Stage III thymic epithelial neoplasms are not homogeneous with regard to clinical, pathological, and prognostic features

The Prognostic Role of the Number of Involved Structures in Thymic Epithelial Tumors: Results from the ESTS Database

BACKGROUND

The role of the number of involved structures (NIS) in thymic epithelial tumors (TETs) has been investigated for inclusion in future staging systems, but large cohort results still are missing. This study aimed to analyze the prognostic role of NIS for patients included in the European Society of Thoracic Surgeons (ESTS) thymic database who underwent surgical resection.

METHODS

Clinical and pathologic data of patients from the ESTS thymic database who underwent surgery for TET from January 2000 to July 2019 with infiltration of surrounding structures were reviewed and analyzed. Patients' clinical data, tumor characteristics, and NIS were collected and correlated with CSS using Kaplan-Meier curves. The log-rank test was used to assess differences between subgroups. A multivariable model was built using logistic regression analysis.

RESULTS

The final analysis was performed on 303 patients. Histology showed thymoma for 216 patients (71.3%) and NET/thymic carcinoma [TC]) for 87 patients (28.7%). The most frequently infiltrated structures were the pleura (198 cases, 65.3%) and the pericardium in (185 cases, 61.1%), whereas lung was involved in 96 cases (31.7%), great vessels in 74 cases (24.4%), and the phrenic nerve in 31 cases (10.2%). Multiple structures (range, 2-7) were involved in 183 cases (60.4%). Recurrence resulted in the death of 46 patients. The CSS mortality rate was 89% at 5 years and 82% at 10 years. In the univariable analysis, the favorable prognostic factors were neoadjuvant therapy, Masaoka stage 3, absence of metastases, absence of myasthenia gravis, complete resection, thymoma histology, and no more than two NIS. Patients with more than two NIS presented with a significantly worse CSS than patients with no more than two NIS (CSS 5- and 10-year rates: 9.5% and 83.5% vs 93.2% and 91.2%, respectively; p = 0.04). The negative independent prognostic factors confirmed by the multivariable analysis were incomplete resection (hazard ratio [HR] 2.543; 95% confidence interval [CI] 1.010-6.407; p = 0.048) and more than two NIS (HR 1.395; 95% CI 1.021-1.905; p = 0.036).

CONCLUSIONS

The study showed that more than two involved structures are a negative independent prognostic factor in infiltrative thymic epithelial tumors that could be used for prognostic stratification.

Early Postoperative Results after Thymectomy for Thymic Cancer: A Single-Institution Experience

BACKGROUND

Surgery for thymic cancers is considered the key of curative treatment. Preoperative patients' characteristics and intraoperative features might influence postoperative outcome. We aim to verify short-term outcomes and possible risk factors for complications after thymectomy.

METHODS

We retrospectively investigated patients undergoing surgery for thymoma or thymic carcinoma in the period between January 1, 2008, and December 31, 2021, in our department. Preoperative features, surgical technique (open, bilateral VATS, RATS), intraoperative characteristics and incidence of postoperative complications (PC) were analyzed.

RESULTS

We included in the study 138 patients. Open surgery was performed in 76 patients (55.1%), in 36 VATS (26.1%) and in 26 RATS (36.1%). Resection of one or more adjacent organs due to neoplastic infiltration was required in 25 patients. PC appeared in 25 patients (52% Clavien-Dindo grade I, 12% grade IVa). Open surgery had a higher incidence of PC (p < 0.001), longer postoperative in-hospital stay (p = 0.045) and larger neoplasm (p = 0.006). PC were significant related to pulmonary resection (p = 0.006), phrenic nerve resection (p = 0.029), resection of more than one organ (p = 0.009) and open surgery (p = 0.001), but only extended surgery of more organs was confirmed as independent prognostic factor for PC (p = 0.0013). Patients with preoperative myasthenia symptoms have a trend toward stage IVa complications (p = 0.065). No differences were observed between outcomes of VATS and RATS.

CONCLUSIONS

Extended resections are related to a higher incidence of PC, while VATS and RATS guarantee a lower incidence of PC and shorter postoperative stay even in patients that require extended resections. Symptomatic myasthenia patients might have a higher risk toward more severe complications.

Prognostic value of tumor size in thymic epithelial tumors: A systematic review and meta-analysis

BACKGROUND

Whether the size of thymic epithelial tumors (TETs) has an impact on prognosis has long been a controversial issue. Our study was designed to investigate the value of tumor size in the prognosis (overall survival (OS) and relapse-free survival) of patients with TETs.

METHODS

We searched the databases such as PubMed, EMBASE, Web of Science, and clinical trials registration system for articles illustrating the impact of tumor size on survival data in TETs patients. We did a meta-analysis for OS and relapse-free survival.

