Effect of topotecan on serum CA-125 in patients with advanced epithelial ovarian cancer

Lack of reliability of CA125 response criteria with anti-VEGF molecularly targeted therapy

BACKGROUND

CA125 is an accepted indicator of epithelial ovarian cancer (EOC) response and is used to monitor patients treated with cytotoxic chemotherapy. It is uncertain how CA125 is affected by molecularly targeted drugs. In this pilot study, the authors analyzed the utility of CA125 to predict disease behavior in patients who were receiving sorafenib, a Raf-kinase/VEGFR2 inhibitor, and bevacizumab, an anti-VEGF monoclonal antibody.

METHODS

Fifteen of 42 patients had recurrent EOC. Patients received sorafenib 200 mg orally twice daily or D1-5 of 7 and bevacizumab 5 mg/kg to 10 mg/kg intravenously every 2 weeks for 28-day cycles. Computed tomography (CT) scans were performed every 2 cycles for restaging, and CA125 was measured monthly. CA125 concentrations were retrospectively analyzed as a function of clinical behavior.

RESULTS

Fourteen of 15 patients had abnormal CA125 concentrations at study entry (median 1056 U/mL; range, 67 U/mL to 9813 U/mL). Seven (47%) patients had partial response by imaging criteria. Five of these 7 patients had partial response by CA125 criteria (71% sensitivity). Eight (53%) patients would have had partial responses if CA125 criteria were used; only 5 were confirmed by CT (63 % specificity). Imaging and CA125 criteria combined yielded a higher total response rate of 10 of 15 (67%). Three patients with objective partial response by imaging lasting >20, >22, and >24 cycles would have terminated treatment prematurely if CA125 had been used.

CONCLUSIONS

CA125 changes may not correspond to imaging response criteria for EOC patients who are receiving sorafenib and bevacizumab. Caution is recommended when using CA125 as a response criterion of molecularly targeted agents until prospective studies validate CA125 changes with objective imaging response results.

Topotecan for ovarian cancer

BACKGROUND

Chemotherapeutic agents such as topotecan can be used to treat ovarian cancer. The effects of using topotecan as a therapeutic agent have not been previously been systematically reviewed.

OBJECTIVES

To systematically evaluate the effectiveness and safety of topotecan for the treatment of ovarian cancer.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), (Issue 4, 2006); Cochrane Gynaecological Cancer Review Group (CGCRG) Specialised Register (Cochrane Library Issue 4, 2006); MEDLINE (January 1990 to 27 July 2006); EMBASE (January 1990 to 27 July 2006); The European Organization for the Research and Treatment of Cancer (EORTC) database (to 1 August 2006); CBM (Chinese Biomedical Database) (January 1990 to 27 July 2006).

SELECTION CRITERIA

Randomised controlled trials (RCTs) which randomized patients with ovarian cancer to single or combined use of topotecan versus interventions without topotecan, or different remedies of topotecan.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and analysed data.

MAIN RESULTS

Six studies including 1323 participants were eligible for this review (Gordon 2004a; Gore 2001a; Gore 2002; Hoskins 1998; Huinink 2004; Placido 2004) All studies, as reported, were identified as being of poor methodological quality. Topotecan had comparable effectiveness to prolong progression-free survival (PFS) compared with pegylated liposomal doxorubicin (PLD), (16.1 weeks versus 17.0 weeks; p = 0.095). Overall survival (OS) time was similar in participants using PLD compared with topotecan (56.7 weeks versus 60 weeks; p = 0.341). Topotecan was more hematologically toxic compared with paclitaxel or PLD, relative risks (RRs) of hematological events: ranged from 1.03 to 14.46 and 1.73 to 27.12 respectively. A 21-day cycle of topotecan was more toxic than a 42-day cycle (RRs of hematological and non-hematological events ranged from 1.03 to 8). Intravenous and oral topotecan had comparable toxicity. Topotecan delayed progression more effectively compared with paclitaxel (23.1 weeks versus 14 weeks, p = 0.0021). Participants were more likely to respond to topotecan on a 21-day cycle as opposed to a 42-day cycle (RR 7.23, 95% CI 0.94 to 55.36). Small tumor diameter, sensitivity to platinum-based chemotherapy was associated with better prognosis. Small sample size, methodological flaws and poor reporting of the included trials made measurement bias of the trials difficult to assess.

AUTHORS' CONCLUSIONS

Topotecan appears to have a similar level of effectiveness as paclitaxel and PLD, though with different patterns of side effects. Larger, well-designed RCTs are required in order to define an optimal regime.

