compare survival curves. These statistical analyses were performed by SPSS.

RESULTS

they were 23 women and 17 males of ages ranging from 14 to 76 years (mean age 51 years). The distribution of histological WHO types was: 1 type A, 7 type AB, 6 type B1, 17 type B2, 6 type B3, 2 cases of micronodular thymoma with lymphoid stroma and 1 case of metaplastic thymoma. According to Masaoka stage, 10 patients were in stage I, 11 stage II, 9 stage IIIa, 4 stage IIIb, 5 stage Iva and 1 stage IVb. The average overall survival was 56 months. Univariate analyses showed that Masaoka stage, completeness surgical resection and age were prognostic factors whereas in multivariate analysis, age was the only prognostic factor. Neither myasthenia gravis nor histological WHO subtypes had effect in survival.

CONCLUSION

masaoka stage, completeness surgical resection and age are the prognostic factors predicting survival in our series.

Chemotherapy and prognosis in advanced thymic carcinoma patients

OBJECTIVE

The role of chemotherapy in treating advanced thymic carcinoma is unclear. The purpose of the current study was to investigate the efficacy of chemotherapy and the prognostic factors for patients with advanced thymic carcinoma.

METHODS

A retrospective review of the medical records of 86 patients treated with chemotherapy for advanced thymic carcinoma was conducted between 2000 and 2012 at our institution. The clinical characteristics, chemotherapy regimens and prognostic factors were analyzed. Survival curves were plotted using the Kaplan-Meier method and the Cox proportional hazard model was used for multivariate analysis.

RESULTS

Of the 86 patients, 56 were male and 30 were female. The median survival time was 24.5 months. For the first-line chemotherapy treatment, the objective response rate was 47.7% and the disease control rate was 80.2%. The median progression-free survival for all patients was 6.5 months for first-line chemotherapy. No significant differences in progression-free survival were observed among the different chemotherapy regimens. Multivariate analyses revealed that the prognostic factors for overall survival included performance status (p=0.043), histology grade (p=0.048), and liver metastasis (p=0.047).

CONCLUSION

Our results suggest that there is no difference in efficacy between multiagent and doublet regimens. The prognosis of patients with advanced thymic carcinoma can be predicted based on histological grade, liver metastasis and performance status.

Prognostic grading after complete resection for thymic malignancies

OBJECTIVE

Despite the World Health Organization (WHO) and Masaoka classifications have been widely accepted as the main describers of prognosis determinants in thymic malignancies, so far, these have been considered independently from one another. We have reviewed our single-centre 40-year results after surgical treatment of thymic malignancies evaluating the inter-relationships between the clinical, surgical and pathological variables and investigating their prognostic impact in completely resected patients.

PATIENTS AND METHODS

A surgical series of 347 patients was reviewed and, of these, 305 with complete resection enrolled. Long-term and disease-free survival (LTS, DFS) analyses were performed. Kaplan-Meir curves for WHO histotypes and Masaoka-stages were inspected and matched with the log-rank test; the Cox regression analysis was adopted in a multivariable approach.

RESULTS

Considered independently, the WHO-histotypes did not differentiate clearly from one to another in terms of LTS and DFS; however, types A-AB-B1-B2 and B3-C clustered in 2, statistically different, malignancy groups (LTS, DFS: Cox-p < 0.001). Masaoka staging was confirmed to be a relevant prognostic determinant, even if no evident difference between stages I vs II and stages III vs IV emerged when the Masaoka-classification was factored in. Thus, when investigating 13 surgical and pathological factors of invasiveness, these showed a clustering in 2 groups according to the presence/absence of pathological proven infiltration in the peri-thymic structures (LTS, DFS: Cox-p < 0.001). By matching the WHO-malignancy clusters and infiltration clusters, 4 classes may be identified, which proved to have a distinct prognostic significance: (LTS-Cox: stage-I vs stage-II, p = 0.003; III: p < 0.001, IV: p < 0.001; DFS-Cox: stage-I vs stage-II, p < 0.001; III: p < 0.001; IV: p < 0.001).

CONCLUSIONS

When analyzing the long-term outcome of patients underwent complete resection for thymic malignancies, the combination between pathological and surgical variables showed accurate prognosis predictability.

The major prognostic factors of thymomas: about a Tunisian study of 100 cases

AIM

Thymomas are characterised by their rarity, histologic variability and peculiar patterns of recurrence. Herein, we present the experience of a single institution and aim to highlight the major prognostic factors of these tumours.

MATERIALS AND METHODS

We present a retrospective study on 100 thymomas diagnosed between 1994 and 2011. Statistical analyses were performed using version 18.0 SPSS. The Kaplan Meier method was used to estimate survival, and survival curves were compared using the Log-Rank test. A p < 0.05 was considered statistically significant.

RESULTS

50 men and 50 women underwent surgical resection for thymoma. Radiologic findings highlighted a diagnosis of thymoma in 51% of cases. The thymomas were classified as stage I in 25 cases, stage II in 47 cases, stage III in 25 cases and stage IV in 3 cases. According to the WHO classification, tumours were classified as type A in 14 cases, type AB in 24 cases, type B1 in 17 cases, type B2 in 20 cases, type B3 in 8 cases, B1/B2 in 8 cases and B2/B3 in 9 cases. The mean survival of patients was 136 months. Age, sex, tumour size, WHO classification and Masaoka stage were evaluated as prognostic factors. Univariate analysis showed that the major prognostic factors were WHO classification (p = 0.019) and Masaoka Stage (p = 0.0001).

CONCLUSION

Our results place emphasis on the prognostic value of WHO classification and Masaoka stage in thymomas; in addition, the necessity of improving reproducibility of microscopic classification to avoid discrepancies among prognostic groups is highlighted.

