Progress in the therapy of small cell lung cancer

Synthesis and biological evaluation of novel penindolone derivatives as potential antiproliferative agents against SCLC in vitro

Small cell lung cancer (SCLC) keeps on the leading cause of cancer mortality world widely, while there is lack of efficient therapeutic drugs especially for the resistant ones. In this work, a compound named penindolone (PND) with new skeleton was found to show weak inhibitory effect (IC50 = 42.5 µM) on H69AR cells (SCLC, adriamycin-resistant) proliferation by screening our in-house compound library. With the aim of improving its low potency, a series of PND derivatives were synthesized and biologically evaluated by the Sulforhodamine B (SRB) assay. Among all tested derivatives, compound 5h possessed higher antiproliferation potency (IC50 = 1.6 µM). Furthermore, preliminary mechanism investigation revealed that 5h was able to induce apoptosis and arrest the cell cycle at G0/G1 phase. These findings suggest that this novel skeleton has expanded the anti-SCLC compound reservoir and provided a new drug lead.

Potential role of pre-treatment bone marrow SUVmean to liver SUVmean ratio (BM/L) and comparison of primary tumour FDG uptake with brain FDG uptake in predicting survival in limited-stage lung cancers

INTRODUCTION

The survival rates of patients with limited-stage small-cell lung cancer are low despite curative treatment. Accordingly, we investigated the disease prognosis by comparing the pre-treatment bone marrow mean standardised uptake values (SUVmean) / liver SUVmean ratio (BM/L) and primary tumour FDG uptake and brain FDG uptake to prognosis.

MATERIALS AND METHODS

This was an observational, retrospective, single-centre study of patients with limited-stage small-cell lung cancer. Maximum standardised uptake values before treatment SUVmax, mean SUV (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), liver (KC) SUVmean, bone marrow SUVmean, BM/L ratio (grouped as BM/L <1 and BM/L<1), FDG uptake level of the primary tumour are higher than brain FDG uptake. The association of low prevalence with overall survival (OS) and progression-free survival (PFS) was evaluated.

DISCUSSION

A total of 125 patients were included in the study. The risk of death was found to be two times higher in patients with primary tumour FDG uptake higher than brain FDG uptake compared to those with less brain involvement. The risk of death in patients with BM/L>1 was found to be 1.6 times higher than in patients with BM/L<1.

CONCLUSION

Comparison of BM/L, FDG uptake of the primary tumour and brain FDG uptake as new prognostic parameters can be guiding in the classification of patients with LD-SCLC with a higher risk of death or progression and in planning new treatment strategies.

Small cell lung cancer transformation after EGFR-TKIs treatment in lung adenocarcinoma: A case report and literatures review

RATIONALE

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are commonly used in the treatment of advanced non-small cell lung cancer. However, patients will inevitably develop resistance to EGFR-TKIs in the long-term treatment process. In this paper, we report a case of small cell lung cancer transformation after EGFR-TKIs treatment in lung adenocarcinoma. We summarize the characteristics of this case and the treatment after transformation, and emphasized the repeat biopsy and dynamic monitoring its genetic mutation was necessary.

PATIENT CONCERNS

A 75-years-old man with no smoking history was admitted to our hospital with repeated cough and expectoration for 1 month and chest enhancement computed tomography showed paracbronchial soft tissue mass in the lower lobe of the left lung, which was considered to be central lung cancer.

DIAGNOSES

The first pathological analysis of lung biopsy confirmed left lung adenocarcinoma and clinical stage was T3N3M1 IVA. In June 2021, the second bronchoscopic biopsy was performed, and pathology showed small cell neuroendocrine carcinoma in the left lung.

INTERVENTIONS

Gefitinib was given to patients when the first next generation sequence test showed EGFR L858 mutation. When the second next generation sequence test revealed EGFR T790M mutation, the patient received with osimertinib. The patient got 2 cycles chemotherapy of etoposide plus netaplatin when diagnosed with small cell lung cancer.

OUTCOMES

Progression-free survival was only 8 months after gefitinib treatment. Moreover, the patient was insensitive to Oxitinib, and the disease progressed after 2 months of treatment with Oxitinib. Finally, he died of severe infection and hepatic failure after a diagnosis of small cell lung cancer.

LESSONS

Our case highlights that if a patient has rapid disease progression, increase of serum neuron-specific enolase, and TP53 and Rb1 inactivation during EGFR-TKIs treatment, we should be alert to the pathological type transformation to small cell lung cancer.

Overcoming multidrug-resistant lung cancer by mitochondrial-associated ATP inhibition using nanodrugs

Despite the development of therapeutic modalities to treat cancer, multidrug resistance (MDR) and incomplete destruction of deeply embedded lung tumors remain long-standing problems responsible for tumor recurrence and low survival rates. Therefore, developing therapeutic approaches to treat MDR tumors is necessary. In this study, nanodrugs with enhanced intracellular drug internalization were identified by the covalent bonding of carbon nanotubes of a specific nano size and doxorubicin (DOX). In addition, carbon nanotube conjugated DOX (CNT-DOX) sustained in the intracellular environment in multidrug-resistant tumor cells for a long time causes mitochondrial damage, suppresses ATP production, and results in the effective therapeutic effect of drug-resistant tumors. This study identified that H69AR lung cancer cells, an adriamycin (DOX) drug-resistant tumor cell line, did not activate drug resistance function on designed nano-anticancer drugs with a specific nano size. In summary, this study identified that the specific size of the nanodrug in combination with DOX overcame multidrug-resistant tumors by inducing selective accumulation in tumor cells and inhibiting ATP by mitochondrial damage.

Real World Analysis of Small Cell Lung Cancer Patients: Prognostic Factors and Treatment Outcomes

In this observational study, we assessed treatment patterns and prognostic factors in patients with small cell lung cancer (SCLC) in a large state-mandated healthcare organization in Israel. Methods: All incident cases with histologically confirmed SCLC who initiated systemic anti-cancer treatment between 2011 and 2017 were identified. Treatment patterns and overall survival (OS) were evaluated for each line of therapy. Results: A total of 235 patients were identified (61% male, median age 64 years, 95% ever smokers, 64% had extensive stage). The first-line treatment was platinum-etoposide regimen for 98.7% of the cohort. The second and third-line regimen were given to 43% and 12% of patients, respectively. Mean OS for extensive and limited stage patients was 9.1 and 23.5 months respectively. In a multivariable model, increased risk for mortality was observed among patients with an ECOG performance status (PS) of 2 compared to a PS of 0-1 for the extensive stage patients (Hazard ratio (HR) = 1.63, 95% confidence ratios (CI): 1.00-2.65); and for males compared to females for the limited stage patients (HR = 2.17; 95% CI: 1.12-4.20). Regarding all 2nd line patients in a multivariable model incorporating relevant confounding factors, demonstrated a significantly better outcome with platinum-based regimens compared to topotecan. Median survival after initiation of 2nd line in platinum-sensitive patients was longer (p = 0.056) for those re-challenged with platinum-based regimen (n = 7): 6.8mo (6.1-not reported (NR)), compared with those switched to a different treatment (n = 27): 4.5 mo (2.6-6.6) for extensive stage patients, and a non-significant difference was also observed for limited stage patients. Conclusion: To our knowledge, this is one of the largest real-world studies of SCLC patients. OS for SCLC patients was similar to that reported in clinical trials. PS for extensive stage patients and sex for limited stage patients were significant correlates of prognosis. Re-challenge of the platinum-based doublet was associated with longer OS compared to switching treatment in extensive stage patients.

