Multidisciplinary Management of Small Cell Lung Cancer

The role of surgery in stage I to III small cell lung cancer: A systematic review and meta-analysis

Background

The role of surgery in treating small cell lung cancer (SCLC) remains controversial. This meta-analysis aims to determine whether surgical-based treatment improves survival in comparison to radiotherapy, chemotherapy, and chemoradiotherapy for stage I to III SCLC.

Methods

PubMed, PubMed Central, EMBASE, Web of Science, and Cochrane Library were searched for relevant articles. The main outcome were overall survival (OS), reported as hazard ratios (HRs), and 95% confidence intervals (CIs).

Results

Two randomized control trials (RCTs) and 13 retrospective studies that included a total of 41,483 patients were eligible. Surgical resection significantly improved OS when compared to non-surgical treatment in retrospective studies (HR = 0.56, 95% CI: 0.49–0.64, P < 0.001), but not in the 2 “older” RCTs (HR = 0.77, 95% CI: 0.32–1.84, P = 0.55). In the subgroup analysis for retrospective studies, surgical resection was associated with superior OS in stage I (HR = 0.56, 95% CI: 0.49–0.64, P < 0.001), stage II (HR = 0.75, 95% CI: 0.57–0.99, P = 0.04), and stage III diseases (HR = 0.70, 95% CI: 0.56–0.88, P = 0.002). Sublobar resection resulted in worse OS than a lobectomy (HR = 0.64, 95% CI: 0.56–0.74, P < 0.001) for patients undergoing surgical resection.

Conclusions

Surgery-based multi-modality treatment appears to be associated with a favorable survival advantage in stage I and selected stage II to III SCLC. Lobectomy is likely to provide superior OS when compared to sublobar resection. Further prospective RCTs are needed to confirm these findings.

Efficacy of surgery and prophylactic cranial irradiation in stage II and III small cell lung cancer

Background: The role of surgery for stage II and III small cell lung cancer (SCLC) remains controversial. The use of prophylactic cranial irradiation (PCI) for resected SCLC was limited. This study aimed to assess the efficacy of surgery in patients with stage II and III SCLC, and evaluate the value of PCI on resected disease. Methods: A total of 269 consecutive patients with stage II-IIIA SCLC were retrospectively reviewed from January 2010 to December 2015. Of these, 116 patients received surgical resection, and 153 underwent non-surgical treatment. Resected patients were matched 1:1 with non-surgical patients (n=70 in each group). Results: The median follow-up was 30 months. The 1-, 3- and 5-year overall survival (OS) for matched patients were 80.0%, 44.3% and 31.7% in surgical group, and 80.0%, 24.3% and 20.0% in non-surgical group (P=0.009), respectively. Multivariate analysis in matched patients showed that surgery (HR=0.603, 95%CI: 0.404-0.900) and PCI (HR=0.637, 95%CI: 0.427-0.950) were independent prognostic factors for OS. In subgroup analysis, OS benefit related to surgery was marginal for stage II (P=0.09) and IIIA patients (P=0.061), but was significant for selected stage IIIA patients who received adjuvant chemo-radiation and PCI (P=0.01). PCI was associated with improved OS for non-surgical patients (P=0.036), and stage IIIA of surgical patients (P=0.047). Conclusions: These findings suggest a potential OS benefit of surgery in stages II and IIIA patients, particularly in selected stage IIIA patients who received adjuvant chemo-radiation and PCI. The use of PCI for surgical patients with stage IIIA was associated with improved OS.

NK Cells Mediate Synergistic Antitumor Effects of Combined Inhibition of HDAC6 and BET in a SCLC Preclinical Model

Small-cell lung cancer (SCLC) has the highest malignancy among all lung cancers, exhibiting aggressive growth and early metastasis to distant sites. For 30 years, treatment options for SCLC have been limited to chemotherapy, warranting the need for more effective treatments. Frequent inactivation of TP53 and RB1 as well as histone dysmodifications in SCLC suggest that transcriptional and epigenetic regulations play a major role in SCLC disease evolution. Here we performed a synthetic lethal screen using the BET inhibitor JQ1 and an shRNA library targeting 550 epigenetic genes in treatment-refractory SCLC xenograft models and identified HDAC6 as a synthetic lethal target in combination with JQ1. Combined treatment of human and mouse SCLC cell line-derived xenograft tumors with the HDAC6 inhibitor ricolinostat (ACY-1215) and JQ1 demonstrated significant inhibition of tumor growth; this effect was abolished upon depletion of NK cells, suggesting that these innate immune lymphoid cells play a role in SCLC tumor treatment response. Collectively, these findings suggest a potential new treatment for recurrent SCLC.Significance: These findings identify a novel therapeutic strategy for SCLC using a combination of HDAC6 and BET inhibitors. Cancer Res; 78(13); 3709-17. ©2018 AACR.

