Question about male upper body development?

I am an 18 yr old male, currently 5'5" and 130 lbs. I am a long distance runner, so I don't do much for my upper body, but my chest is only 34" and I can see my ribs. I've noticed that as men get older, even if they don't gain weight, body fat migrates to the upper body more. Will this happen in my case, i.e. will I get a slightly larger chest with time?