Adjuvant radiation therapy for stage II thymoma

doi:10.1016/S0003-4975(02)03828-6

The Annals of Thoracic Surgery

Volume 74, Issue 4, October 2002, Pages 1033-1037

https://doi.org/10.1016/S0003-4975(02)03828-6 Get rights and content

Abstract

Background. Thymoma is difficult to study because of its indolent natural history. The criteria for administration of adjuvant radiation therapy remain controversial, and it is unclear whether patients with Masaoka stage II thymoma benefit from adjuvant radiation. The goal of this report was to determine whether or not this group benefits from radiation therapy in terms of disease-specific survival and tumor recurrence.

Methods. Case records of the Massachusetts General Hospital were retrospectively reviewed from 1972 to 1999. One hundred fifty-five patients underwent resection for thymoma, of which, 49 had stage II disease. The world literature was reviewed using a Medline search (1966 to 2001), and a secondary review of referenced works was performed.

Results. Fourteen stage II patients underwent radiation therapy. Thirty-five did not receive radiation therapy. Baseline prognostic factors between radiated and nonradiated groups were similar. All patients underwent complete resection. The addition of adjuvant radiotherapy did not significantly alter local or distant recurrence rates in stage II thymoma. Disease-specific survival at 10 years in stage II patients was 100% with radiotherapy and without radiotherapy (p = 0.87). There was one recurrence in the nonradiated group at 180 months, which was outside the usual radiation portal.

Conclusions. Most stage II patients do not require adjuvant radiation therapy and can be observed after complete resection.

Section snippets

Patient population and follow-up

After approval from the Institutional Review Board, the surgical logs and pathology files at the Massachusetts General Hospital were retrospectively reviewed between 1972 and 1999. One hundred fifty-five patients underwent thymoma resection. Of these, 49 had stage II disease and form the basis for this report. Hospital and office medical records were reviewed, and demographic and tumor-related data were entered into a computerized database. Patient follow-up was obtained by review of hospital

Results

The median age at diagnosis was 56 years (range, 13 to 82 years). Twenty-seven (55%) patients were male. Sixteen patients (32.7%) had myasthenia gravis. There were no significant demographic differences between radiated and nonradiated patients.

Surgery was offered as initial treatment to all patients. Seven surgeons performed thymoma resection with total thymectomy via median sternotomy. All 49 patients with stage II disease underwent complete resection, with negative microscopic margins.

Comment

The most important determinants of long-term survival in thymoma are completeness of resection [11], Masaoka stage [15], and Mueller-Hermelink histologic classification 16, 17, 18, 19, 20. The prognostic importance of these determinants has been verified in several large studies. Unfortunately, recommendations for the appropriate use of adjuvant radiation therapy for stage II thymoma are wide ranging and controversial. Current recommendations advocate radiation of all patients with stage II

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Cited by (111)

