Mediastinal radiotherapy after multidrug chemotherapy and prophylactic cranial irradiation in patients with SCLC – treatment results after long-term follow-up and literature overview

Serum uric acid level can predict asymptomatic brain metastasis at diagnosis in patients with small cell lung cancer

BACKGROUND

The aim of this study was to determine the relationship between serum uric acid level at diagnosis and asymptomatic brain metastasis in patients with extensive-stage small cell lung cancer.

METHODS

A total of 69 patients with extensive-stage small cell lung cancer without symptomatic brain metastases, whose serum uric acid level was measured at the time of diagnosis, were included in this retrospective cross-sectional study. The patients were divided into two groups as those with and without asymptomatic brain metastases. The Mann-Whitney U test was used for comparison between groups, and Spearman's correlation test was used for correlation analysis. The cut-off level of serum uric acid level was analyzed, and sensitivity, specificity, and accuracy rates were determined for brain metastasis. Independent factors affecting asymptomatic brain metastasis were determined by multivariate Cox regression analysis.

RESULTS

The median serum uric acid level of all patients was 6.9 mg/dL. Twenty-two percent of patients had asymptomatic brain metastases, and serum uric acid levels were significantly higher in these patients (P = 0.0014). The cut-off value for serum uric acid level was calculated as 6.2 mg/dL. The sensitivity, specificity, and accuracy of this value for brain metastasis were 84%, 76%, and 78%, respectively. High serum uric acid level was an independent risk factor for asymptomatic brain metastasis (OR 3.446 95% CI 1.337-5.480; P = 0.005).

CONCLUSION

In conclusion, a serum uric acid level of 6.2 mg/dL and above at the time of diagnosis may predict asymptomatic brain metastasis in patients.

Factors associated with overall survival, progression-free survival and toxicity in patients with small cell lung cancer and thoracic irradiation in a clinical real-world setting

BACKGROUND

Small-cell lung cancer (SCLC) is a malignant tumor known for its poor prognosis. In addition to chemotherapy and immunotherapy irradiation plays a big role especially in inoperability. This study evaluated prognostic factors in patients with SCLC, receiving chemotherapy and thoracic irradiation, that may affect overall survival (OS), progression-free survival (PFS) and toxicity.

METHODS

Patients with limited disease (LD) SCLC (n = 57) and extensive disease (ED) SCLC (n = 69) who received thoracic radiotherapy were analyzed retrospectively. The prognostic factors sex, age, Karnofsky performance status (KPS), tumor-, nodal-stage and timepoint of start of irradiation in relation to the first cycle of chemotherapy were evaluated. Start of irradiation was stratified as early ([Formula: see text] 2 cycles of chemotherapy), late (3 or 4 cycles) and very late ([Formula: see text] 5 cycles). Results were analyzed by Cox univariate and multivariate as well as logistic regression analysis.

RESULTS

The median OS of LD-SCLC patients was 23.7 months in early, and 22.0 months in late start of irradiation. In very late start, median OS was not reached. PFS was 11.8, 15.2 and 47.9 months, respectively. In patients with ED-SCLC OS was 4.3 months in early, 13.0 months in late and 12.2 months in very late start of irradiation. PFS was 6.7, 13.0 and 12.2 months, respectively. Prognosis of patients with LD- or ED-SCLC receiving late or very late start of irradiation was significantly prolonged in OS and PFS compared to an early start (p < 0.05). KPS [Formula: see text] 80 shows a significant increase of OS and PFS in ED-SCLC. Female sex and smaller mean lung dose were associated with lower risk of toxicity.

CONCLUSION

Late or very late start of irradiation is a prognosis-enhancing factor in LD-SCLC and ED-SCLC for OS and PFS. KPS [Formula: see text] 80 increases prognosis of OS and PFS in ED-SCLC as well. Toxicity is less common in female sex and patients with low mean lung dose in LD-SCLC.

