Comparative characterization of pulmonary surfactant aggregates and alkaline phosphatase isozymes in human lung carcinoma tissue

[Importance of early detection of lung cancers with initial paraneoplastic manifestations]

INTRODUCTION

Lung cancers are mostly detected in the developed clinical stages, with clearly manifested pulmonary, extrapulmonary or metastatic manifestations. In the early disease stages, radiographic and clinical manifestations may be absent or mimicked.

OBJECTIVE

The aim of this study was the timely detection of early pulmonary, extrapulmonary and paraneoplastic manifestations of lung cancers in order to apply the most appropriate treatment protocols.

METHODS

We examined 230 patients with lung cancer, among them 125 of the working study group with minimal pulmonary and/or initial paraneoplastic symptoms, and 105 patients in the control group with clear tumour manifestations.

RESULTS

The symptom analysis revealed a statistically significantly lesser presence of the respiratory symptoms in the working study group (68%) in comparison with the control group of patients (97%) (chi2 = 29.996; p < 0.001). The analysis of radiographic presentations of lung cancer showed that there were significantly more patients with normal findings in the working group (6.4%) than in the control group--1.9% (p > 0.05), and a positive bronchoscopic finding of the centrally localized tumour (mainly right upper lobe) was confirmed in patients of both groups with normal radiographic findings. The number of diagnosed patients in earlier clinical disease stages (I, II, IIIa) with better prognosis in non-small cell lung cancer was significantly higher (chi2 = 19.149; p < 0.001) in the working group (71.1%) in comparison with the control group (38.1%). Small cell lung cancer was more frequently diagnosed in the stage of limited disease in the working (80%) than in the control group (38.1%) (chi2 = 10.039; p < 0.05). With regard to treatment administration, there is a statistically significant difference (chi2 = 4.013; p = 0.0452) in the frequency between the use of chemotherapy and highly significant difference (chi2 = 22.044; p < 0.001) in the frequency of use of surgical treatment in the working group in comparison with the control group--both chemotherapy and surgery treatment were more frequent in the patients of the working group.

CONCLUSION

Recognizing the initial pulmonary, extrapulmonary or paraneoplastic manifestations as well as performing diagnostic procedures in due time represent the most important guidelines in early detection and the most efficacious therapeutic choice in lung cancer.

TLR signaling by tumor and immune cells: a double-edged sword

The tumor cell signaling pathways that trigger the uncontrolled proliferation, resistance to apoptosis, metastasis and escape from immune surveillance are partially understood. Toll-like receptors (TLRs), which recognize a variety of pathogen-associated molecular patterns, are centrally involved in the initiation of the innate and adaptive immune responses. However, recent evidence shows that functional TLRs are also expressed on a wide variety of tumors suggesting that TLRs may play important roles in tumor biology. Activation of tumor cell TLRs not only promotes tumor cell proliferation and resistance to apoptosis, but also enhances tumor cell invasion and metastasis by regulating metalloproteinases and integrins. Moreover, the activation of TLR signaling in tumor cells induces the synthesis of proinflammatory factors and immunosuppressive molecules, which enhance the resistance of tumor cells to cytotoxic lymphocyte attack and lead to immune evasion. Thus, the neoplastic process may usurp TLR signaling pathways to advance cancer progression, which suggests that targeting tumor TLR signaling pathways may open novel therapeutic avenues.