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

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

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

Perioperative management and postoperative outcomes of locally advanced thymic epithelial tumors: a narrative review

Background and Objective

Thymic epithelial tumors (TETs) are frequently diagnosed at an advanced stage, highlighting the importance of understanding the treatment strategies for these cases. Surgical intervention after chemotherapy or chemoradiotherapy presents specific challenges and underscores the crucial role of perioperative management. This study aimed to explore the perioperative management and postoperative outcomes in patients with locally advanced TETs.

Methods

Relevant studies published between 2000 and 2022 were identified through PubMed searches using a combination of the following terms: "Locally advanced TETs", "Thymoma", "Thymic cancer", "Surgery", "Induction therapy", and "Postoperative outcomes". We analyzed available data to describe the perioperative management and postoperative outcomes of locally advanced TETs.

Key Content and Findings

Surgical outcomes after induction therapy for locally advanced TETs were analyzed for 18 references (total n=646) between 2000 and 2022. The primary objective of induction therapy for locally advanced TETs is complete tumor resection. In recent years, many medical centers have adopted systemic chemotherapy and chemoradiation for the treatment of thymoma and thymic carcinoma, respectively. During surgical intervention, resecting the surrounding organs, such as the lungs, pericardium, and phrenic nerves, is a common practice. Additionally, there may be cases wherein vascular resection of the superior vena cava (SVC) and innominate veins is necessary. Techniques and strategies for revascularization without complications are crucial in these situations. The incidence of postoperative complications varied significantly, ranging from 4.8% to 42%. However, perioperative mortality is typically reported to be approximately 0%, with only two reports showing mortality rates of 1.8% and 9.0%.

Conclusions

The short-term postoperative outcomes of surgical treatment following induction therapy for locally advanced TETs were generally deemed acceptable. However, incomplete resection may occur, particularly when the tumor invades the pulmonary artery or aorta. Hence, careful evaluation the indications for surgery is crucial, considering the patient's overall condition and treatment response.

Prognostic value of preoperative chemotherapy for thymic epithelial tumors: A propensity-matched analysis based on the SEER database

Background

The aim of this study was to assess the impact of preoperative chemotherapy on long-term survival (≥1 month) in patients with thymic epithelial tumors (TETs) and conditions suitable for chemotherapy using data from surveillance, epidemiology, and end-result databases.

Methods

This retrospective study controlled for confounding factors by propensity score matching (PSM), analyzed overall survival (OS) and cancer-specific survival (CSS) by Kaplan-Meier methods, and analyzed factors affecting the prognosis of patients undergoing surgery for thymic epithelial tumors by univariate and multifactorial Cox regression.

Results

A total of 2,451 patients who underwent surgery for TETs were identified from the Surveillance, Epidemiology, and End Results database. Preoperative chemotherapy significantly improved OS and CSS in patients with stage III/IV TETs compared to patients without preoperative chemotherapy. Subgroup analysis showed that patients younger than 60 years of age with TETs, patients with thymic carcinoma, and patients with TETs with multiple cancers were more likely to benefit from preoperative chemotherapy.

Conclusion

This study found that preoperative chemotherapy is a viable option for advanced thymoma with favorable overall and cancer-specific survival rates, but patient history and physical condition should be fully considered in conjunction with diagnostic imaging findings to assess patient tolerance to chemotherapy.

Induction Strategy for Locally Advanced Thymoma

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Long-term outcomes of advanced thymoma in patients undergoing preoperative chemotherapy or chemoradiotherapy followed by surgery: a 20-year experience

OBJECTIVES

The results of preoperative chemotherapy or chemoradiotherapy followed by surgery for locally advanced thymoma were analysed.

METHODS

Between 1997 and 2016, 29 patients with a thymoma underwent preoperative chemotherapy or chemoradiotherapy followed by surgery. These cases were retrospectively reviewed.

RESULTS

The study population included 9 men and 20 women, with a mean age of 48.8 years (range 31-68 years). The preoperative Masaoka stage was III in 12, IVa in 13 and IVb in 4 patients, whereas histological type was B3 in 11, B2 in 9 and others in 5 patients. The mean tumour size was 8.0 ± 2.5 cm (3.4-15.0 cm). The site of infiltration shown in preoperative radiological examinations was the aorta in 6 patients, the superior vena cava in 14 patients and the pulmonary artery trunk in 3 patients, with pleural dissemination detected in 14. Three patients underwent chemoradiotherapy. Chemotherapy regimens given were cisplatin + doxorubicin + vincristine + cyclophosphamide in 9 patients, carboplatin + paclitaxel in 6 patients, cisplatin + doxorubicin + methylprednisolone in 5 patients and others in 9 patients, with partial response obtained in 11 patients and stable disease noted in 18 patients. Complete resection was achieved in 24 (83%) cases. There were no perioperative mortalities, whereas 6 (21%) patients developed postoperative complications. The 5- and 10-year overall survival rates were 100% and 87%, respectively, and 5- and 10-year disease-free survival rates were 50% and 50%, respectively.

CONCLUSIONS

Preoperative chemotherapy or chemoradiotherapy followed by surgery for locally advanced thymoma can be performed with an acceptable degree of surgical risk. Such a strategy should be proactively considered, as it can lead to favourable long-term results.

