c:\@Work\Perl\monks>perl -wMstrict -le
"my $str = 'xyzxyzxyz - Prod Cache Broker - 16100';
 ;;
 my $word = qr{ [[:alpha:]]+ }xms;
 ;;
 my ($phrase) = $str =~ m{ - \s+ ($word (?: \s+ $word)*) }xms;
 print qq{'$phrase'};
"
'Prod Cache Broker'