Stomach cancer

A family member has recentley been diagnosed with stomach cancer. We don't know what stage or how far it is. We've been told there is shadowing on his lung. He is so poorly at the moment in and out of hospital , 3 blood transfusions also been on the drip because of dehydration  and he is just generally very unwell. They are waiting for another appointment so haven't actually seen anyone since diagnosis. My question is do you think the cancer is very advanced and this is why he is so poorly. It's all happening very quickly x