Serum neuron-specific enolase and immunohistochemical markers of neuroendocrine differentiation in lung cancer

Predictive value of blood biomarkers in elderly patients with non-small-cell lung cancer

Aim: Whether GRHL1 can be considered as a potential biomarker for screening non-small-cell lung cancer (NSCLC) is still uncertain. We aimed to investigate the value of circulating blood GRHL1 on detecting NSCLC in an older population. Materials & methods: Diagnostic models from 351 older patients with NSCLC were constructed to assess the predictive value of blood GRHL1 on distinguishing NSCLC. Results: We observed that GRHL1 (odds ratio: 3.25; 95% CI: 1.70-6.91; p < 0.001) maintained a strong relationship with an elevated rate of NSCLC after adequate clinical confounding factors were controlled for. Importantly, serum GRHL1 (area under the curve: 0.725; 95% CI: 0.708-0.863; p < 0.001) had a good predictive value. Conclusion: This is the first time that circulating GRHL1 has been shown to have good value for early detection of NSCLC in an elderly population.

Clinical implications for pro-GRP in small cell lung cancer. A single center experience

BACKGROUND

Recently, pro-gastrin-releasing peptide (pro-GRP) became available as an alternative sensitive, specific and reliable tumor marker for patients with small cell lung cancer (SCLC), both in limited (LD) and diffuse disease (DD).

METHODS

We retrospectively analyzed pro-GRP, neuron-specific enolase (NSE) and CEA in patients with SCLC and non-small cell lung cancer (NSCLC). Serum pro-GRP level was measured with electrochemiluminescence at our laboratory (cutoff 77.8 pg/mL). Continuous variables were analyzed with the Mann-Whitney test, contingency data with Fisher's exact test. Receiver operator characteristic (ROC) curve analysis was performed to identify threshold values to set the highest sensitivity (Sn) and specificity (Sp) values.

RESULTS

A total of 65 patients were studied (49 men, median age 67 years, range 27-79). Thirty-seven patients had SCLC (29 DD, 8 LD) and 28 advanced NSCLC. Median pro-GRP level was 919 pg/mL (range 22-147,350) in SCLC and 32 pg/mL (range 10-119.2) in NSCLC (p<0.0001). NSE was 4.38-fold higher in SCLC patients (p = 0.0005); CEA did not reveal significant differences between groups. Pro-GRP Sn and Sp were 86.4% and 96.4%, respectively. With ROC curve analysis, a cutoff value of 329.3 pg/mL showed a Sn of 75.8% and Sp of 87.5% in discriminating DD from LD. Pro-GRP was not influenced by either liver metastases or renal impairment.

CONCLUSIONS

Pro-GRP is sensitive for SCLC diagnosis. Since high marker levels are related to high disease burden, pro-GRP may have a negative prognostic significance. Follow-up studies are required to define its role in clinical practice in monitoring responses to treatment and early relapses.

Neuroendocrine phenotype of non-small cell lung carcinoma: immunohistological evaluation and biochemical study

AIMS AND METHODS

The prevalence and distribution of neuroendocrine differentiation in non-small cell lung cancer (NSCLC) was estimated by assays for synaptophysin (SYN), chromogranin A (CgA), Leu7 and neuron-specific enolase (NSE). Serum NSE and CgA were determined in parallel to find the values of these markers for distinguishing neuroendocrine differentiation in NSCLC. Fifty-eight resected NSCLC specimens and 34 sera of NSCLC patients entered the study. Neuroendocrine differentiation was graded according to the percentage of neuroendocrine tumor cells as NE0--0%, NE1-NE4--1%->76%. Serum NSE <12.5 ng/mL and serum CgA <46 U/L were taken as cutoff levels.

RESULTS

63.8% (37/58) of NSCLC were scored as NE1-NE4 according to the SYN, CgA and Leu7 levels; 34.5% as NE1; 29.3% as NE2-NE4. 56.8% of tumors were positive for SYN, 34.4% for CgA, 22.4% for Leu7, and 79.3% for NSE. A significant relationship was found between tumor SYN and tumor CgA expression, and between tumor SYN expression and tumor stage. Adenocarcinomas showed a significantly higher rate of neuroendocrine differentiation than squamous cell carcinomas. All normal serum CgA levels corresponded to a lack of CgA expression in the tumors. The increased serum NSE levels presented by 26% of NSCLC patients (mainly <16 ng/mL) did not correlate with tumor NSE expression.

