SUVmax during 18FDG-PET scanning in small cell lung cancer: Similar information as in non-small cell lung cancer?

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.

Clinical insights into small cell lung cancer: Tumor heterogeneity, diagnosis, therapy, and future directions

Small cell lung cancer (SCLC) is characterized by rapid growth and high metastatic capacity. It has strong epidemiologic and biologic links to tobacco carcinogens. Although the majority of SCLCs exhibit neuroendocrine features, an important subset of tumors lacks these properties. Genomic profiling of SCLC reveals genetic instability, almost universal inactivation of the tumor suppressor genes TP53 and RB1, and a high mutation burden. Because of early metastasis, only a small fraction of patients are amenable to curative-intent lung resection, and these individuals require adjuvant platinum-etoposide chemotherapy. Therefore, the vast majority of patients are currently being treated with chemoradiation with or without immunotherapy. In patients with disease confined to the chest, standard therapy includes thoracic radiotherapy and concurrent platinum-etoposide chemotherapy. Patients with metastatic (extensive-stage) disease are treated with a combination of platinum-etoposide chemotherapy plus immunotherapy with an anti-programmed death-ligand 1 monoclonal antibody. Although SCLC is initially very responsive to platinum-based chemotherapy, these responses are transient because of the development of drug resistance. In recent years, the authors have witnessed an accelerating pace of biologic insights into the disease, leading to the redefinition of the SCLC classification scheme. This emerging knowledge of SCLC molecular subtypes has the potential to define unique therapeutic vulnerabilities. Synthesizing these new discoveries with the current knowledge of SCLC biology and clinical management may lead to unprecedented advances in SCLC patient care. Here, the authors present an overview of multimodal clinical approaches in SCLC, with a special focus on illuminating how recent advancements in SCLC research could accelerate clinical development.

Primary tumor SUVmax and ratio of SUVmax to primary tumor size on pretreatment 18F-FDG-PET/CT scan in small cell lung cancer : Which is superior for the prognosis?

BACKGROUND

The prognostic impact of tumor SUVmax (t-SUVmax) in small cell lung cancer (SCLC) has been questioned with controversial results, and the significance of the ratio of tumor SUVmax to primary tumor size (SUVmax/t-size) in SCLC has yet to be clarified as well. In this study, a retrospective analysis was carried out to figure out the prognostic and predictive powers of pretreatment primary t‑SUVmax and t‑SUVmax/t-size ratio in patients with SCLC.

METHODS

A total of 349 SCLC patients who underwent pretreatment staging with PET/CT scan were enrolled in the study and analyzed retrospectively.

RESULTS

In limited disease SCLC (LD-SCLC), tumor size was significantly associated with both t‑SUVmax (p = 0.02) and t‑SUVmax/t-size (p = 0.0001). Furthermore, performance status, tumor size (p = 0.001), and liver metastasis were significantly associated with t‑SUVmax in extended disease SCLC (ED-SCLC). Moreover, tumor size (p = 0.0001), performance status, cigarette smoking history, and pulmonary/pleural metastasis were found to be correlated with t‑SUVmax/t-size. No associations were found between clinical stages and either t‑SUVmax or t‑SUVmax/t-size (p = 0.9 for both), and t‑SUVmax and t‑SUVmax/t-size values were found to have similar survival rates in both LD-SCLC and ED-SCLC patients. In univariate and multivariate analyses, both t‑SUVmax and t‑SUVmax/t-size were found not to be associated with overall survival (p > 0.05) CONCLUSION: This study does not advocate the use of either t‑SUVmax or t‑SUVmax/t-size on pretreatment 18F‑FDG-PET/CT scan as prognostic and predictive tools for both LD-SCLC and ED-SCLC patients. Likewise, we did not find that t‑SUVmax/t-size was superior to t‑SUVmax in that respect.

