Where is Pancreatic Cancer here? Astronomical CA19.9 levels...

My father is a 16-month pancreatic cancer survivor. Originally, when he was diagnosed, he had a very strange CA19.9 level of 180,000U/mL. Luckily, when he started chemo, this number started to go down and he actually reached 10 percent of the original number (1,500) before it turned around. What is strange is that the normal range for the CA19.9 has always been around 0-35U/mL and he has never been below 1,500. His blood work two weeks ago showed 95,000.

Some of the professionals (truly great people) dealing with my father have guessed that the actual CA19.9 value is not as important as the trend it takes on. But, NOONE has ever been able to definitely answer this question of why it is so high. However, I have read several articles suggesting that there are many other factors that affect the CA19.9 levels (i.e. inflammation).

I guess, therefore, my question is: has anyone ever heard of such astronomical figures of CA19.9? It has always bothered us.

Secondly, two weeks after a reading of 95,000U/mL, his blood work had been sent to an entirely new company (which apparently uses different machines). The first and newest reading from them is 270,000U/mL (with a range of 0-35U/mL). My father’s oncologist said “not to worry” because it is an entirely different reading and they should only use it as a base number. Can readings between two different laboratories be that different??? (three times that number in a matter of two weeks is hard to believe). Not surprisingly, the laboratories refuse to answer even general questions about their machines and such results.

Thank you for any help or input in advance.