HGH is a wonder drug, but it's tricky. Not only for the expense factor, but like everything else, when you add exogenous hormones, your body stops producing them.
So if you supplement with HGH for years or even months, your body stops making it and the ability to produce more may take a very long time to come back. It may never come back.
Also, there are many types of tumors that have HGH receptors, and HGH has an even bigger impact on the tumor than it does on the rest of your body. So you're basically supercharging your cancer.