Topic Caching Question

This might be a silly question, but I'm not quite seeing it in the code.
It appears that topics are being cached using ICacheManager.  However, if a topic is updated using the admin portal, I do not think that the cache is thus being updated.
To be sure, I set a conditional breakpoint on Set in MemoryCacheManager and it did not trigger.
Is the cache being updated when a topic is updated or inserted?  Am I missing something?

MemoryCacheManager is not the only class implementing ICacheManager. If you mean caching in presentation layer, then in this case we use PerRequestCacheManager (used for caching requests)