[Effect of tumor burden on differentiation of T lymphocytes in the peripheral blood of patients with colorectal cancer].

OBJECTIVE

To analyze the effect of tumor burden on the differentiation of T1 and T2 cells and its implication in patients with colorectal cancer.

METHODS

Peripheral venous blood samples were obtained from 20 patients with primary colorectal cancer before and 7 days after the operation, radical operation in 17 patients and palliative resection in 3 patients. Twenty sex and age-matched patients with benign diseases treated in the same period were used as controls. T1 and T2 cells in the peripheral blood were evaluated by detecting the intracellular interferon-gamma and interleukin-4 production with 4-color flow cytometry. Lymphocyte subsets in the peripheral blood were also measured by flow cytometry.

RESULTS

At the time of diagnosis, the percentage of T1 and T2 cells in the peripheral lymphocytes of the case group was lower significantly than that of the control group (P = 0.006, and P = 0.017). There was no significant difference in the T, CD4(+) T, CD8(+) T, B, and NK cells between the two groups. After getting rid of the tumor burden, the percentage of T1 cells increased, however, not significantly (P > 0.05). And the percentage of T2 cells increased significantly (P = 0.020). The percentages of T1 cell of the patients with the tumor > or = 5 cm and of the patients with poorly differentiated tumors were significantly lower than those of the patients with the tumor < 5 cm and of the patients with well or moderately differentiated tumors (P = 0.064, and P = 0.072). The percentage of T1 cells in the patients with lymph node metastasis and stage III approximately IV tumor were lower significantly than those of the patients without lymph node metastasis and those with stage I approximately II tumor (P = 0.033 and P = 0.033). No significant differences were found between the population of T1 cells and such factors as tumor size, serosa invasion, and distant metastasis.

CONCLUSION

Tumor load suppresses the differentiation of T1 and T2 cells in the patients with colorectal cancer significantly, and may be an important factor in the development of immunosuppression. After getting rid of the tumor burden, the percentages of T1 and T2 increase in a short time, and the immunologic function is improved. Determination of T1 may be helpful to indicate the prognosis of colorectal cancer.