Evaluation of short-term and long-term efficacy of surgical and non-surgical treatment in patients with early-stage small cell lung cancer: A comparative study

OBJECTIVE

The aim of this study is to compare surgery with adjuvant chemoradiotherapy versus non-surgical treatments for patients with early-stage small cell lung cancer (SCLC) based on the short-term and long-term efficacy.

METHODS

SCLC patients who underwent a pulmonary lobectomy with post-surgical radiotherapy or chemotherapy were assigned to the surgical group. SCLC patients who received radiotherapy or chemotherapy alone were classified into the non-surgical group. The clinical efficacy was evaluated as complete remission (CR), partial remission (PR), stable disease (SD), or progressive disease (PD). The total effectiveness rate was calculated as CR + PR. The 1-, 3-, and 5-year survival rates of the two groups were compared.

RESULTS

Compared with the non-surgical group, the CR rate and the total effectiveness rate were higher in the surgical group, and the total effectiveness rate for male patients and patients without a smoking history were also higher in the surgical group. Distant metastasis and local recurrence concurrent with distant metastasis in the surgical group were both lower in the surgical group than in the non-surgical group. Compared with the non-surgical group, the local recurrence in male patients was lower in the surgical group, and patients in the surgical group had lower distant metastasis at TNM stage IIb. The 1-, 3-, and 5-year survival rates were higher in the surgical group than in the non-surgical group.

CONCLUSIONS

These findings indicate that for patients with early-stage SCLC, better scores in effectiveness rate, disease progression, and 1-, 3-, and 5-year survival rates were observed in patients who underwent surgery followed by adjuvant chemoradiotherapy when compared with patients without surgical treatment.

Prognostic Value of Metabolic Parameters of Metastatic Lymph Nodes on 18F-FDG PET/CT in Patients With Limited-stage Small-cell Lung Cancer With Lymph Node Involvement

INTRODUCTION

We assessed the prognostic value of the metabolic parameters of different lesions, including primary tumors and metastatic lymph nodes (LNs), measured by fluorine-18 fluorodeoxyglucose positron emission tomography (PET)/computed tomography in patients with limited-stage small-cell lung cancer (LS-SCLC) with LN metastasis.

MATERIALS AND METHODS

The present retrospective study included 46 patients with clinical stage II-III N1-N2 LS-SCLC who had undergone pretreatment fluorine-18 fluorodeoxyglucose PET/computed tomography scanning from January 2011 to December 2014. All patients underwent complete first-line therapy (concurrent chemoradiotherapy and prophylactic cranial irradiation). The metabolic parameters, including maximal standardized uptake value, mean standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) values of the PTs and metastatic LNs were measured on PET. Kaplan-Meier survival curves were used for evaluation of progression-free survival (PFS) and overall survival (OS). Univariate and multivariate Cox proportional hazards models were used to analyze the prognostic factors.

RESULTS

The median OS and PFS were 25.9 months (range, 8.2-63.5 months) and 21 months (range, 6.4-55.3 months), respectively. Univariate analysis demonstrated that the Eastern Cooperative Oncology Group performance status, N1 station involvement, subcarinal LN metastasis, LN MTV, LN TLG, sum of the MTV, and summary of the TLG were significant predictive factors (P < .05). The Eastern Cooperative Oncology Group performance status, subcarinal nodal metastasis, LN MTV, and LN TLG were independent predictive factors of PFS and OS on multivariate analysis.

CONCLUSION

The metabolic parameters of metastatic LNs, other than lung lesions, are independent prognostic factors in patients with LS-SCLC with LN metastasis. These parameters could further stratify the prognosis of these patients, and these findings might provide functional imaging evidence for the future study of the mechanisms of metastasis.

Benefits of postoperative thoracic radiotherapy for small cell lung cancer subdivided by lymph node stage: a systematic review and meta-analysis

BACKGROUND

Whether postoperative thoracic radiotherapy (PORT) is beneficial for small cell lung cancer (SCLC) of different lymph node stages remains uncertain; therefore, the purpose of this meta-analysis was to explore the clinical significance of PORT for SCLC patients subdivided by lymph node status.

METHODS

The PubMed, OVID, Web of SCI, EMBASE, Google Scholar, Cochrane Library, Chinese National Knowledge Infrastructure and Wanfang databases were systematically searched to identify eligible studies where SCLC patients received PORT based on lymph node stage. The main outcome measures were 1-, 3- and 5-year overall survival (OS) rates, as well as 1-, 2- and 3-year local regional recurrence (LRR) rates. All data were analyzed using STATA 12.0 and expressed as risk ratios (RR) with their corresponding 95% confidence intervals (95% CI).