SUVmax Above 20 in 18F-FDG PET/CT at Initial Diagnostic Workup Associates with Favorable Survival in Patients with Cancer of Unknown Primary

Cancer of unknown primary (CUP) is a heterogeneous entity with a limited prognosis. Novel prognostic markers are needed for patient stratification in prospective clinical trials exploring innovative therapies. Methods: In CUP patients treated at the West German Cancer Center Essen, the prognostic value of ¹⁸F-FDG PET/CT at the initial diagnostic workup was analyzed by comparing overall survival (OS) in patients who underwent ¹⁸F-FDG PET/CT with those who did not. Results: Of 154 patients with a CUP diagnosis, 76 underwent ¹⁸F-FDG PET/CT at the initial diagnostic workup. The median overall survival (OS) of the full analysis set was 20.0 mo. Within the PET/CT subgroup, an SUV_max above 20 was associated with significantly superior OS (median OS, not reached vs. 32.0 mo; hazard ratio, 0.261; 95% CI, 0.095-0.713; P = 0.009). Conclusion: Our retrospective work shows that an SUV_max above 20 on ¹⁸F-FDG PET/CT at the initial diagnostic workup is a favorable prognostic factor in patients with CUP. This finding deserves further prospective studies for validation.

Treatment of malignant pleural effusion in non-small cell lung cancer with VEGF-directed therapy

BACKGROUND

Vascular endothelial growth factor (VEGF) is a critical regulator of malignant pleural effusion (MPE) in non-small-cell lung cancer (NSCLC). Bevacizumab (BEV) and apatinib (APA) are novel VEGF blockers that inhibit lung cancer cell proliferation and the development of pleural effusion.

METHODS

In this study, we established Lewis lung cancer (LLC) xenograft mouse models to compare the therapeutic effect of APA and BEV in combination with cisplatin (CDDP) against MPE. The anti-tumour and anti-angiogenic effects of this combination therapy were evaluated by ¹⁸F-FDG PET/CT imaging, TUNEL assay and Immunohistochemistry.

RESULTS

The triple drug combination significantly prolonged the overall survival of the tumour-bearing mice by reducing MPE and glucose metabolism and was more effective in lowering VEGF/soluble VEGFR-2 levels in the serum and pleural exudates compared to either of the monotherapies. Furthermore, CDDP + APA + BEV promoted in vivo apoptosis and decreased microvessel density.

CONCLUSIONS

Mechanistically, LLC-induced MPE was inhibited by targeting the VEGF-MEK/ERK pathways. Further studies are needed to establish the synergistic therapeutic effect of these drugs in NSCLC patients with MPE.KEY MESSAGESCombined treatment of MPE with apatinib, bevacizumab and cisplatin can prolong the survival time of mice, reduce the content of MPE, decrease the SUV_max of thoracic tumour tissue, down-regulate the content of VEGF and sVEGFR-2 in serum and pleural fluid, and promote the apoptosis of tumour cells. Angiogenesis and MPE formation can be inhibited by down-regulation of HIF-1α, VEGF, VEGFR-2, MEK1 and MMP-2 molecular signalling pathway proteins.

Molecular Characterization and Therapeutic Approaches to Small Cell Lung Cancer: Imaging Implications

Small cell lung cancer (SCLC) is a highly aggressive malignancy with exceptionally poor prognosis, comprising approximately 15% of lung cancers. Emerging knowledge of the molecular and genomic landscape of SCLC and recent successful clinical applications of new systemic agents have allowed for precision oncology treatment approaches. Imaging is essential for the diagnosis, staging, and treatment monitoring of patients with SCLC. The role of imaging is increasing with the approval of new treatment agents, including immune checkpoint inhibitors, which lead to novel imaging manifestations of response and toxicities. The purpose of this state-of-the-art review is to provide the reader with the latest information about SCLC, focusing on the subtyping of this malignancy (molecular characterization) and the emerging systemic therapeutic approaches and their implications for imaging. The review will also discuss the future directions of SCLC imaging, radiomics and machine learning.

