CA-125

My mother was recently dianosed with Stage 3C ovarian cancer.  Initial treatment is three chemotherapy treatments, three week apart, followed by evaluation for surgery.

Her initial CA 125 was 219.   Following her first chemo, the CA 125 level was 389.   Is this indicative at this point that the cancer is spreading or is it an initial rise due to chemo?   When would CA 125 be expected to drop as related to chemo treatments?

Thank you