Tumor Infiltrating Lymphocytes as Prognostic Factor of Early Recurrence and Poor Prognosis of Colorectal Cancer After Radical Surgical Treatment

Abstract

Sixty percent of patients with colorectal cancer (CRC) are afflicted with distant metastases (liver or lung metastatic process) or a local relapse of malignancy (Bird et al., 2006). The possibilities of surgical and oncological treatment of this disease offer us a large spectrum of treatments including the combination of surgical procedures and consecutive oncological treatments. In the case of radical surgical therapy we can consider the curative access. The main medical problem of CRC is the high rate of recurrences after radically performed surgical therapy. The operability of recurrence is only about 30% in the case of local relapse and 20% in the case of distant metastases (Coleman et al., 2008; Kobayashi et al., 2007). The second dominant problem is the early recurrence of CRC after radical surgical treatment, when the patients undergo a difficult and exhausting procedure with a high risk of perioperative complications without any significant differences in overall survival against modern palliative therapy (Van den Eynde & Hendlisz, 2009). Contemporary clinical and histopathological prognostic factors (staging, grading, etc.) used for the detection of patients with a high risk of relapse and a short overall survival rate and for the indication of adjuvant oncological treatment after radical surgery are not sufficient. Tumor infiltrating lymphocytes (TIL) were described as a good prognostic factor for patients with a high risk of relapse. They are critical indicators of efficient antitumor immunological response. Their number, type and morphology of TIL cells determine resulting tumor prognosis (Atreya & Neurath, 2008; Galon et al., 2006). They could be connected also with the suppression of micrometastatical disease after radical surgery (Gajewski et al., 2006; Pages et al., 2005). We can recognize either the type of immune cells or distinguish their morphological aspects (infiltration of any part of tumor or surrounding of tumor or tributary lymph nodes) (Talmadge et al., 2007).