I think you have to knit cables flat.
ETA I think what you would do is start with a provisional cast on, work to the length you want, put the live stitches at the beginning on a needle and then Kitchener stitch them together for a seamless joining of the ends.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper