Case report: combined small cell lung cancer in a lung transplant recipient

Clinicopathological Difference and Survival Impact of Patients with c-SCLC and SCLC

Background

Combined small cell lung cancer (c-SCLC) distinguishes itself from small cell lung cancer (SCLC) due to its inclusion of both SCLC and non-small cell lung cancer (NSCLC) components. Few studies have compared clinicopathological characteristics, prognosis and factors affecting survival. We therefore addressed the issues in this study.

Patients and Methods

A total of 400 c-SCLC and 20,841 SCLC patients were enrolled using SEER database. Difference in clinicopathological characteristics of SCLC and c-SCLC patients was analyzed using chi-square. Kaplan–Meier was applied to compare their survival before and after propensity score matching (PSM). Cox regression model was adopted to assess the impact of different clinical variables on survival. Logistic regression was applied to identify risk factors for c-SCLC and SCLC patients.

Results

Differences in race, sex, T stage, N stage, surgery, bone, brain and liver metastasis were detected between c-SCLC and SCLC patients. c-SCLC patients had better overall survival (OS) than SCLC patients before PSM. Age, race, sex, T stage, N stage, surgery, bone, brain, liver and lung metastasis were prognostic factors affecting OS for c-SCLC and SCLC (P < 0.05). However, a significant OS benefit was not observed in c-SCLC after adjusting for clinicopathological variables (HR, 0.950; 95% CI, 0.842–1.073; P=0.411). No significant OS difference was found between c-SCLC and SCLC patients after PSM (P = 0.789). c-SCLC patients had lower risk of lymph node (OR: 0.555; 95% CI: 0.439–0.703; P < 0.001) and liver metastasis (OR: 0.591; 95% CI: 0.448–0.779; P < 0.001), whereas had no significant differences in bone and brain metastasis risks (P > 0.05) compared with SCLC patients.

Conclusion

The prognosis of c-SCLC did not significantly differ from that of SCLC if clinicopathological characteristics are controlled. Better prognosis for c-SCLC patients over SCLC patients may be ascribed to fewer liver and lymph node metastases upon diagnosis.

The role of prophylactic cranial irradiation in surgically resected combined small cell lung cancer: a retrospective study

Background

Combined small cell lung cancer (C-SCLC) is defined as small cell lung cancer (SCLC) combined with any of non-small cell lung cancer (NSCLC) histological types, such as large cell carcinoma, squamous cell carcinoma, or adenocarcinoma. Since C-SCLC is an increasingly recognized subtype of small cell carcinoma, we conducted a retrospective study in our institution to explore the value of prophylactic cranial irradiation (PCI) in patients with C-SCLC treated by surgery.

Methods

Between 2005 and 2014, the records of all consecutive patients with pathologically diagnosed C-SCLC after surgery in our institution were reviewed. Overall survival (OS), disease-free survival (DFS), and brain metastasis free survival (BMFS) were estimated by Kaplan-Meier method. Survival differences were evaluated by log-rank test, while multivariate analysis was performed by a Cox proportional hazards model.

Results

Of the total 91 patients included in this analysis, 11 patients (12.1%) were in PCI group and 80 (87.9%) in non-PCI group. The 5-year cumulative incidence of brain metastasis in the whole group was 22.2% (26.3% in non-PCI group vs. 0% in PCI group), and 5-year OS rate was 44.1%. Patients treated with PCI had significantly longer OS (P=0.011) and DFS (P=0.013), also had the trend to live a longer BMFS with marginal significance (P=0.092) than non-PCI-treated patients. The multivariate analysis showed that PCI [hazard ratio (HR) =0.102, P=0.024] was one of independent prognostic factors of the OS in surgery-treated C-SCLC patients.

Conclusions

C-SCLC patients have a relative high risk of developing brain metastases based on our study. These data showed that PCI could improve OS and DFS, as well as tend to decrease brain metastases in surgically resected C-SCLC. However, whether PCI could be part of comprehensive treatment modalities in C-SCLC should be assessed in prospective studies.

Post-transplant native pneumonectomy for interstitial fibrosis and small cell lung cancer

Lung transplantation is a definitive treatment for select patients with end-stage pulmonary disease. Following transplantation, the reported rate of lung cancer is between 1-9% and is associated with a variety of risk factors, including smoking history and chronic immunosuppression. The majority of post-transplant lung cancer reported in the literature is histologically classified as non-small cell lung carcinoma (NSCLC). We report a unique case of early stage small cell lung carcinoma (SCLC) identified in the native lung following single lung transplantation.