A Prospective Study of Apatinib in Patients with Extensive-Stage Small Cell Lung Cancer After Failure of Two or More Lines of Chemotherapy

Background

Because of rapid disease progression and lack of optimal treatment strategies beyond the second‐line, the prognosis of patients with extensive‐stage (ES) small cell lung cancer (SCLC) still remains depressing. Alternative treatment strategies are required to improve their prognosis. In this prospective clinical study, we aimed to evaluate the feasibility of single‐agent apatinib, a vascular endothelial growth factor receptor‐2 tyrosine kinase inhibitor, as a treatment option for patients with ES‐SCLC after failure of at least two prior chemotherapy regimens.

Materials and Methods

Twenty‐two patients with ES‐SCLC treated with 500 mg single‐agent apatinib as subsequent‐line regimen in our institution from November 2016 to August 2018 were enrolled in the study. The primary endpoint was progression‐free survival (PFS). The secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and adverse events (AEs).

Results

Clinical outcomes included partial response in 3 patients (13.6%), stable disease in 18 patients (81.8%), and disease progression in 1 patient (4.5%), with an ORR of 13.6% and DCR of 95.5%. The median PFS and OS were 5.4 and 10.0 months, respectively. Apatinib demonstrated a manageable toxicity profile, with grade I–III secondary hypertension and proteinuria as the most common AEs. No grade IV and V AEs were observed among the patients. Multivariate analysis revealed secondary hypertension as an independent predictor of OS (p = .047); however, the association became insignificant after Q correction (p = .455).

Conclusions

Apatinib was safe and effective in the management of patients with ES‐SCLC and can be considered as a treatment option after failure of at least two prior chemotherapy regimens. http://ClinicalTrials.govidentifier. NCT02995187

Implications for Practice

This study indicated the acceptable toxicity profile and promising efficacy of apatinib in the management of patients with extensive‐stage small cell lung cancer after failure from at least two prior chemotherapy regimens. Secondary hypertension can be a potential prognostic factor for apatinib treatment.

Alternative treatment strategies are needed to improve prognosis for patients with small‐cell lung cancer. This article evaluates the feasibility of single‐agent apatinib as a treatment option for patients with extensive‐stage small‐cell lung cancer.

Weighted gene expression profiles identify diagnostic and prognostic genes for lung adenocarcinoma and squamous cell carcinoma

OBJECTIVE

To construct a diagnostic signature to distinguish lung adenocarcinoma from lung squamous cell carcinoma and a prognostic signature to predict the risk of death for patients with nonsmall-cell lung cancer, with satisfactory predictive performances, good stabilities, small sizes and meaningful biological implications.

METHODS

Pathway-based feature selection methods utilize pathway information as a priori to provide insightful clues on potential biomarkers from the biological perspective, and such incorporation may be realized by adding weights to test statistics or gene expression values. In this study, weighted gene expression profiles were generated using the GeneRank method and then the LASSO method was used to identify discriminative and prognostic genes.

RESULTS

The five-gene diagnostic signature including keratin 5 (KRT5), mucin 1 (MUC1), triggering receptor expressed on myeloid cells 1 (TREM1), complement C3 (C3) and transmembrane serine protease 2 (TMPRSS2) achieved a predictive error of 12.8% and a Generalized Brier Score of 0.108, while the five-gene prognostic signature including alcohol dehydrogenase 1C (class I), gamma polypeptide (ADH1C), alpha-2-glycoprotein 1, zinc-binding (AZGP1), clusterin (CLU), cyclin dependent kinase 1 (CDK1) and paternally expressed 10 (PEG10) obtained a log-rank P-value of 0.03 and a C-index of 0.622 on the test set.

CONCLUSIONS

Besides good predictive capacity, model parsimony and stability, the identified diagnostic and prognostic genes were highly relevant to lung cancer. A large-sized prospective study to explore the utilization of these genes in a clinical setting is warranted.

Analysis of dose distribution between contemporary and standard planning in high-dose-rate endobronchial brachytherapy based on three-dimensional imaging

Purpose

The treatment planning (TP) in high-dose-rate (HDR) endobronchial brachytherapy (EB) can be based on various forms of imaging. In the case of lung cancer, one-dimensional or two-dimensional imaging is standard. The dose coverage of the target (planning target volume – PTV) and organs at risk (OAR) is unknown, because the doses are calculated on the basis of the dose points. In modern brachytherapy, TP can be based on three-dimensional (3D) images. A plan created in this way contains information about the dose distribution in the PTV and OAR. Treatment plans based on standard planning (SP) and contemporary planning (CP) may differ in dose distribution in the patient’s body. Those differences between SP and CP may have an effect on the dose distribution in PTV, OAR and follow-up.

Material and methods

The study involved a group of 31 patients prospectively treated with advanced, inoperable, non-small cell lung cancer. As many as 76 treatment fractions were analyzed. Firstly, the coverage of the PTV parameter in 2D and 3D for V₈₅, V₁₀₀ and V₁₁₅ was analyzed. Secondly, the dosage that OAR would take in was evaluated. In the cases of the heart, spinal cord and esophagus, the examined dosage equaled D_0.1cm³, D_1cm³ and D_2cm³ for each of the structures. Also, heart D₂₀ was examined as well as D₅ for the healthy lung.

Results

The median dose to the target volume was on average 43.33% higher for V₈₅ with the contemporary planning method when compared to standard planning, with statistical significance. This came with the cost of an OAR mean dose increase of 1 Gy in D_0.1cm³ for the heart.

Conclusions

Contemporary TP in EB allows one to adjust the dose distribution for individual clinical situations and allows one to improve clinical target volume (CTV) coverage, increase doses to the OAR and increase overall survival. The use of new methods of treatment plans in EB has significantly increased the follow-up to 21 months in a treated group of patients.

Prognostic significance of metabolic parameters measured by 18F-FDG PET/CT in limited-stage small-cell lung carcinoma

PURPOSE

Metabolic parameters measured by [18F]-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) are important prognostic factors in several types of cancers. We evaluated the predictive value of tumor metabolic parameters measured by 18F-FDG PET/CT in limited-disease small-cell lung cancer (LD-SCLC).

METHODS

This retrospective study included 30 LD-SCLC patients who underwent standard chemotherapy after radiotherapy with 18F-FDG PET/CT. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and blood glucose-corrected values were used to evaluate metabolic parameters in primary tumors.

RESULTS

For the median follow-up of 41.1 months, median overall survival (OS) was 75.0 months [95% confidence interval (CI) 20.9-129.1 months], and median progression-free survival (PFS) was 9.5 months (95% CI 6.8-12.1 months). Two-year OS was 78.6%, and PFS was 32.7%. OS analysis indicated that MTV and TLG were significant predictors of OS following standard treatment. High glucose-corrected SUVmax (glu-SUVmax) was related to shorter median PFS. On multivariate analysis, MTV was an independent factor of OS, and glu-SUVmax was significantly related to PFS.

