New to the board here on behalf of my father

I've been lurking and reviewing posts the last few days. I am here on behalf of my Dad and figured I'd make an introductory post. 

Dad had the flu in January and afterwards he had some rib pain. The NP he had been using as his defacto GP diagnosed him with broken ribs. 

Fast forward to March, he has his medicare physical and he is proclaimed "healthier than I am" by his 28 year old NP. Dad was a bit puzzled because he hadn't felt well, but happy with the physical. I joked with him that he actually wanted a diagnosis to explain his aches and pains, and he did get one. "You're just old." he'd laugh then joke with me about my upcoming 40th birthday. 

Well his overall well being was still bothersome to him so he had the NP do some scans. I'm not sure what, so we will just say "scans". She called them back to the office and cried as she handed them scans with kidney and bone lesions. 

He was set up with a Vanderbilt oncologist that he really liked. The Dr. said they didn't find any cancer in any of his organs, only in his bones and that they "can't tell where it came from" but that they need to get busy treating the adenocarcinoma in the bones because it is causing him pain. The kidney scan wasn't mentioned. I supposed we were happy that he didn't seem to have kidney cancer and we all moved on. 

In the meantime, I am researching bone cancer but I kept focusing on the phrase "we don't know where it came from." I eventually find out from a Dr. friend that this is what is referred to as "Cancer of Unknown Primary". 

Once I had a search term, then I could get down to some serious research. By this time a month had past, Dad had weakened significantly -- was hospitalized once for GI tract bleeding that turned out to be from NSAIDs and again for severe constipation that turned out being from his opiate meds. A month and a half in, he had one chemo treatment under his belt, and was know mostly wheel chair bound and severely weak. 

I was able to find the national expert for Cancer of Unknown Primary, and it turned out he was literally a mile away from my house in Nashville. I emailed him and he responded within 10 minutes.

We take Dad to see him, he says he is 90+% sure that Dad has kidney cancer, and that there are treatments for it. He set an appointment for a week later, to start Dad on "Cabo". 

Dad took his first 60mg dose yesterday. I've read where it does wonders for bone mets. We are hoping for the best. He is very weak and his appetite is poor. He has bone mets in his ribs extensively, and in his hip and spine. The ribs is giving him the most trouble. He is on constant pain. 

If he has Kidney cancer, his primary kidney tumor is fairly small, small enough as to be inconclusive to another oncologist. Isn't there a correlation between tumor size and it's propensity to metastasize? 

Is our diagnosis favorable because Dad's only mets are bone mets, even though they are pretty extensive? 

I had a very weird feeling that his other oncologist was just throwing a generic chemo at him and hoping for the best, then we get this 2nd opinion and the new oncologists confirms this. How is it that me, an underachieving college drop-out knows this? It freaks me out that I was able to discern this as a layman. 

If Dad responds well to the cabo we can then go with other treatments to hopefully knock this thing down into remission. I wish I found this oncologist, Dr. Greco, a month ago but it is what it is, as they say. 

Sorry for being so long winded, I just wanted to get this introductory first post out of the way, and jump in the deep end here with you guys, while I am on this journey with my Dad.