Tumor-infiltrating lymphocytes in tissue material combined with systemic lymphocyte inflammation in patients with colorectal cancer

The efficacy of cancer immunotherapy has been actively explored in the treatment of various malignant neoplasms of the gastrointestinal tract. In light of recent reports, the present study aimed to investigate the combination of the absolute lymphocyte count (ALC), percentage of tumor-infiltrating lymphocyte (TILs) and tumor progression status in patients with colorectal cancer (CRC) who underwent surgery. The medical records of 160 patients diagnosed with CRC were retrospectively reviewed. TILs were determined as a percentage of mononuclear inflammatory cells in the total intratumoral or stromal area as determined in five high power fields (magnification, x200-400), at the invasive front and in the centre of the tumour. Blood samples were obtained within 3 days prior to and 7 days following the surgical treatment. The assessment of the TIL percentage was performed in the tissue at the invasive front and in the centre of the primary tumour mass in combination with the determination of ALC in whole blood samples. The samples were obtained prior to and after surgery from patients with CRC, and the tumour progression status was also assessed (TILs/ALC/tumour progression status). A significant association was observed between the percentage of TILs in the main mass of tumour and the tumour size (P=0.031), the pT stage (P=0.049) and the incidence of necrosis (P=0.037) following surgery. The histological type was associated with the evaluated combined parameters prior to surgery (P=0.046). Lymph node pouch invasion was associated with TILs at the invasive front of tumour and with ALC prior to and after surgery (P=0.006 and P=0.037). Furthermore, the data indicated that the percentage of TILs located on the invasive front and centre of the tumour, and the ALC prior to and following surgery correlated with the treatment status (P=0.032, P=0.018, P <= 0.001 and P <= 0.001). A significant association was noted between eight features and evaluated combined parameters following surgery. These included the tumour size (P=0.021), TNM stage (P<0.001), tumour deposits (P=0.001), incidence of necrosis (P=0.042) and lymph node metastasis (P<0.001). Furthermore, the degree of invasion of venous (P<0.001), lymphatic (P<0.001) and perineural (P<0.001) sites was also significantly associated with TILs, ALC obtained after surgical treatment and tumor progression status. The data demonstrated that local and systemic chronic inflammation was associated with tumour progression in patients with CRC.