RESULTS

We recruited 9 studies in our meta-analysis. Our study illustrates that TETs patients with small tumor size had better relapse-free survival (hazard ratio = 1.66, 95% confidence interval 1.18-2.35, P = .004) and OS (hazard ratio = 1.93, 95% confidence interval 1.30-2.80, P = .001) in comparison to patients with large tumor size.

CONCLUSIONS

In conclusion, the results of our meta-analysis showed that TET size was significantly associated with overall and relapse-free survival of patients, with relatively small tumors tending to have a better prognosis.

Prognostic Impact of Number of Organ Invasions in Patients with Surgically Resected Thymoma

PURPOSE

This study aimed to explore the clinical implications and prognostic value of the number of organ/structure invasions (NOI) in patients with thymoma after curative surgical resection.

METHODS

We retrospectively analyzed 306 consecutive Japanese patients with thymoma who underwent curative surgical resection. Tumor invasions of pericardium, mediastinal pleura, phrenic nerve, lung, and venous structures were examined histopathologically. Cases were classified into four subgroups according to NOI: group 0, no tumor invasion; group 1, tumor invasion into single organ/structure; group 2, tumor invasion of two organs/structures; group 3, invasion of three or more organs/structures. Associations with NOI and several clinical characteristics and their prognostic significance were analyzed.

RESULTS

Pleural invasion was found in 100 cases (32.7%), lung invasion in 48 cases (15.7%), pericardial invasion in 46 cases (15%), phrenic nerve invasion in 29 (9.5%), and venous invasion in 22 cases (7.2%). NOI was classed as group 0 in 201 cases (65.0%), group 1 in 42 cases (13.7%), group 2 in 20 cases (6.5%), and group 3 in 43 cases (14.1%). Cases with higher NOI showed significantly worse relapse-free survival (RFS) and overall survival (OS). Cox's proportional hazard model analysis also identified NOI as a prognostic factor affecting RFS and OS.

CONCLUSIONS

Cases with higher NOI of thymoma after radical surgical resection showed significantly worse recurrence rates and survival.

Analysis of surgical treatment of Masaoka stage III-IV thymic epithelial tumors

OBJECTIVE

The purpose of this study is to elucidate the outcomes after surgical resection of Masaoka stage III-IV thymic epithelial tumors.

METHODS

We retrospectively reviewed patients with Masaoka stage III-IV thymic epithelial tumor who underwent surgical resection from January 1995 to January 2017. The clinicopathological features, surgical procedures, and postoperative outcomes were investigated.

RESULTS

Thirteen patients with thymoma and 18 patients with thymic carcinoma were assessed. The postoperative Masaoka stages were III/IVa/IVb = 8/4/1 in thymoma and III/IVa/IVb = 11/2/5 in thymic carcinoma. In patients with thymoma, the World Health Organization pathological subtypes were A/B1/B2/B3 = 2/1/4/6. We performed combined resection and reconstruction for brachiocephalic vein or superior vena cava in 3 patients with thymoma and 7 patients with thymic carcinoma. In all patients, the patency rate of the grafts was very low for the left brachiocephalic vein and well maintained for the right brachiocephalic vein. Macroscopically and pathologically complete resection was achieved in 11 and 6 patients with thymoma, respectively, and in 15 and 9 patients with thymic carcinoma, respectively. The 10-year survival rates were 85.7% in thymoma and 70.3% in thymic carcinoma. Postoperative recurrences were observed in 2 and 9 patients with thymoma and thymic carcinoma, respectively. Recurrences were observed within 5 and 10 years after surgery in 2 patients with thymoma and within 2 years in all patients with thymic carcinoma.

CONCLUSIONS

Patients with Masaoka stage III-IV thymic epithelial tumor showed relatively favorable long-term survival after surgical treatment. Therefore, aggressive surgical resection for complete resection may be a treatment option for these conditions.

Behind and Beyond the Masaoka Staging: A 25-Year Follow-up Study of Tumor Recurrence in Completely Resected Thymic Epithelial Tumors in a Single Institution