Prognostic Value of 18F-FDG-PET Parameters in Patients with Small Cell Lung Cancer: A Meta-Analysis and Review of Current Literature

Many studies have suggested a prognostic value of one or several positron emission tomography (PET) parameters in patients with small cell lung cancer (SCLC). However, studies are often small, and there is a considerable interstudy disagreement about which PET parameters have a prognostic value. The objective of this study was to perform a review and meta-analysis to identify the most promising PET parameter for prognostication. PubMed^®, Cochrane, and Embase^® were searched for papers addressing the prognostic value of any PET parameter at any treatment phase with any endpoint in patients with SCLC. Pooled hazard ratios (HRs) were calculated by a random effects model for the prognostic value of the baseline maximum standardized uptake value (SUV_max) and metabolic tumor volume (MTV). The qualitative analysis included 38 studies, of these, 19 studies were included in the meta-analyses. The pooled results showed that high baseline MTV was prognostic for overall survival (OS) (HR: 2.83 (95% confidence interval [CI]: 2.00–4.01) and progression-free survival (PFS) (HR: 3.11 (95% CI: 1.99–4.90)). The prognostic value of SUV_max was less pronounced (OS: HR: 1.50 (95% CI: 1.17–1.91); PFS: HR: 1.24 (95% CI: 0.94–1.63)). Baseline MTV is a strong prognosticator for OS and PFS in patients with SCLC. MTV has a prognostic value superior to those of other PET parameters, but whether MTV is superior to other prognosticators of tumor burden needs further investigation.

Combining 18F-FDG PET/CT and Serum Lactate Dehydrogenase for Prognostic Evaluation of Small Cell Lung Cancer

Objective: To investigate the value of using ¹⁸F-FDG PET/CT in combination with serum lactate dehydrogenase (LDH) for prognostic evaluation of newly diagnosed small cell lung cancer (SCLC). Methods: We reviewed 118 patients with pathologically proven SCLC who underwent ¹⁸F-FDG PET/CT imaging evaluation in our hospital. Among these patients, 64 patients had extensive disease (ED) and 54 patients had limited disease (LD). The maximum standardized uptake value (SUV_max) of primary tumor was measured. A Cox proportional hazards model was used to evaluate age, sex, performance status, serum LDH, tumor stage and SUV_max on the prediction of overall survival (OS) and median survival time (MST) of patients. Subgroup analysis was performed based on the SUV_max in combination with serum LDH. Results: According to the Receiver Operating Characteristic (ROC) curve, the optimal cut-off value of SUV_max was 10.95. The AUC was 0.535 (95% CI: 0.407-0.663). The patients were divided into four groups according to the SUV_max (higher or lower than 10.95) and LDH (higher or lower than 245 U/L). The univariate and multivariate analyses showed that curative thoracic radiotherapy, Prophylactic Cranial Irradiation (PCI) and the combination of primary tumor SUV_max ≤ 10.95 and LDH ≤ 245 U/L were prognostic factors of OS in patients with all patients (p < 0.05). Smoking status, PCI, the combination of primary tumor SUV_max ≤ 10.95 and LDH ≤ 245 U/L were prognostic factors of OS in patients with LD (p < 0.05). N stage and PCI were significant predictors in both of univariate and multivariate analysis of OS for ED SCLC (p < 0.05). Among all patients, 27 had low SUV_max and normal LDH, and their MST was 36 months (95% CI: 12.98-59.02). Ninety-one patients had high SUV_max and/or high LDH, and their MST was 20 months (95% CI: 15.47-24.53). The difference between these two groups was significant (p = 0.045). In patients with LD, 16 patients had low SUV_max and normal LDH, and their MST was 72 months (95% CI: 26.00-118.0). Thirty-eight patients had high SUV_max and/or high LDH, and their MST was 27 months (95% CI: 20.80-33.21). The difference between these two groups was significant (p = 0.012). In patients with ED SCLC, 10 patients had low SUV_max and normal LDH, with an MST of 18 months (95% CI: 13.69-22.32. Fifty-four patients had high SUV_max and/or high LDH, and their MST was 12 months (95% CI: 10.61-13.39). The difference of MST between these two groups was not statistically significant (p = 0.686). Conclusion: ¹⁸F-FDG PET/CT in combination with serum LDH were prognostic factors of overall survival in patients with SCLC. The prognosis of patients with LD SCLC who had low SUV_max of primary tumor and normal LDH was better than those with high SUV_max and/or high LDH.

Prognostic value of 18F-FDG PET/CT metabolic parameters in small cell lung cancer

Objective

To compare the prognostic values of metabolic parameters from pretreatment PET/CT between limited disease (LD) and extensive disease (ED) small cell lung cancer (SCLC) patients.