CONCLUSIONS

MTV and glu-SUVmax measured on pretreatment 18F-FDG PET/CT were independent prognostic factors for LD-SCLC patients after chemoradiotherapy with curative intent. These metabolic markers need validation in larger prospective studies but may be useful in the clinical care of LD-SCLC patients.

Comprehensive analysis of differential expression profiles reveals potential biomarkers associated with the cell cycle and regulated by p53 in human small cell lung cancer

Small cell lung cancer (SCLC) is the subtype of lung cancer with the highest degree of malignancy and the lowest degree of differentiation. The purpose of this study was to investigate the molecular mechanisms of SCLC using bioinformatics analysis, and to provide new ideas for the early diagnosis and targeted therapy of SCLC. Microarray data were downloaded from Gene Expression Omnibus. Differentially expressed genes (DEGs) in SCLC were compared with the normal lung samples and identified. Gene Ontology (GO) function and pathway analysis of DEGs was performed through the DAVID database. Furthermore, microarray data was analyzed by using the clustering analysis tool GoMiner. Protein-protein interaction (PPI) networks of DEGs were constructed using the STRING online database. Protein expression was determined from the Human Protein Atlas, and SCLC gene expression was determined using Oncomine. In total, 153 DEGs were obtained. Functional enrichment analysis suggested that the majority of DEGs were associated with the cell cycle. CCNB1, CCNB2, MAD2L1 and CDK1 were identified to contribute to the progression of SCLC through combined use of GO, Kyoto Encyclopedia of Genes and Genomes enrichment analysis and a PPI network. mRNA and protein expression were also validated in an integrative database. The present study indicated that the formation of SCLC may be associated with cell cycle regulation. In addition, the four crucial genes CCNB1, CCNB2, MAD2L1 and CDK1, which are downstream of p53, may have important roles in the occurrence and progression of SCLC, and thus may be promising potential biomarkers and therapeutic targets.

Pretreatment metabolic parameters measured by 18F-FDG-PET to predict the outcome of first-line chemotherapy in extensive-stage small-cell lung cancer

OBJECTIVE

Patients' pretreatment metabolic burden, as measured by radiotracer fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT), has been shown to predict treatment outcome in various malignancies. However, its predictive role in extensive-stage small cell lung cancer (SCLC) has not been definitively determined. This retrospective study investigated the viability of using common pretreatment metabolic parameters, obtained through F-FDG-PET/CT, to predict outcomes of first-line chemotherapy in extensive-stage SCLC.

PARTICIPANTS AND METHODS

The study population comprised 154 consecutive patients with extensive-stage SCLC who underwent a pretreatment F-FDG-PET/CT scan and received standard first-line chemotherapy between January 2011 and December 2015.

RESULTS

Ten (6.5%) and 66 (42.9%) patients achieved a complete or a partial response, respectively (considered an objective response); 35 (22.7%) and 43 (27.9%) experienced stable or progressive disease. The metabolic tumor volume (MTV) was a significant factor for predicting an objective response. For predicting disease control (objective response or stable disease), MTV and total lesion glycolysis (TLG) were nonindependent factors.

CONCLUSION

Greater MTV and TLG could indicate a poorer response to first-line chemotherapy for patients with extensive-stage SCLC, but the predictive efficiency was not high enough for routine reliance. For patients who are not suitable to receive first-line chemotherapy, MTV and TLG may help guide clinical decisions.

Vorinostat enhances the cisplatin-mediated anticancer effects in small cell lung cancer cells

BACKGROUND

Vorinostat, a histone deacetylase (HDAC) inhibitor, is a promising agent for cancer therapy. Combining vorinostat with cisplatin may relax the chromatin structure and facilitate the accessibility of cisplatin, thus enhancing its cytotoxicity. Studies have not yet investigated the effects of the combination of vorinostat and cisplatin on small cell lung cancer (SCLC).

METHODS

We first assessed the efficacy of vorinostat with etoposide/cisplatin (EP; triple combination) and then investigated the effects of cotreatment with vorinostat and cisplatin on H209 and H146 SCLC cell lines. The anticancer effects of various combinations were determined in terms of cell viability, apoptosis, cell cycle distribution, and vorinostat-regulated proteins. We also evaluated the efficacy of vorinostat/cisplatin combination in H209 xenograft nude mice.

RESULTS

Our data revealed that the triple combination engendered a significant reduction of cell viability and high apoptotic cell death. In addition, vorinostat combined with cisplatin enhanced cell growth inhibition, induced apoptosis, and promoted cell cycle arrest. We observed that the acetylation levels of histone H3 and α-tubulin were higher in combination treatments than in vorinostat treatment alone. Moreover, vorinostat reduced the expression of thymidylate synthase (TS), and TS remained inhibited after cotreament with cisplatin. Furthermore, an in vivo study revealed that the combination of vorinostat and cisplatin significantly inhibited tumor growth in xenograft nude mice (tumor growth inhibition T/C% = 20.5 %).

CONCLUSIONS

Combined treatments with vorinostat promote the cytotoxicity of cisplatin and induce the expression of vorinostat-regulated acetyl proteins, eventually enhancing antitumor effects in SCLC cell lines. Triple combinations with a low dosage of cisplatin demonstrate similar therapeutic effects. Such triple combinations, if applied clinically, may reduce the undesired adverse effects of cisplatin. The effects of the combination of vorinostat and cisplatin should be evaluated further before conducting clinical trials for SCLC treatment.

Radiation-enhanced Endostatin Gene Expression and Effects of Combination Treatment

Targeting cells that support tumor growth by administering potent angiogenesis inhibitors is currently an area of intense interest. In the present study, a unique plasmid vector for the mouse endostatin gene, pXLG-mEndo, was constructed and evaluated with and without radiation using the Lewis lung carcinoma (LLC) cell line. The physical properties of the expressed endostatin protein were validated by PCR, gel electrophoresis, and Western blot. Enzyme-linked immunosorbent and immunocytochemical analyses for the therapeutic gene demonstrated that transfected LLC cells secreted the protein into the medium. Exposure of the cells to 2 gray (Gy) γ-rays reduced the time to reach the maximum expression level of the endostatin gene and also increased the amount of secreted endostatin protein (P<0.001). Biological activity of the endostatin was demonstrated by the inhibition of tube formation by human umbilical vein endothelial cells (HUVEC). Based on 3 H-thymidine incorporation, endostatin expression significantly depressed DNA synthesis in HUVEC and LLC cells compared to controls transfected with parental vector or no vector (P>0.005). In addition, radiation increased the efficiency of endostatin-mediated inhibition of both cell types over a 3-day period post-exposure (P<0.05 or less). Intratumoral injection of 100 μg pXLG-mEndo combined with 10 Gy radiation significantly delayed LLC tumor growth, especially when each modality was delivered twice (P<0.05 or less compared to all other groups). No toxicity was observed. These findings are very promising and suggest that endostatin therapy with a plasmid vector, such as pXLG-mEndo, may enhance the efficacy of radiotherapy for lung cancer.

Increased Biological Effective Dose of Radiation Correlates with Prolonged Survival of Patients with Limited-Stage Small Cell Lung Cancer: A Systematic Review

OBJECTIVE

Thoracic radiotherapy (TRT) is a critical component of the treatment of limited-stage small cell lung cancer (LS-SCLC). However, the optimal radiation dose/fractionation remains elusive. This study reviewed current evidence and explored the dose-response relationship in patients with LS-SCLC who were treated with radiochemotherapy.

