Lack of relationship between the levels of prolactin receptors and steroid receptors in women with breast cancer.
The levels of prolactin receptors (PRL-R), based on a new micro-method, estrogen receptors (ER) and progesterone receptors (PG-R), were determined in 159 breast cancer specimens. Sixty-seven of 159 tumors (42%) had PRL-R levels of 20 fmol/mg protein or higher, and were regarded as PRL-R positive. In 60 of the 159 samples (38%), no PRL-R could be detected, and the remaining 32 samples (20%) were considered borderline. While a positive correlation was found between the presence of ER and PGR, no correlation was detected between PRL-R and any steroid receptors (r = -0.024 for ER vs PRL-R, 0.052 for PGR vs PRL-R and 0.002 for ER + PGR vs PRL-R). Furthermore, PRL-R in levels of 20 fmol/mg protein or higher were found in 35% of samples in which no steroid receptors were detected as well as in 38% and in 27% of samples which exhibited positive ER or PGR respectively (greater than or equal to 20 fmol/mg protein). On the other hand, in 47% of the samples possessing both ER and PGR, the PRL receptors could not be found. These results clearly demonstrate that in the human breast cancer, the presence of PRL-R is independent of the status of either ER or PGR. It is suggested that the measurement of PRL-R could serve as a chemical marker to guide a possible therapeutic use of PRL-suppressing drugs in women with breast cancer.
Ben-David
M
M
Endocrine, Polypeptide and Cancer Institute, Veterans' Administration Medical Center, New Orleans, LA.
Wittliff
J L
JL
Fekete
M
M
Kadar
T
T
Biran
S
S
Schally
A V
AV
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D001943:Breast Neoplasms / Q000032:analysis* / Q000188:drug therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D011869:Radioligand Assay; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D011981:Receptors, Prolactin / Q000032:analysis*
D015415:Biomarkers; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011981:Receptors, Prolactin