Methods

Data on 118 newly diagnosed SCLC patients (50 LD and 68 ED) who underwent pretreatment positron emission tomography–computed tomography (PET/CT) were reviewed. For PET, metabolic parameters were measured for: (1) primary tumor, maximum standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis; and (2) all tumor lesions, SUVmax of the hottest tumor, whole body metabolic tumor volume (WBMTV), and whole body total lesion glycolysis (WBTLG). Prognostic values of metabolic parameters and other clinical variables were analyzed to predict overall survival (OS).

Results

In LD, SUVmax of the primary tumor was an independent prognostic factor for OS. Patients with high SUVmax showed significantly worse OS than those with low SUVmax. In ED, WBMTV and WBTLG were independent prognostic factors for OS. Patients with high WBMTV or WBTLG showed significantly worse OS than those with low WBMTV or WBTLG.

Conclusions

SUVmax of primary tumor was the only independent prognostic factor for OS in LD SCLC patients. WBMTV and WBTLG were independent prognostic factors in ED SCLC patients.

Correlation study on 18F-FDG PET/CT metabolic characteristics of primary lesion with clinical stage in lung cancer

BACKGROUND

¹⁸F-FDG PET/CT metabolic characteristics provide the crucial biologic and molecular information for tumors. To explore the relationships between ¹⁸F-FDG PET/CT derived parameters such as maximum standardized uptake value (SUV<inf>max</inf>), metabolic tumor volume (MTV), total lesion glycolysis (TLG) of primary tumor and clinical stage in different histopathologic subtypes of lung cancer.

METHODS

A total of 97 newly diagnosed lung cancer patients (69 males, 28 females; average age 65.1 years) with pathologically proven were retrospectively analyzed, who had undergone ¹⁸F-FDG PET/CT scan before treatment from September 2016 to November 2017. SUV<inf>max</inf>, MTV and TLG of primary tumor were measured. Clinical stage was mainly determined by ¹⁸F-FDG PET/CT, in conjunction with conventional imaging and endoscopic biopsy. Mann-Whitney U test, χ² test, Spearman correlation test and ROC curve analysis were used for statistical analysis.

RESULTS

There were 53 adenocarcinomas (AC), 28 squamous carcinomas (SCC), 13 small cell carcinomas (SCLC), one adenosquamous carcinoma, one mucoepidermoid carcinoma, and one sarcomatoid carcinoma in 97 patients. Both AC and SCLC revealed more cases in stage IV than in stage I-III (P<0.01). There was no significant difference in four stages of SCC (P>0.05). Metabolic parameters of SCC were higher than AC including SUV<inf>max</inf>, MTV and TLG (P<0.01). SCLC showed a higher value than AC in TLG (P<0.05). No significant differences were found between AC and SCLC in SUV<inf>max</inf> and MTV, also between SCC and SCLC in SUV<inf>max</inf>, MTV and TLG (P>0.05). MTV and TLG except SUV<inf>max</inf> were positively correlated with stage in AC (P≤0.001). Only MTV showed a positive correlation with stage in SCC (P<0.05). Whereas there were no definitive relationships between metabolic parameters and stage in SCLC (P>0.05). AC with a higher MTV (MTV≥5.965 cm³) indicated a significantly higher rate of distant metastasis than those with a lower MTV (77.5% (31/40) vs. 30.8% (4/13), χ²=9.553, P<0.01), as well as AC with a higher TLG (TLG≥46.922) than those with a lower TLG (88.5% (23/26) vs. 44.4% (12/27), χ²=11.422, P<0.01).

CONCLUSIONS

Histopathologic subtypes have a significant influence on the relationships between MTV/TLG not SUV<inf>max</inf> of primary foci and stage in lung cancer. Primary MTV/TLG is related to clinical stage closely in AC, and a higher MTV/TLG results in a higher risk of distant metastasis.