MATERIALS AND METHODS

A quantitative analysis was performed through a systematic search of PubMed, Web of Science, and the Cochrane Library. The correlations between the biological effective dose (BED) and median overall survival (mOS), median progression-free survival (mPFS), 1-, 3-, and 5-year overall survival (OS) as well as local relapse (LR) were evaluated.

RESULTS

In all, 2389 patients in 19 trials were included in this study. Among these 19 trials, seven were conducted in Europe, eight were conducted in Asia and four were conducted in the United States. The 19 trials that were included consisted of 29 arms with 24 concurrent and 5 sequential TRT arms. For all included studies, the results showed that a higher BED prolonged the mOS (R2 = 0.198, p<0.001) and the mPFS (R2 = 0.045, p<0.001). The results also showed that increased BED improved the 1-, 3-, and 5-year OS. A 10-Gy increment added a 6.3%, a 5.1% and a 3.7% benefit for the 1-, 3-, and 5-year OS, respectively. Additionally, BED was negatively correlated with LR (R2 = 0.09, p<0.001). A subgroup analysis of concurrent TRT showed that a high BED prolonged the mOS (p<0.001) and the mPFS (p<0.001), improved the 1-, 3-, and 5-year OS (p<0.001) and decreased the rate of LR (p<0.001).

CONCLUSION

This study showed that an increased BED was associated with improved OS, PFS and decreased LR in patients with LS-SCLC who were treated with combined chemoradiotherapy, which indicates that the strategy of radiation dose escalation over a limited time frame is worth exploring in a prospective clinical trial.

Survival analysis in second-line and third-line chemotherapy with irinotecan followed by topotecan or topotecan followed by irinotecan for extensive-stage small-cell lung cancer patients: a single-center retrospective study

Purpose

The number of patients who make it to receive third-line chemotherapy is increasing owing to the improvements in adverse-event management of chemotherapy for small-cell lung cancer (SCLC). Sequencing of optimal treatment for SCLC is still a challenge for oncologists. In this paper, we aim to present a different approach to the treatment of SCLC.

Methods

Between January 2008 and July 2014, all patients diagnosed with extensive-stage SCLC and treated with third-line chemotherapy at Gaziantep University Oncology Hospital were analyzed retrospectively. Disease control rates and progression-free survival (PFS) for first-, second-, and third-line chemotherapy, and overall survival (OS) were recorded. Survival analysis was calculated by using Kaplan–Meier method.

Results

A total of 255 SCLC patients were screened, and 25 of those patients who received third-line chemotherapy were included in this study. Median age was 57±10.131 years (range: 39–74 years). Disease control rates at first-, second-, and third-line chemotherapy were 92%, 68%, and 44%, respectively. Fourteen patients received irinotecan followed by topotecan, and eleven patients received topotecan followed by irinotecan. Second-line median PFS was statistically better in patients treated with irinotecan at second-line compared with those treated with topotecan (21 vs 12 weeks, P=0.018). Comparison of third-line median PFS of the two groups was not statistically significant (14 vs 12 weeks, P=0.986). Median OS was not statistically significant in patients who received irinotecan followed by topotecan vs those who received topotecan followed by irinotecan (18 vs 14 months, P=0.112).

Conclusion

Sequential monotherapy with topotecan and irinotecan provides a considerable contribution to OS, and second-line irinotecan showed a better PFS, despite a similar OS, compared with topotecan.

Phase I/IIa study of sequential chemotherapy regimen of bendamustine/irinotecan followed by etoposide/carboplatin in untreated patients with extensive disease small cell lung cancer (EDSCLC)

PURPOSE

The sequence bendamustine (B) + Irinotecan (I) followed by etoposide (E) + carboplatin (C) was hypothesized to increase progression-free survival (PFS) and overall survival (OS) in untreated extensive-disease small cell lung cancer (EDSCLC) patients compared to historical controls by exploiting mitotic catastrophe. Absent expression of ERCC-1 and expression of topoisomerases were hypothesized to be predictive for PFS and OS.

METHODS

This was a phase I/IIa trial in 30 patients to determine the maximum tolerated dose (MTD) of B + I and the PFS of B + I E + C with secondary end points including overall response rate (ORR) and OS. Biomarkers measured by immunohistochemistry (IHC) obtained from diagnostic specimens were correlated with outcome.

RESULTS

The MTD of B + I was not reached. During treatment with B + I, there were two grade 5 toxicities from neutropenic sepsis and metabolic encephalopathy. Other toxicities included fatigue, nausea/vomiting, diarrhea, and weight loss. For the sequence, the PFS and OS were 6.0 months and 10 months, respectively. The ORR for B + I and the sequence were 82% and 83%, respectively. Topoisomerase-2 expression was predictive for TTP and OS, but absent ERCC-1 expression was not, contrary to our hypothesis.

CONCLUSIONS

B + I is an active regimen in EDSCLC. Toxicities included two grade 5 events but were otherwise manageable. The novel sequence B + I E + C increased PFS and OS compared to historical controls. Correlative studies are conflicting regarding the mechanism of action of this novel sequence.

Association between serum tumor markers and metabolic tumor volume or total lesion glycolysis in patients with recurrent small cell lung cancer

The aim of the present study was to investigate the association between serum tumor markers and the metabolic tumor volume (MTV) or total lesion glycolysis (TLG), as determined by fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography-computed tomography (PET/CT) in patients with recurrent small cell lung cancer (SCLC). Data from 21 patients with recurrent SCLC were collected. The levels of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA) and cytokeratin 19 fragment 21-1 were measured at the time of the ¹⁸F-FDG PET/CT examination. The MTV and TLG of all lesions were calculated. Pearson correlation analyses were used to estimate the correlations between NSE level and PET findings. Pearson correlation analyses showed that NSE was the only tumor marker to have a strong correlation with MTV or TLG (r=0.787, P<0.001; r=0.866, P<0.001, respectively). In patients with a normal NSE level, no correlation was found between NSE and MTV or TLG (r=0.018, P=0.958; r=-0.003, P=0.92, respectively), but a significant correlation was found in patients with an abnormal NSE level (r=0.789, P<0.01; r=0.872, P=0.01, respectively). Therefore, TLG and MTV may serve as sensitive markers of tumor burden in patients with recurrent SCLC, with TLG showing greater sensitivity. In patients with an abnormal NSE level, a higher NSE level indicates greater MTV and TLG.

