Methyl-p-hydroxyphenyllactate-esterase activity in breast cancer: a potentially new prognostic factor in short-term follow-up.

We assayed methyl-p-hydroxyphenyllactate esterase (MeHPLAase) activity in 48 cases of primary breast cancer. MeHPLAase activity did not show significant correlation with estrogen receptor and progesterone receptor levels. No significant relationship was found between enzymatic activity and tumor diameter, lymph node status, mitotic activity, degree of nuclear differentiation, and proportion of the S-phase fraction. During the follow-up period (median, 18.8 months; range, 6-69 months), recurrences were observed in 18 of 48 (37%) cases. The Weibull survival regression model using the enzymatic activity as a continuous covariate showed that levels of enzymatic activity were directly associated with the risk of recurrence (P = 0.02). Assuming the mean value of enzymatic activity as the cutoff value, we found a statistically significant relationship between high MeHPLAase activity and shorter recurrence-free survival. On multivariate analysis, MeHPLAase activity proved to be an independent factor for predicting a short period of recurrence-free survival.