Single-centre 20-year experience with surgical treatment of thymic tumours

BACKGROUND

Large single-centre institutional series on thymic tumours are rare. Complete resection remains the mainstay of successful treatment. Characteristics and survival were reviewed in all patients treated between 1993-2013.

METHODS

Hospital databases revealed 134 patients with pathologically-proven thymic tumour. Follow-up (median 63 months) was through patient notes and telephone contact with general practitioner.

RESULTS

Patients were classified in Masaoka-Koga stages: I: 50 (37%); IIa: 14 (10%); IIb: 14 (10%); III: 27 (20%); IVa: 19 (14%); IVb: 4 (3%); unknown: 6 (5%). According to WHO classification, pathological subtypes were A: 19 (14%); AB: 25 (19%); B1: 21 (16%); B2: 31 (23%); B3: 15 (11%); thymic carcinoma: 23 (17%). Parathymic syndromes were diagnosed in 45 patients : myasthenia gravis (84%); pure red-cell aplasia (4%); hypogammaglobulinemia (2%); and others. 124 patients (93%) underwent surgery with complete resection in 104 (84%). Surgical approach was: sternotomy: 79; thoracotomy: 35; cervicotomy: 2; other/unknown: 8. In 73 patients (59%) no biopsy was taken prior to surgical resection, 25 were treated with induction chemotherapy, 36 received adjuvant radiotherapy. Hospital mortality was 0.81%. 35 patients died during follow-up (13 of tumour or treatment-related causes). Overall and recurrence-free survival at 5, 10, and 15 years were 86%; 64%; 47% and 67%; 49%; and 31%, respectively and were significantly (p < 0.01) different according to Masaoka-Koga stage. There was a significant association between WHO classification and Masaoka-Koga stages I-IIa-IIb versus III-IVa-IVb (p < 0.01).

CONCLUSIONS

Operability and complete resectability of thymic tumours in our experience is high resulting in prolonged overall and recurrence-free survival. Masaoka-Koga stage is an important predictor for survival and shows a significant association with WHO classification.

Long-term follow-up and prognostic factors for advanced thymic carcinoma

The aim of this study was to evaluate the long-term survival outcomes in patients with advanced thymic carcinoma and identify prognostic factors influencing the survival. We retrospectively analyzed 90 consecutive patients with pathologically confirmed advanced thymic carcinoma (Masaoka III and IV) in our institute, from December 2000 to 2012. Age, sex, clinical characteristics, laboratory findings, Masaoka and tumor node metastasis staging, pathologic grade, and treatment modalities were analyzed to identify prognostic factors associated with the progress-free survival (PFS) and the overall survival (OS) rates. Statistical analysis was conducted using SPSS, version 19.0 (SPSS, Inc, Chicago, IL). A total of 73 (81.1%) male and 17 (18.9%) female patients participated in the study. The median follow-up time was 75 months (range, 20-158 months). The 5-year PFS and OS rates were 23.6% (95% confidence interval [CI], 14.6%-33.8%) and 35.7% (95% CI, 25.1%-46.4%), respectively. The multivariate Cox regression model analysis showed that factors improving the PFS were the normal lactate dehydrogenase (LDH) level (P<0.001), Masaoka III stage (P=0.028), and radiotherapy (RT) (P<0.001). The LDH (P<0.001), T stage (P<0.001), and the pathologic grade (P=0.047) were independently prognostic of OS. Long-term follow-up of the advanced thymic carcinoma showed poor outcomes of PFS and OS. LDH, Masaoka stage, and RT affected the PFS, and LDH, T stage, and pathologic grade seemed to affect the OS. Establishing a better staging system for predicting outcomes would be warranted.

Thymic epithelial tumors: a clinicopathologic study of 249 cases from a single institution

The WHO histological classification for thymic epithelial tumors of 2004 edition is widely used, but its prognostic value is still controversial. In the present study we collected 249 Chinese patients with thymic epithelial tumors from West China Hospital of Sichuan University since 1999-2009 to assess the prognosis relating to tumor stages, histological classifications, MG and adjuvant therapy. There were 18 cases of type A (7.2%), 97 of type AB (39.0%), 22 of type B1 (8.8%), 63 of type B2 (25.3%), 16 of type B3 (6.5%) thymomas and 33 of thymic carcinomas (13.3%). According to the Massaoka staging, there were 107 patients in stage I (43%), 73 patients in stage II (29.3%), 50 patients in stage III (20.1%) and 19 in stage IV (7.6%). 101 patients (40.6%) complicated with MG, the incidence of MG was highest in type B3 thymomas, then in B2, none of thymic carcinomas complicated with MG. Cox regression analysis showed the Masaoka stage was the most important prognostic factor. Besides of staging, WHO histological classification was also an independent prognostic factor. The age, gender, MG and adjuvant therapy have no significant influence to the prognosis of the patients.

Results of S-1-based chemotherapy for platinum (and antrathycline)-refractory advanced thymic carcinoma

AIM

The aim of the present study was to retrospectively evaluate the role of S-1-based chemotherapy for patients with relapsed advanced thymic carcinoma (TC).

PATIENTS AND METHODS

This study was a retrospective review of TC patients who had received S-1-based chemotherapy for patients with platinum- and antrathycline-failure TC. Patients received S-1 monotherapy or S-1/gemcitabine combination therapy, that were repeated until disease progression.

RESULTS

The patients consisted of 4 males and 4 females with a median age of 59 years (range=41-71); 2 with squamous cell carcinoma, 3 with undifferentiated carcinoma, 1 with poorly-differentiated neuroendocrine carcinoma and 2 not otherwise specified. Grade 3 or higher toxicity was only neutropenia (25.0%). No treatment-related death was observed. The response rate was 50.0% (95% confidence interval (CI)=21.5-78.5%). The median progression free-survival (PFS) and overall survival (OS) of S-1-based chemotherapy were 6.0 and 13.5 months, respectively.

