Evaluation of tumor vascularization and microenvironment in follicular lymphoma

AIM: To characterize the degree of follicular lymphoma (FL) vascularization and microenvironment by immunohistochemical studies (IHCS) of lymph node biopsy paraffin-embedded sections in 2 different disease pattern groups/MATERIAL AND METHODS: The investigation included 59 patients: 39 (67%) women and 20 (33%) men whose age was 27 to 83 years (median age 53 years) treated at the Hematology Research Center, Ministry of Health of the Russian Federation (n=49), and the N.N. Blokhin Russian Cancer Research Center, Russian Academy of Medical Sciences (n=10), in April 2001 to May 2011. In accordance with the clinical features of the disease, the authors identified 2 patient groups: 1) 31 patients with the good results of FL treatment and 2) 28 patients with its poo/RESULTS: IHCS was performed on lymph node tumor biopsy paraffin-embedded sections prior to treatment using antibodies to CD34, D2-40, CD68, and granzyme B. Morphometric analysis was made applying microscopy and a Leica ×400 digital camera. The images of histological specimens were processed by the computer program VideoTesT-Morphology 5.2: the specific vessel area (%) in relation with tumor tissue was estimated under visual guidance of an investigator. Cytotoxic lymphocytes (CTL) and macrophages were quantitatively characterized using 1 mm2 of tumor tissue (12 fields of vision with the objective lens magnifying ×400). Immunohistochemical specimens to be examined were chosen randomly, by using the random number table/RESULTS: In Group 2, the specific area of blood vessels was statistically significantly higher than in Group 1: 0.04% (95% confidence interval (CI), 0.03 to 0.05%) versus 0.02% (95% CI, 0.01 to 0.03%; p=0.05). In Group 2, that of lymphatic vessels was significantly higher than in Group 1: 0.06% (95% CI, 0.04 to 0.07%) versus 0.03% (95% CI, 0.01 to 4%; p=0.03). With a nodular diffuse growth, Group 2 showed a significantly more CD68-positive macrophages than did Group 1: 800 (95% CI, 380 to 1222) versus 79 (95% CI, 10 to 566; р=0.01). In Group 1, the count of CTL was statistically significantly (p=0.05) higher than in Group 2 in both the nodule (with a nodular growth pattern: 14 (5-27) versus 5 (1-11)) and the internodular space (with a nodular growth pattern: 158 (118-410) versus 35 (5-287) and with a nodular diffuse growth pattern: 126 (102-360) versus 35 (3-120))/CONCLUSION: Increased tumor vascularization (estimated by the specific density of tumor vasculature) and a pronounced macrophageal reaction are associated with the poor outcomes of FL; the marked cytotoxic component in tumor tissue is linked to the favorable outcomes of the disease.