Lung cancer biology

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.

Prediction of survival and recurrence by serum and cytosolic levels of CEA, CA125 and SCC antigens in resectable non-small-cell lung cancer

Risk of death and risk of recurrence in 108 potentially curable non-small-cell lung cancer patients were analysed with respect of TNM stage, histological type and carcinoembryonic antigen (CEA), CA125 antigen and squamous cell carcinoma antigen (SCC) levels in serum and cytosol. CA125 and CEA levels were closely related to outcome figures. Multivariate analyses indicated that TNM stage and histological type had the best predictive power, but serum and cytosolic CA125 and serum CEA contained additional, independent prognostic information. Predictive information drawn from serum and cytosolic levels proved mutually complementary. We conclude that CA125 and CEA complement TNM classification and histological type for the purpose of quantifying risk of death or recurrence.

[Epidermal growth factor receptor in non-small cell cancer of the lung]

In this study we determined the concentration of epidermic growth factor receptors (EGFr) in non-small cell carcinoma of the lung (NSCCL) and analyzed its relation to the anatomical, pathological and clinical factors of these neoplasms. The concentration of EGFr in 62 tumor tissue samples was 9.9 +/- 14 fmol/mg, higher than that found in 14 tissue samples from cases of spontaneous pneumothorax (3.9 +/- 3.6 fmol/mg) (p = 0.005). EGFr concentration in lung tissue with no signs of neoplasm was 6.5 +/- 10 fmol/mg. In 21 (33%) cases of NSCCL the concentration exceeded the normal threshold of 10 fmol/mg. EGFr concentration was higher in cases of epidermoid carcinoma than in other tissue samples (p = 0.042). No significant association was found between EGFr levels and status of tumor node metastasis, degree of differentiation and mitotic index. The probability of remaining free of tumor recurrence and of survival after 24 months among patients whose tumoral EGFr concentration was below 10 fmol/mg was 34 and 40%, respectively. The rates for patients with concentrations that exceeded the threshold were 20% (p = 0.32) and 25% (p = 0.26), respectively. The results seem to indicate that the study of EGFr concentration alone does not yield practically important information for the management of patients with NSCCL who have undergone surgery. The concentration of EGFr marks degree of differentiation in NSCCL and has prognostic implications derived from its association with other factors.

Prognostic significance of serum CA 125 antigen assay in patients with non-small cell lung cancer

BACKGROUND

The serum levels of CA 125 tumor-associated antigen in patients with lung cancer have been previously related to TNM stage, histologic type, and survival rate. In the current study, the prognostic information provided by the CA 125 antigen assay was analyzed.

METHODS

Preoperative serum of CA 125 antigen was determined in 137 patients with non-small cell lung cancer. The assay was performed by means of a solid-phase enzyme-immunoassay test. The influence of CA 125 serum level on postoperative outcome was studied by a multivariate analysis, performed with Cox's proportional hazards regression model.

RESULTS

Patients whose initial CA 125 level was higher than 15 U/ml had a 3.25-fold greater likelihood of relapse (95% confidence interval [CI], 1.7-6.21) (P < 0.001) and a 4.27-fold greater likelihood of deaths (95% CI, 2.42-7.55) (P < 0.001) due to cancer than patients with lower values. For patients with serum levels over 15 U/ml, the 36-month survival rate posttreatment was lower (67% versus 20%) (P < 0.001), as was the disease-free rate (64% versus 13%) (P < 0.001). After adjustment for TNM stages, histologic type, sex, and age, patients with CA 125 values over 15 U/ml continued exhibiting higher risk of relapse (hazard ratio, 2.2; 95% CI, 1.04-4.69) (P = 0.04) and higher risk of death (hazard ratio, 2.42; 95% CI, 1.29-4.54) (P = 0.006).

CONCLUSIONS

CA 125 is an independent prognostic factor of survival and tumor relapse in non-small cell lung cancer. The preoperative serum level of CA 125 antigen is inversely correlated with the outcome figures. The authors suggest that CA 125 be included in any future multifactorial analysis of survival.

In vitro effect of suramin on lung tumour cells

In the search for new therapeutic concepts in lung cancer chemotherapy, suramin, a potential anticancer drug which evades multidrug resistance, was tested in vitro on 25 lung-derived cell lines, either non-tumorigenic cells, or established cell lines from five different tumour types. Suramin treatment resulted in a time- and dose-dependent decrease in [3H]thymidine incorporation, except in one adenocarcinoma cell line where DNA synthesis was highly stimulated. [3H]Leucine incorporation was less affected, indicating that suramin acted cytostatically rather than cytotoxically. Our results show that suramin affected DNA synthesis of the different types of lung derived cells, including non-tumorigenic and tumour cell lines, to a similar extent.

Neuroendocrine and epithelial markers in diagnostic bronchial lung cancer biopsy specimens

The incidence of neuroendocrine and epithelial markers was investigated by immunocytochemistry in archival, lung cancer, bronchial biopsy specimens (n = 48). No correlation of antigenicity with histological type was observed. 79% non-small cell lung carcinoma (NSCLC) and 61% small cell lung carcinoma (SCLC) were positive for epithelial markers. HuTu-m3 did not discriminate adenocarcinomas and squamous cell carcinomas from SCLC. 83% SCLC and 93% NSCLC were positive for one or more neuroendocrine marker. Multiple neuroendocrine markers were found in 61% SCLC, 83% NSCLC and 83% squamous cell carcinomas, this incidence being greater in the NSCLC group, and in the squamous carcinomas in particular, than previously reported.