On the best or the least harmful fruit juices for cancer in general
by Leonard, copyright © 2004 & 2005 Healing Cancer Naturally
The Gerson therapy includes the drinking of organic (green/granny smith) apple (20 oz/day, mixed with carrot juice), but juice only 8 oz at a time. I would also juice organic dark grapes (effective with lung & prostate cancer and leukemia), pomegranate, kiwi (with its peel), and lemon and lime (detoxes liver and kidneys).
I would AVOID all fruit juice that's not fresh-pressed from a masticating juicer (except perhaps low-sodium tomato/V-8). I would even avoid fresh-pressed juice from fruits other than those above, unless they're very-low-glycemic fruit. Also, juice only a little bit of fruit at a time; drinking too much pure fruit juice at one time elevates blood sugar too quickly. The fruit juices most commonly consumed by people who have "spontaneous remissions" are fresh-squeezed grape and apple juices [compare The Grape Cancer Cure].
Addendum by Healing Cancer Naturally
Perhaps one of the healthiest ways to take advantage of tasty fresh fruit and its natural sugar content is blending it with medicinal wild herbs such as dandelion, nettles or plantain into a smoothie. The rich nutrient content of the herbs (vitamins, minerals and trace elements, chlorophyll, bitter and other secondary plant compounds) is likely to "neutralize" the potential harm done by the fructose while the fruit sugar and aroma makes the smoothie pleasing to the taste. For inspiration, see e.g. Cure testimony: terminal lung cancer with metastases: healed via detoxification with wild herb smoothies and raw foods.