An Updated Review on Radiation Treatment Management in Thymus Cancers
2022, Clinical Lung Cancer
This narrative review aims to summarize the currently available evidence for the role of radiation in the treatment of thymus cancers. Thymus cancers are rare, heterogeneous tumors with limited evidence to guide their clinical management. There remains some controversy over the role of radiation in the adjuvant and induction/definitive setting. We performed a systematic search of the MEDLINE/PubMed database, focusing on studies published within the last 30 years. Our search queried “thymoma [OR] thymic carcinoma [AND] radiation” and was limited only to prospective and retrospective studies and metanalyses, omitting books, documents, and reviews. Our search resulted in 174 total references, of which only 31 references were within the scope of interest ranging from 1988 to 2021. For resectable disease, there is prospective evidence to support the avoidance of postoperative radiation (PORT) in completely resected Masaoka stage I thymoma, but there is a lack of prospective evidence guiding the use of PORT in other situations. Several retrospective studies and metanalyses have suggested a benefit with PORT for positive margins and advanced stage disease, although it remains controversial whether PORT is beneficial for all completely resected Masaoka stage II thymoma. For unresectable disease, induction chemotherapy followed by reassessment of resectability is the preferred management. Prospective evidence exists to support the use of induction chemoradiation for patients unable to tolerate anthracycline-based chemotherapy and the use of definitive chemoradiation for those unable to undergo surgery. An effective multidisciplinary approach is the optimal strategy for achieving the best outcomes in patients with thymus cancers.
Thymic epithelial tumors. Thymoma
2021, Medicine (Spain)
Los tumores del epitelio tímico (TET) son tumores infrecuentes con etiología y factores de riesgo desconocidos. Es conocida su asociación con síndromes paraneoplásicos, sobre todo la miastenia gravis. Se han descrito varias clasificaciones histopatológicas, siendo la más empleada la de la Organización Mundial de la Salud. El diagnóstico definitivo de los TET se realiza mediante la toma de biopsia. La tomografía computarizada (TC) es la prueba de elección para el diagnóstico de extensión. Es necesario el diagnóstico diferencial con otros tumores del mediastino anterior. El sistema de estadificación más utilizado es el Masaoka, que se correlaciona adecuadamente con la supervivencia. El tratamiento de los TET se basa en la resección completa del tumor. La radioterapia y la quimioterapia pueden ser utilizadas como tratamiento de inducción, adyuvante o paliativo. Sin embargo, la terapia óptima aún es motivo de discusión.
Thymic epithelial tumors (TET) are rare tumors with an unknown etiology and risk factors. They have a known association with paraneoplastic syndromes, especially myasthenia gravis. Various histopathological classifications have been described, the most used of which is the World Health Organization classification. A definitive diagnosis of TET is made via a biopsy. A differential diagnosis with other tumors of the anterior mediastinum is necessary. A computerized tomography (CT) scan is the test of choice for the staging of the disease. The most used staging system is the Masaoka system, which adequately correlates with survival. Treatment of TET is based on a complete tumor resection. Radiotherapy and chemotherapy can be used as induction, adjuvant, or palliative treatment. However, optimal therapy is still a subject of debate.
Thymic tumors and results of radiotherapy
2018, Reports of Practical Oncology and Radiotherapy
The aim of this study was to evaluate thymic epithelial tumors (TETs) for treatment outcomes and prognostic factors on survival.
TETs are very rare neoplasms and multidisciplinary approach is recommended according to prognostic factors.
Between 1995 and 2013, 31 patients were treated with median 5400 cGy (range: 1620–6596 cGy) radiotherapy (RT). Eleven patients received adjuvant or concurrent chemotherapy. There were 25 thymomas, 4 thymic carcinomas and 2 thymic neuroendocrin carcinomas. According to Masaoka, staging and WHO classification, cases were divided to good (n: 10), moderate (n: 9) and poor (n: 12) prognostic risk groups. Survival was calculated from diagnosis.
In January 2016, 22 cases were alive with median 51.5 months (range: 2–170.5) follow-up. Recurrences were observed in 29% of patients in median 29.5 months (range: 6.5–105). Local control, mean overall (OS) and disease-free survival (DFS) rates were 86%, 119 and 116 months, respectively. There was a significant difference for R0 vs. R+ resection (81% vs. 43%, p = 0.06, and 69% vs. 46%, p = 0.05), Masaoka stage I–II vs. III–IV (75% vs. 52%, p = 0.001, and 75% vs. 37%, p < 0.001), and also prognostic risk groups (100% vs. 89% vs. 48%, p = 0.003, and 100% vs. 87% vs. 27%, p = 0.004) in terms of 5-year OS and DFS, respectively.
In our study, prognostic risk stratification was shown to be a significant predictor of survival. There is a need to investigate subgroups that may or may not benefit from adjuvant RT.
Survival Impact of Adjuvant Radiation Therapy in Masaoka Stage II to IV Thymomas: A Systematic Review and Meta-analysis
2016, International Journal of Radiation Oncology Biology Physics
To evaluate the survival impact of postoperative radiation therapy (PORT) in stage II to IV thymomas, using systematic review and meta-analysis.
A database search was conducted with EMBASE, PubMed, Web of Science, Cochrane Library, and Ovid from inception to August 2015. Thymic carcinomas were excluded, and studies comparing overall survival (OS) with and without PORT in thymomas were included. The hazard ratios (HRs) of OS were extracted, and a random-effects model was used in the pooled analysis.
Seven retrospective series with a total of 1724 patients were included and analyzed. Almost all of the patients underwent macroscopically complete resection, and thymoma histology was confirmed by the World Health Organization criteria. In the overall analysis of stage II to IV thymomas, OS was not altered with the receipt of PORT (HR 0.79, 95% confidence interval [CI] 0.58-1.08). Although PORT was not associated with survival difference in Masaoka stage II disease (HR 1.45, 95% CI 0.83-2.55), improved OS was observed with the addition of PORT in the discrete pooled analysis of stage III to IV (HR 0.63, 95% CI 0.40-0.99). Significant heterogeneity and publication bias were not found in the analyses.
From the present meta-analysis of sole primary thymomas, we suggest the potential OS benefit of PORT in locally advanced tumors with macroscopically complete resection, but not in stage II disease. Further investigations with sufficient survival data are needed to establish detailed treatment indications.
Judge a man by his questions rather than his answers
2016, Journal of Thoracic and Cardiovascular Surgery
The effectiveness of postoperative radiotherapy in patients with completely resected thymoma: A meta-analysis
2016, Annals of Thoracic Surgery
This meta-analysis aimed to provide a pooled analysis of clinical studies correlating postoperative radiotherapy (PORT) with survival in patients with completely resected thymoma.
According to the recommendations of the Cochrane Collaboration, we established a rigorous study protocol. An electronic search was conducted using online databases. Hazard ratios (HRs) and 95% confidence intervals (CIs) were used in this meta-analysis and were calculated from published survival data. A meta-analysis was conducted to assess the impact of PORT in completely resected thymoma on overall survival (OS), disease-free survival (DFS). and disease-specific survival (DSS). We also performed a subgroup analysis for OS of patients with stage II and stage III thymoma.
Fourteen studies, which included 3,823 patients (2,096 patients who received PORT and 1,727 patients who did not receive PORT), met the selection criteria. From the available data, the thymoma patients with PORT who did not undergo resection did not have significantly improved OS (HR 0.99; 95% CI 0.87 to 1.13; p = 0.87), DFS (HR 1.21; 95% CI 0.97 to 1.51; p = 0.09), or DSS (HR 0.66; 95% CI 0.39 to 1.13; p = 0.13) compared with the patients who did not undergo PORT. However, our subgroup analysis showed a significant difference in OS in patients with stage II thymoma (HR 0.57; 95% CI 0.41 to 0.80; p = 0.001) and patients with stage III thymoma (HR 0.73; 95% CI 0.59 to 0.90; p = 0.004).
Our results showed that for completely resected thymoma, PORT had no advantage in the overall group of patients but increased OS in the patients with stage II and III thymoma after a complete resection. On the basis of this study, PORT is beneficial in patients with stage II and III patients after a complete resection.

