CA-125 response in patients with recurrent ovarian or primary peritoneal cancer treated with pegylated liposomal doxorubicin or topotecan

CA125-related tumor cell kinetics variables after chemotherapy in advanced ovarian cancer: a systematic review

Various kinetic parameters, based on a minimum of two time points, have been built with CA125 determinations. The aim of this study is to review studies about the clinical application of CA125-related tumor cell kinetics variables in patients with advanced ovarian cancer (AOC) receiving chemotherapy. A literature search for studies about CA125-related variables in patients with AOC was undertaken on three databases, by predefined search criteria, and a selection of studies was performed. Sixty-two studies were selected. CA125-related variables were summarized in three groups: response-related, time-to-event, and other CA125-related tumor cell kinetics variables. Even though CA125 changes and half-life after chemotherapy were the most studied, other variables and two models have been well defined, and often showed an interesting power to predict survival. These kinetics variables are related to the CA125 regression curve, pre- and post-chemotherapy kinetics, or are variables inferred from a population model of CA125 kinetics.

MUC16 (CA125): tumor biomarker to cancer therapy, a work in progress

Over three decades have passed since the first report on the expression of CA125 by ovarian tumors. Since that time our understanding of ovarian cancer biology has changed significantly to the point that these tumors are now classified based on molecular phenotype and not purely on histological attributes. However, CA125 continues to be, with the recent exception of HE4, the only clinically reliable diagnostic marker for ovarian cancer. Many large-scale clinical trials have been conducted or are underway to determine potential use of serum CA125 levels as a screening modality or to distinguish between benign and malignant pelvic masses. CA125 is a peptide epitope of a 3-5 million Da mucin, MUC16. Here we provide an in-depth review of the literature to highlight the importance of CA125 as a prognostic and diagnostic marker for ovarian cancer. We focus on the increasing body of literature describing the biological role of MUC16 in the progression and metastasis of ovarian tumors. Finally, we consider previous and on-going efforts to develop therapeutic approaches to eradicate ovarian tumors by targeting MUC16. Even though CA125 is a crucial marker for ovarian cancer, the exact structural definition of this antigen continues to be elusive. The importance of MUC16/CA125 in the diagnosis, progression and therapy of ovarian cancer warrants the need for in-depth research on the biochemistry and biology of this mucin. A renewed focus on MUC16 is likely to culminate in novel and more efficient strategies for the detection and treatment of ovarian cancer.

A high response rate to liposomal doxorubicin is seen among women with BRCA mutations treated for recurrent epithelial ovarian cancer

OBJECTIVE

Ten percent of ovarian cancer is attributed to hereditary syndromes, most commonly to mutations in the BRCA1 or BRCA2 genes. These cancers are characterized by a prolonged sensitivity to platinum agents in spite of presentation at advanced stages. We hypothesized that women with BRCA-associated ovarian cancer would also show a high response rate to pegylated liposomal doxorubicin (Doxil).

METHODS

A retrospective cohort study was conducted to compare the response rate, progression-free, and overall survival among women with BRCA-associated or sporadic ovarian cancer who were treated with Doxil.

RESULTS

A response to Doxil was seen in 13 of 23 patients with BRCA mutations (56.5%; 3 by RECIST criteria and 10 by CA125 levels) compared with only 8 of 41 women with non-hereditary cancers (19.5%; 2 by RECIST criteria and 6 by CA125 levels; p=0.004). This was associated with an improved progression-free and overall survival as measured from the time of Doxil administration. Notably, platinum sensitivity did not directly correlate with a response to Doxil.

CONCLUSIONS

Women with BRCA-associated ovarian tumors demonstrate a greater sensitivity to cytotoxic therapy with Doxil than has previously been reported in unselected cases.

Correlation between CA-125 serum level and response by RECIST in a phase III recurrent ovarian cancer study

OBJECTIVES

To evaluate in a large phase III recurrent ovarian cancer trial (OVA-301): 1) the concordance between CA-125 level vs. best overall response (OR) and progression-free survival (PFS) determined by radiological assessment 2) the impact of early CA-125 changes over the subsequent radiological response, and 3) the prognostic value of CA-125 response and CA-125 PFS to predict radiological response and PFS.

