SPONTANEOUS TUMORS IN LONG-TERM VASECTOMIZED MICE - INCREASED INCIDENCE AND ASSOCIATION WITH ANTI-SPERM IMMUNITY

  • 1 January 1983
    • journal article
    • research article
    • Vol. 111  (2) , 129-139
Abstract
In 2 independent studies observed, a significantly higher incidence of spontaneous tumors in vasectomized BDF1 mice over the long term than in age-matched sham-vasectomized control mice was observed. In the 1st study, necropsies were performed on the animals at 30 mo of age (27 mo. after surgery), and 15 of 24 vasectomized vs. 2 of 14 sham-vasectomized mice (P .ltoreq. 0.025) had detectable tumors in various tissues. In a 2nd study, necropsies were performed on the animals at a younger age (18 mo., 15 mo. after surgery), and liver tumors predominated: 82 of 171 vasectomized vs. 33 of 97 controls (48% vs. 34%, P .ltoreq. 0.037) had at least 1 hepatic tumor, and a significantly higher percentage of vasectomized animals had large (.gtoreq. 31 sq mm) hepatic tumor burdens (80% vs. 49%; P .ltoreq. 0.002) and multiple hepatic tumors (19% vs. 5%; P .ltoreq. 0.002). In combined data from both studies, the vasectomy group had a higher incidence of: at least 1 tumor (P .ltoreq. 0.025); multiple tumors (P .ltoreq. 0.005); and more than 1 type of tumor (P .ltoreq. 0.005). In both studies tumor number and size were significantly associated with antisperm immunity detected by antibody or aspermatogenesis evaluation. Sperm degradation products and/or the autoimmune response to sperm that commonly accompanies vasectomy may affect tumor induction or growth directly or indirectly by interfering with immunosurveillance mechanisms.