BOA9
Pegylated liposomal doxorubicin for epithelial ovarian cancer: the utility of Ca125 trends in guiding treatment decisions and subsequent response to platinum retreatment
J. S. Tanguay1, L. Buckley2, J. Ansari1, I. Fernando1
1University Hospital Birmingham, Birmingham, UK, 2Cancer Research UK Clinical Trials Unit,, Birmingham, UK
Background
In
epithelial ovarian cancer early Ca125 changes guide clinical management
decisions with rising trends prompting discontinuation of treatment. A
retrospective review of case records of women treated with pegylated liposomal
doxorubicin (PLD) at two cancer units between 2003 and 2007 was performed to
establish the utility of Ca125 trends in guiding treatment decisions and to
assess response to platinum retreatment after PLD.
Method
All
patients treated with PLD had disease progression within twelve months of prior
platinum therapy. Ca125 fluctuations were categorised as variance from baseline
(+/-10%, +/-10-25%, and >25%). Response to chemotherapy was defined as
either Ca125 reduction from baseline of >50% or clinical or radiological
response.
Results
59
women were identified. Mean age 60, FIGO stage >/=3c 78%, papillary serous
or clear cell histology 29%. Response rate (RR) to PLD 28.9%, median overall
survival from commencement of PLD 62 weeks.
45 patients (76%) had data evaluable for trends in Ca125. The number of women
demonstrating a >25% reduction in Ca125 from baseline increased
progressively with each cycle: before cycle 2 = 5(11%), cycle 3 = 8(18%), cycle
4 = 10(22%), cycle 5 = 12(27%). This trend was statistically significant
between cycles 2 and 4 (p=0.004).
18 patients were retreated with platinum following progression after PLD with
15/18(83%) responding. The response rate (RR) to platinum retreatment after PLD
compares favourably to historical data on response to second line platinum
retreatment (overall RR 83% versus 59% p=0.04, RR with platinum free interval
<12 months 83% vrs 33% p=<0.02, RR with platinum free interval >12
months from last course of platinum treatment 83% vrs 67.5% p=0.2).
Conclusion
The sole use of early Ca125 trends in PLD treatment prior to cycle 4 may result in erroneous discontinuation of PLD in potential responders. Retreatment with platinum after PLD may yield a good response rate in selected patients even those with disease progression within 12 months after prior platinum treatment.
