A reduced incidence of 9,10-dimethyl-1,2-benzanthracene (DMBA)-produced breast carcinoma has been demonstrated in rats having an end-to-side portacaval shunt. As the liver plays an important part in estrogen metabolism, the growth of established breast carcinoma in rats with and without a portacaval anastomosis was studied after bilateral ovariectomy was performed in both groups. Average increase in tumor size at death or one year after DMBA was 2.48 ±0.57 cm for rats with no shunt (sham operation) and 0.82 ± 0.39 cm for rats with a shunt (P<.05). Following bilateral ovariectomy, the suppression of DMBA-produced mammary carcinoma growth was significantly greater in the rats with a portacaval shunt.
O'Grady JF, Reichle RM, Gruenstein M, Reichle FA. Ovariectomy in Rats With Portacaval ShuntsReduction of Mammary Carcinoma. Arch Surg. 1974;109(1):87-88. doi:10.1001/archsurg.1974.01360010065016