Predictive Indicators of Survival in Patients With Surgically Resected Lung Carcinoid Tumors at a Greek Medical Center

Introduction Lung carcinoid tumors are neuroendocrine neoplasms, less frequent than other lung tumors. They are subdivided into typical carcinoids (TC) and atypical carcinoids (AC), according to the rate of mitosis and the presence of necrosis. Lung carcinoids are often asymptomatic and only discovered incidentally. They may also present with cough, wheezing, asthma, and chronic obstructive pulmonary disease, chest pain, and hemoptysis depending on the location of the tumor and, less commonly, present with carcinoid syndrome. In our study, we describe the clinical and pathological features of patients with surgically resected lung carcinoids at our institution over a period of 14 years. We also examine if these features, including age, gender, tumor size, type of carcinoid, stage, nodal involvement, and Ki-67 expression are associated with patients' survival. Materials and methods We retrospectively reviewed patients that underwent surgery with a final histologic diagnosis of a pulmonary carcinoid tumor from March 2005 to March 2019. The evaluation included history, physical examination, chest radiographs, computerized tomography of the chest, upper abdomen, and brain, and bone scintiscan. All specimens resected during the surgical procedures were sent for pathological examination, including mediastinal and hilar lymph nodes. The patients' age, gender, tumor size, type of carcinoid, nodal involvement, stage, and Ki-67 expression were recorded and correlated to the patients' survival rates. Results The study included 108 patients - 52 males and 56 females - with a mean age of 51.5 years (range 11-80 years). Atypical carcinoid was the diagnosis in 28 patients (16 males and 12 females) and 80 patients had the diagnosis of typical carcinoid (36 males and 44 females). Tumor size was ≤3.7 cm in 84 patients (68 with TC and 16 with AC) and >3.7 cm in 22 patients (12 with TC and 10 with AC). Sixteen patients had nodal deposits, 12 in N1 nodes and four in N2 nodes. Eighty patients were classified in stage I, 18 patients in stage II, and 10 patients in stage III. None of the patients had distant metastases. The Ki-67 proliferation index was examined in 84 specimens and Ki-67 was <2.5 in 50 patients and ≥2.5 in 34 patients. Of the 108 patients, eight died, all with disease-related death. According to the Cox regression univariate analysis, four factors were correlated to shorter survival: atypical histology, tumor size >3.7 cm, nodal involvement, and advanced stage Conclusions In conclusion, we found that histological type, tumor size, nodal involvement, and stage are associated with survival in patients with surgically resected lung carcinoids without distant metastases. Other parameters, such as age at operation, gender, and Ki-67 index, did not have a role in survival in these patients according to the Cox regression univariate analysis.