How to cancel save an entity when stay in prePersist function

I have one problem: in a process, I want to cancel saving an entity in prePersit function:

/**
 * @ORM\PrePersist
 */
public function setTranslationsValue2()
{
    if((null===$this->getContent())or($this->getContent()==''))
    {
        //wanna stop saving this item???
       return false;
    }
}

At above function, I don't want to save this entity any more, and don't want to stop my process (the process still save another s)