Turn everything to lowest except texture quality because 1/8 makes it impossible to read things. (EDIT: you can't really see barbed wire at 1/8 which is no bueno) Play in 720. In console (F1) when the game loads in type:
"gfx af 0" (disable texture filtering)
"gfx pp enable 0" (disable post processing)
If you still can't get it to an acceptable framerate:
"dt 0" (disables distant terrain -- last resort)
You can also enter a launch option in your steam shortcut's path field to start without the friends list and store which brings the memory usage down. Disabling the steam overlay is helpful. Maybe disable the info gathering in the 7 days launcher.
I had an integrated graphics card for like 5 years and this made it playable for me. The latest optimizations made a huge (relatively, 10 fps) difference as well.