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Original article: general thoracicAdjuvant radiation therapy for stage II thymoma

Abstract

Section snippets

Patient population and follow-up

Results

Comment

Thymoma-associated systemic lupus erythematosus, exacerbating after thymectomya case report and review of the literature

Rheumatology

Clinical and pathologic predictors of survival in patients with thymoma

Ann Surg

Association between thymoma and second neoplasms

JAMA

Thymomatrends over time

Ann Thorac Surg

Role of staging in prognosis and management of thymoma

Ann Thorac Surg

Thymomaa multivariate analysis of factors predicting survival

Ann Thorac Surg

Invasive thymomathe role of mediastinal irradiation following complete or incomplete surgical resection

J Clin Oncol

Stage III thymomaresults of postoperative radiation therapy

Radiology

Prognostic factors and outcome of incompletely resected invasive thymoma following radiation therapy

J Clin Oncol

Stage III thymomapattern of failure after surgery and postoperative radiotherapy and its implication for future study

Int J Radiat Oncol Biol Phys

Prognostic factors and long-term results after thymoma resectiona series of 307 patients

J Thorac Cardiovasc Surg

Recurrence of thymomaclinicopathological features, therapy, and prognosis

Ann Thorac Surg

Thymomaresults with complete resection and adjuvant postoperative irradiation in 141 consecutive patients

J Thorac Cardiovasc Surg

Thymomaresults of 241 operated cases

Ann Thorac Surg

Follow-up study of thymoma with special reference to their clinical stages

Cancer

New approaches to the diagnosis of thymic epithelial tumors

Prog Surg Pathol

Original article: general thoracic
Adjuvant radiation therapy for stage II thymoma