The prognostic role of circulating CD8+ T cell proliferation in patients with untreated extensive stage small cell lung cancer

BACKGROUND

Immunosuppression caused by tumorigenesis may promote tumor progress and invasion. Here, we investigated whether the characteristics of circulating T lymphocyte subtypes in patients with extensive small cell lung cancer (ED-SCLC) can be used as an alternative marker of tumor progression.

METHODS

This study included 36 newly diagnosed ED-SCLC patients before treatment and the patients were followed up. 22 age and sex-matched healthy volunteers were selected as control. The percentages and proliferation potential of T lymphocyte subpopulations from peripheral blood were measured.

RESULTS

CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells (Tregs) were elevated in ED-SCLC patients compared with healthy controls (p = 0.0083). In contrast, the percentages of CD3⁺ and CD3⁺CD4⁺ T cells were significantly lower in SCLC patients (p < 0.001; p = 0.0014). The proliferation (%divided) of CD8⁺ T cells of SCLC patients was suppressed compared with healthy controls (p = 0.0058), but not of CD4⁺ T cells (p = 0.1611). Multivariate analyses showed that the %divided of CD8⁺ T cells is an independent predictor for PFS (HR: 4.342, 95% CI 1.324-14.245; p = 0.015). The percentages of peripheral Tregs and the degree of chemotherapy or radiotherapy induced lymphopenia negatively correlated with the proliferation of CD8⁺ T cells (p = 0.0225, r = - 0.379; p = 0.0003, r = - 0.464).

CONCLUSION

The present study indicates that SCLC patients have impaired immunity in peripheral blood, and the proliferation potential of circulating CD8⁺ T cells is a significant predicator for PFS.

Urinary Neopterin in Patients with Advanced Colorectal Carcinoma

In previous studies, mostly in patients with early stage colorectal carcinoma, neopterin, an indicator of systemic immune activation, has been associated with poor prognosis. The aim of the present study was to evaluate urinary neopterin in patients with advanced or metastatic colorectal carcinoma treated with chemotherapy. A retrospective analysis was performed of urinary neopterin, determined by high-performance liquid chromatography, in 88 patients with advanced or metastatic colorectal carcinoma. Peripheral blood cell count and serum carcinoembryonic antigen (CEA) were determined in 72 patients before the start of chemotherapy. Urinary neopterin in colorectal carcinoma patients was significantly increased compared to controls, but lower than in patients with inflammatory bowel disease. Neopterin correlated significantly with serum CEA, age, peripheral blood leukocyte and platelet counts. The median survival of colorectal carcinoma patients with urinary neopterin below 214 μmol/mol creatinine was significantly longer compared to that of patients with higher neopterin concentrations (median 18 vs 5 months, log-rank test p=0.003). CEA and hemoglobin were also associated with survival in univariate analysis, but in multivariate analysis only urinary neopterin and serum CEA were independent predictors of survival. High urinary neopterin during follow-up was also predictive of poor prognosis.

Antiphospholipid Antibodies and Acute-Phase Response in Non-Metastatic Colorectal Cancer Patients

Aim

To investigate the plasma levels and prevalence of the most common antiphospholipid antibodies, as well as their relationships with several plasma markers of inflammation, in order to characterize some aspects of cancer thrombophilia.

Materials and methods

Eighty-three cancer patients with non-metastatic colorectal solid tumors and 94 control subjects were tested for the presence of IgG/IgM/IgA anti-cardiolipin and anti-β2-glycoprotein I antibodies and of several acute-phase reactants, i.e., fibrinogen, factor VIII:C and C4b-binding protein.

Results

In cancer patients the plasma levels of the acute-phase reactants and the IgA/IgG anti-cardiolipin and IgA anti-β2-glycoprotein I antibodies were significantly higher; the acute-phase reactants were significantly correlated with anti-cardiolipin antibodies; the prevalence of antiphospholipid antibodies was not significantly higher.

Conclusions

In patients with non-metastatic colorectal cancer the acute-phase response is associated with antiphospholipid generation. This could represent a further pathogenetic mechanism for the short-term post-surgery thrombotic complications of patients with colorectal cancer.

Host response to colorectal cancer

It has long been established that inflammation and immunity play critical roles in the pathogenesis, control and eventual metastasis of cancers. With the advent of more sophisticated animal models and immunohistochemical techniques a greater understanding of the immune system and its interactions has occurred. Individual immune cells are dynamic structures that have variable behaviour controlled by complex interactions in the tumour microenvironment. In the setting of colorectal cancer it was first observed that peritumoral inflammatory infiltrates were associated with improved prognosis. Immunohistochemistry has shown the individual cells types within these infiltrates. It now appears that an adaptive immune response, differentiated along the T-helper 1 pathway controls tumour invasion and metastasis. Furthermore, the immune system exerts selection pressure leading to the evolution of tumour cell variants that can induce tolerance and disable adaptive immunity. These tumour cells then use the mechanisms of innate immunity to facilitate further growth, angiogenesis, invasion and eventual metastasis. These issues are investigated with particular relevance to colorectal cancer. Using the immune response to defeat CRC has been under intense investigation but has so far been unsuccessful. Nevertheless, researchers remain optimistic that immunotherapy will play an important role in the treatment of this common disease.