Prognostic value of the maximum standardized uptake value of pre-treatment primary lesions in small-cell lung cancer on 18F-FDG PET/CT: a meta-analysis

Background 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) has been widely used in clinical practice. However, the prognostic value of the pre-treatment standardized uptake value (SUV) for patients with small-cell lung cancer (SCLC) remains controversial. Purpose To investigate the prognostic role of pre-treatment 18F-FDG PET on SCLC patients by meta-analysis. Material and Methods Extensive literature searches of the PubMed, EMBASE, Web of Science, and Cochrane Library databases were conducted to identify literature published until 5 May 2017. Comparative analyses of the pooled hazard ratios (HRs) for event-free survival (EFS) and overall survival (OS) were performed to assess their correlations with the pre-treatment maximum SUV (SUVmax). Either the fixed- or the random-effects model was adopted, depending on the heterogeneity observed across the studies. Subgroup analyses were performed to assess the robustness of the results. Results Twelve studies with 1062 patients were included. The pooled HR for OS of 11 studies was 1.13 (95% confidence interval [CI] = 1.05-1.22; P = 0.001; I²= 0%) and the pooled HR for EFS of nine studies was 1.09 (95% CI = 1.02-1.17; P = 0.014; I²= 0%), indicating that patients with high SUVs may have poorer prognoses. Begg's test detected no significant publication bias. The prognostic role of the SUVmax remained similar in the subgroup analyses. Conclusion Our meta-analysis indicated that the pre-treatment SUVmax of primary lesions can be an important prognostic factor for OS and EFS in patients with SCLC. A high SUVmax may indicate poorer prognosis.

Prognostic value of fluorine-18 fludeoxyglucose positron emission tomography parameters differs according to primary tumour location in small-cell lung cancer

OBJECTIVE

To investigate the prognostic value of fluorine-18 fludeoxyglucose (FDG) positron emission tomography (PET) parameters for small-cell lung cancer (SCLC), according to the primary tumour location, adjusted by conventional prognostic factors.

METHODS

From 2008 to 2013, we enrolled consecutive patients with histologically proven SCLC, who had undergone FDG-PET/CT prior to initial therapy. The primary tumour location was categorized into central or peripheral types. PET parameters and clinical variables were evaluated using univariate and multivariate analysis.

RESULTS

A total of 69 patients were enrolled in this study; 28 of these patients were categorized as having the central type and 41 patients as having the peripheral type. In univariate analysis, stage, serum neuron-specific enolase, whole-body metabolic tumour volume (WB-MTV) and whole-body total lesion glycolysis (WB-TLG) were found to be significant in both types of patients. In multivariate analysis, the independent prognostic factor was found to be stage in the central type, but WB-MTV and WB-TLG in the peripheral type. Kaplan-Meier analysis demonstrated that patients with peripheral type with limited disease and low WB-MTV or WB-TLG showed significantly better overall survival than all of the other groups (p < 0.0083).

CONCLUSION

The FDG-PET volumetric parameters were demonstrated to be significant and independent prognostic factors in patients with peripheral type of SCLC, while stage was the only independent prognostic factor in patients with central type of SCLC.

ADVANCES IN KNOWLEDGE

FDG-PET is a non-invasive method that could potentially be used to estimate the prognosis of patients, especially those with peripheral-type SCLC.

Prognostic Value of Preradiotherapy (18)F-FDG PET/CT Volumetrics in Limited-Stage Small-Cell Lung Cancer

BACKGROUND

Whether (18)F-fludeoxyglucose positron emission tomography (PET)/computed tomography (CT) metrics predict outcome in limited-stage (LS) small-cell lung cancer (SCLC) has not been well established; most previous reports have only analyzed maximal standardized uptake values (SUVmax). We investigated multiple pretreatment PET metrics, including SUVmax, mean SUV (SUVmean), total lesion glycolysis, and metabolic tumor volume (MTV) in LS-SCLC patients undergoing chemoradiotherapy (CRT) and correlated them with survival and disease control outcomes.

PATIENTS AND METHODS

All patients received platinum-based chemotherapy and a median radiation dose of 45 Gy. Kaplan-Meier and competing-risks analyses were performed to assess the prognostic value of PET metrics with respect to overall survival (OS), distant failure (DF), disease-free survival (DFS), and locoregional failure (LRF). Univariate and multivariate analyses were performed to account for the effect of other clinical factors on outcomes.