Safety of topotecan in the treatment of recurrent small-cell lung cancer and ovarian cancer

The topoisomerase I inhibitor, topotecan, is approved for the treatment of recurrent small-cell lung cancer (SCLC) and ovarian cancer (OC). Patients with recurrent SCLC and OC typically experience multiple relapses and receive multiple rounds of chemotherapy. In these settings, disease stabilisation is considered a treatment benefit, and quality-of-life effects and cumulative toxicities of treatments should be considered. Many patients with recurrent cancer may be predisposed to treatment-related adverse events because of advanced age, renal impairment or extensive prior therapy. The standard regimen of topotecan, 1.5 mg/m(2) on days 1-5 of a 21-day cycle, has generally mild nonhaematological toxicity and a well-defined haematological toxicity profile characterised by reversible and noncumulative neutropenia. Alternative regimens may lower the incidence of haematological toxicities and maintain antitumour efficacy. Topotecan may provide physicians with a versatile therapeutic option for the treatment of patients with relapsed SCLC or OC.

Topotecan in heavily pretreated patients with recurrent ovarian, peritoneal, and fallopian tube carcinoma

Topotecan has demonstrated antitumor activity in heavily pretreated patients with ovarian carcinoma. This report examines the activity and toxicity of topotecan in 29 heavily pretreated patients with recurrent ovarian, peritoneal, and fallopian tube carcinoma. Topotecan 1.5 mg/m2 was administered intravenously on days 1-5, every 21 days. It was second-line chemotherapy in 6 (20.7%) patients, third-line in 15 (51.7%), fourth-line in 4 (13.8%), fifth-line in 3 (10.3%), and seventh-line in 1 (3.4%). Median dose intensity was 1.667 mg/m(2)/week, and median relative dose intensity was 0.67. Disease complete response was observed in 5 (17.2%) patients, partial response in 1 (3.4%), stable disease in 12 (41.4%), and progressive disease in 11 (37.9%). CA-125 complete response was observed in 3 (10.3%) patients, partial response in 11 (37.9%), stable level in 5 (17.2%), and progressive level in 9 (31%), and no data were available in 1 (3.4%) patient. Toxicity was mainly hematologic: grade 3-4 neutropenia was observed in 20 (69%) patients, grade 3-4 leukopenia in 12 (41.4%), grade 3-4 thrombocytopenia in 9 (31%), and grade 3-4 anemia in 2 (6.9%). It is concluded that topotecan has considerable activity and noncumulative hematologic toxicity in heavily pretreated patients with recurrent ovarian, peritoneal, and fallopian tube carcinoma.

Efficacy and tolerability of lower-dose topotecan in recurrent ovarian cancer: a retrospective case review

Topotecan (1.5 mg/m(2)/day for 5 consecutive days of a 21-day cycle) is an established recurrent ovarian cancer treatment, but myelosuppression can be dose limiting. This study evaluates the activity and tolerability of low-dose topotecan in our clinical experience. Case records were reviewed for patients with recurrent ovarian cancer in first through third relapse. Eligible patients had received > or =2 cycles of < or =1.25 mg/m(2) topotecan. Adverse events were evaluated using laboratory and clinical evaluation data. Twenty-seven eligible patients, most with advanced disease, received a total of 209 cycles (median, six cycles). Grade 3 or 4 hematologic toxicities during 184 cycles in 24 assessed patients were neutropenia, leukopenia, thrombocytopenia, and anemia in 35%, 28%, 36%, and 11% of cycles, and 21, 19, 16, and 10 patients, respectively. Only four grade 4 toxicities occurred: anemia (one) and thrombocytopenia (three). Myelosuppression was reversible, noncumulative, and manageable. Moreover, nonhematologic toxicity was generally mild to moderate, and the only two grade 3 events were constipation and deep vein thrombosis. Low-dose topotecan was active in this setting. Lower-dose topotecan is generally well tolerated and active in patients with pretreated ovarian cancer. Prospective clinical trials of low-dose topotecan in recurrent ovarian cancer are warranted.