RESULTS

Five cohort studies, including 3,497 SCLC patients (578 receiving PORT and 2,919 not) were included in this study. PORT significantly decreased the 1-, 2- and 3-year LRR rates (RR =0.14, 0.28 and 0.27, respectively; P_all<0.05), but did not improve the 1-, 3- or 5-year OS rates when all patients were analyzed together. However, subgroup analysis showed that in the pN0 group PORT did not improve the 1-, 3- or 5-year OS rates or decrease the 1-, 2- or 3-year LRR rates; in the pN1 group PORT reduced the 1-, 2- and 3-year LRR rates (RR =0.11, 0.16 and 0.17, respectively; P_all<0.05) and improved the 1-year OS rate (RR =0.40; P<0.001), but not the 3- or 5-year OS rates; in the pN2 group PORT significantly reduced the 1-, 2- and 3-year LRR rates (RR =0.14, 0.15 and 0.15 respectively; P_all<0.05) and improved the 1-, 3- and 5-year OS rates (RR =0.46, 0.72 and 0.85, respectively; P_all<0.05).

CONCLUSIONS

This is the first meta-analysis of the benefits of PORT for SCLC patients. Although derived from retrospective cohort studies, the data showed that PORT significantly reduced the risk of recurrence and improved survival for patients with pN2-SCLC; however, patients with pN0-SCLC did not benefit from PORT, whereas for patients with pN1-SCLC, PORT reduced the LRR rates and improved the 1-year survival rate. The long-term survival benefits of PORT remain unclear and will require further prospective studies.

Adverse prognostic impact of TGFB1 T869C polymorphism in non-small-cell lung cancer

Previously, several polymorphisms in TGFB1 have been identified in non-small-cell lung cancer (NSCLC), and the variants, C-509T, T869C, and G915C, have been demonstrated to associate with higher circulating levels of TGF-β1. However, little is known about the prognostic value of TGF-β1 polymorphisms in cancers. In this study, by genotyping the TGF-β1 T869C polymorphism in a total of 261 patients with NSCLC using DNA from blood lymphocytes, we first found that NSCLC patients, especially those with allele C carriers, had significantly higher serum TGF-β1 levels than healthy individuals. By using chi-square (χ²) test and Fisher's exact test, we noticed that TC/CC genotypes were positively correlated with smoking, clinical TNM stage, lymph node, and distant metastasis in NSCLC patients. Kaplan-Meier analysis showed that patients with TT genotype had a better overall survival than the allele C carriers (TC + CC). Finally, multivariate analysis confirmed histology, lymph node, and distant metastasis but not T869C polymorphism as independent prognostic factors for NSCLC. Taken together, our data, as a proof of principle, suggest that T869C polymorphism in TGFB1 may act as a genetic modifier in NSCLC progression and a promising prognostic marker of survival in NSCLC patients.

Analysis of risk factors for pulmonary complications in patients with limited-stage small cell lung cancer : A single-centre retrospective study

INTRODUCTION

The most effective therapy in patients with limited-stage small cell lung cancer (LS SCLC) seems to be chemotherapy (using platinum-based regimens) and thoracic radiotherapy (TRT), which is followed by prophylactic cranial irradiation.

MATERIALS AND METHODS

The analysed group comprised 217 patients who received combined treatment for LS SCLC, i.e. chemotherapy (according to cisplatin and etoposide schedule) and TRT (concurrent in 101 and sequential in 116 patients). The influence of chemoradiotherapy (ChT-RT) schedule on treatment results (frequency of complete response, survival rates, and incidence of treatment failure and complications) was evaluated, and the frequency and severity of pulmonary complications were analysed to identify risk factors.

RESULTS

The 5‑year survival rates in concurrent vs. sequential ChT-RT schedules were 27.3 vs. 11.7% (overall) and 28 vs. 14.3% (disease-free). The frequencies of adverse events in relation to concurrent vs. sequential therapy were 85.1 vs. 9.5% (haematological complications) and 58.4 vs. 38.8% (pulmonary fibrosis), respectively. It was found that concurrent ChT-RT (hazard ratio, HR 2.75), a total dose equal to or more than 54 Gy (HR 2.55), the presence of haematological complications (HR 1.89) and a lung volume receiving a dose equal to or greater than 20 Gy exceeding 31% (HR 1.06) were the risk factors for pulmonary complications.

CONCLUSION

Pulmonary complications after ChT-RT developed in 82% of patients treated for LS SCLC. In comparison to the sequential approach, concurrent ChT-RT had a positive effect on treatment outcome. However, this is a factor that can impair treatment tolerance, which manifests in the appearance of side effects.

