- preg_replace: documentation ( source)
<?php
$re = '/\b(?:All DLC BG|DLC Comfort)\b(*SKIP)(*FAIL)|\bDLC\b/m';
$title = 'test All DLC BG test DLC Comfort and DLC here
test here All DLC BG All DLC BG BG ALL DLC';
$result = preg_replace($re, '', $title);
echo $result;