Advisor and co-advisor withholding information, should I leave the lab? I am a second-year PhD student in Biomedicine and I was assigned to my current advisor and co-advisor since day one. My advisor is very busy. So, most of the meetings and discussions about my PhD project is done only with my co-advisor. My advisor knows about my research plans, but since we only have meetings like 3 times so far, my co-advisor is the one who understands most about my project. However, I just discovered yesterday (by accident) that my co-advisor published a study, with my advisor as the last author, about something related to my project that would make my project pointless. They never told me about their analysis and never updated me about their results. I don't feel like I need to know everything that they are doing, but isn't it their job to let me know things related to my project?

My project is making prediction based on data that is expensive and time consuming to generate. What they published was that they made a prediction model for the same outcome based on the same dataset, but using a more cost-effective method. In the paper, they claimed that this grouping predicts 100% the outcome in our data. I do not understand why they would give me the green light to do this project and say nothing about this better method. Also, I learned about this paper not from them directly, but because I happen to subscribe to the journal they published in. I was so surprised reading the title. 

I feel lost and would appreciate your advice. Is this thing common? I never met such behavior during my undergraduate and Master's, but this is my first time studying in Europe. My previous advisors (in Asia and in the US) always lets everyone in the lab/team know what everyone is doing (eg through lab meetings or proofread each others publications). Also, does this warrant changing advisors? I feel tricked and so stupid for trusting them. It seems that they do not have my best interest in mind, there is a lack of good communication, and makes me question why they accepted me in the lab in the first place.
I don't understand the details of your project, but the methods in your project and in the study by your advisors seem to differ not just in detail. Therefore, you should probably bring up the paper in a meeting, and if you do not see "the point" of your project any more in the light of the other outcomes, and ask/discuss with your advisors the added value of your project, given the findings of their other study.

I doubt that anyone has the money and time to support a PhD student working on a project that they do not see any value in.