If you can't slurp the whole file then you could do something like this.

#! perl -slw
use strict;

my $buffer;

while( <DATA> ) {
     $buffer .= $_; # Accumulate lines in a buffer
     
       # Use \s+ instead of space to allow for newlines between words
       # The /g option is required to set pos()
     if( $buffer =~ /Content\s+Compression\s+to\s+Date/g ) {
          print "Content Compression to Date found";
             
             # Once you find something your looking for
             # throw away everything that preceded it with substr()
          substr( $buffer, 0, pos( $buffer ) ) ='';
     }
     
}

__DATA__
Content Compression to Date
other stuff
other stuff
other stuff
Content 
Compression to Date
other stuff
other stuff
other stuff

Content Compression 
to Date

Content Compression to 
Date
other stuff
other stuff

Content 
Compression 
to 
Date
other stuff
other stuff
[download]

Output

P:\test>test2
Content Compression to Date found
Content Compression to Date found
Content Compression to Date found
Content Compression to Date found
Content Compression to Date found
[download]

Notes:

You will need to use the /g option on ALL the regexes, even though you are only looking for the first match each time in order for pos to be set. (I never quite understood that?).

You will also need to do the substr thing to throw away everything already matched after each successful match.