MEG3 LncRNA from Exosomes Released from Cancer-Associated Fibroblasts Enhances Cisplatin Chemoresistance in SCLC via a MiR-15a-5p/CCNE1 Axis

PURPOSE

Long non-coding RNAs (lncRNAs) may act as oncogenes in small-cell lung cancer (SCLC). Exosomes containing lncRNAs released from cancer-associated fibroblasts (CAF) accelerate tumorigenesis and confer chemoresistance. This study aimed to explore the action mechanism of the CAF-derived lncRNA maternally expressed gene 3 (MEG3) on cisplatin (DDP) chemoresistance and cell processes in SCLC.

MATERIALS AND METHODS

Quantitative real-time PCR was conducted to determine the expression levels of MEG3, miR-15a-5p, and CCNE1. Cell viability and metastasis were measured by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-h-tetrazolium bromide and invasion assays, respectively. A xenograft tumor model was developed to confirm the effect of MEG3 overexpression on SCLC progression in vivo. Relationships between miR-15a-5p and MEG3/CCNE1 were predicted using StarBase software and validated by dual luciferase reporter assay. Western blotting was used to determine protein levels. A co-culture model was established to explore the effects of exosomes on MEG3 expression in SCLC cell lines.

RESULTS

MEG3 was overexpressed in SCLC tissues and cells. MEG3 silencing significantly repressed cell viability and metastasis in SCLC. High expression of MEG3 was observed in CAF-derived conditioned medium (CM) and exosomes, and promoted chemoresistance and cancer progression. Additionally, MEG3 was found to serve as a sponge of miR-15a-5p to mediate CCNE1 expression. Overexpression of miR-15a-5p and knockout of CCNE1 reversed the effects of MEG3 overexpression on cell viability and metastasis.

CONCLUSION

MEG3 lncRNA released from CAF-derived exosomes promotes DDP chemoresistance via regulation of a miR-15a-5p/CCNE1 axis. These findings may provide insight into SCLC therapy.

Correlation analysis of serum cystatin C, uric acid and lactate dehydrogenase levels before chemotherapy on the prognosis of small-cell lung cancer

Related studies have reported that cystatin C (Cys C), uric acid (UA) and lactate dehydrogenase (LDH) affect tumor growth and invasion; however, the correlation between them and the prognosis of patients with small-cell lung cancer (SCLC) remains unclear. The present study aimed to investigate the effects of serum Cys C, UA and LDH concentrations on the prognosis of patients with SCLC prior to initial treatment, in order to identify potential targets for determining the clinical outcome of patients with SCLC. A total of 205 patients with SCLC were enrolled in the present study, and the clinical and laboratory data were obtained from the medical records. The receiver operating characteristic curve was used to determine the optimal cut-off values of Cys C, UA and LDH, while the Kaplan-Meier method was used for survival analysis. The Cox proportional hazard model was used for univariate and multivariate analyses to identify independent prognostic factors. The optimal cut-off values for Cys C, UA and LDH were 0.775 mg/l, 296.45 µmol/l and 198.5 U/l, respectively. The survival curves demonstrated that progression-free survival (PFS) and overall survival (OS) time were shorter in patients with high levels of Cys C, UA and LDH prior to chemotherapy. Univariate and multivariate analyses indicated that LDH concentration prior to chemotherapy may be an independent prognostic factor for both PFS and OS in patients with SCLC, while Cys C concentration may be an independent prognostic factor for PFS in patients with SCLC. The concentrations of Cys C, UA and LDH prior to chemotherapy were associated with prognosis of patients with SCLC. PFS and OS time were shorter, and the prognosis was poor in patients with elevated serum levels of Cys C, UA and LDH. Taken together, the results of the present study suggest that high concentrations of LDH and Cys C prior to chemotherapy may indicate rapid disease progression, thus it is important to focus on the progression and recurrence of the disease. High LDH concentration may also indicate a shorter survival time.

YY1-induced lncRNA ZFPM2-AS1 facilitates cell proliferation and invasion in small cell lung cancer via upregulating of TRAF4

Background

Newly identified lncRNA zinc finger protein, FOG family member 2 antisense RNA 1 (ZFPM2-AS1) is identified as an oncogenic gene. However, the role of ZFPM2-AS1 in small cell lung cancer (SCLC) is poorly comprehended.

