ICI discovered tamoxifen before AstraZeneca bought them. They're British. Femara (letrozole) and Afinitor (everolimus) are Novartis (Switzerland). Campostar was discovered by Pharmacia, a Swedish company that's now part of Pfizer.
The U.S. by no means has a monopoly on "cancer drugs".
The U.S. by no means has a monopoly on "cancer drugs".