CONCLUSION

S-1-based chemotherapy was found to be potentially useful for patients with relapsed TC.

Sorafenib efficacy in thymic carcinomas seems not to require c-KIT or PDGFR-alpha mutations

PURPOSE

To retrospectively evaluate sorafenib activity and safety in patients with metastatic thymic carcinoma (TC) and to correlate outcome with c-KIT and PDGFR-alpha mutational status.

PATIENTS AND METHODS

Patients with metastatic thymic carcinoma treated with sorafenib after at least one prior line of chemotherapy were included. Objective response rate (ORR) and toxicity were evaluated. Analysis of c-KIT and PDGFR-alpha mutational status was performed retrospectively.

RESULTS

From October 2007 to August 2011, 5 patients with metastatic thymic carcinoma were evaluated. A median of 8 cycles of sorafenib (range=3-29) were administered. Two patients (40%) displayed a partial response (PR), two patients presented stable disease (SD), while one patient had progression. The median progression-free (PFS) and overall survival were 28 weeks and 92 weeks, respectively. At mutational analysis, only one patient with PR had c-KIT mutation in exon 17 and was successfully treated with sunitinib for 12 months after progression to sorafenib. No PDGFR-alpha mutations were found.

CONCLUSION

Sorafenib activity seems independent from the c-KIT and PDGFR-alpha mutational status. After progression, sequence treatment with a different tyrosine kinase inhibitor can be considered. These results are promising and need further confirmation on larger, possibly prospective, series of patients.

Natural course and survival of neuroendocrine tumors of thymus and lung in MEN1 patients

CONTEXT

The natural course and survival of neuroendocrine tumors (NETs) of thymus (Th) and lung in multiple endocrine neoplasia type 1 (MEN1) patients are still unknown.

OBJECTIVE

Our objective was to assess prevalence, tumor growth, and survival of Th and lung NETs in an unselected MEN1 population with long-term follow-up.

DESIGN

This was an observational study.

PATIENTS AND METHODS

A longitudinal study was performed using the Dutch national MEN1 database, including >90% of the Dutch MEN1 population >16 years of age. Patients under care of the Dutch University Medical Centers (1990-2011) (n = 323) were included.

MAIN OUTCOME MEASURES

The prevalence and survival of Th and lung NETs were assessed. Linear mixed-models analysis was applied to assess tumor growth with age as a possible confounder and gender, genotype and baseline tumor size as possible effect modifiers.

RESULTS

Th NETs occurred in 3.4% of patients, almost exclusively in males with a 10-year survival of 25% (95% confidence interval = 8%-80%). A thoracic computed tomography scan was available in 188 patients (58.2%). A lung NET was identified in 42 patients (13.0%) with a 10-year survival of 71.1% (95% confidence interval = 51%-100%). Tumor volume of lung NETs increased 17% per year (P < .001) (tumor doubling time 4.5 years). Tumor doubling time in males was 2.5 vs 5.5 years in females (P = .05). Lung NET growth was not associated with genotype or with baseline tumor size (<1 vs ≥1 cm).

CONCLUSION

In MEN1 patients, Th NETs almost exclusively occurred in males and had a very low prevalence and a high mortality. Lung NETs occurred more often than previously thought, had an indolent course, and occurred equally in both sexes. Tumor growth in males was double compared with female patients.

Multidisciplinary treated thymomas with fatal outcome. A retrospective study

The aim of the study was to assess factors concurring to fatal outcome of patients operated for thymoma with or without myasthenia gravis.

MATERIAL AND METHODS

A retrospective observational study was carried out on a series of 10 patients treated for thymoma in the IIIrd Surgical Unit of "St. Spiridon" University Hospital.

RESULTS

Mean survival time was 4.45 years and mortality rate was 38.4%. In 8 patients III and IV Osserman stage myasthenia gravis was associated. 2 patients without myasthenia gravis were diagnosed with a locally advanced stage of thymic carcinoma. According to WHO pathological classification of thymoma, 2 cases were included in type C, those without myasthenia gravis associated and the rest in type B1 (2 cases) and B2 (6 cases). According to Masaoka classification all cases presented invasive thymoma: 6 cases type II, 3 cases type III and one case with type IV. Apart of one case in stage IV, all cases benefitted of complete surgical resection. No perioperative and early postoperative mortality was recorded. On long-term follow-up the cause of death was related to aggravation of myasthenia gravis in 6 cases, to cardiac failure in 2 cases (acute myocardial infarction and constrictive pericarditis) and in 2 cases to metastatic disease (thymoma related death - 20%).

CONCLUSIONS

Aggravation of myasthenia gravis was the first cause of death in this series in spite of complete resection and intensive immunosupressive treatment. Completeness of surgical resection is the most important prognostic factor. The histopathological type of thymoma with fatal outcome was type B and C after WHO classification.

[Re-operation for relapsed thymic carcinoid; report of a case]

A 68-year-old male patient underwent extended thymectomy via median sternotomy, 4 years ago. The pathological diagnosis was thymic atypical carcinoid having invaded the pleura and vessel. During follow-up, the new nodular shadows in the anterior mediastinum were pointed out by a chest computed tomography (CT) scan, 40×38 mm and 11×10 mm in size. We performed again tumor resection and resection of pleural disseminations. The patient was free of clinically evident recurrence 3 years after treatment.

Clinicopathological analysis of thymic malignancies with a consistent retrospective database in a single institution: from Tokyo Metropolitan Cancer Center

BACKGROUND

Thymic epithelial tumors (TETs), which comprise thymoma and thymic carcinoma, are rare cancers with specific morphological and clinical features. Their clinical characteristics and outcomes have gradually been clarified by assessing large-scale, retrospective data obtained with international cooperation.

