Nomogram for predicting the survival rate of primary pulmonary mucoepidermoid carcinoma patients: a retrospective study based on SEER database

Background

Primary pulmonary mucoepidermoid carcinoma (PMEC) is a rare malignant tumor, and the clinical manifestations lack specificity. The study evaluates the prognostic factors and constructs a practicable nomogram to estimate the individualized survival status for PMEC patients.

Methods

Surveillance, Epidemiology, and End Results (SEER) database was used to selected eligible patients between 1975 and 2016. The baseline characteristics including age, sex, race, marital status, tumor stage, differentiated degree, tumor laterality, primary tumor site, tumor size, lymph node metastases status, distant metastases status, surgery, chemotherapy, and radiation. We identified independent variables to build 3-, 5-, 10-year overall survival (OS) and cancer-specific survival (CSS) nomograms by univariate and multivariate analyses.

Results

A total of 438 PMEC patients met our selection criteria. In multivariate analysis, age, tumor stage, differentiated grade, tumor size, lymph node metastases status, distant metastases status, surgery and radiation were involved in the nomogram. The C-index (0.887 (95% CI: 0.863-0.911), calibrate plots and ROC curves (AUC =0.941, 0.951, 0.935 for 3-, 5-, 10-year OS, respectively) indicated the satisfied accuracy and practicability of our nomograms. Compared to TNM system, our model also showed a superior prediction (IDI =0.167, 0.171, 0.172, P<0.001).

Conclusions

We built OS (CSS) nomograms that can accurately estimate individualized survival time and identify the risk classification of PMEC.

CT features and differential diagnosis of primary pulmonary mucoepidermoid carcinoma and pulmonary adenoid cystic carcinoma

Background

The differential diagnosis of primary pulmonary mucoepidermoid carcinoma (PMEC) and pulmonary adenoid cystic carcinoma (PACC) is difficult, because both tumors could be similar in terms of certain characteristics on CT.

Methods

The CT findings from 24 cases of PMEC and 30 cases of PACC were retrospectively analyzed. According to the position of the lesion in airway, we divided these cases into three types: central, hilar, and peripheral.

Results

In PMEC, there were 7 cases of central type, 14 cases of hilar type, and 3 cases of peripheral type. And, 57.1% PMEC cases of the hilar type were accompanied by distal bronchial dilatation with mucoid impaction. Patchy areas of low density were observed in 79.2% cases of PMEC. The solid part of most lesions showed moderate (37.5%) or severe enhancement (45.8%). However, in PACC, there were 24 cases of central type, 3 cases of hilar type, and 3 cases of peripheral type. PACC had more cases of central type than PMEC. Moreover, longitudinal extent greater than 3 cm was observed in 62.5% PACC cases of the central type, while infiltration of the luminal perimeter more than 1/2 perimeter was observed in 95.8% PACC cases of the central type. Patchy areas of low density were observed in 26.7% cases of PMEC. In PACC cases, the solid part of 76.7% lesions showed slight enhancement. Cavities could be observed in PMEC, but not in PACC.

Conclusions

PMEC and PACC have different CT features in various airway locations. PMEC is usually the hilar type, accompanied by distal bronchial dilatation with mucoid impaction. However, PACC is usually the central type, with longitudinal extent greater than 3 cm and infiltration of the luminal wall more than 1/2 perimeter. Patchy areas of low density and moderate or severe enhancement are more prominent in PMEC. However, slight enhancement is more common in PACC.

Prognostic factors of primary pulmonary mucoepidermoid carcinoma: a clinical and pathological analysis of 34 cases

Pulmonary mucoepidermoid carcinoma (PMEC) is a rare malignant neoplasm, and little is known about the prognostic factors. The aim of the present study was to identify the relationship between tumor's histological features and clinical behaviors and to analyze the survival of patients with PMEC. A total of 34 patients with PMEC from May 2001 to April 2013 were included in the investigation. The clinical data, radiological manifestation, pathological findings, treatment strategy, and prognoses of all patients were analyzed retrospectively. The patients were classified into low-grade group (n = 25) and high-grade group (n = 9), based on histological grades. High-grade PMEC was more common in patient with elevated serum carcinoembryonic antigen (CEA) (P = 0.033), advanced tumor-node-metastasis (TNM) stage (P = 0.004) and lymph node metastasis (P < 0.001). The 5-year PFS and OS of all patients were 75.7% and 83.6%, respectively. Age, pathological grade, lymph node metastasis and TNM stage were correlated with the survival of PMEC patients. Lymph node metastasis was an independent predictor of OS (HR, 0.080; P = 0.029) and PFS (HR, 0.090; P = 0. 004). A higher tumor histological grade indicated a more aggressive behavior. Patients who had undergone complete resection for PMEC without any lymph node metastasis were expected to be cured.