Efficacy of 3D conformal thoracic radiotherapy for extensive-stage small-cell lung cancer: A retrospective study

The aim of the present study was to evaluate the effect of 3-dimensional conformal thoracic radiotherapy (TRT) on extensive-stage small-cell lung cancer (ES-SCLC). A total of 165 patients with ES-SCLC were enrolled in the present study, including 82 patients receiving chemotherapy combined with TRT (the ChT/TRT group) and 83 patients receiving chemotherapy alone (the ChT group). The overall survival (OS) and progression-free survival (PFS) rates were compared between the ChT/TRT and ChT groups, and the prognostic factors for OS rate were identified. It was found that the patients had a median OS time of 15 months, and 2- and 5-year OS rates of 31.5 and 2.4%, respectively. The 2- and 5-year OS rates were 35.3 and 2.4% in the ChT/TRT group, and 14.5 and 2.4% in the ChT group, respectively (P<0.05). The 1- and 2-year PFS rates were 35.4 and 6.0% in the ChT/TRT group, and 20.5 and 6.0% in the ChT group, respectively (P<0.05). The median PFS was 11 months in the 20 patients receiving TRT at 45 Gy/30 fractions twice daily, and 9 months in the 22 patients receiving TRT at 60 Gy/30 fractions daily (P=0.043). Multivariate analysis revealed that receiving ≥4 cycles of chemotherapy (P=0.001) and TRT (P=0.008) were favorable prognostic factors for OS. It was concluded that the addition of TRT improves the OS and PFS rates of patients with ES-SCLC, and TRT administration at 45 Gy/30 fractions twice daily is feasible and tolerable for the treatment of ES-SCLC. Thus, TRT and receiving ≥4 cycles of chemotherapy are independent, favorable prognostic factors for OS in patients with ES-SCLC.

Small cell lung cancer: where do we go from here?

Small cell lung cancer (SCLC) is an aggressive disease that accounts for approximately 14% of all lung cancers. In the United States, approximately 31,000 patients are diagnosed annually with SCLC. Despite numerous clinical trials, including at least 40 phase 3 trials since the 1970s, systemic treatment for patients with SCLC has not changed significantly in the past several decades. Consequently, the 5-year survival rate remains low at <7% overall, and most patients survive for only 1 year or less after diagnosis. Unlike nonsmall cell lung cancer (NSCLC), in which major advances have been made using targeted therapies, there are still no approved targeted drugs for SCLC. Significant barriers to progress in SCLC include 1) a lack of early detection modalities, 2) limited tumor tissue for translational research (eg, molecular profiling of DNA, RNA, and/or protein alterations) because of small diagnostic biopsies and the rare use of surgical resection in standard treatment, and 3) rapid disease progression with poor understanding of the mechanisms contributing to therapeutic resistance. In this report, the authors review the current state of SCLC treatment, recent advances in current understanding of the underlying disease biology, and opportunities to advance translational research and therapeutic approaches for patients with SCLC.

Medical management of lung cancer: Experience in China

Lung cancer is the leading cause of death from cancer worldwide, as well as in China. A multidisciplinary treatment strategy for lung cancer, which includes medical and radiation oncology, surgery, and pathology is used in clinical practice in China. Chinese lung cancer patients are treated according to different pathologic and genetic types of the disease. For those with active epidermal growth factor receptor (EGFR) mutation, EGFR tyrosine kinase inhibitors (EGFR-TKIs) are used in first-, second- or third-line and maintenance treatment of non-small cell lung cancer (NSCLC). For patients with anaplastic lymphoma kinase (ALK) gene rearrangement, Crizotinib is a promising treatment in advanced NSCLC patients. A platinum-based regimen remains the mainstay of first-line systemic therapy for advanced NSCLC patients who are negative for EGFR mutation or ALK gene rearrangement. For patients with non-squamous NSCLC, Pemetrexed plus Cisplatin is recommended in first-line systemic therapy. An Endostatin combination with chemotherapy is used in first- and second-line advanced NSCLC patients. S-1 presents a new option of chemotherapy in advanced NSCLC cases. Cisplatin-based doublet chemotherapy is commonly used in NSCLC patients after surgery as adjuvant therapy. EGFR-TKIs are now being assessed in the adjuvant setting. The standard first-line chemotherapy regimen of small cell lung cancer (SCLC) is platinum with Etoposide (PE). Amrubicin provides similar survival compared with the PE regimen with an acceptable toxicity profile in extensive stage SCLC patients. Supportive care, such as traditional Chinese medicine and pegylated filgrastim, play an important role in improving patients' quality of life.

Lorvotuzumab mertansine, a CD56-targeting antibody-drug conjugate with potent antitumor activity against small cell lung cancer in human xenograft models

Lorvotuzumab mertansine (LM) is an antibody-drug conjugate composed of a humanized anti-CD56 antibody, lorvotuzumab, linked via a cleavable disulfide linker to the tubulin-binding maytansinoid DM1. CD56 is expressed on most small cell lung cancers (SCLC), providing a promising therapeutic target for treatment of this aggressive cancer, which has a poor five-year survival rate of only 5-10%. We performed immunohistochemical staining on SCLC tumor microarrays, which confirmed that CD56 is expressed at high levels on most (~74%) SCLC tumors. Conjugation of lorvotuzumab with DM1 did not alter its specific binding to cells and LM demonstrated potent target-dependent cytotoxicity against CD56-positive SCLC cells in vitro. The anti-tumor activity of LM was evaluated against SCLC xenograft models in mice, both as monotherapy and in combination with platinum/etoposide and paclitaxel/carboplatin. Dose-dependent and antigen-specific anti-tumor activity of LM monotherapy was demonstrated at doses as low as 3 mg/kg. LM was highly active in combination with standard-of-care platinum/etoposide therapies, even in relatively resistant xenograft models. LM demonstrated outstanding anti-tumor activity in combination with carboplatin/etoposide, with superior activity over chemotherapy alone when LM was used in combinations at significantly reduced doses (6-fold below the minimally efficacious dose for LM monotherapy). The combination of LM with carboplatin/paclitaxel was also highly active. This study provides the rationale for clinical evaluation of LM as a promising novel targeted therapy for SCLC, both as monotherapy and in combination with chemotherapy.

[A retrospective study of the efficacy and toxicity of irinotecan in combination with nedaplatin versus irinotecan in combination with cisplatin as salvage treatment in refractory or relapsed small cell lung cancer]

背景与目的

对初治进展或复发的小细胞肺癌，目前尚无标准的二线方案，本研究旨在比较伊立替康联合奈达铂或联合顺铂治疗敏感复发或难治性小细胞肺癌的疗效和安全性。

方法

回顾了中国医学科学院肿瘤医院2009年4月-2012年4月诊治的1, 140例小细胞肺癌患者，筛选二线接受伊立替康联合奈达铂（IN）或伊立替康联合顺铂（IC）方案化疗的患者进行分析。

结果

入组的54例患者中，中位无进展生存时间（progression free survival, PFS）为4.9个月，中位总生存时间（overall survival, OS）为13.3个月，IC组的PFS为4.3个月，IN组的PFS为5.4个月（P=0.465）。两组OS分别为13.3个月和14.3个月（P=0.704）。对生存时间的Cox多因素分析显示：二线治疗前的PS评分（P=0.003）、二线治疗前的转移部位个数（P=0.023）、接受化疗的周期数（P=0.003）是独立预后因素。整体的不良反应可耐受，IN组血液学毒性较重，IC组腹泻发生率较高，但均无统计学意义。

结论

伊立替康联合铂类是对于敏感复发和难治性小细胞肺癌有效且耐受性好的方案，伊立替康联合奈达铂在疗效及安全性方面都不劣于其联合顺铂。

Small cell lung cancer

Neuroendocrine tumors account for approximately 20% of lung cancers; most (≈15%) are small cell lung cancer (SCLC). These NCCN Clinical Practice Guidelines in Oncology for SCLC focus on extensive-stage SCLC because it occurs more frequently than limited-stage disease. SCLC is highly sensitive to initial therapy; however, most patients eventually die of recurrent disease. In patients with extensive-stage disease, chemotherapy alone can palliate symptoms and prolong survival in most patients; however, long-term survival is rare. Most cases of SCLC are attributable to cigarette smoking; therefore, smoking cessation should be strongly promoted.

