Stage of differentiation, proliferative index of tumor cells and cytotoxic activity of peripheral blood lymphocytes in colorectal cancer patients.

Aim: To evaluate prognostic value of activity of cytotoxic lymphocytes of peripheral blood (CTL) of patients with colorectal cancer (CRC).

Methods: 2-year survival of 30 patients with colorectal cancer stage II (T2-3N0-1M0G1-3) was investigated in relation with clinical data, cytotoxic activity of peripheral blood lymphocytes (by MTT-test) and immunohistochemical peculiarities of tumor cells using anti-Ki-67-MABs.

Results: It was revealed that some factors had prognostic significance, namely regional lymph nodes involvement (r = -0.69), proliferative activity of tumor cells (Ki-67-positivity) (r = -0.67), restoration of CTL function after operation (r = 0.46), adjuvant chemotherapy (r = 0.41) and differentiation stage of tumor (r = 0.40). Negative correlation between CTL activity before operation and tumor proliferative activity also exists (r = -0.35).

Conclusion: the data point to the involvement of natural killer cells in the control of tumor growth.