Document Type : Research Articles
Faculty of Medicine, University Finis Terrae, Santiago, Chile.
Department of Coloproctology, Hospital de Carabineros de Chile, Santiago, Chile.
Department of Medicine, Hospital de Carabineros de Chile, Santiago, Chile.
Aims: To determine the association of micro-metastatic matrix metalloproteinase-2 (MMP-2) expression, the absolute lymphocyte count (ALC)) and outcome in stage II colon cancer. Materials and Methods: A single centre, prospective observational study, one month post-surgery blood for ALC, circulating tumour cell (CTC) detection and a bone marrow biopsy for micro-metastasis detection were obtained. CTCs were detected using differential gel centrifugation and immunocytochemistry with anti-CEA and anti-MMP-2, the bone marrow biopsy for the detection of micro-metastasis was processed as for CTCs . At each follow-up ALC and CTC counts were determined. Bone marrow sampling was repeated if the ALC decreased by >10%, at relapse or at the end of the study period. Three MRD subgroups were defined, Group I MRD negative, Group II only positive for micro-metastasis and Group III in which CTCs were detected. Results: One hundred and eighty one patients participated; 105 (58%) patients formed Group 1, 36 (20%) formed Group II and 40 (22%) formed Group III for a median follow-up of 4 years . Of Group I 3/105 (3%), Group II 16/36 (44%) and Group III 34/40 (84%) patients relapsed. The ALC was significantly higher in Groups I and II, the expression of MMP-2 and MMP-2 score in Group II was significantly lower than in Group III patients. A low ALC was associated with a higher expression of MMP-2 in the micro-metastasis and presence of CTCs. Conclusions: Patients with stable ALCs did not relapse; decreasing ALCs were associated with increasing MMP-2 scores, the appearance of CTCs and relapse.