METHODS

The study is a retrospective review of 187 Japanese patients with TETs who attended our institution from 1976 to 2012. Relevant clinical features of patients with TETs and their tumors, including histology, staging, treatment strategies, and overall survival, were investigated. Differences in survival were assessed by the Kaplan-Meier method and uni- and multi-variate Cox proportional hazards regression analyses.

RESULTS

The 187 patients included 52 patients with stage I, 37 with stage II, 22 with stage III, and 76 with stage IVa/IVb tumors according to the Masaoka-Koga Staging System. As to histological type, five patients had type A, 33 type AB, 19 type B1, 39 type B2, and 15 type B3 thymomas, whereas 68 patients had thymic carcinoma, including 11 with neuroendocrine carcinomas according to the 2004 WHO classification. Either insufficient data were available to classify the tumors of the remaining eight patients or they had rare types. Immunological abnormalities were present in 26 patients, most of whom had thymomas (21.8% of the thymoma group). Most of the patients who presented with symptoms had myasthenia gravis or extensive thymic carcinoma. Secondary cancers were present in 25 patients (13.3%). The overall 5- and 10-year survival rates for thymoma were 85.4 and 71.5%, respectively, and those for thymic carcinoma were 33.8 and 2.3%, respectively. OS differed significantly between stage IVa thymomas and thymic carcinomas. The stage and whether the tumors were thymomas or thymic carcinomas were significant determinants of survival according to multivariate analysis.

CONCLUSION

The efficacy of treatments for thymoma and thymic carcinoma should be investigated separately because these tumors differ in their clinical features and prognosis.

Methylation and expression profiles of MGMT gene in thymic epithelial tumors

OBJECTIVES

A key challenge in diagnosis and treatment of thymic epithelial tumors (TET) is in improving our understanding of the genetic and epigenetic changes of these relatively rare tumors.

METHODS

Methylation specific PCR (MSP) and immunohistochemistry were applied to 66 TET to profile the methylation status of DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) and its protein expression in TET to clarify the association between MGMT status and clinicopathological features, response to chemotherapy and overall survival.

RESULTS

MGMT methylation was significantly more frequent in thymic carcinoma than in thymoma (17/23, 74% versus 13/44, 29%; P<0.001). Loss of expression of MGMT protein was significantly more frequent in thymic carcinoma than in thymoma (20/23, 87% versus 10/44, 23%; P<0.0001). There is a significant correlation between of MGMT methylation and loss of its protein expression (P<0.0003). MGMT methylation and loss of expression were significantly more frequent in advanced thymic epithelial tumors (III/IV) than in early tumors (I/II).

CONCLUSION

MGMT methylation plays a soul role in development of TET, especially in thymic carcinoma. Therefore, translation of our results from basic molecular research to clinical practice may have important implication for considering MGMT methylation as a marker and a target of future therapies in TET.

Predictors of recurrence after thymoma resection

PURPOSE

Recurrence rate is considered a better measure of clinical outcomes after thymoma resection than overall survival due to the indolent behavior of thymomas. This study was designed to determine predictors of recurrence after thymoma resection.

MATERIALS AND METHODS

A single-institution, retrospective study was performed, including 305 patients who had undergone thymoma resection between 1986 and 2009.

RESULTS

Among 305 patients, recurrence was observed in 41 patients (13.4%). The recurrence rates were 0% (0/19), 6.3% (4/63), 4.2% (2/48), 18.6% (11/59) and 20.7% (24/116) for type A, AB, B1, B2 and B3 tumors, respectively. The recurrence rate according to Masaoka stage was 6.1% (8/132), 11.4% (13/114), 26.8% (11/41) and 50.0% (9/18) for stages I, II, III and IV, respectively. After univariate analysis, completeness of resection (R0 versus R1), World Health Organization (WHO) histologic type (A, AB, B1 versus B2, B3), Masaoka stage, and size of tumor (<8 cm versus ≥8 cm) demonstrated significant differences with freedom from recurrence. Upon multivariate analysis, Masaoka stage was the only independent predictor of recurrence.

CONCLUSION

WHO histologic type, Masaoka stage, and size of tumor were associated with recurrence. Particularly, Masaoka stage was the only independent predictor of recurrence after thymoma resection.

A population-based assessment of mortality and morbidity patterns among patients with thymoma

Thymomas are rare tumors of the mediastinum; a limited number of small studies have evaluated the outcomes in these patients. We identified 668 patients with thymoma from the Swedish Cancer Registry, and 2,719 population-based matched controls. We obtained information on autoimmunity from the nationwide inpatient/outpatient hospital discharge Registry. We constructed Kaplan-Meier curves for survival analysis, conditional regression and Cox proportional hazards models to evaluate the association between thymoma and autoimmune diseases, and standardized incidence ratios (SIRs) to evaluate the risk for second cancers following thymoma. Compared with controls, patients with benign or malignant thymoma had a poorer (p < 0.001) 5-year (79%, 53% vs. 91%), 10-year (65%, 39% vs. 78%) and 20-year (43%, 18% vs. 55%) overall survival. For thymoma patients, younger age at diagnosis and being diagnosed in recent years were associated with a better survival. Compared with controls, thymoma patients were more likely to have an autoimmune disease at some point during their lives (32.7% vs. 2.4%, respectively, p < 0.001), most frequently myasthenia gravis (24.5%), systemic lupus erythematosus (2.4%) and red cell aplasia (1.2%). Thymoma patients had twofold excess risk for second cancers compared with the general population, most notably: non-melanoma skin cancer (SIR = 10.6, 95% confidence intervals (CI) = 6.0-17.3), non-Hodgkin lymphoma (SIR = 6.8, 95% CI = 3.00-13.0), and cervical (SIR = 6.9, 95% CI = 1.4-20.1), endocrine (SIR = 4.7, 95% CI = 1.3-12.0), and prostate cancer (SIR = 3.0, 95% CI = 1.7-4.8). Despite the improved survival for thymoma patients over time, they have worse survival than controls. Thymoma patients are in need for follow-up to detect and manage autoimmune diseases and cancer.

