Rise in ca125 on Topetecan

Dear Doctor:

I just finished what my Doctor calls one cyle of Topetecan.

I have had Topetecan for three weeks and now am in my off week.  Will start cycle two next Tuesday.

I just had my ca125 done and it went up from 1250 to 1350.  

I am wondering if this is good or bad news.  I have read that sometimes with Topetecan the drug splits the cells and causes a rise in the ca125.  Is this true?  I guess I am looking for something positive and trying to be positive that it didn't go up very much.

Do you think I should continue with another cycle of Topetecan or should I switch to another drug now.

Thank you for your response.


plady

[Annekathryn Goodman, M.D.]

Dear plady,

it sounds like you are receiving the once a week dosing of topotecan as opposed to the  5 day regimen every 21 days. There has been some debate about whether once a week topotecan is as effective as the 5 day dosing. I have pasted below an abstract from the recent ASCO (American Society of Clinical Oncologist) 2007 meeting.  It looks to me like the 5 day approach works better. It is harder because it requires coming in daily for one week. You should ask your doctor about that.

In general, I usually wait 2 to 3 cycles before making a decision about switching chemo treatments.
you take care

Journal of Clinical Oncology, 2007 ASCO Annual Meeting Proceedings Part I. Vol 25, No. 18S (June 20 Supplement), 2007: 5526
Author(s): J. Sehouli, G. Oskay-Oezcelik, D. Stengel, A. du Bois, S. Markmann, S. Loibl, J. Wilke, A. Nugent, A. Belau, W. Lichtenegger
Abstract: Background: Optimizing the therapeutic index (that is, maintaining drug effectiveness while reducing toxicity) is a major goal in chemotherapy for platinum-resistant ovarian cancer. Early phase-I/II studies suggest that weekly topotecan (T) might be effective and apparently better tolerated than the established 5-day regimen. As yet, no randomized comparison of both regimes was attempted. To prove the hypothesis of an improved therapeutic index with weekly T, we conducted a randomized, multicenter, two-stage phase-II trial, and herein present the data of the planned interim analysis. Methods: Pts with platinresistent ovarian and fallopian tube cancers or primary peritoneal carcinoma, measurable or assessable disease (GCIG-CA-125 response criteria), were eligible. Pts were randomized to receive either weekly T (d1,8,15/q28d, 4 mg/m2) or T from d1-5/q21d at a dose of 1.25 mg/m2. According to Gehan's two-stage-design, both arms were handled as independent studies. Overall response rate (CR + PR) was defined as primary study endpoint, secondary endpoints of the interim analysis were toxicity and safety. Results: 28 pts in the weekly and 21 pts in the conventional group, enrolled at 38 centers form the basis of this report. 230 cycles of chemotherapy were evaluated for toxicity analyses. Median age was 61 years (range, 36 - 82 years). Demographic baseline characteristics, including tumor stage and grade were well balanced between treatment arms. There were 2/28 and 5/21 responses in weekly and the conventional arm, respectively (Risk Ratio [RR] 0.30, 95% confidence interval [CI] 0.06 - 1.40, p=0.122). The risk of early treatment termination due to tumor progression (RR 1.39, 95%CI 0.75 - 2.56), haematological (RR 0.20, 95% CI 0.01 - 3.97) or non- hematological toxicities (RR 1.96, 95% CI 0.18 - 20.83) did not differ significantly between groups. The only three events of neutropenic fever occurred in the conventional arm (RR 1.70, 95% CI 0.99 - 1.16). Conclusions: Weekly T is well tolerated and potentially active. The second stage of this study will require additional 46 patients each arm. Complete enrolment is expected to be accomplished in May 2007.