Hugs to you, I have dealt with men with prostate cancer - end stages, new diagnosis and post surgery. Regardless of where you are on the line, its no fun.
I agree with Haley to just start with hugging, kissing, touching, cuddling and go from there. Don't get caught up in the "performance", instead just enjoy your time with the lady and let things develop on their own.
I know one of the side effects of prostate cancer can be incontinence, if this is an issue for you, plan on using a condom for any play going on when you are naked. They have some kind of poise pad thing for men these days that is discrete and can be slipped inside your regular underpants so the lady may never know you have anything going on there btw.
Whatever you do I hope you are with a lovely, affectionate lady who will make your 67th memorable.