Assessment of multimodality therapy for thymoma

BACKGROUND

This study was designed to analyze the accuracy and reliability of several prognostic indicators for long-term survival of thymoma patients.

METHODS

Data from 142 patients treated for thymoma at the Tianjin Medical University Cancer Hospital from January 1954 to January 2001 were retrospectively analyzed. The Kaplan-Meier method and Cox's proportional hazards model test were used for single and multi-variable analyses respectively. The Log-rank test was used to compare survival between groups.

RESULTS

The sizes and extent of the tumors were classified as I - IV according to the Masaoka clinical staging scale. Respective 5- and 10-year survival rates were: 93.8% and 79.2% in stage I, 79.3% and 55.2% in stage II, 53.1% and 34.4% in stage III, and no survivors in stage IV. Among 30 patients with associated myasthenia gravis, 19 had generalized myasthenia gravis and 11 had ocular myasthenia gravis; 5- and 10-year survival rates were 83.3% and 60.0%, respectively. The 5- and 10-year survival rates for 112 patients without myasthenia gravis were 53.6% and 42.0%, respectively. Eighty-four patients had radical resection and nine had palliative resection. Eighty-nine patients had radiotherapy and 55 patients had postoperative radiotherapy. Single or multi-variable analyses showed that the main prognostic indicators are Masaoka clinical staging, thymoma-associated myasthenia gravis, and the treatment method.

CONCLUSIONS

The most important indicators of long-term survival in thymoma are Masaoka clinical staging and the completeness of resection. The primary treatment method for thymoma should be wide tumor resection. Pre- and/or postoperative radio- and/or chemotherapy should be given according to individual treatment requirements.

[Epithelial tumours of the thymus]

Epithelial tumours of the thymus include thymomas, thymic carcinomas and neuro-endocrine tumours. Rare, they nevertheless represent 20% of all mediastinal tumours and 50% of those located in the anterior mediastinum. Thymomas, in particular, can be associated to auto-immune disorders, among which predominates myasthenia gravis. Their clinical behaviour varies widely, from a relative indolence to the potential of lymph node and/or systematic metastases. However, even patients with an invasive disease may have a long clinical history, explaining that a 10-year or 20-year survival from diagnosis does not imply a definitive cure. In daily practice, both the clinical Masaoka's staging system and the WHO histological classification condition the treatment strategies and allow to anticipate the prognosis. The initial treatment, as well as that of the recurrence, is based mainly on a complete resection. Postoperative radiotherapy is systematically added to the treatment of invasive tumours and/or to those with an aggressive histological subtype. Inoperable or metastatic tumours require a cisplatine and anthracyclin-based chemotherapy, followed by radical surgery and/or radiotherapy.

A phase-II trial of dose-dense chemotherapy in patients with disseminated thymoma: report of a Japan Clinical Oncology Group trial (JCOG 9605)

BACKGROUND

To evaluate the safety and efficacy of dose-dense weekly chemotherapy in the treatment of advanced thymoma.

METHODS

Subjects comprised patients with histologically documented chemotherapy-naïve thymoma with stage-IVa or IVb disease. Thymic carcinoma, carcinoid or lymphoma cases were excluded. Patients received 9 weeks of chemotherapy: cisplatin (25 mg m(-2)) on weeks 1-9; vincristine (1 mg m(-2)) on weeks 1, 2, 4, 6 and 8; and doxorubicin (40 mg m(-2)) and etoposide (80 mg m(-2)) on days 1-3 of weeks 1, 3, 5, 7 and 9. Chemotherapy courses were supported by granulocyte colony-stimulating factor. Post-protocol local therapy was allowed.

RESULTS

From July 1997 to March 2004, 30 patients were entered. Three were ineligible due to different histology. Chemotherapy-associated toxicity was mainly haematological and was well tolerated, with no deaths due to toxicity, and 87% of patients completed the planned 9-week regimen. Overall response rate was 59%, with 16 of the 27 eligible patients achieving partial response. Median progression-fee survival (PFS) was 0.79 years (95% confidence interval: 0.52-1.40 years), and PFS at 1 and 2 years was 37 and 15%, respectively. Overall survival rates at 2 and 5 years were 89 and 65%, respectively.

CONCLUSION

In stage-IV thymoma patients, weekly dose-dense chemotherapy offers similar activity to conventional regimens.

The role of postoperative radiotherapy in the management of patients with thymic tumors -- a retrospective study

BACKGROUND

Thymomas are the most common tumor arising in the anterior mediastinum. Surgery is the cornerstone for the management of these tumors. The role of postoperative radiotherapy in Masaoka stage II thymomas remains controversial, but it is well established in the advanced stages. The aim of this study was to investigate the role of postoperative radiotherapy in the overall management of thymomas, and the evaluation of potential prognostic factors.

PATIENTS AND METHODS

Between 1989 and 2007, 41 thymoma patients underwent surgery and 27 of them received radiotherapy with a curative intent. The Masaoka staging system was used. The histopathological records and specimens of patients were thoroughly reviewed. Clinical and radiological evaluations took place every 6 months. The mean patient follow-up was 69 months (range: 2-212).

RESULTS

DFS (disease free survival), TS (total survival) and DSS (disease specific survival) differed significantly between stages and histological types (p<0.04). Stage I patients were managed only surgically, with none recurring or dying. Concerning stage II patients, TS was significantly longer in non-irradiated cases (10/21) (p=0.025). Stage III (n=8) and IV (n=8) patients underwent postoperative radiotherapy, with 4/8 of stage IV disease also receiving induction chemotherapy. Six out of 8 stage III-IV patients recurred (1 distant and 5 intrathoracic failure), out of whom 4 died due to disease progression despite further treatment (all type C histology). The mean DFS and TS for stage III patients were 49.2 and 50.3 months respectively, with the corresponding values for stage IV being 14.5 and 29.1 months. Patients with myasthenia had a favorable outcome and the ones with complete resection a significantly longer DFS (p=0.0003) and DSS (p=0.039). The Cox regression analysis showed that myasthenia and tumor size are important prognostic factors for DFS (p<0.05).