[A randomized controlled study of chemotherapy: etoposide combined with oxaliplatin or cisplatin regimens in the treatment of extensive-stage small cell lung cancer in elderly patients]

BACKGROUND

Etoposide combined cisplatin (EP) is the most commonly-used first-line treatment combination chemotherapy regimen in the treatment of extensive-stage small cell lung cancer (SCLC), The side-effects of cisplatin, such as nausea and vomiting, influence patients' quality of life. This study aims to compare the efficacy and toxicities between etoposide plus oxaliplatin (EO) and etoposide plus cisplatin (EP) regimens as first-line chemotherapy for elderly patients with SCLC.

METHODS

Seventy-one old, extensive-stage SCLC patients, who had not received anti-tumor treatment, were randomly divided into two groups, namely, EO group (etoposide: 80 mg/m² d1-5+oxaliplatin; 130 mg/m² d1; repeated every 21 days) and EP group (etoposide: 80 mg/m² d1-5+cisplatin; 25 mg/m² d1-3; repeated every 21 days). Efficacy and toxicities were evaluated after 2 or more cycles.

RESULTS

No statistical differences were observed between the EO and EP groups in the response rate (55.9% vs 54.3%, P=0.894), disease control rate (82.4% vs 77.1%, P=0.591), median progression free survival (5.5 months vs 4.7 months, P=0.638), and median survival time (10.5 months vs 9.1 months, P=0.862). In terms of toxicities, the incidence of nausea/vomiting in the EO group was significantly lower than that in the EP group (65.7% vs 97.2%, P=0.001), but the neurotoxicity of grade 1-2 in the EO group was more significant (74.3% vs 11.1%, P<0.001).

CONCLUSIONS

The clinical efficiency of EO and EP regimens is similar to the first-line chemotherapy for extensive-stage SCLC in elderly patients. However, the tolerance of EO regimens is better than that in the EP regiments.

Predictive value of XRCC1 gene polymorphisms on platinum-based chemotherapy in advanced non-small cell lung cancer patients: a systematic review and meta-analysis

PURPOSE

Published data have shown conflicting results about the relationship between X-ray repair cross-complementing group 1 (XRCC1) gene polymorphisms (Arg399Gln and Arg194Trp) and clinical outcome of platinum-based chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). A meta-analysis is needed to provide a systematic review of the published findings.

EXPERIMENTAL DESIGN

We conducted a systematic review and meta-analysis to evaluate the predictive value of XRCC1 gene polymorphisms on clinical outcome up to October 1, 2010. The quality of each study was scored on the basis of predefined criteria.

RESULTS

A total of 13 eligible follow-up studies met all the inclusion criteria. The XRCC1194Trp allele was found to be significantly associated with a favorable response rate relative to 194Arg [Trp vs. Arg: OR, 1.88; 95% confidence interval (CI), 1.48-2.38]. XRCC1399Gln was less favorably associated with both response rate (Gln vs. Arg: OR, 0.67; 95% CI, 0.52-0.87) and overall survival (Gln vs. Arg: HR, 1.30; 95% CI, 1.04-1.63) than 399Arg in analyses using all available studies; but these associations became insignificant when only high-quality studies were used.

CONCLUSION

These findings suggest a predictive role for XRCC1 gene polymorphisms in clinical outcome. However, the role of 399Gln could be considered controversial because its impact on clinical outcome was insignificant in high-quality studies. These findings show the importance of establishing suitable criteria, including genetic epidemiologic, phenotypic, and clinical criteria, to improve quality control of study design and methods in pharmacogenomic studies related to XRCC1 gene polymorphism.

[Clinical significance of detection of serum values of neuron specific enolase before and after treatment for small cell lung cancer]

背景与目的

神经烯醇化酶（neuron specific enolase, NSE）是小细胞肺癌（small cell lung cancer, SCLC）敏感的肿瘤标记物之一。本研究旨在研究血清NSE水平作为SCLC诊断和预后因素的实用性。

方法

治疗前后应用电化学发光法测定57例SCLC患者的血清NSE。应用Kaplan-Meier法构建生存曲线，采用对数秩检验法（Log-rank）进行曲线之间的比较。

结果

SCLC患者治疗前血清NSE水平是患者总生存期的预后因素，广泛期患者与局限期患者的治疗前血清NSE水平有统计学差异（P < 0.001），治疗前后NSE的变化率与总生存期无关（P=0.084）。

结论

NSE是SCLC患者诊断和评估预后的理想肿瘤标记物。

PET/CT imaging in different types of lung cancer: an overview

Lung cancer (LC) still represents one of the most common tumours in both women and men. PET/CT is a whole-body non-invasive imaging procedure that has been increasingly used for the assessment of LC patients. In particular, PET/CT added value to CT is mainly related to a more accurate staging of nodal and metastatic sites and to the evaluation of the response to therapy. Although the most common PET tracer for LC evaluation is 18F-FDG, new tracers have been proposed for the evaluation of lung neuroendocrine tumours (68Ga-DOTA-peptides, 18F-DOPA) and for the assessment of central nervous system metastasis (11C-methionine). This review focuses on the main clinical applications and accuracy of PET/CT for the detection of non-small cells lung cancer (NSCLC), broncho-alveolar carcinoma (BAC), small cells lung cancer (SCLC), lung neuroendocrine tumours (NET) and solitary pulmonary nodules (SPN).

Phase II study of everolimus (RAD001) in previously treated small cell lung cancer

PURPOSE

Mammalian target of rapamycin (mTOR) is a promising target in small cell lung cancer (SCLC). We designed a phase II study of everolimus, an mTOR inhibitor, in previously treated, relapsed SCLC.

EXPERIMENTAL DESIGN

Patients were treated with everolimus 10 mg orally daily until disease progression. The primary endpoint was disease control rate (DCR) at 6 weeks. PI3K/Akt signaling pathway biomarkers were evaluated on baseline tumor tissue.

RESULTS

A total of 40 patients were treated: 23 had 1 prior regimen/sensitive relapse, 4 had 1 prior regimen/refractory, and 13 had 2 prior regimens. Twenty-eight patients received 2 or more cycles of everolimus, 7 received 1 cycle, and 5 did not complete the first cycle. Best response in 35 evaluable patients: 1 (3%) partial response (in sensitive relapse), 8 (23%) stable disease, and 26 (74%) progression; DCR at 6 weeks was 26% (95% CI = 11-40). Median survival was 6.7 months and median time to progression was 1.3 months. Grade 3 toxicities included thrombocytopenia (n = 2), neutropenia (n = 2), infection (n = 2), pneumonitis (n = 1), fatigue (n = 1), elevated transaminases (n = 1), diarrhea (n = 2), and acute renal failure (n = 1). High phosphorylated AKT expression was modestly associated with overall survival (HR = 2.07; 95% CI = 0.97-4.43). Baseline S6 kinase protein expression was significantly higher in patients with disease control versus patients with progression (P = 0.0093).

