port list shows all the ports in Macports thus giving you the large list.
To show all the ports you have requested try
port list requested. This will only show the ports that you explicitly installed, the ones that they depend on are not shown and were installed by dependency resolution. SO this list will be the smalles list you need to reinstall the same ports. If you grep to fins php then this should give the minimum set of ports. The only issue is if there are any ports you have that depend on a php53- port but do not have php53 in the name but then I suspect there are other issues.
Another way is to to uninstall php53 by
sudo port uninstall php53. This will fail giving the list of ports that depend on it which you have to then uninstall. However this could take a few runs to do if a port depends only indirectly on php53.