[Small cell lung cancer--state of the art and future perspectives]

Diagnostic potential of protein serum biomarkers for distinguishing small and non-small cell lung cancer in patients with suspicious lung lesions

BACKGROUND

Biomarkers play a role in identifying, managing, and predicting cancer outcomes. In lung cancer, they are used at various time points. Doubts remain regarding their accuracy for differential diagnosis and histological subtyping. A diagnostic test study was conducted. It included malignant lesions and controls with benign lesions. Before lung biopsy, all patients had the following biomarkers measured in serum (Pro-GRP,NSE,CYFRA21-1,SCC-Ag,CEA).

METHODS

The predictive capacity of serum biomarkers was evaluated to discriminate between lung cancer and benign pathology. The accuracy was also assessed for distinguishing between SCLC and NSCLC and explored their ability to perform histological subtyping.

RESULTS

93 patients were included, 60 with lung cancer, 33 with benign pathology. Pro-GRP and NSE were elevated in SCLC compared with NSCLC or nonmalignant disease. The most accurate for differentiating between malignant and benign pathology were CEA and CYFRA21-1. Pro-GRP had a poor predictive capacity for distinguishing NSCLC from SCLC. However, combined with CEA and CYFRA21-1, performance improved. For SCLC, the diagnostic capacity of Pro-GRP increased by combining with biomarkers, such as NSE/CYFRA21-1.

CONCLUSIONS

Biomarkers lacked the sensitivity and specificity for independent differential diagnosis or histological subtyping. However, the observed patterns in biomarker levels associated with specific histological subtypes suggest potential utility in a multi-biomarker approach or in conjunction with other diagnostic tools. This insight could guide future research to improve diagnostic accuracy and personalized treatment strategies in lung cancer.

Serum pleiotrophin as a diagnostic and prognostic marker for small cell lung cancer

Pleiotrophin (PTN) is involved in tumour progression, angiogenesis and metastasis. The purpose of this study was to investigate the expression level of PTN in the serum of patients with small cell lung cancer (SCLC) and to explore the clinical significance of PTN. Serum samples from 128 patients with SCLC, 120 healthy volunteers (HV) and 60 patients with benign lung disease (BLD) were collected. The levels of serum PTN were determined with ELISA and its correlation with the clinical data was examined. The serum PTN levels in SCLC patients were significantly higher than that in BLD patients (P < 0.05) or HV (P < 0.05). With a cutoff value of 258.18 ng/mL, the sensitivity and specificity of PTN to SCLC patients and BLD patients, SCLC patients and HV were 79.2% and 91.7%, 86.7% and 95.8% respectively. An area under the curve for all stages of SCLC resulting from PTN, which was significantly better than the other tumour markers tested including progastrin‐releasing peptide and neuron‐specific enolase. High serum PTN levels appear to correlate with poor survival in patients with SCLC. These results suggest that PTN levels in the serum could be a new effective biomarker for the diagnosis and prognosis of SCLC.

Ratio of C-Reactive Protein/Albumin is An Inflammatory Prognostic Score for Predicting Overall Survival of Patients with Small-cell Lung Cancer

Recent studies have indicated that the C-reactive protein/ albumin (CRP/Alb) ratio is associated with clinical outcomes in patients with hepatocellular carcinoma (HCC). We examined the prognostic value of this ratio in patients with small-cell lung cancer (SCLC). In this retrospective study, a total of 367 eligible SCLC patients were analyzed and the correlation between the pretreatment CRP/Alb ratio and overall survival (OS) was investigated. The optimal cutoff level of CRP/Alb ratio was at 0.441. A low and high CRP/Alb ratio was assigned to 65.1% and 34.9% of patients, respectively. The median OS of patients with a high CRP/Alb ratio was worse than those in the low group (13.70 vs 18.90 months HR, 1.34; p = 0.005). Disease stage (p < 0.001), performance status (PS) (p < 0.001) and pretreatment LDH (p < 0.001) were also significant predictors of OS. Multivariate analyses showed that the CRP/Alb ratio is an independent prognostic factor (p = 0.025). This study demonstrated that the CRP/Alb ratio could independently predict OS in patients with SCLC, and had comparable prognostic value to other known prognostic markers. Therefore, the CRP/Alb ratio could have prognostic value and be a measurable biomarker in patients with SCLC.

The prognostic nutritional index (PNI) predicts overall survival of small-cell lung cancer patients

Recent studies have shown the prognostic nutritional index (PNI) had prognostic value in some solid tumors. However, no studies have examined its prognostic role in small-cell lung cancer (SCLC) patients. In this retrospective study, 724 consecutive SCLC patients were included between 2006 and 2013. Demographic, clinical, and laboratory data were collected. The PNI was calculated as 10 × serum albumin value (g/dl) +  .005 × peripheral lymphocyte count (per mm(3)). Univariate and multivariate analyses were performed to assess the prognostic value of relevant factors. The optimal cut-off value of PNI for OS stratification was determined to be 52.48. A total of 464 and 260 patients were assigned to low and high PNI groups, respectively. Compared with low PNI, high PNI was associated with older age, advanced stage, and elevated lactate dehydrogenase (LDH). Median overall survival (OS) was worse in the low PNI group (low vs high, 15.90 vs 25.27 months; HR, 0.62; p < 0.001). In multivariate analysis, stage, performance status, LDH, and PNI were independent prognostic factors for OS. Subgroup analysis showed PNI was generally a significant prognostic factor in different clinical situations. The assessment of PNI could assist the identification of patients with poor prognosis and be a hierarchical factor in the future SCLC clinical trials.

Serum YKL-40 level is associated with the chemotherapy response and prognosis of patients with small cell lung cancer

This study was to explore the association between the serum YKL-40 level and the clinical characteristics, the response to chemotherapy and prognosis in small cell lung cancer (SCLC). Serum YKL-40 levels were detected and compared in 120 patients with SCLC pre- and post-chemotherapy, and in 40 healthy controls. Receiver operating characteristics (ROC) curves were adopted for diagnosis and calculation of area under ROC curve in SCLC. The Kaplan–Meier method, univariate and multivariate Cox regression analysis were used to analyze the correlation between pre-chemotherapy serum YKL-40 levels and progression-free survival (PFS) and overall survival (OS). The pre-chemotherapy serum YKL-40 levels were significantly higher than those of the controls (p<0.001). The post-chemotherapy serum YKL-40 levels in the SCLC cases were lower than pre-chemotherapy serum YKL-40 levels in these cases (p = 0.026). The patients with high serum YKL-40 showed a poorer response to chemotherapy than those patients with low serumYKL-40 (p = 0.031). Univariate analysis revealed that SCLC patients with high serum YKL-40 had a shorter PFS and OS than those with low serum YKL-40 (HR of 1.74, p = 0.033; HR of 1.33, p = 0.001). Cox multivariate analysis indicated that YKL-40 was an independent prognostic indicator of PFS and OS (HR of 1.12, p = 0.029; HR of 1.84, p = 0.025). Kaplan–Meier survival curves further confirmed that patients with low serum YKL-40 have longer PFS and OS (p = 0.016 and p = 0.041, respectively). These results suggest that YKL-40 is a potential prognostic marker of chemotherapy response in SCLC.