Nonsurgical management of malignant thymoma

et al. 2009

Cancer Investigation

The purpose of this study was to identify the prognostic predictors treated with postoperative irradiation in patients with thymoma. Two hundred forty-one patients with histologically confirmed thymoma were collected and retrospectively reviewed in this study. Fifty-four patients had stage I disease; 57, stage II; 120, stage III; 10, stage IV. One hundred sixty patients underwent total thymectomy; 63, partial resection; 18, debulking or biopsy. Patients were irradiated after surgery with median dose of 50 Gy by conventional fractionation. The overall survival rates at 5 and 10 years were 83.1% and 72.6%, respectively. The 10-year overall survival was 87% for stage I, 78.7% for stage II, 57.4% for stage III, and 24.3% for stage IV. The conclusions were drawn from this analysis. For stage I, the role of postoperative irradiation needed further investigation. For stage II-III, surgery and postoperative irradiation should be part of standard care. The favorable prognostic predictors were female, early stage, and surgical extirpation.

Section: Postoperative Radiotherapy In Stage II and Iii Thymomassupporting

confidence: 85%

Prognostic Predictors and Long-Term Outcome of Postoperative Irradiation in Thymoma: A Study of 241 Patients

Mao

et al. 2009

Cancer Investigation

“…The incidence of intrathoracic recurrence for patients with Stage II and III tumors who do not receive adjuvant therapy has been approximately 28–40% 7, 13, 24, 40. Therefore, there is general agreement that postoperative radiotherapy should be used in the treatment of patients with Stage II and Stage III tumors 7, 13, 16, 17, 33–35…”

Section: Discussionmentioning

confidence: 99%

“…Although postoperative irradiation of invasive thymoma has been recommended commonly, the optimal radiation fields and doses remain uncertain 5, 19, 22, 24, 32, 34–37, 41. The dose response in patients who receive irradiation for thymoma has not been established clearly.…”

Section: Discussionmentioning

confidence: 99%

“…WM irradiation also can cover the lower mediastinum, which may be at risk for gravitational metastases. Several authors also have stated that it is advantageous that the treatment field include the whole mediastinum 11, 34…”

Section: Discussionmentioning

confidence: 99%

“…In patients with completely resected, Masaoka Stage I (noninvasive) tumors, routine postoperative irradiation has not been recommended because of the low incidence of recurrence even without postoperative irradiation 7, 16, 32. In contrast, in patients with completely resected, Stage II and III (invasive) tumors, postoperative mediastinal irradiation has been recommended routinely to prevent local recurrence 7, 13, 16, 17, 33–35. However, a controversy exists concerning the optimal postoperative radiotherapy for tumors at these stages, especially with regard to the total dose and treatment field 32, 36.…”

mentioning

confidence: 99%

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Postoperative radiotherapy for patients with completely resected thymoma

