Cyclops And Havok Are Brothers In X-Men: Apocalypse
With so many mutants, some of them were bound to be related...
While he doesn't specifically use the word brothers, the caption leaves little wiggle-room. Scott and Alex are are indeed siblings in the comics, so to do the same in the film makes sense, especially when you consider they have similar energy-based powers.
Havok (Lucas Till) appeared in the '60s set First Class, while Apocalypse will take place during the '80s and feature a younger Cyclops (recast from the previous films, with Tye Sheridan getting the role), so quite how this is all worked out will be interesting - it was assumed after First Class that in the film continuity Alex would actually be Scott's father. But then this is the X-Men franchise, where pasts, presents and futures are all seemingly re-written at will. Aside from the Summers Bros. and the returning First Class cast, new versions of Nightcrawler, Jean Grey, Angel and presumably many others are set to appear in the film, which is scheduled for release in May next year.