Progesterone receptors should be measured in postmenopausal women negative for estrogen receptor.

To the Editor: In response to the Letter by Eross et al. (1): we appreciate their comments on our work with glycated hemoglobin (gHb) from blood samples dried on filter paper (2, 3) but we believe that some important points in our paper were missed. We, too, have had extensive experience with the thiobarbituric acid (TBA) method (4-7) and have used it with blood samples dried on glucose oxidase-pretreated ifiter paper. As described in our recent paper (3) measurement of glib by affinity chromatography from blood dried on pretreat-ed filter paper showed an increase in gHb during 14 days, with no further increase thereafter. For highly reproducible results we therefore standardized the day of elution. (Even with our TBA method we found a statistically significant increase from day 1 to day 7, with no change thereafter up to 21 days of testing.) We chose to use affinity chromatography rather than TBA colorimetry for several important reasons. First, if the day of elution is standardized, repro-ducibility is excellent: our most recent data show inter-assay CVs of 4.1 and 3.8% for repeated spotting of frozen low-and high-glib blood samples, respectively , over a six-month period. More importantly, the assay requires only 20 tL of blood (a sixth the quantity required for the TEA method) and is technically easier and faster than the TBA method. In addition, many clini-cians find the reported units, % gHb, much easier to understand than nmol IIMF. We see no clinical advantage in being able to store blood-spotted paper for three months; glib reflects glycemic status for only the previous two to three months. A commercially available paper sample collection method for measuring glycated hemoglobin evaluated: are all of these people diabetic? [Tech. England JD, Goldstein DE. Collection of blood on filter paper for measurement of glycated hemoglobin by affinity chromatog-al. Measurement of glycosylated whole-blood protein for assessing glucose control in diabetes: collectionand storage of capillary blood on filter paper. Receptor To the Editor: We disagree with some conclusions reached by Brocklehurst et al. in their which they discuss the incidence of estrogen receptor (ER) negative, pro-gesterone receptor (PR) positive tumors in pre-and post-menopausal women with breast cancer. There is no disputing the fact that receptor-positive tumors are more likely to respond to hormone therapy than are their receptor-negative counterparts , but the association between receptor positivity in the primary tumor and an increased disease-free interval is much …