RESULTS

A total of 120 patients with LS-SCLC had analyzable pre-CRT PET/CTs. The median follow up was 34 months. Median OS was 26.9 months. OS was 53.2% at 2 years and 33.1% at 5 years. SUVmax, SUVmean, MTV, and total lesion glycolysis of the primary tumor were not significantly associated with OS, LRF, and DFS on univariate analysis. MTV was significantly associated with DF (P = .024) on univariate but not multivariate analysis.

CONCLUSION

This is the largest reported series to date evaluating the prognostic value of baseline PET metrics in LS-SCLC. Neither SUVmax nor other analyzed PET metrics demonstrated significant correlation with OS or LRF. MTV was correlated with DF and DFS, but this association was no longer significant after adjustment for other clinical factors. This analysis suggests that pretreatment PET scans, even with the use of advanced metrics, do not have independent prognostic value for outcomes in LS-SCLC patients after CRT.

PET/CT in therapy evaluation of patients with lung cancer

FDG-PET/CT is a well documented and widespread used imaging modality for the diagnosis and staging of patient with lung cancer. FDG-PET/CT is increasingly used for the assessment of treatment effects during and after chemotherapy. However, PET is not an accepted surrogate end-point for assessment of response rate in clinical trials. The aim of this review is to present current evidence on the use of PET in response evaluation of patients with lung cancer and to introduce the pearls and pitfalls of the PET-technology relating to response assessment. Based on this and relating to validation criteria, including stable technology, standardization, reproducibility and broad availability, the review discusses why, despite numerous studies on response assessment indicating a possible role for FDG-PET/CT, PET still has no place in guidelines relating to response evaluation in lung cancer.

Relationship between primary lesion metabolic parameters and clinical stage in lung cancer

OBJECTIVES

The relation of PET-derived parameters as maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), metabolic tumor volume (MTV) with clinical stage in lung cancer and correlation of SUVmax of primary tumor and that of metastatic lesion was studied in lung cancer patients.

MATERIALS AND METHODS

Patients with lung cancer who were referred for FDG PET/CT were included in the study.

RESULTS

PET/CT scans and pathology reports of 168 patients were assessed. A total of 146 (86.9%) of these patients had a diagnosis of non-small cell lung cancer (NSCLC) and 22 (13.1%) had small cell lung cancer (SCLC). Metabolic parameters such as SUVmax, TLG and MTV showed significant differences in all the stages in NSCLC patients (p<0.001). However, after tumors sizes <25 mm were excluded, no significant differences in SUVmax between stages were observed. No significant differences were found between these metabolic parameters and limited or extended disease SCLC. Tumor diameter correlated with primary tumor SUVmax and significant correlations between primary lesion SUVmax and metastatic lesion SUVmax were found.

CONCLUSIONS

Although differences were found regarding indices between stages of NSCLC cases, SUVmax differences between stages seem to be caused by underestimation of SUVmax in small lesions. Other glucose metabolism indexes such as MTV and TLG show promising results in terms of prognostic stratification. Future studies are needed for better understanding of their contribution to clinical cases.

Clinical applicability of staging small cell lung cancer according to the seventh edition of the TNM staging system

The two-stage system of limited and extensive disease has been widely employed for small cell lung cancer (SCLC). However, the International Association for the Study of Lung Cancer has proposed that the TNM classification should be incorporated into clinical practice. The purpose of this study was to evaluate the applicability of the Union for International Cancer Control (UICC) 7th TNM staging system to SCLC. We retrospectively reviewed the medical records of consecutive patients with newly diagnosed histologically proven SCLC between March 2005 and January 2010. Patients who had other concurrent malignancies or had combined-type SCLC were excluded. We assessed overall survival (OS) according to the T descriptor, N descriptor, M descriptor, and TNM stage grouping. In total, 320 SCLC patients were included. Median age was 65 years and 286 patients (89.4%) were male. Median OS was 12.7 months. There were no significant differences in OS according to the T descriptor (P = 0.880). However, there were significant differences in OS according to the N (P < 0.001) and M (P < 0.001) descriptors and TNM stage grouping (P < 0.001). Hazard ratios for OS, adjusted for known prognostic factors, differed significantly according to the N and M descriptor, and TNM stage grouping, but not according to the T descriptors. The UICC 7th TNM staging system may contribute to a more precise prognosis in SCLC patients. Further studies are required to evaluate the applicability of the TNM staging system to SCLC.