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

INTRODUCTION

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Favourable health-related quality of life reported in survivors of thymic malignancies

OBJECTIVES

The management of patients with locally advanced thymic malignancies remains controversial. Differing combinations of surgical resection, chemotherapy and radiation are used in the management of initial and relapsed disease. Treatment-related toxicities and quality of life could inform therapeutic options. This study describes health utility scores (HUS) in survivors with locally advanced thymic malignancies and investigates the impact of multimodality regimens on HUS.

METHODS

In a cross-sectional study (2014-2017), patients with Masaoka Stage II-IVa thymic malignancies completed various self-reported questionnaires, including EuroQol-5-Dimensions with visual analogue scale (VAS), Eastern Cooperative Oncology Group (ECOG) and Edmonton Symptom Assessment Scale tools. Trimodality versus uni- or bimodality regimens and aggressive versus non-aggressive management of recurrent disease were compared using regression analyses.

RESULTS

Of the 72 patients, 43 (60%) were male with a median age of 58 years, 65 (90%) had thymoma while 7 (10%) had thymic carcinomas; and median time since diagnosis was 50.5 months (range: 3-266). Median HUS and VAS did not differ between groups (trimodality n = 24 vs uni- or bimodality n = 48: HUS = 0.77 vs 0.80, P = 0.29; VAS = 80 vs 75, P = 0.79, respectively). The distributions of patient-reported ECOG were also similar (P = 0.86). Edmonton Symptom Assessment Scale scores for every assessed symptom were similar for different modalities of therapy. Median scores on these tools were also similar regardless of recurrence status or management of relapsed disease (aggressive versus non-aggressive).

CONCLUSION

Survivors with Stage II-IVa thymic malignancies report favourable HUS, VAS and self-reported ECOG with minimal symptom burden. These outcomes may be independent of number and type of initial treatment modalities or management of recurrence.

Comparison of Neoadjuvant Chemotherapy Followed by Surgery to Upfront Surgery for Thymic Malignancy

BACKGROUND

The oncologic benefit of neoadjuvant chemotherapy in thymic malignancies remains unclear. Postoperative oncologic outcomes of curative resection after neoadjuvant chemotherapy were compared with those of upfront surgery.

METHODS

Based on records from a multicenter database, 1,486 patients with surgically resected thymic malignancies between 2000 and 2013 were included in the final study cohort. Of these, 110 patients (7.4%) underwent surgical resection after neoadjuvant chemotherapy, and 1,376 patients (92.6%) underwent upfront surgery. A propensity score-matched analysis was performed to minimize differences in preoperative and intraoperative variables. Postoperative outcomes and survivals were compared between the two groups.

RESULTS

In the matched cohort, there were no significant differences in postoperative mortality (p value not calculated), postoperative complications (p = 0.405), and hospital length of stay (p = 0.821) between the two groups. However, the neoadjuvant chemotherapy group showed significantly higher transfusion rates (p = 0.003) and longer operation times (p < 0.001) than the upfront surgery group. Pathologically complete resection rates (p = 0.382) and tumor sizes (p = 0.286) were similar between the two groups. The 5-year overall survival rates were 77.4% and 76.7%, respectively (p = 0.596). The 3-year recurrence-free survival rates were 62.9% and 71.5%, respectively (p = 0.070).

CONCLUSIONS

Neoadjuvant chemotherapy, followed by resection, obtained similar resectability and long-term survival rates to those of upfront surgery. Therefore, the role of neoadjuvant chemotherapy should be refined in randomized controlled trials.

The expanding role of radiation therapy for thymic malignancies

The role of radiation therapy (RT) in thymic malignancies has long been subject to considerable controversy. The main role for RT is in the setting of adjuvant therapy after surgical tumor resection, especially in advanced or incompletely resected cases. However, recent studies with larger patient numbers and cleaner study populations than previous studies have indicated a potentially clearer than previously assumed benefit after post-operative RT (PORT) even for completely resected patients with earlier stages of thymoma. In marginally resectable patients RT may be used in combination with neoadjuvant chemotherapy to shrink tumors and thereby potentially enable resection. In unresectable patients concurrent or sequential chemotherapy and RT can be employed as the definitive nonsurgical approach. The tendency of thymic tumors to recur in the pleural space highlights the necessity for more effective approaches to identify and treat high risk patients. Experiences in other pleural malignancies may pave the way to novel treatment modalities, for example pleural IMRT. The role of these techniques in thymic malignancies has yet to be determined and is not advisable at the current time outside of a clinical study. As the disease often takes an indolent course with excellent long-term local control (LC) and survival, late toxicities related to radiation of the mediastinum and adjacent organs at risk (OARs) have to be taken into consideration and may jeopardize the benefit patients experience from RT, especially in younger patients with a long-anticipated life expectancy. Radiation techniques, such as intensity modulated RT (IMRT) and proton beam therapy (PBT), have substantially reduced the exposure of OARs to ionizing radiation which is expected to translate into reduced long-term toxicities. Hence, the risk-benefit ratio of RT in early stage thymoma patients may be shifted favorably.

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

背景与目的

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

方法

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

结果

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

结论

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