CONCLUSIONS

The prevalence of neuroendocrine differentiation in NSCLC varies and depends on the immunohistochemical criteria used; this warrants standardization of the immunohistochemical criteria for neuroendocrine differentiation in NSCLC. NSE expression in the tumor and a mild increase in serum NSE are poor markers for distinguishing neuroendocrine differentiation in NSCLC.

The prognostic significance of circulating neuroendocrine markers chromogranin a, pro-gastrin-releasing peptide and neuron-specific enolase in patients with advanced non-small-cell lung cancer

BACKGROUND

Chromogranin A (CGA), Pro-gastrin-releasing peptide (ProGRP) and neuron-specific enolase (NSE) are known as immunohistochemical tissue markers closely associated with neuroendocrine differentiation in non-small-cell lung carcinoma (NSCLC). The aim of the present study was to assess the value of serum levels of these markers in predicting response to chemotherapy and survival of patients with unresectable NSCLC.

METHODS

The study included 67 patients with advanced NSCLC treated with chemotherapy. Before treatment, serum levels of CGA, ProGRP and NSE were measured with commercial kits.

RESULTS

No association was found between serum NSE and age, gender, histology, performance status or extent of the disease. Distribution of serum CGA differed significantly according to gender and histology, with higher levels being found in men (p = 0.01) and in squamous cell carcinoma (p = 0.01). Serum ProGRP levels correlated with disease extent, being higher in patients with metastatic disease (M1) than in those with locoregional disease (M0; p = 0.02). The association of NSE, CGA and ProGRP levels with response to chemotherapy was not significant. While NSE had no impact on survival, the median survival was shorter for patients with elevated serum CGA and longer for patients with high ProGRP levels. Association with survival was significant when the Classification and Regression Tree (CART)-derived or median cutoff points were explored. On inclusion in multivariate Cox models, both CGA and ProGRP retained significance with high levels showing an opposite effect on survival [CART-derived cutoff points: CGA, relative risk (RR) -4.0; p < 0.001, and ProGRP, RR -0.4; p = 0.006, and median cutoff points: CGA, RR -1.8; p = 0.04, and ProGRP, RR -0.5; p = 0.03]. The combined use of CGA, ProGRP and NSE allowed for definition of two sets of patients with significantly different median survival times (25.2 vs. 8.8 months, p = 0.0001).

CONCLUSIONS

In the circulation, CGA and Pro-GRP appear to bear important information related to the prognosis for NSCLC patients before chemotherapy. While a high CGA before treatment was found as an unfavorable prognostic determinant, a high ProGRP conferred a survival advantage. The combined use of serum CGA, ProGRP and NSE may supply additional information to prognosis.

Pro-gastrin-releasing peptide, neuron specific enolase and chromogranin A as serum markers of small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) yields neuroendocrine properties. Pro-gastrin-releasing peptide (ProGRP), neuron specific enolase (NSE) and chromogranin A (CGA) are therefore putative serum markers in this disease.

AIM

To assess any difference in the sensitivity-specificity relationship between these neuroendocrine markers regarding various control populations and disease extent.

METHOD

A total of 146 patients were prospectively assessed clinically and biologically. Serum marker titrations were performed using commercial immunoradiometric assays (NSE, CGA) or ELISA (ProGRP). Areas under receiver operating characteristic curves (AUC-ROC) were calculated in order to assess the sensitivity-specificity relationship of each marker and to compare marker accuracy. Maximum Youden indices were used to determine marker thresholds able to produce the best overall diagnostic information.

RESULTS

Assessing the sensitivity in the SCLC population and the specificity in benign lung disease, ProGRP demonstrated the best sensitivity relationship in as much as its AUC-ROC was significantly greater than the ones calculated using NSE and CGA (respective values, 0.95, 0.89, 0.70; two-tailed Z-test <0.05). The ProGRP threshold value, which offered the best sensitivity-specificity relationship was 53 pg/ml corresponding to a 0.80 sensitivity and a 0.96 specificity. In addition, when specificity was assessed in NSCLC and again the sensitivity in the whole SCLC population, ProGRP continued to demonstrate a greater AUC-ROC in comparison with other markers. Using the 53 pg/ml threshold the specificity of this marker was excellent with no false positives in NSCLC. On the other hand, none of the markers were able to discriminate limited from extensive SCLC as suggested by the fact that AUC-ROC, constructed when sensitivity was defined as a positive test in extensive disease and specificity as a true negative test in limited disease, did not reach the upper left octant (AUC 0.65, 0.71 and 0.63 for ProGRP, NSE and CGA, respectively).

CONCLUSION

ProGRP yields the best sensitivity-specificity feature in SCLC, a result deserving further studies designed to evaluate the clinical applicability of this marker.