METHODS

Assessment of response in the entire randomized population was performed by the Response Evaluation Criteria in Solid Tumors 1.0 (RECIST) and modified Rustin criteria for CA-125 determination.

RESULTS

Most CA-125 decreases were observed in RECIST responders (82% of patients treated with the combination and 74% in the PLD alone). CA-125 progression preceded RECIST progression in 35% of patients with a median lead time of 8.4 weeks. A high concordance rate between CA-125 PFS status at 4 months (PFS4) and CA-125 response as a predictor of PFS4 (87%) and radiological response (79%) was found in the combination, with high positive predictive value for radiological PFS4 (92%) and high negative predictive value for OR (90%). An early CA-125 decrease was predictive for the ultimate response since it was found in a high rate of RECIST responders.

CONCLUSION

Radiological response was preceded by a favorable predictive CA-125 decrease in a high proportion of patients, suggesting that CA-125 evaluation may be an appropriate tool for tumor assessment in patients with ovarian cancer.

CA-125 response patterns in patients with recurrent ovarian cancer treated with pegylated liposomal doxorubicin (PLD)

INTRODUCTION

: In recurrent ovarian cancer, CA-125 could be the only objective response criteria. This study analyzes response patterns regarding CA-125 in responders versus nonresponders and determines whether a specific cutoff value for CA-125 could predict clinical response, compared with response evaluation criteria in solid tumors, in patients receiving pegylated liposomal doxorubicin (PLD).

METHODS

: Sixty-eight patients were identified, 78% were platinum resistant. Relative changes in CA-125 values were calculated, and response was defined as higher than 50% reduction in CA-125 from baseline. Receiver operating characteristic (ROC) curves were constructed based on CA-125 value after the first cycle of PLD to evaluate the most precise cutoff point for the decision model predicting response.

RESULTS

: Fifty-three patients were assessable for response: 16 patients responded and 37 did not; the median increase of CA-125 was 0.20 (-63; 312) and 52 (-29; 620), respectively. Our ROC curve generated a cutoff value with a sensitivity of 35% (positive test, the proportion of patients who will not respond) and a predictive positive value of 80%. According to the predictive positive value, 20% of the responder patients will be identified as nonresponders; P = 0.025.

CONCLUSIONS

: Our ROC analysis did not demonstrate any reliable CA-125 cutoff on response. Discontinuation of the therapy before cycle 3 may exclude some patients who will benefit from PLD.

Pegylated liposomal doxorubicin in ovarian cancer

The encapsulation of doxorubicin in a pegylated liposomal matrix led to a reformulated agent with a different toxicity profile and improved clinical utility. Liposomal doxorubicin is devoid of the cardiac toxicity associated with doxorubicin, but is associated with predictable muco-cutaneous toxicity. The liposomal formulation leads to improved delivery to the target tumor tissue, allowing enhanced uptake by cancer cells. These properties translate into clinical utility in recurrent ovarian cancer as demonstrated by phase II and III trials, this proven clinical efficacy leading to FDA approval in second-line therapy for ovarian cancer. New combinations with cytotoxics, in particular with carboplatin, have demonstrated an acceptable toxicity profile and clinical utility in platinum-sensitive ovarian cancer. A favorable toxicity profile renders liposomal doxorubicin an ideal partner for combination regimens with other cytotoxics, and more recently with biological agents. Such combinations are the subject of ongoing clinical trials.

Epithelial ovarian cancer: role of pegylated liposomal Doxorubicin in prolonging the platinum-free interval and cancer antigen 125 trends during treatment

BACKGROUND

Epithelial ovarian cancer's response to platinum retreatment depends on the duration of response to first-line platinum therapy. Platinum-free interval predicts subsequent platinum sensitivity and is a prognostic factor. Little has been published on the effect of pegylated liposomal doxorubicin (PLD) in the prolongation of treatment-free interval.

