The second situation: he doesn't like you. In this case, he was not only cold, but also said nothing to you. Over time, he spent less and less time with you and finally disappeared. In this case, there is no way, and you can't force it if you like it.
The third situation: follow your heart. Cancer people have strange feelings, ups and downs, good times and bad times, and can't figure it out. Married people are not so good, because they put their family first, and they will tell their wives what they think and won't hide it any more. In this case, he is sick and he still likes you. It'll be all right in a minute.
In short, you can decide for yourself which situation is really bad, just ask. I estimate that there is little possibility of getting the result, but it is better to ask than not to say hello.