I’ve been using James Chan as my English name for quite a long time. I did some search years ago (at that time there was even no Google) and found that people usually use Chan for my Chinese last name 陈, so I took it as mine too.
This confuse people a lot, especially for those from Mainland China Chan looks and sounds quite odd. Chan is used widely in Hong Kong, where 陈 is pronounced like that in Cantonese.
I speak Mandarin, so I decide to change it back to Chen, which is the Pinyin form of 陈. This one is more natural for me. Now I need to do many extra work to update my online profiles.