Hähnel R, Parasiliti R, Twaddle E, Woodings T
Aust N Z J Surg. 1981 Apr;51(2):183-5. doi: 10.1111/j.1445-2197.1981.tb05935.x.
The seasonal variation of the incidence of oestrogen receptor-positive mammary carcinomas was investigated in 556 postmenopausal women. In addition, the seasonal variation in receptor concentration in 289 oestrogen receptor-positive breast carcinomas was studied. Neither the proportion of oestrogen receptor-positive carcinomas, nor the concentration of the receptor in the tumours, varied significantly during the year.