CONCLUSIONS

Everolimus was well tolerated but had limited single-agent antitumor activity in unselected previously treated patients with relapsed SCLC. Further evaluation in combination regimens for patients with sensitive relapse may be considered.

Retrospective review of extra-pulmonary small cell carcinoma at King Chulalongkorn memorial hospital cases during 1998-2005

OBJECTIVE

The aim of this study was to review cases of extra-pulmonary small cell carcinoma (EPSCC), including their clinical manifestations and treatment outcomes.

METHODS

We retrospectively reviewed the medical records and pathological reports of patients who were diagnosed with EPSCC from 1998 to 2005.

RESULTS

Overall 21 EPSCC patients were eligible for this study. The most common primary sites were the gastrointestinal organs and the nasal cavity. Eleven patients (52.3%) had limited disease (LD) and 10 patients (47.7%) had extensive disease (ED). Nine patients underwent radical surgery alone, four received only radical radiation and two received only palliative chemotherapy. Two patients received adjuvant radiation or chemotherapy following surgical resection and one received a combination of all three treatment modalities. Three patients declined specific treatment and were treated with best supportive care. The median overall survival in the ED group was only 3 months (range 1-16 months), compared to 30 months (range 20-61 months) for LD. EPSCC of pancreas demonstrated a favorable clinical outcome with treatment, whereas primary EPSCC of the liver, esophagus and rectum had an aggressive natural history and a poor response to treatment.

CONCLUSION

Our report suggests that EPSCC may have a different biology from that of pulmonary small cell carcinoma. When detected at an early stage, EPSCC may have an excellent prognosis with treatment. Additional studies involving more patients with EPSCC are warranted to further define the optimal roles of each treatment modality.

Evidence for self-renewing lung cancer stem cells and their implications in tumor initiation, progression, and targeted therapy

The discovery of rare tumor cells with stem cell features first in leukemia and later in solid tumors has emerged as an important area in cancer research. It has been determined that these stem-like tumor cells, termed cancer stem cells, are the primary cellular component within a tumor that drives disease progression and metastasis. In addition to their stem-like ability to self-renew and differentiate, cancer stem cells are also enriched in cells resistant to conventional radiation therapy and to chemotherapy. The immediate implications of this new tumor growth paradigm not only require a re-evaluation of how tumors are initiated, but also on how tumors should be monitored and treated. However, despite the relatively rapid pace of cancer stem cell research in solid tumors such as breast, brain, and colon cancers, similar progress in lung cancer remains hampered in part due to an incomplete understanding of lung epithelial stem cell hierarchy and the complex heterogeneity of the disease. In this review, we provide a critical summary of what is known about the role of normal and malignant lung stem cells in tumor development, the progress in characterizing lung cancer stem cells and the potential for therapeutically targeting pathways of lung cancer stem cell self-renewal.

High impact of 18F-FDG-PET on management and prognostic stratification of newly diagnosed small cell lung cancer

PURPOSE

We evaluated whether 18F-FDG-PET altered stage classification, management, and prognostic stratification of newly diagnosed small cell lung cancer (SCLC).

PROCEDURES

We identified 46 consecutive patients undergoing staging positron emission tomography for SCLC from 1993-2008 inclusive. Updated survival data from the state Cancer Registry was available on 42 of 46 patients.

RESULTS

PET altered stage classification in 12 of 46 (26%) patients. PET altered treatment modality in nine patients, and the target mediastinal radiation field in another three patients. Therefore, PET altered management in 12 of 46 (26%) patients. Patients with limited disease (LD) on pre-PET staging had significantly longer overall survival (OS) than those upstaged to extensive disease (ED; median 18.6 months versus 5.7 months; log-rank p < 0.0001). In patients with ED on pre-PET staging, those downstaged to LD by PET had significantly longer OS than those with ED on PET (median 10.9 months versus 5.9 months; log-rank p = 0.037).

CONCLUSION

PET had a major impact on stage classification, management, and prognostic stratification of newly diagnosed SCLC.

Modifications of human carboxylesterase for improved prodrug activation

BACKGROUND

Carboxylesterases (CEs) are ubiquitous enzymes responsible for the hydrolysis of numerous clinically useful drugs. As ester moieties are frequently included in molecules to improve their water solubility and bioavailability, de facto they become substrates for CEs.

OBJECTIVE

In this review, we describe the properties of human CEs with regard to their ability to activate anticancer prodrugs and demonstrate how structure-based design can be used to modulate substrate specificity and to increase efficiency of hydrolysis.

METHODS

A specific example using CPT-11 and a human liver CE is discussed. However, these techniques can be applied to other enzymes and their associated prodrugs.

RESULTS

Structure-guided mutagenesis of CEs can be employed to alter substrate specificity and generate novel enzymes that are efficacious at anticancer prodrug activation.

Phase II Study of Gemcitabine and Cisplatin in Patients with Previously Untreated Extensive Stage Small Cell Lung Cancer: Southwest Oncology Group Study 9718

BACKGROUND

This phase II study (S9718) evaluated the antineoplastic activity and tolerability of the combination of gemcitabine and cisplatin in previously untreated patients with extensive stage small cell lung cancer (ES-SCLC).

METHODS

Chemonaive patients with ES-SCLC, received gemcitabine 1250 mg/m intravenously (IV) over 30 minutes on days 1 and 8 and cisplatin 75 mg/m IV over 30 to 60 minutes on day 1. Treatments were repeated every 21 days for a maximum of six cycles.

RESULTS

A total of 88 patients were enrolled in the study; seven patients were not eligible and one did not receive treatment; 80 patients were fully assessable for survival, response, and toxicity. Objective response was observed in 42 patients (53%; 95% confidence interval [CI]: 41%-64%) with two patients (3%; 95% CI: 0%-8%) achieving a complete response. Median PFS was 5 months (CI, 4.2-5.9 months), and median overall survival was 8.8 months (95% CI: 7.8-9.5 months). The 1- and 2-year survival rates were 27.5% (95% CI: 17.7%-37.3%) and 4% (95% CI: 0%-8%), respectively. The most common toxicity was neutropenia. Grade 3 and 4 neutropenia was noted in 17 (21%) and 17 (21%) patients, respectively. Two patients developed febrile neutropenia, with subsequent full recovery. Twenty-one patients (23%) developed grade 3 thrombocytopenia. Grade 4 thrombocytopenia was seen in only one patient. The most common nonhematologic toxicities included grade 3 and 4 vomiting in 12 (21%) patients and fatigue in nine (10%) patients. Two patients (3%) died of respiratory infections while on treatment.

CONCLUSION

The combination of gemcitabine and cisplatin is an active and reasonably well tolerated regimen for the treatment of ES-SCLC. It does not appear to offer any compelling advantages over other commonly used two drug regimens in this disease.

Staging and Monitoring of Small Cell Lung Cancer Using [18F]Fluoro-2-deoxy-D-glucose-Positron Emission Tomography (FDG-PET)

BACKGROUND

[18F]Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) scan is widely used for the staging evaluation of nonsmall cell lung cancer, however, its use in small cell lung cancer (SCLC) remains investigational.

PATIENT AND METHODS

We designed a prospective study to evaluate the role of PET in SCLC. Patients with SCLC underwent PET scanning as well as conventional imaging before and after treatment.