Methods

The expression of genes in SCLC tissues and cells was measured by qRT-PCR. Colony formation, EdU, CCK-8, transwell and wound healing as well as in vivo assays revealed the function of ZFPM2-AS1 in SCLC. ChIP, luciferase reporter, RIP and RNA pull down assays demonstrated the binding relation among genes.

Results

ZFPM2-AS1 was significantly upregulated in SCLC tissues and cells. ZFPM2-AS1 deficiency attenuated SCLC cell proliferation, invasion and migration. In addition, ZFPM2-AS1 was transcriptionally activated by Yin Yang 1 (YY1) factor. Further, miR-3612 was confirmed as downstream miRNA of ZFPM2-AS1. Moreover, TNF receptor associated factor 4 (TRAF4) was the target gene of miR-3612 in SCLC. ZFPM2-AS1, miR-3612 and TRAF4 jointly constituted a competing endogenous RNA (ceRNA) network in SCLC. Finally, TRAF4 could countervail ZFPM2-AS1 downregulation-mediated function on SCLC cell proliferation and invasion in vitro and tumor growth in vivo.

Conclusion

Our study elucidated the oncogenic effect of ZFPM2-AS1 in SCLC progression, indicating it may be a therapeutic target for SCLC.

Sequential Versus Concurrent Thoracic Radiotherapy in Combination With Cisplatin and Etoposide for N3 Limited-Stage Small-Cell Lung Cancer

At present, concurrent chemoradiotherapy (CRT) is considered the standard treatment of limited-stage small cell lung cancer (LS-SCLC). However, LS-SCLC is highly heterogeneous in the T stage, N stage, and prognosis. Increasing evidence has shown that individual treatment should be considered when treating LS-SCLC patients. The aim of the present study was to explore the optimal combination model of thoracic radiotherapy (TRT) and chemotherapy in N3 LS-SCLC. We retrospectively analyzed 93 N3 LS-SCLC patients treated in the Department of Oncology of Binzhou Medical University Hospital (Shandong, China) between March 2010 and October 2015. A total of 52 (52/93; 55.9%) patients received sequential CRT, and 41 (41/93; 44.1%) patients received concurrent CRT. All patients received 4-6 cycles of chemotherapy and TRT (50-60 Gy). The median follow-up time was 25.4 months (range was 6-65 months).The overall response rate was 88.5% in the sequential CRT group (9.6% complete response rate and 78.8% partial response rate) and 90.2% in the concurrent CRT group (14.6% complete response rate and 75.6% partial response rate). The PFS and OS were 15.4 months and 19.1 months in sequential CRT group, and 16.9 months and 20.5 months in concurrent CRT group. There was no significant difference in treatment response rate, PFS, and OS between sequential and concurrent CRT patients. The most common treatment-related toxicities were nausea/vomiting, neutropenia, and esophagitis. In conclusion, when concurrent CRT is performed in N3 LS-SCLC patients, tolerance to treatment should be fully considered. In our study, sequential CRT and concurrent CRT showed the same efficacy, and sequential CRT demonstrated better tolerance. However, these results require confirmation in future follow-up studies.

SBF2-AS1: An oncogenic lncRNA in small-cell lung cancer

The long noncoding RNAs (lncRNAs) SBF2 antisense RNA 1 (SBF2-AS1) was found to act as an oncogenic lncRNA in non-small-cell lung cancer (NSCLC), but the role of SBF2-AS1 in small-cell lung cancer (SCLC) was still unclear. The purpose of this study was to provide the clinical significance and biological function of SBF2-AS1 in SCLC. In our results, SBF2-AS1 was found to be upregulated in SCLC tissues compared with NSCLC tissues or adjacent normal lung tissues. Besides, SBF2-AS1 expression was also elevated in SCLC cell lines compared with the normal bronchial epithelial cell line or NSCLC lines. Moreover, high expression of SBF2-AS1 was associated with clinical stage, tumor size, lymph node metastasis and distant metastasis in SCLC patients. Survival analysis showed SCLC patients with high expression of SBF2-AS1 had shorter overall survival than patients with low expression of SBF2-AS1, and high expression of SBF2-AS1 acted as an independent poor prognostic factor for overall survival in SCLC patients. The study in vitro suggested inhibition of SBF2-AS1 obviously depressed cell proliferation, migration, and invasion in SCLC. In conclusion, SBF2-AS1 acts as a novel oncogenic lncRNA in SCLC.

