Drink a glass of water slowly without taking your lips off the glass. This should steady the breathing and therefore calm the twitch of the diaphragm which causes the hiccups.
It is usually the Dexamethosone (anti nausea med) administered with the Chemo that does it, should settle 24/48 hours after treatment, mention it to the team on your next cycle.
Met her a few times as she was going out with a restaurateur who was a friend of ours. This was long ago, and I have tried out the suggestion for myself. Sorry to hear about your chemo sessions. Must be horrible for you.