ABSTRACT
Thymic epithelial tumors are the most common mediastinal tumors. Surgery is the mainstay of treatment and complete resection provides the best survival rate. However, advanced tumors often require multimodality treatment and thus we analyzed the prognostic potential of routine circulating biomarkers that might help to risk-stratify patients beyond tumor stage and histology. Preoperative values for white blood cell count (WBC), C-reactive protein (CRP) and lactate dehydrogenase (LDH) were analyzed in 220 thymic epithelial tumor patients operated between 1999 and 2018. Increased CRP levels (>1 mg/dl) were significantly more often measured in thymic carcinoma and neuroendocrine tumors when compared to thymoma. LDH serum activity was higher in thymic neuroendocrine tumors when compared to thymoma or thymic carcinoma. The median disease specific survival was significantly longer in thymoma cases than in thymic carcinoma and neuroendocrine tumors. Increased preoperative LDH level (>240 U/L) associated with shorter survival in thymus carcinoma (HR 4.76, p = 0.0299). In summary, higher CRP associated with carcinoma and neuroendocrine tumors, while LDH increased primarily in neuroendocrine tumors suggesting that biomarker analysis should be performed in a histology specific manner. Importantly, preoperative serum LDH might be a prognosticator in thymic carcinoma and may help to risk stratify surgically treated patients in multimodal treatment regimens.
Subject(s)
Biomarkers, Tumor/metabolism , C-Reactive Protein/metabolism , L-Lactate Dehydrogenase/metabolism , Neoplasms, Glandular and Epithelial/pathology , Neuroendocrine Tumors/pathology , Preoperative Care , Thymus Neoplasms/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Leukocyte Count , Male , Middle Aged , Neoplasms, Glandular and Epithelial/blood , Neoplasms, Glandular and Epithelial/metabolism , Neoplasms, Glandular and Epithelial/surgery , Neuroendocrine Tumors/blood , Neuroendocrine Tumors/metabolism , Neuroendocrine Tumors/surgery , Prognosis , Retrospective Studies , Survival Rate , Thymus Neoplasms/blood , Thymus Neoplasms/metabolism , Thymus Neoplasms/surgery , Young AdultABSTRACT
BACKGROUND: Thymic epithelial and neuroendocrine carcinomas are rare malignancies, and only a few prognosticators are defined. Surgery is the mainstay of treatment, and complete resection contributes to superior outcome. Systematic lymph node dissection is not routinely performed in thymic malignancies. The aim of this study was to assess the impact of histologically confirmed lymph node metastases on the outcome after thymectomy. METHODS: We identified 53 patients with thymic epithelial or neuroendocrine carcinomas who underwent surgical resection at our center between 1999 and 2016. The clinical follow-up was retrospectively collected, and the impact of clinicopathologic factors on overall survival was analyzed. RESULTS: Ninety-one percent of the patients were treated taking a multimodal approach. Median overall survival was 11.3 years. Lymph node metastases were identified in 16 patients (30.2%; 11 pN1 and 5 pN2). Lymph node metastasis was associated with inferior overall survival (hazard ratio [HR] 3.03, 95% confidence interval [CI]: 1.03 to 8.87, p = 0.044). Masaoka-Koga stage (4 versus 1 to 3) was another significant prognosticator (HR 7.01, 95% CI: 2.52 to 19.50, p = 0.0002). Organ metastases were present in 18 patients at the time of thymectomy and were associated with inferior outcome (HR 5.8, 95% CI: 2.04 to 16.79, p = 0.001). CONCLUSIONS: This retrospective, single-center analysis demonstrates a high rate of lymph node metastasis in resectable thymic neuroendocrine tumors or carcinomas. Positive lymph nodes are associated with an inferior outcome. Prospective studies are warranted to explore whether this outcome can be improved by systematic lymphadenectomy and adjuvant therapies. Nevertheless, lymphadenectomy provides optimal staging and should be a routine part of surgery for patients with thymic malignancies.
