Are you riding 8 hours a day every day? No? Get a well-fitting seat that doesn't make your balls go numb and you'll be fine.
(AFAIK link between cycling and TC is inconclusive, link papers if you know otherwise)
I think it’s just a Lance joke - cycling has no correlation with TC.
Perhaps TC increases cycling rates!
The context for the downvoters is that at the time, Lance attributed his performance to treatment for TC. (And being down even one T would almost certainly improve saddle comfort.)
There is no consensus that cycling increases the risk of testicular cancer.