CONCLUSION

Myasthenic patients have a more favorable prognosis. Radiotherapy can be omitted in totally resected stage I-II patients, whereas it is beneficial in more advanced stages.

Limited thymectomy for stage I or II thymomas

BACKGROUND

Once an anterior mediastinal tumor has been diagnosed as a thymoma, complete excision including the thymic gland and perithymic fat is currently the procedure of choice. However, little is known about the clinical outcome of grossly encapsulated thymomas excised only with the surrounding tissue while leaving a part of the thymic gland.

METHODS

A retrospective historical comparative study was conducted on 79 patients who had received surgery for stage I (n=25) or stage II (n=54) thymomas. Total thymectomy was performed in 61 patients (Total Thymectomy Group), whereas resection of tumors with only the surrounding tissue was carried out in 18 (Limited Thymectomy Group). The follow-up interval was longer in the Limited Thymectomy Group because these patients were treated longer ago (104.2+/-58.1 months vs 67.3+/-54.8 months, p<0.05).

RESULTS

One case in the Limited Thymectomy Group showed postoperative myasthenia gravis (5.6%). Two patients with multiple thymomas (2.5%) were treated with total thymectomy. One case in the Limited Thymectomy Group, which had been diagnosed as Masaoka stage II and WHO type B3 at initial surgery, recurred. None died of tumor progression in this study. Disease free survival rates at 10 years did not differ between the Limited Thymectomy and Total Thymectomy Groups (85.7% and 82.0%, respectively). There were no statistical differences in the incidence of postoperative myasthenia gravis and disease free survival between the two groups.

CONCLUSION

Resection of thymomas with surrounding tissue instead of total thymectomy can be indicated for stage I or II thymomas in light of disease free and overall survival, post-operative onset of MG, and the incidence of multiple lesions.

[Thymoma with long-term survival treated by polysurgery; report of a case]

A 50-year-old man was found to have a chest abnormal shadow during a check-up and visited our hospital in 1991. Tumor shadow was observed in the anterior mediastinum. Resection of the tumor was performed by partial thymectomy. The pathological diagnosis was a thymoma type B1 and stage I based on Masaoka' s classification. In 2004, he underwent radical thymectomy and partial resection of the lung to remove the local recurrent tumor followed by postoperative radiation therapy. In 2006, 3rd operation was performed and the tumor in the superior mediastinum was resected. Since then, the patient is well without signs of recurrence. We experienced a case of thymoma with long-term survival treated by polysurgery.

Comparison of patterns of relapse in thymic carcinoma and thymoma

OBJECTIVE

Thymic carcinomas are considered to be more aggressive than thymomas and carry a worse prognosis. We reviewed our recent experience with the surgical management of thymic tumors and compared the outcomes and patterns of relapse between patients with thymic carcinoma and those with thymoma.

METHODS

We performed a single-institution retrospective cohort study. Data included patient demographics, stage, treatment, pathologic findings, and postoperative outcomes.

RESULTS

During the period 1995-2006, 120 patients with thymic tumors underwent surgical intervention, including 23 patients with thymic carcinoma and 97 patients with thymoma, as classified according to the World Health Organization 2004 histologic classification. The overall 5-year survival was significantly different between patients with thymic carcinoma and those with thymoma (thymic carcinoma, 53%; thymoma, 89%; P = .01). Data on relapse were available for 112 patients. The progression-free 5-year survival was also significantly different between patients with thymic carcinoma and those with thymoma (thymic carcinoma, 36%; thymoma, 75%; P < .01). Using multivariate analysis, thymic carcinoma and incomplete resection were found to be independent predictors of progression-free survival. Relapses in patients with thymic carcinoma tended to occur earlier, and occurred significantly more frequently at distant sites than in patients with thymoma (60% vs 13%, P = .01).

CONCLUSIONS

Patterns of relapse differ significantly between patients with thymic carcinoma and those with thymoma, with lower progression-free survival, earlier onset, and more distant relapses in patients with thymic carcinoma. Given the greater propensity for distant failures, the inclusion of systemic therapy in the treatment of thymic carcinoma might take on greater importance. Despite significantly higher rates of distant relapse, good overall survival in patients with thymic carcinoma can be achieved.

[Metastatic ectopic cervical thymoma with prolonged survival; report of a case]

A 60-year-old woman presented with a palpable and painful nodule of her neck. Physical examination revealed that the anterior neck mass was enlarged without other positive findings. The tumor was not diagnosed with a fine needle aspiration biopsy, so that the excision of the tumor was underwent. The diagnosis at permanent section analysis revealed a non-invasive thymoma. The patient did not receive adjunctive postoperative therapy. For the duration of 6.5-year follow-up, metastasis of the left lobe of thyroid and right upper lobe of lung in twice have been sequentially detected and resected, and now she has been healthy with no known recurrence of the tumor. The recurrence of a non-invasive cervical ectopic thymoma has been reported as extremely rare, and this case indicates that the surgical control for recurrence lesion of cervical ectopic thymoma is effective when the tumor is resectable.

[Prognostic factors for thymic epithelial tumor: a retrospective study of 137 cases]

OBJECTIVE

To analyze the clinic and pathologic data of thymic epithelial tumor (TET) and to explore its prognostic factors.