Chemotherapy-induced changes of CA 125 in patients with epithelial ovarian cancer

OBJECTIVES

CA 125 is a tumor marker widely used to diagnose, monitor, and follow-up women with epithelial ovarian cancer, as the marker is well related to the amount of vital tumor cells. However, CA 125 before the operation or during the first 2 courses of chemotherapy does not provide enough information concerning survival to serve as a prognostic marker. The present investigation was inspired by studies describing a paradoxical increase of tumor markers (CEA, CA 125, and CA 15-3) in the days after chemotherapy of women with breast cancer. If CA 125 increases within days after chemotherapy, the increase may be caused by death of the cancer cells. It was therefore speculated if a CA 125 spike may serve as an early prognostic parameter. The aim of the present investigation was to evaluate if CA 125 increases within days after the first course of chemotherapy of women with ovarian cancer.

PATIENTS

Twenty women with epithelial ovarian cancer were included in the study. CA 125 was measured in each woman on day 0 (the day of, but before initiation of chemotherapy) and 1, 3, 5, 7, 9, and 14 days after chemotherapy.

RESULTS

One woman was excluded due to normal CA 125 values. The remaining 19 patients displayed a significant decrease in CA 125 during the 14-day period after chemotherapy.

CONCLUSION

In the present study, no chemotherapy-induced increase of CA 125 within the first 14 days after chemotherapy could be demonstrated.

Topotecan Dosing Guidelines in Ovarian Cancer: Reduction and Management of Hematologic Toxicity

Topotecan dosing considerations and alternative dosing schedules to reduce and manage myelosuppression during the treatment of relapsed ovarian cancer were reviewed. The myelosuppression patterns from phase I, II, and III clinical trials were analyzed to evaluate the degree of hematologic toxicity and to determine risk factors predictive of myelosuppression. Additionally, recent publications of alternative topotecan doses and schedules were examined. Extent of prior therapy, prior platinum therapy (particularly carboplatin), advanced age, impaired renal function, and prior radiation therapy were identified as potential risk factors for greater hematologic toxicity after topotecan therapy. Reducing the starting topotecan dose to 1.0 or 1.25 mg/m2/day is recommended to reduce the incidence of severe myelosuppression in high-risk individuals receiving topotecan for 5 consecutive days. Hematopoietic growth factors, transfusion therapy, and schedule adjustments may also help manage myelosuppression. Alternative schedules of 3-day or weekly dosing appear to have less myelotoxicity and are currently under evaluation. The clinical aspects of topotecan-related myelosuppression and results from clinical trials indicate that the dose, and possibly the dosing schedule, of topotecan can be modified to reduce hematologic toxicity and improve tolerance without compromising efficacy. Prospective individualization of topotecan dosing may prevent or minimize dose-limiting myelosuppression and allow patients to achieve the maximum topotecan benefit by improving their ability to complete therapy with fewer treatment delays. Ongoing clinical trials evaluating alternative dosing schedules with superior hematologic tolerability may facilitate the inclusion of topotecan in combination regimens for patients with ovarian cancer. Proposed topotecan dosing guidelines to reduce and manage myelosuppression are outlined.

Update on the role of topotecan in the treatment of recurrent ovarian cancer

Ovarian cancer is the fifth leading cause of cancer death in women. Most patients with ovarian cancer respond to first-line chemotherapy, but many relapse within 18 to 22 months. The development of efficacious salvage therapies that increase overall survival while maintaining quality of life is a great challenge in the treatment of this disease. Topotecan, a novel topoisomerase I inhibitor, is currently indicated for the treatment of recurrent metastatic carcinoma of the ovary. In patients with relapsed ovarian cancer, the overall response rates on treatment with topotecan range from 19%-33% in platinum-sensitive patients, 14%-18% in platinum-resistant patients, and 5%-11% in platinum-refractory patients. The proportion of patients achieving stable disease ranges between 17% in refractory and 48% in sensitive patients. In phase III studies, topotecan was shown to be equivalent in efficacy to both paclitaxel and liposomal doxorubicin as second-line therapy in patients with relapsed ovarian cancer. Further, non-cross-resistance between topotecan and paclitaxel was demonstrated in a third-line, phase III crossover study, suggesting that topotecan may be effective in the first-line setting with paclitaxel and/or platinum. Hematologic toxicities include neutropenia, thrombocytopenia, and anemia; however, these toxicities are usually short lived, noncumulative, and manageable with dose modifications, including low-dose topotecan regimens. Nonhematologic toxicities are usually mild to moderate in severity. These data support the use of topotecan for second-line therapy and suggest that topotecan may also be effective in first-line therapy. Further studies with topotecan alone and in combination with other agents are needed to fully characterize the role and sequencing of topotecan in the salvage and first-line settings.