Prognostic value of pre-treatment 18F-FDG-PET uptake in small-cell lung cancer

PURPOSE

Small-cell lung cancer (SCLC) is an aggressive disease, despite an initially favorable response to treatment, and its prognosis is still poor. Multiple parameters have been studied as possible prognostic factors, but none of them are reliable enough to change the treatment approach. ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is a novel imaging technique for staging of SCLC. The aim of this study was to evaluate the prognostic value of pre-treatment FDG-PET parameters on clinical outcome in limited stage (LS) SCLC patients treated with curative thoracic radiotherapy (RT) and chemotherapy.

METHODS

Clinical records of 46 LS-SCLC patients with pre-treatment FDG-PET imaging were retrospectively reviewed. Patients were treated with definitive RT for a total dose of 50-60 Gy and chemotherapy. The clinical endpoints were progression-free survival (PFS) and overall survival (OS).

RESULTS

The median age was 59 (range 30-82) years, and median follow-up time was 23.2 months (range 5-82.8 months). Median OS was 30.9 months for pre-treatment tumor maximum standardized uptake value (SUV_max) <9.3 and 20.6 months for SUV_max ≥9.3 (p = 0.027) and PFS was 55.6 months for SUV_max <9.3 and 38.6 months for SUV_max ≥9.3 (p = 0.16). Median OS was 73 months for pre-treatment lymph node SUV_max <5.8 and 21 months for ≥5.8 (p = 0.01) and PFS was 38.6 months (range 6.8-70.3 months) for SUV_max-LN ≥5.8; all patients with SUV_max-LN <5.8 were alive (p = 0.07). Median survival time was 28.2 months (range 21.7-34.7 months) for patients younger than 65 and 8.7 months (range 5.7-11.8 months) for those ≥65 years (p = 0.00).

CONCLUSIONS

Pre-treatment FDG-PET uptake may be a valuable tool to evaluate prognosis in SCLC patients. Patients with a higher pre-treatment FDG uptake may be considered at increased risk of failure and may benefit from more aggressive treatment approaches.

PET-CT guided curative conformal radiation therapy in limited stage small cell lung cancer

BACKGROUND

The prognosis of small cell lung cancer (SCLC) has been improving with the advances in diagnostic and therapeutic modalities. Positron emission tomography/computed tomography (FDG-PET/CT) which has been studied in non-small cell lung cancer (NSCLC) for a long time, and it has only recently been applied to SCLC. Therefore we sought to observe firstly the prognostic importance of the FDG uptake in limited disease small cell lung cancer (LD-SCLC) patients and secondly the clinical outcomes and toxicity profiles of LD-SCLC patients treated with conformal radiation therapy (RT) using FDG-PET/CT simulation.

METHODS

Between 2009 and 2011, 33 LD-SCLC patients with LD-SCLC underwent disease staging using FDG-PET/CT conformal RT. Thoracic radiation was administered at a daily fraction of 2 Gy. Total dose was prescribed according to the treatment protocol such as, concurrent or sequential chemotherapy and in some patients according to the response of CT. All patients underwent chemotherapy. Survival was estimated using the Kaplan-Meier method.

RESULTS

The median age of the patients was 58 years (range, 38-77 years). The median follow-up time was 20 months (range, 6.6-47.6 months). The 3-year overall survival (OS) and locoregional control rates were 23% and 48%, respectively.

CONCLUSIONS

There are few studies examining the impact of PET-CT and the prognostic significance of FDG-uptake on outcomes in patients with LD-SCLC. Higher RT doses in response to higher FDG uptake may be safely applied for the purpose of locoregional control.