RESULTS

A total of 39 PET scan examinations were performed in 21 patients with SCLC; 18 studies were performed before first-line chemotherapy and 21 studies were done during or after treatment. PET findings were compared with findings on CT scans of the chest or abdomen and bone scan. Discordant findings were detected in 14 out of 383 comparisons (4%) for 10 anatomic sites. In the thorax and the abdomen, PET agreed with CT scan in 92% to 100% of examinations assessing potential disease sites, including the contralateral chest, liver, and adrenals. PET agreed with bone scan in detecting bony lesions in 27 out of 32 imaging studies (84%): in 4 out of 5 discordant cases, PET findings were true and in 1 case indeterminate. Staging at baseline (limited, n = 6; extensive, n = 12) was identical when PET and sum of other staging procedures were compared. Response assessment was concordant between PET and CT scans in 8 of 9 patients who had evaluation before and after first-line chemotherapy.

CONCLUSIONS

PET is potentially useful for the initial staging and monitoring of patients with SCLC and it may be superior to bone scan in detecting bone metastasis. The cost effectiveness of PET scan in SCLC remains to be determined.

Intracellular inhibition of carboxylesterases by benzil: modulation of CPT-11 cytotoxicity

Carboxylesterases are ubiquitous proteins responsible for the detoxification of xenobiotics. However, these enzymes also activate prodrugs, such as the anticancer agents capecitabine and CPT-11. As a consequence, overexpression of carboxylesterases within tumor cells sensitizes these cells to CPT-11. We have recently identified two classes of carboxylesterase inhibitors based on either a benzil (diphenylethane-1,2-dione) or a benzene sulfonamide scaffold and showed that these compounds inhibit carboxylesterases with Kis in the low nanomolar range. Because both classes of inhibitors show reversible enzyme inhibition, conventional in vitro biochemical assays would not accurately reflect the in situ levels of carboxylesterase activity or inhibition. Therefore, we have developed a novel assay for the determination of intracellular carboxylesterase activity using 4-methylumbelliferone as a substrate. These studies show that benzil and a dimethylbenzil analogue efficiently enter cells and inhibit human intestinal carboxylesterase and rabbit liver carboxylesterase intracellularly. This inhibition results in reduced cytotoxicity to CPT-11 due to the lack of carboxylesterase-mediated conversion of the prodrug to SN-38. These results suggest that intracellular modulation of carboxylesterase activity with benzil or its analogues may be applied to minimize the toxicity of normal cells to CPT-11.

Decision Analysis for Prophylactic Cranial Irradiation for Patients With Small-Cell Lung Cancer

Purpose

Prophylactic cranial irradiation (PCI) has been shown to provide survival benefit in patients with limited disease small-cell lung cancer (LD-SCLC) who have achieved complete response. However, PCI may also produce long-term neurotoxicity (NT). The benefits and risks of PCI in LD-SCLC are evaluated.

Methods

We developed a decision-analytic model to compare quality-adjusted life expectancy (QALE) in a cohort of SCLC patients who do or do not receive PCI by varying survival rates and the frequency and severity of PCI-related NT. Sensitivity analyses were applied to examine the robustness of the optimal decision.

Results

At current published survival rates (26% 5-year survival rate with PCI and 22% without PCI) and a low NT rate, PCI offered a benefit over no PCI (QALE = 4.31 and 3.70 for mild NT severity; QALE = 4.09 and 3.70 for substantial NT severity, respectively). With a moderate NT rate, PCI was still preferred. If the PCI survival rate increased to 40%, PCI outperformed no PCI with a mild NT severity. However, no PCI was preferred over PCI (QALE = 5.72 v 5.47) with substantial NT severity. Two-way sensitivity analyses showed that PCI was preferred for low NT rates, mild NT severity, and low long-term survival rates. Otherwise, no PCI was preferred.

Conclusion

The current data suggest PCI offers better QALE than no PCI in LD-SCLC patients who have achieved complete response. As the survival rate for SCLC patients continues to improve, NT rate and NT severity must be controlled to maintain a favorable benefit-risk ratio for recommending PCI.

Phase II study of irinotecan plus cisplatin with concurrent radiotherapy for the patients with limited-disease small-cell lung cancer

BACKGROUND

A recently conducted randomized, phase III study that compared irinotecan plus cisplatin (IP) with etoposide plus cisplatin for the patients with extensive disease SCLC revealed a superior median survival rate and a superior 2-year survival rate for the IP combination therapy. Yet there have been few such reports on the patients suffering with limited disease SCLC (LD-SCLC). We conducted a phase II trial to evaluate the efficacy and toxicity of administering IP with concurrent radiotherapy for the patients with LD-SCLC.

PATIENTS AND METHODS

Twenty chemotherapy-naïve patients with LD-SCLC were enrolled in our study. The patients were treated with 40 mg/m(2) irinotecan on days 1, 8 and 15 and with 60 mg/m(2) cisplatin on day 1 every 4 weeks until a maximum of six cycles was delivered. Once-daily radiotherapy included the administration of 50.4 Gy in 28 fractions. After completion of the radiation therapy, the dose of irinotecan was increased to 60 mg/m(2).

RESULTS

The response rate was 85% (CR: 6; partial response, PR: 11). The median survival was 20.0 months (95% CI: 15.6-24.4 months) with 1-year and 2-year overall survival rates of 85 and 35%, respectively. The median progression free survival (PFS) was 12 months (95% CI: 6.2-18.1 months) with a 1-year PFS of 36%. The major hematologic toxicities of this regimen were neutropenia (60%), leukopenia (55%), anemia (20%) and thrombocytopenia (10%). The non-hematologic toxicities were nausea/vomiting (55%), diarrhea (35%) and dysphagia (15%).

CONCLUSIONS

Our data show that IP with concurrent radiotherapy is an effective and tolerable regimen for the treatment of LD-SCLC and these findings warrant further investigation.

Hedgehog signaling in small-cell lung cancer: frequent in vivo but a rare event in vitro

The hedgehog (HH) signaling pathway plays multiple roles during embryonic development and increasing evidence suggests that this embryonic pathway is involved in development and progression of several human cancers including those of the brain, skin, lung and gastrointestinal tract. To investigate HH signaling activity in small-cell lung cancer (SCLC), we have performed gene expression analysis on members of the HH pathway on a panel of 20 SCLC cell lines. Sonic hedgehog (SHH) expression was detected in only DMS79 and GLC16 and only DMS114 expressed detectable protein levels of GLI1, one of the key transcription factors of the pathway. Involvement of HH signaling in SCLC proliferation was investigated in a subset of cell lines using the HH signaling inhibitor cyclopamine or small interfering RNA (siRNA) against GLI1. Cells expressing GLI1 responded only weakly to both cyclopamine and RNA interference, suggesting that HH signaling plays only a minor role in the growth of SCLC cell lines. To investigate HH pathway activity in vivo, GLI1 immunohistochemistry was performed on SCLC tumors. Interestingly, GLI1 was expressed in most SCLC tumors studied, indicating that HH signaling is important for in vivo growth of SCLC but establishment of cell lines from SCLC tumors may lead to loss of expression of key HH pathway members. Thus, the data support the idea that the HH pathway may be a therapeutic target in SCLC. However, the data also suggest that the SCLC cells can circumvent the apparent in vivo requirement of HH signaling.