Dawn,
Mu husband actually had hiccups as his very first chemo side effect - they began hours withing his first treatment, and persisted for maybe 24 hours after that treatment. Since then, hiccups have been only an occasional bother after chemo treatments.
If I recall correctly, the symptom is caused by the chemo drugs irritating the diaghram...and the treatment, if needed, was listed as Thorazine. Thorazine is a major drug with it's own side effects, so I hope that the hiccups subside quickly and don't need to be treated.
The following link has a few paragraphs addressing tis issue: www.cancer.org/docroot/MBC/content/MBC_ ... tearea=MBC
Good luck!