METHODS

Patients treated with PLD were reviewed to assess response to platinum retreatment after PLD and to establish the use of cancer antigen 125 (Ca125) trends. All patients treated with PLD had progressed within 12 months of prior platinum therapy. Cancer antigen 125 fluctuations were categorized as the variances from the baseline (+/-10%, +/-10%-25%, and >25%). The response to chemotherapy was defined as Ca125 reduction from the baseline of more than 50%, clinical, or radiological response.

RESULTS

Fifty-nine women were identified. The response rate (RR) to PLD was 28.9%, and the median overall survival from PLD initiation was 62 weeks. The number of women demonstrating more than 25% reduction in Ca125 from the baseline increased progressively with each cycle; at cycle 2, 11%; cycle 3, 18%; cycle 4, 22%; and cycle 5, 27% (trend significant between cycles 2 and 4, P = 0.004). Fifteen patients were re-treated with platinum after progression after PLD with 80% (12/15) of the patients responding. The RR to platinum retreatment after PLD compares favorably with the historical data on the response to second-line platinum retreatment.

CONCLUSIONS

The sole use of early Ca125 trends in PLD treatment before cycle 4 may result in an erroneous discontinuation of PLD in potential responders. Retreatment with platinum after PLD may yield a good RR in selected patients even those with disease progression within 12 months after prior platinum treatment.

Efficacy of pegylated liposomal doxorubicin (PLD) plus carboplatin in ovarian cancer patients who recur within six to twelve months: a phase II study

OBJECTIVES

Pegylated liposomal doxorubicin is one of the preferred alternatives for ovarian cancer patients with early relapse (<6 months) and taxane/carboplatin for late relapse (>12 months), but the optimal therapy for the partially platinum-sensitive (6-12 months) population has not been defined. This single-arm phase II trial was designed to assess the efficacy of pegylated liposomal doxorubicin (PLD)/carboplatin in ovarian cancer patients who relapse between 6 and 12 months after initial treatment with platinum-based chemotherapy.

METHODS

Ovarian cancer patients who previously completed a course of therapy with paclitaxel/carboplatin were administered PLD 30 mg/m(2) followed by carboplatin AUC 5 mg/mL/minute every 4 weeks.

RESULTS

Fifty-eight patients were enrolled in the study and 54 were eligible for the efficacy analysis, of whom most (75%) received at least 6 cycles of PLD/carboplatin. The objective response rate was 46% (4% CR and 42% PR), with an additional 33% experiencing disease stabilization >6 months. For those patients with measurable CA-125, the response rate was 66% (28% CR and 38% PR), with an additional 18% experiencing disease stabilization >6 months. Median time-to-progression was 10 months (1.5-25). Median overall survival was 19.1 months (2.2-38.9). The most frequent adverse effects were neutropenia, thrombocytopenia, and constipation.

CONCLUSIONS

The combination of PLD/carboplatin is efficacious and well tolerated in women with partially platinum-sensitive ovarian cancer and represents a valuable alternative for patients who relapse within 6-12 months of completing paclitaxel/carboplatin chemotherapy.

Three-Day Topotecan Schedule in Heavily Pretreated Recurrent Ovarian Cancer Patients

Objective:

To evaluate the clinical benefit of a 3-day topotecan schedule in heavily pretreated recurrent ovarian cancer patients scheduled for palliative treatment.

Methods:

Eligibility criteria were 2 or more prior chemotherapy regimens, Eastern Cooperative Oncology Group performance status of 2 or less; adequate organ function, assessable disease by serum CA-125 measurement before each cycle; and 1 or more cycle of topotecan (1.5 mg/m2per day) on 3 consecutive days of a 28-day treatment cycle. Toxicity was graded according to the National Cancer Institute Common Toxicity Criteria version 3. Tumor response, stable disease, and progression were evaluated on the basis of CA-125 levels.

