Figure 2.

Castration did not affect tumor latency in NRL-TGF-α/PRL male mice. Bitransgenic, single transgenic, and nontransgenic male mice underwent castration or sham surgery at 3 months of age and were monitored for tumor development. End stage was defined when tumors reached 1.5 cm in diameter. The latencies were compared by Kaplan-Meier analysis, and differences were detected using the Mantel-Haenszel test. All bitransgenic male mice developed mammary tumors with no significant difference in latency (P = 0.14). No castrated and sham-treated single transgenic and nontransgenic littermates developed mammary lesions.