Ogawa

Umemura

Toita

et al. 2002

Cancer

138

BACKGROUND Optimal management of postoperative radiotherapy for patients with completely resected thymoma remains controversial. This study was conducted to assess the efficacy of postoperative mediastinal irradiation in patients with completely resected thymoma. METHODS The records of 103 patients with completely resected thymoma who received postoperative mediastinal irradiation during the period between 1979 and 1998 were reviewed. The distribution according to Masaoka stage was Stage I in 17 patients, Stage II in 61 patients, and Stage III in 25 patients. Fifty‐two patients were treated with involved field (IF) irradiation, and 51 patients were treated with irradiation of the whole mediastinal field with or without boost (WM irradiation). The total radiation dose to the primary tumor bed was 30–61 grays (Gy), with a median dose of 40 Gy. No patients received chemotherapy during the initial treatment. The median follow‐up of the 82 living patients was 112 months (range, 24–244 months). RESULTS The 10‐year actuarial overall and disease free survival rates for all patients were 81% and 79%, respectively. The 10‐year actuarial overall survival rate was 100% for patients with Stage I disease, 90% for patients with Stage II disease, and 48% for patients with Stage III disease. In the analysis, clinical stage alone had a statistically significant impact on both overall survival and disease free survival (P < 0.0001 for both). Recurrent disease was observed in 17 patients, and the pleura was the most frequent site of first recurrence. Of 12 patients who had pleural recurrences, 11 patients had pleural dissemination remote from the initial tumor site. No recurrence was observed in any of the 17 patients with Stage I disease, and 6 of 61 patients (10%) with Stage II disease and 11 of 25 patients (44%) with Stage III disease experienced recurrences. With regard to intrathoracic recurrences, there were no recurrences within the irradiated field in any of the 103 patients, and no dose response correlation was seen in intrathoracic control (incidence of intrathoracic recurrence: 2 of 19 patients in the group that received < 40 Gy, 6 of 45 patients in the group that received 40 Gy, and 7 of 39 patients in the group that received > 40 Gy). With respect to treatment field, mediastinal recurrences were observed in 4 of 52 patients (8%) who were treated with IF irradiation, whereas 0 of 51 patients who were treated with WM irradiation experienced mediastinal recurrences. Pleural‐based recurrences were observed both in patients who were treated with IF irradiation (7 of 52 patients) and in patients who were treated with WM irradiation (5 of 51 patients). According to the degree of pathologic tumor invasion, 0 of 71 patients without pleural invasion had pleural‐based recurrences (0 of 17 patients with Stage I disease, 0 of 51 patients with Stage II disease, and 0 of 3 patients with Stage III disease), whereas 12 of 32 patients (38%) with pleural invasion had pleural‐based recurrences (4 of 10 patients with Stage II disea...

New WHO histologic classification predicts prognosis of thymic epithelial tumors

Marx

et al. 2002

Cancer

353

276

BACKGROUNDIn 1999, a World Health Organization (WHO) committee published histologic criteria for distinct thymoma entities (labeled as Type A, AB, B1, B2, B3 thymomas) and for the heterogeneous group of thymic carcinomas, collectively called Type C thymomas. Whether WHO‐defined histologic thymoma subtypes are of independent prognostic relevance has yet to be proved.METHODSTwo hundred thymomas from the Shanghai Chest Hospital with a mean follow‐up time of 15 years (range, 1–246 months) were studied for the relevance of WHO histologic subtype and other factors (stage, therapy, and myasthenia gravis [MG]) for survival.RESULTSIn order of frequency, 68 patients (34.0%) had Type AB, 39 (19.5%) had Type B2, 36 (18.0%) had Type C, 27 (13.5%) had Type B3, 17 (8.5%) had Type B1, and 8 (4.0%) had Type A thymoma. Five cases (2.5%) were rare thymomas not mentioned in the WHO classification. Survival data showed significant differences among the histologic subtypes (log rank test: P < 0.001). Among patients with Type A and AB thymomas, none died of tumor; of the Type B1 thymoma patients, only one (5.9%) died at 22 months. Type B2, B3, and C thymomas had a significantly worse prognosis with 5‐year survival rates of 75.0%, 70.0%, and 48.0%, respectively. Ninety‐six patients (48.0%) were in Masaoka Stage I, 26 (13.0%) were in Stage II, 65 (32.5%) were in Stage III, and 13 (6.5%) were in Stage IV. Stage was highly significant in predicting survival (log rank, test P < 0.001). The association between histologic subtype and invasive behavior (stage) was statistically significant (P < 0.001). However, histology was an independent predictive factor of survival in Stage I and II thymomas: Type B2, B3, and C thymomas had a worse prognosis than Type A, AB, and B1 thymomas (log rank test: P < 0.003). Thirty patients (15.0%) presented with MG. MG was significantly more frequent in Type B2 and B3 than in Type A, AB, and B1 thymomas (P < 0.01). On multivariate analysis, MG had no adverse effect on survival (P = 0.17). Radiation or chemotherapy improved patients' survival at 5 and 10 years in Type B2, B3, and C thymomas (log rank test: P < 0.003).CONCLUSIONSTumor stage is the most important determinant of survival in thymoma patients, but the WHO histologic subtype is an independent prognostic factor in Stage I and II thymomas, among which WHO Type A, AB, and B1 thymomas form a low‐risk group. Patients with high‐risk thymomas might profit from novel adjuvant radiochemotherapy regimens. Cancer 2002;95:420–9. © 2002 American Cancer Society.DOI 10.1002/cncr.10665