Comparison of lipid profile between premenopausal test group and control group showed no difference of statistical significance as premenopausal patients were oestrogen receptor negative
. Tamoxifen was more effective in oestrogen receptor positive post-menopausal patients.
"This work tells us that cancers which become refractory to anti-oestrogen treatment often do so by elevating their levels of ELF5 and becoming functionally oestrogen receptor negative
," said Ormandy.
Study leader Dr Christopher Li, from the Fred Hutchinson Cancer Research Center in Seattle, said: "This is of concern, given the poorer prognosis of ER negative (oestrogen receptor negative
) tumours, which are also more difficult to treat."
However, the TaqI polymorphism was associated with a significantly increased risk for oestrogen receptor positive tumours (OR = 1.18, 95% confidence interval [CI] = 1.00 to 1.38, comparing t allele carriers with noncarriers) but not for oestrogen receptor negative
tumours (OR = 0.88, 95% CI = 0.69 to 1.13; P for interaction = 0.04).
Here the lymph node size and the oestrogen receptor status is compared; in most of the cases the lymph node numbers were between 4 and 10 and they were mostly oestrogen receptor negative. The study was done with Fisher exact test and p value was found to be 0.008 which is highly significant.
Here the grade of the tumour is compared with the oestrogen receptor status; in this study most of the cases were Grade 2 and they showed oestrogen receptor negative and the negativity is found to increase with increase in grade of the tumour.
We also see that although mammographic density is one of the strongest risk factors for breast cancer it doesn't seem to influence tumour development in any specific way; for instance, it isn't more associated with oestrogen receptor positive tumours than oestrogen receptor negative
tumours, but seems to act as a general stimulator of tumour development," she noted.