METHODS

From June 1997 to September 2007, 137 patients with TET were surgically treated in our hospital. The data included age, gender, symptoms, histological type, stage and grade, pathological findings, and operation reports. The patients were followed up by telephones and mails. The patients were divided into Masaoka I/II group and III/IV group, and WHO A/AB/B1 group and B2/B3/C group. Kaplan-Meier method, log-rank test, and COX regression model were used to analyze the prognostic factors for TET.

RESULTS

Among the 137 patients, 124 (90.5%) received complete resection, 9 (6.6%) incomplete resection, and 4 (2.9%) surgical biopsy. The rate of complete resection was significantly higher in Masaoka stages I/II than that in stages III/IV (P<0.001). The overall 5-year and 10-year survival rate was 71.4å and 50.1å, respectively. Patients in stage I/II had better long-term survival than those in stage III/IV (P<0.001). According to WHO histological classification, the 5-year and 10-year survival rate in patients with Type A/AB/B1 TET was significantly higher than that in patients with Type B2/B3/C TET (P<0.001). The 5-year and 10-year survival rate in patients with complete resection was significantly higher than that in patients with incomplete resection and biopsy (P<0.001).Cox regression analysis showed that the prognosis of patients with TET was related to Masaoka stage, WHO histological classification, extent of resection, and age at operation.

CONCLUSION

Masaoka stage, WHO histological classification, extent of resection, and age at operation are important prognostic factors in patients with TET.

Treatment of advanced thymoma and thymic carcinoma

Although thymic epithelial tumors are rare, they are relatively common among neoplasms of the anterior superior mediastinum. They usually exhibit indolent behavior, but do have the capacity to invade surrounding structures and metastasize to distant sites. Thymic carcinomas are rare, but are highly aggressive tumors that are associated with a poor prognosis. The mainstay of therapy is complete surgical resection. Locally advanced thymoma and thymic carcinoma require a multimodality treatment approach with a combination of surgery, chemotherapy, and radiation therapy to decrease the chances of recurrence and improve survival. The risk of disease recurrence lasts for a number of years after completion of primary therapy. A majority of cases of recurrent disease present as pleural recurrences. Once again, surgical resection of recurrent disease represents the cornerstone of successful therapy and is critical to long-term survival. In recent years, a better understanding of the biologic basis of thymic epithelial tumors has led to the emergence of targeted therapy directed against this malignancy.

CRMP5 antibodies in patients with small-cell lung cancer or thymoma

The collapsin response mediator protein 5 (CRMP5) antibody is usually associated with paraneoplastic neurological syndrome (PNS) and small-cell lung cancer (SCLC) or thymoma. The objective of this study was to assess the frequency of CRMP5 antibodies in patients with such tumours and to see if the presence of antibodies was associated with prognosis in these cancers. A multi-well adapted immunoprecipitation assay using radiolabelled recombinant CRMP5 protein, produced by coupled in vitro transcription/translation, was used for the detection of CRMP5 antibodies. Sera from 200 patients with SCLC, 73 patients with thymoma and myasthenia gravis (MG) and from 300 healthy blood donors were examined for CRMP5 antibodies. Positive sera were also examined by immunofluorescence and immune blots. The serological results were compared with disease severity of the patients with thymoma or SCLC. CRMP5 antibodies were detected in 10/200 (5%) of the SCLC, 9/73 (12%) of the thymomas and in 2/300 (0.6%) of the healthy controls by immunoprecipitation. The antibodies were less frequently detected by immunofluorescence or immune blots. There was no significant correlation between CRMP5 antibodies and disease severity. CRMP5 antibodies are more than twice as frequent, and the antibody levels are higher in patients with thymoma and MG than in patients with SCLC. The antibodies are correlated to these tumours, but not to disease severity.

Thymome - Inzidenz, Klassifikation und Therapie

Thymomas are a rare tumor entity. However, they represent 50 % of all tumors of the anterior mediastinum. There are no specific early symptoms. Overall in 10 - 15 % of patients with myasthenia gravis a thymoma is evident. Two major classifications are relevant in clinical practise: the Masaoka-classification and the WHO-classification. For their clinical and prognostic significance both classifications should be used for patients with thymomas. Additional, only resection status (RO) is known as a significant prognostic factor. Thymomas are compulsory malignant tumors. Distant metastasis is found as well as local recurrence in all stages of the disease. The 5-year-mortality rate constitutes about 80 %, not meaning any healing because local recurrences occur as late as five years after surgery. 60 % of all patients die from tumor-independent reasons making a clear prognostic statement difficult. Surgical treatment remains the gold standard and must be performed whenever possible. The most common approach is a median sternotomy. When dealing with a thymuscarcinoma, radical lymph node dissection is advisable. With respect of treatment only adjuvant radiation can possibly improve long term survival and reduces local recurrence rates for incomplete resected patients. There is no evidence for a benefit in patients with thymoma receiving adjuvant chemotherapy. A neo-adjuvant chemotherapy in combination with an adjuvant radiotherapy improves outcome after surgical resection in stage III and IV and goes along with better survival rates. Larger studies have not been performed so far. A multimodal therapy strategy is advised when dealing with thymomas in stage III and IV.

Aberrant V(D)J recombination is not required for rapid development of H2ax/p53-deficient thymic lymphomas with clonal translocations

Histone H2AX is required to maintain genomic stability in cells and to suppress malignant transformation of lymphocytes in mice. H2ax(-/-)p53(-/-) mice succumb predominantly to immature alphabeta T-cell lymphomas with translocations, deletions, and genomic amplifications that do not involve T-cell receptor (TCR). In addition, H2ax(-/-)p53(-/-) mice also develop at lower frequencies B and T lymphomas with antigen receptor locus translocations. V(D)J recombination is initiated through the programmed induction of DNA double-strand breaks (DSBs) by the RAG1/RAG2 endonuclease. Because promiscuous RAG1/RAG2 cutting outside of antigen receptor loci can promote genomic instability, H2ax(-/-)p53(-/-) T-lineage lymphomas might arise, at least in part, through erroneous V(D)J recombination. Here, we show that H2ax(-/-)p53(-/-)Rag2(-/-) mice exhibit a similar genetic predisposition as do H2ax(-/-)p53(-/-) mice to thymic lymphoma with translocations, deletions, and amplifications. We also found that H2ax(-/-)p53(-/-)Rag2(-/-) mice often develop thymic lymphomas with loss or deletion of the p53(+) locus. Our data show that aberrant V(D)J recombination is not required for rapid onset of H2ax/p53-deficient thymic lymphomas with genomic instability and that H2ax deficiency predisposes p53(-/-)Rag2(-/-) thymocytes to transformation associated with p53 inactivation. Thus, H2AX is essential for suppressing the transformation of developing thymocytes arising from the aberrant repair of spontaneous DSBs.

