The best way is to make your own Cache adapter by following one of theese 2 approaches:

Approach 1: Use dedicated manager for uncaching:

namespace AppBundle\CacheManagers;

use Doctrine\Common\Cache\FlushableCache;

class PurgeAllcachesManager
{

    /**
     * @var FlushableCache
     */
    private $purgeCachingHandler=null;

    public function __construct(FlushableCache $purgeCachingHandler)
    {
        $this->purgeCachingHandler=$purgeCachingHandler;
    }

    /**
     * Method that does all the dirty job to uncache all the keys
     */
    public function uncache()
    {
        $this->purgeCachingHandler->flushAll();
    }
}

Approach2: Do as Doctrine does:

namespace AppBundle\CacheManagers;

use Doctrine\Common\Cache\Cache as CacheHandler;

class PurgeAllcachesManager
{

    /**
     * @var CacheHandler
     */
    private $cacheHandler=null;

    public function __construct(CacheHandler $cacheHandler)
    {
        $this->cacheHandler=$cacheHandler;
    }

    /**
     * Method that does all the dirty job to uncache all the keys
     * @throws Exception
     */
    public function uncacheAllKeys()
    {
        if(!method_exists($this->purgeCachingHandler) ){
          throw new Exception("You cannot empty the cache");
        }
        $this->purgeCachingHandler->flushAll();
    }

    //Yet another methods to handle the cache
}

Also have a look on this question for extra info on how to use it.