The testicle being cancerous is the least of your worries.
WHY would you breed your dog? They're both likely incredibly badly bred, as apparent by the male dogs condition alone.... We simply do NOT need more pet quality dogs. Period. Have you even been to a shelter lately? If so, all those dogs living miserably in cages are due to idiots like you carelessly breeding their dogs. Sorry to be blunt, but the truth hurts.
Dogs are only worth breeding if they have all the necessary health tests done, such as OFA, have titles in a certain work or show, have had a temperament test, and come from a long line of WELL BRED DOGS. You also clearly know nothing, so even if your dog was breeding material, which it's not, you should not be involved in breeding dogs at all.
Be responsible and spay your damn dog, and tell your friend to neuter theirs as well.
Some peoples stupidity truly astound me.