Increasing Immune Dysfunction is Associated with Increasing Matrix-Metalloproteinase-2 Expression and Predicts Biochemical Failure in Men with Bone Marrow Micro-Metastasis Positive Localized Prostate Cancer.

Abstract

To determine if there was an association of the ALC (absolute lymphocyte count) and LCP (lymphocytopenia) with the expression of MMP-2 in bone marrow micro-metastasis, the changes occurring during follow-up and association with biochemical failure. One month after surgery blood and bone marrow samples were taken to determine the presence of micro-metastasis, the presence of circulating prostate cells (CPCs) and ALC. CPCs and micro-metastasis were detected using immunocytochemistry and MMP-2 expression determined in micro-metastasis. Only men positive for micro-metastasis participated in the study. At end follow blood was taken for serum PSA, ALC and CPCs, if the ALC decreased by more than 10% bone marrow sampling was repeated and MMP-2 expression determined, similarly for men with BF. Men who had stable ALCs had an end of study evaluation of the bone marrow. 402 men underwent radical prostatectomy, one month post surgery 79 men were positive for only bone marrow micro-metastasis and formed the study group; of whom 36/79 (45%) underwent BF. Clinical pathological findings were not significantly different between men with or without BF. In men with BF the ALC was significantly lower one-month post surgery. The 5 and 10 year Kaplan-Meier survival was 100% at 5-years and 65% at 10-years for the whole cohort. Men without BF had stable ALCs. A decrease of >10% in the ALC was associated with increasing MMP-2 expression in the micro-metastasis and surrounding stromal tissue, the appearance of CPCs 6-12 months later and BF. the immune host-tumour cell interaction in the microenvironment is dynamic and changes with time. A decreasing ALC may be a valuable marker in identifying men with high risk of BF and changes in immune mediated dormancy before the PSA rises.