Since I'm kinda new here, you can take this with a grain of salt. But I do wish the best for you and yours, since cancer does affect everyone around you. Sorry if it's a long read, but some background might help.
I have always had some belief in the idea of 'Let your food be your medicine and your medicine be your food'. My biggest problem has been sticking with that cause I get lazy and fall into not so healthy eating habits.
Almost 8 years ago I was diagnosed with Triple Negative Breast Cancer and a golf ball sized lump in my left breast that showed up in just a few short months. I didn't want chemo, but after finding out how fast & aggressive it could be, I caved. I didn't think there was enough time to make alternative choices. I did the 6 rounds of chemo that included what's called 'Red Death' amongst other drugs, but refused radiation, then had a lumpectomy to remove whatever was left. I am glad chemo saved my life, but now I live with the side effects. Mostly peripheral nerve damage and whatever else I'm struggling with. The one thing about Triple Negative, is that it's not hormone related, is the fastest most aggressive and hardest to treat of the BC's and has a higher re-occurrance within the first 5 years. But if you survive the 5 year mark, all chances drop to the lowest of reoccurring.
Then my husband was diagnosed with Stage 3b Squamish Cell Lung Cancer (sorry, don't remember the exact names given) almost 2 years to the day of my own diagnosis. After a 3 year battle of ongoing chemo treatments, and radiation, he did not survive. Surgery was never an option because of the location of the tumor. At, on, around the bronchial tubes to the entrance of the lung and arteries to the heart.
Anyway, during all that I found out a few things about cancer.....
1. We all have cancer cells in our bodies from birth, they only become a problem when they chose to attack our systems and/or our immune system isn't up to par to keep them in check.
2. Cancer feeds on sugars, Acids feeds on cancer.......maybe try eating more acidic and/or fermented foods (pickles, kraut, yogurts, keifers, etc)
3. Kale is a biggy, cooked, raw, or however you can stand it. If you don't like it, try dehydrating and grind to a powder, then sprinkle into other foods or dishes. You'll still get the same benefits.
4. Besides kale, but other brassicas/cruciferous type veggies are also good.....along with lots of greens. Did you know you can also eat radish and carrot greens as they contain a ton more nutrition than their root.
5. Turmeric with pepper does the most good. Turmeric on it's own is ok, but works better when combined with a pepper. Not sure if the type of pepper matters (black, cayenne, etc). Word of caution, even just a few bits of turmeric will turn everything yellow, so it's hard to hide.
I know there's alot more info about it, but I just wanted to include some of my own findings with those listed above....
While I kinda played with it during my cancer, I really stepped it up for my hubby. He was all about conventional medicine going to be his miracle and wasn't interested in anything remotely 'alternative witch doctor stuff' so that made it difficult for me but I did start putting kale and turmeric in just about everything I could hide it in......until he got suspicious and swore I was trying to poison him and he refused to eat my cooking. Only drive thru or frozen/canned.
Whether it really was the additions of kale & turmeric, or just the course his cancer took or modern medicine or what....we'll never know for sure BUT as long as I was doing his cooking with the hide ins, his tumor had stopped growing and had even shrunk a little. Once he refused to eat my cooking, it wasn't long before it started growing again.
Again, I take no credit here and it could very well just be coincidence.......,BUT
ok, enough of my ramblings but I do wish you the best and pray for you to have a successful journey
Never give up, You'll make it thru.. 