Capsaicin induces apoptosis in human small cell lung cancer via the TRPV6 receptor and the calpain pathway

Capsaicin, the pungent ingredient of chili peppers, displays potent anti-neoplastic activity in a wide array of human cancer cells. The present manuscript examines the signaling pathways underlying the apoptotic activity of capsaicin in human small cell lung cancer (SCLC) in vitro and in vivo. Studies in neuronal cells show that capsaicin exerts its biological activity via the transient receptor potential vanilloid (TRPV) superfamily of cation-channel receptors. The TRPV family is comprised of six members (TRPV1-6). Capsaicin is a known agonist of the TRPV1 receptor. We observed that capsaicin-induced apoptosis in human SCLC cells was mediated via the TRPV receptor family; however it was independent of TRPV1. Surprisingly, the apoptotic activity of capsaicin required the TRPV6 receptor. Depletion of TRPV6 receptor by siRNA methodology abolished the apoptotic activity of capsaicin in SCLC cells. Immunostaining and ELISA showed that TRPV6 receptor was robustly expressed on human SCLC tissues (from patients) and SCLC cell lines but almost absent in normal lung tissues. This correlates with our results that capsaicin induced very little apoptosis in normal lung epithelial cells. The pro-apoptotic activity of capsaicin was mediated by the intracellular calcium and calpain pathway. The treatment of human SCLC cells with capsaicin increased the activity of calpain 1 and 2 by threefold relative to untreated SCLC cells. Such calpain activation, in response to capsaicin, was downstream of the TRPV6 receptor. Taken together, our data provide insights into the mechanism underlying the apoptotic activity of capsaicin in human SCLCs.

Cytotoxic effects of fascaplysin against small cell lung cancer cell lines

Fascaplysin, the natural product of a marine sponge, exhibits anticancer activity against a broad range of tumor cells, presumably through interaction with DNA, and/or as a highly selective cyclin-dependent kinase 4 (CDK4) inhibitor. In this study, cytotoxic activity of fascaplysin against a panel of small cell lung cancer (SCLC) cell lines and putative synergism with chemotherapeutics was investigated. SCLC responds to first-line chemotherapy with platinum-based drugs/etoposide, but relapses early with topotecan remaining as the single approved therapeutic agent. Fascaplysin was found to show high cytotoxicity against SCLC cells and to induce cell cycle arrest in G1/0 at lower and S-phase at higher concentrations, respectively. The compound generated reactive oxygen species (ROS) and induced apoptotic cell death in the chemoresistant NCI-H417 SCLC cell line. Furthermore, fascaplysin revealed marked synergism with the topoisomerase I-directed camptothecin and 10-hydroxy-camptothecin. The Poly(ADP-ribose)-Polymerase 1 (PARP1) inhibitor BYK 204165 antagonized the cytotoxic activity of fascaplysin, pointing to the involvement of DNA repair in response to the anticancer activity of the drug. In conclusion, fascaplysin seems to be suitable for treatment of SCLC, based on high cytotoxic activity through multiple routes of action, affecting topoisomerase I, integrity of DNA and generation of ROS.

Benefits of postoperative radiotherapy in multimodality treatment of resected small-cell lung cancer with lymph node metastasis

AIM

The purpose of this study is to evaluate the role of postoperative radiotherapy (PORT) in resected small-cell lung cancer (SCLC).

METHODS

This study retrospectively analyzed 143 patients with completely resected SCLC in our institution between 1996 and 2011. The primary endpoint was overall survival (OS). The log-rank test and Cox regression model were used to evaluate the factors influencing local-regional recurrence (LRR) and OS.

RESULTS

The median OS for the entire population was 34 months, and the 5-year OS rate was 34.6%. In multivariate analysis, age, surgical procedure, pathology stage, adjuvant chemotherapy and distant relapse were significant factors for survival. For the whole population, PORT had no effect on OS, with a median OS of 40 months in the PORT group versus 27 months in the non-PORT group (p = 0.260). However, in patients with N1 disease, the median OS were 40 months in the PORT group versus 14 months in the non-PORT group (p = 0.032). The corresponding OS in N2 patients were 35 months versus 17 months, respectively (p = 0.040). Similarly, PORT significantly reduced the LRR in patients with positive lymph node. For patients with N1 disease, the 3-year LRR rate was 0.0% in the PORT group versus 14.3% in the non-PORT group (p = 0.037). The corresponding LLR rate in N2 patients was 4.2% versus 56.6% (p < 0.001).

CONCLUSION

PORT significantly reduced LRR and improved OS in patients with regional metastasis SCLC. We suggest supplementing PORT in the multimodality treatment of resected SCLC with lymph node metastasis.