Cache invalidation on Index (HomeController)

I have added in-memory cache in index of home controller. But I don't know how to apply cache invalidation for it. Since cache key is : $"Book-{sTearm}-{genreId}", we can have many cache entries based on this combination and  its hard to retrieve this cache key during add/update/delete action of book. Either I have to change the caching strategy or find a solution. I am leaving it for future. 