Results:

A total of 68 patients were considered eligible for the study. Median age was 58 years (range, 40-77 years), and the median number of prior chemotherapy regimens was 2 (range, 2-6). A total of 272 cycles of topotecan were administered, with a median of 4 cycles per patient (range, 1-8). No treatment delays or dose reduction was recorded. Major toxicities were grade 3/4 (18%) neutropenia, neutropenic fever (6%), grade 4 thrombocytopenia (3%), requirements for blood (5%), and platelet transfusions (3%). Thirty-five (54%) of the 64 evaluable patients showed a clinical benefit. Of these, 11 patients (17%) had a partial response, and 24 (37%) had stable disease with a median time to progression of 7.5 months (range, 6-10 months) and 4 months (range, 2-6 months), respectively.

Conclusion:

More than half of heavily pretreated ovarian cancer patients may benefit from 3-day topotecan.

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.

Phase III Trial of Gemcitabine Compared With Pegylated Liposomal Doxorubicin in Progressive or Recurrent Ovarian Cancer

Purpose

We aimed at investigating the efficacy, tolerability, and quality of life (QOL) of gemcitabine (GEM) compared with pegylated liposomal doxorubicin (PLD) in the salvage treatment of recurrent ovarian cancer.

Patients and Methods

A phase III randomized multicenter trial was planned to compare GEM (1,000 mg/m2 on days 1, 8, and 15 every 28 days) with PLD (40 mg/m2 every 28 days) in ovarian cancer patients who experienced treatment failure with only one platinum/paclitaxel regimen and who experienced recurrence or progression within 12 months after completion of primary treatment.

Results

One hundred fifty-three patients were randomly assigned to PLD (n = 76) or GEM (n = 77). Treatment arms were well balanced for clinicopathologic characteristics. Grade 3 or 4 neutropenia was more frequent in GEM-treated patients versus PLD-treated patients (P = .007). Grade 3 or 4 palmar-plantar erythrodysesthesia was documented in a higher proportion of PLD patients (6%) versus GEM patients (0%; P = .061). The overall response rate was 16% in the PLD arm compared with 29% in the GEM arm (P = .056). No statistically significant difference in time to progression (TTP) curves according to treatment allocation was documented (P = .411). However, a trend for more favorable overall survival was documented in the PLD arm compared with the GEM arm, although the P value was of borderline statistical significance (P = .048). Statistically significantly higher global QOL scores were found in PLD-treated patients at the first and second postbaseline QOL assessments.

Conclusion

GEM does not provide an advantage compared with PLD in terms of TTP in ovarian cancer patients who experience recurrence within 12 months after primary treatment but should be considered in the spectrum of drugs to be possibly used in the salvage setting.

Early Changes in CA125 After Treatment with Pegylated Liposomal Doxorubicin or Topotecan Do Not Always Reflect Best Response in Recurrent Ovarian Cancer Patients

PURPOSE

To examine early changes in CA125 relative to objective response in patients with recurrent ovarian cancer treated with pegylated liposomal doxorubicin (PLD) or topotecan and to compare the CA125 trends between the two chemotherapeutics.

PATIENTS AND METHODS

Patients with recurrent ovarian cancer, all of whom had measurable or evaluable disease, were randomized to receive 50 mg/m2 PLD every 28 days (n = 239) or 1.5 mg/m2 topotecan for 5 days every 21 days (n = 235) as part of a previously reported multicenter study. CA125 measurements were obtained prior to therapy and with each cycle of administration. Assessable patients underwent radiographic evaluation for response after two cycles of therapy. Objective responses were compared to trends in CA125 values at the end of cycles 1 and 2. CA125 changes were categorized as baseline (+/-10%), +/- 10%-25% variance, and > 25% variance.

RESULTS

Among patients treated with PLD, 50% of complete responders (CR) and 41% of partial responders (PR) had increases in CA125 from baseline to cycle 1. Increases in CA125 were also seen in topotecan-treated patients; however, fewer patients had increases (20% and 8%, respectively). Overall, 15% of responding patients (CR + PR) receiving PLD and 6% receiving topotecan had elevated CA125 after two cycles of therapy. For those patients achieving a partial response, 19% of PLD-treated patients and 8% of topotecan-treated patients had CA125 levels above baseline at cycle 2.

CONCLUSIONS

Considerable intrapatient variation in CA125 values is present among responding patients. Early increases in CA125 may not predict ultimate outcome, especially in PLD-treated patients.