[Evaluation of tumor vascularization and microenvironment in follicular lymphoma]

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.

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 poor 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 x400 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 x400). Immunohistochemical specimens to be examined were chosen randomly, by using the random number table.

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; p=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)).

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.