We analyzed prognosticators for recurrence and post-recurrence survival in completely resected thymic epithelial tumors for the past 25 years in a single institution.Between June 1988 and December 2013, 238 patients undergoing intent-to-treat surgery for thymic epithelial tumors were reviewed. Sex, age, myasthenia gravis (MG), tumor histology, Masaoka staging, characteristic of locoregional invasion and recurrence, and the treatment for recurrence were collected. Comparison between groups was conducted using the Student t test and χ test. Survival analysis was performed using the Kaplan-Meier method and log-rank test. The Cox proportional hazards model was used for univariate and multivariate analyses of prognostic factors.One hundred sixteen of 135 patients with completely resected thymoma and 35 of 56 patients with thymic carcinoma remained free of recurrence. In patients with completely resected thymoma, Masaoka staging, MG, tumor invasion into the lung, pericardium, and innominate vein or superior vena cava (SVC) invasion were associated with recurrence-free survival in univariate analysis (P = 0.004, 0.003, 0.001, 0.007, and 0.039, respectively). In multivariate analysis, MG was the positive independent prognosticator (P = 0.039). In patients with completely resected thymic carcinoma, Masaoka staging and innominate vein or SVC invasion were associated with recurrence-free survival in univariate analysis (P = 0.045 and 0.005, respectively), whereas innominate vein or SVC invasion was the negative independent prognosticator (P = 0.012). In patients with recurrent thymoma, those treated with surgery followed by chemotherapy had a significantly better post-recurrence survival than those undergoing chemoradiotherapy (P = 0.029) and those without treatment (P = 0.007). Patients with recurrent thymic carcinoma undergoing surgery followed by chemotherapy had a significantly better post-recurrence survival than those without treatment (P = 0.004), but not significantly better than those undergoing chemoradiotherapy (P = 0.252).In patients with completely resected thymoma, MG was the positive independent prognosticators of recurrence-free survival. Surgery should be attempted for recurrent disease for better post-recurrence survival. In patients with completely resected thymic carcinoma, innominate vein or SVC invasion was the negative independent prognosticator. Surgery for recurrence could be considered since it provided benefit for post-recurrence survival as chemoradiotherapy did.

Thymic epithelial tumors: prognostic determinants among clinical, histopathologic, and computed tomography findings

BACKGROUND

The Masaoka-Koga staging system has been known as the strongest prognostic factor for both survival and recurrence of thymic epithelial tumor (TET). The purpose of our study was to find prognostic determinants among computed tomography (CT), histopathologic, and clinical features of TET.

METHODS

Two radiologists reviewed retrospectively CT findings of 437 patients (male 242, female 195; mean age, 51 years) with TET. With medical record review, surgico-histopathologic results were subcategorized into Masaoka-Koga stages I through IV and World Health Organization histopathologic classifications A-B1, B2-B3, and carcinoma. Overall survival and progression-free survival were analyzed. Clinical, histopathologic, and CT features were correlated from each other.

RESULTS

In all, 437 tumors were in Masaoka-Koga stage I (n = 147, 33.6%), stage II (n = 121, 27.7%), stage III (n = 76, 17.4%), or stage IV (n = 93, 21.3%); A and B1 (n = 114, 26.1%) and B2 and B3 TET (n = 223, 51.0%); and thymic carcinoma (n = 100, 22.9%). In multivariable analyses, age, Masaoka-Koga stage IV, thymic carcinoma, and CT stages III and IV were significantly correlated with overall survival (p < 0.05), whereas adjuvant treatment, Masaoka-Koga stages III and IV, World Health Organization B2 and B3, thymic carcinoma, R2 resection, CT size, and CT stage IV were significantly associated with progression-free survival (p < 0.05). Computed tomography stages showed moderate association with Masaoka-Koga stages (K = 0.621).

CONCLUSIONS

For TET, CT staging is effective in distinguishing both overall survival and progression-free survival, and patients with Masaoka-Koga stage IV or thymic carcinoma or CT stage IV have the worst prognosis.

Is There a Role of Postoperative Radiation Therapy in Completely Resected Stage I/II Thymic Epithelial Tumor?

PURPOSE

Retrospective analyses of patients with stage I-II thymic epithelial tumors (TET) who were treated with either surgery alone (S) or surgery plus postoperative radiation therapy (SRT) were conducted to evaluate the role of adjuvant radiation therapy (RT).

MATERIALS AND METHODS

A total of 110 stage I-II TET patients following complete resection were included in this study. Postoperative radiation therapy was recommended for those with aggressive histologic type and/or invasive features according to the surgeons' judgment during the operation. A median dose of 54.0 Gy (range, 44 to 60 Gy) focused on the primary tumor bed was administered to 57 patients (51.8%).

RESULTS

In all patients, the rates of overall survival, disease-specific survival, and disease-free survival at 10 years were 91.7%, 97.1%, and 95.8%, respectively. No significant differences in disease-specific survival (100% in the S group and 93.5% in the SRT group at 10 years, p=0.12) and disease-free survival (98.1% in the S group and 94.5% in the SRT group at 10 years, p=0.41) were observed between the treatment groups, although a significantly larger number of World Health Organization (WHO)-type B2-C (p<0.001) and Masaoka stage II (p=0.03) tumors were observed in the SRT group than in the S group. No local recurrence was observed in the SRT group. No grade 2 or greater RT-related toxicities were observed in the SRT group.

CONCLUSION

Excellent outcomes were achieved in patients with stage I-II TET who underwent complete resection. Considering excellent local control and low morbidity, adjuvant RT may be considered in high risk patients with WHO-type B2-C histology and Masaoka stage II.