Adjuvant Radiotherapy for Thymic Epithelial Tumor

OBJECTIVE

To determine whether the use of adjuvant radiation in the treatment of invasive thymic tumors affects survival and to identify prognostic factors.

METHODS

The files of 47 patients with thymic tumors treated by adjuvant radiation in our institute from 1984 to 2003 were reviewed for data on prognosis and survival. All patients underwent thoracotomy followed by either total macroscopic resection (n = 42) or biopsy (n = 5). The radiation dose ranged from 26 to 60 Gy.

RESULTS

Median duration of follow-up was 10.6 years. Overall 5-year survival was 73% (60%-88%): 77% for thymoma (n = 35/45) versus 33% for thymic carcinoma (n = 2/6) (P = 0.14). Better survival was associated with lower disease stage (II vs. III/IVA, P = 0.01), resection (P = 0.0004), myasthenia gravis at presentation (P = 0.04), and higher radiation dose (<or=45 vs. >45 Gy, P = 0.02); sex, smoking, tumor size, pathology, and margin status had no effect. Locoregional relapse occurred in 11 patients and distant metastasis in 4. The 5-year disease-free survival was 67% (52%-86%), with a median time to recurrence of 8.3 years. The better overall survival and disease-free survival associated with higher doses of radiation were also true for stage II patients. On multivariate analyses after adjusting for age, higher disease stage and lower radiation dose were found to adversely affect overall survival and disease-free survival. Thymic carcinoma had an impact only on disease-free survival.

CONCLUSION

Postoperative radiation therapy to doses above 45 Gy may improve the disease-free and overall survival of patients with invasive thymoma, especially stage II. Thymic carcinoma has a worse prognosis.

Prosthetic replacement and tangential resection of the superior vena cava in chest tumors

AIM

Infiltration of the superior vena cava (SVC) due to advanced non small cell lung cancer (NSCLC) or thymoma can be treated by prosthetic replacement or tangential resection. These two technical procedures and their results are described.

METHODS

From 1988 to 2002, we performed 37 SVC resections: 21 replacements with polytetrafluoroethylene (PTFE) prostheses and 16 tangential exereses. Sixteen patients affected by locally advanced NSCLC (12 T4; 4 extracapsular N2) and 5 subjects with thymoma (Stage III Masaoka) underwent prosthetic replacement of the SVC. After neoadjuvant polychemotherapy, tangential resection was performed on 12 patients with extracapsular N2 NSCLC, and in 1 patient with T4 and in 3 patients with T3a disease. We performed prosthetic replacement in 18 cases using a straight prosthesis (?18-20 mm). A bridge (10-14 cm) between the innominate vein and the right atrium was created in 3 patients. The main indication for a prosthetic replacement was infiltration of more than 30% of the circumference of the SVC. There were 4 thromboembolic complications (19%), with one intraoperative death (4.8%). Tangential resection of the SVC for infiltration <20% was performed both manually and with staplers (double clamping) without any major complications.

RESULTS

Mean survival was 23 months in those patients who had undergone PTFE replacement for T4 lung cancer and for thymoma. Mean survival was 15 months in those who had undergone tangential resections for NSCLC with extracapsular N2. We performed restaging of the tumor using chest angio-CT scan in 11 patients, one year after the operation. We found 80% patency in 7 SVC prostheses and 50% patency in 4 others: the two bridges between the left innominate vein and the right atrium appeared to be partially closed but were compensated by important collateral circles.

CONCLUSION

SVC replacement, associated with pulmonary resection or removal of mediastinal masses, can be performed in selected cases. It should not be considered as palliative treatment because of the important perioperative risks. SVC tangential resection involves fewer surgical problems. However, since this procedure is used mostly for N2 NSCLC subjects, patients have a low mean survival in spite of adjuvant therapy.

Outcome of surgical treatment for recurrent thymic epithelial tumors with reference to world health organization histologic classification system

BACKGROUND AND OBJECTIVES

The aim of this study was to clarify the significance of surgical treatment for recurrent thymic epithelial tumors with reference to the World Health Organization (WHO) histological classification system.

PATIENTS

Among 67 patients with tumor recurrence, 22 underwent a re-resection. There were 1 patient with a type AB tumor, 5 with type B1 tumors, 10 with type B2 tumors, 5 with type B3 tumors, and 1 with a carcinoma.

RESULTS

The 10-year survival rate following the initial resection was 70% in patients who underwent a re-resection and 35% in those who did not. The average intervals from the initial resection to re-resection were 10.3, 7.8, 6.0, 2.4, and 2.6 years for patients with type AB, B1, B2, B3 tumors, and carcinoma, respectively. The patient with a type AB tumor was alive at 2.4 years after re-resection, 12.7 years after the initial resection. The 5-year survival rates following re-resection in the patients with type B1, B2, and B3 tumors were 100, 56, and 60, respectively. The patient with a carcinoma died as a result of the tumor 2 years after re-resection.

CONCLUSION

WHO histological classification indicates the outcome of surgical treatment for recurrent thymic epithelial tumors.