I have worked in public schools as an English teacher for over 40 years, and I have served as English department chairperson at both a junior high and a high school for over 30 years.  In our school system, we have never had a problem with parential complaints due to requiring the reading of sensitive material.  I believe this is due to the fact that we require all English teachers to send a list of all materials that are not in our literature book to parents at the start of the year.  In the letter, we ask parents to contact us if they have questions, and we offer alternative selections if a parent objects to a book or selection.  This has worked for our system for years.  I strongly believe that this is something that is best left to each locality!