Early versus delayed treatment of relapsed ovarian cancer (MRC OV05/EORTC 55955): a randomised trial.

BACKGROUND: Serum CA125 concentration often rises several months before clinical or symptomatic relapse in women with ovarian cancer. In the MRC OV05/EORTC 55955 collaborative trial, we aimed to establish the benefits of early treatment on the basis of increased CA125 concentrations compared with delayed treatment on the basis of clinical recurrence. METHODS: Women with ovarian cancer in complete remission after first-line platinum-based chemotherapy and a normal CA125 concentration were registered for this randomised controlled trial. Clinical examination and CA125 measurement were done every 3 months. Patients and investigators were masked to CA125 results, which were monitored by coordinating centres. If CA125 concentration exceeded twice the upper limit of normal, patients were randomly assigned (1:1) by minimisation to early or delayed chemotherapy. Patients and clinical sites were informed of allocation to early treatment, and treatment was started as soon as possible within 28 days of the increased CA125 measurement. Patients assigned to delayed treatment continued masked CA125 measurements, with treatment commencing at clinical or symptomatic relapse. All patients were treated according to standard local practice. The primary outcome was overall survival. Analysis was by intention to treat. This study is registered, ISRCTN87786644. FINDINGS: 1442 patients were registered for the trial, of whom 529 were randomly assigned to treatment groups and were included in our analysis (265 early, 264 delayed). With a median follow-up of 56·9 months (IQR 37·4-81·8) from randomisation and 370 deaths (186 early, 184 delayed), there was no evidence of a difference in overall survival between early and delayed treatment (HR 0·98, 95% CI 0·80-1·20, p=0·85). Median survival from randomisation was 25·7 months (95% CI 23·0-27·9) for patients on early treatment and 27·1 months (22·8-30·9) for those on delayed treatment. INTERPRETATION: Our findings showed no evidence of a survival benefit with early treatment of relapse on the basis of a raised CA125 concentration alone, and therefore the value of routine measurement of CA125 in the follow-up of patients with ovarian cancer who attain a complete response after first-line treatment is not proven. FUNDING: UK Medical Research Council and the European Organisation for Research and Treatment of Cancer.

A prospective randomized controlled trial of tumour chemosensitivity assay directed chemotherapy versus physician's choice in patients with recurrent platinum-resistant ovarian cancer.

The primary aim of this randomized trial was to determine response rate and progression-free survival following chemotherapy in patients with platinum-resistant recurrent ovarian cancer, who had been treated according to an ATP-based tumour chemosensitivity assay in comparison with physician's choice. A total of 180 patients were randomized to assay-directed therapy (n=94) or physician's-choice chemotherapy (n=86). Median follow-up at analysis was 18 months. Response was assessable in 147 patients: 31.5% achieved a partial or complete response in the physician's-choice group compared with 40.5% in the assay-directed group (26 versus 31% by intention-to-treat analysis respectively). Intention-to-treat analysis showed a median progression-free survival of 93 days in the physician's-choice group and 104 days in the assay-directed group (hazard ratio 0.8, 95% confidence interval 0.59-1.10, not significant). No difference was seen in overall survival between the groups, although 12/39 (41%) of patients who crossed over from the physician's-choice arm obtained a response. Increased use of combination therapy was seen in the physician's-choice arm during the study as a result of the observed effects of assay-directed therapy in patients. Patients entering the physician's-choice arm of the study during the first year did significantly worse than those who entered in the subsequent years (hazard ratio 0.44, 95% confidence interval 0.2-0.9, P<0.03). This small randomized clinical trial has documented a trend towards improved response and progression-free survival for assay-directed treatment. Chemosensitivity testing might provide useful information in some patients with ovarian cancer, although a larger trial is required to confirm this. The ATP-based tumour chemosensitivity assay remains an investigational method in this condition.

The effect of imatinib mesylate (Glivec) on human tumor-derived cells.

Imatinib mesylate is a specific inhibitor of the Bcr-Abl protein tyrosine kinase that competes with ATP for its specific binding site in the kinase domain. It has activity against platelet-derived growth factor receptor alpha and beta (PDGFR-alpha and -beta), and c-kit, the receptor for stem cell factor. We have used a standardized ATP-tumor chemosensitivity assay and immunohistochemistry to determine the cytotoxicity of imatinib mesylate in tumor-derived cells from cutaneous and uveal melanoma, and ovarian carcinoma. Imatinib mesylate was tested at concentrations ranging from 2.0 to 0.0625 micromol/l alone and in combination with a cytotoxic drug (cisplatin, doxorubicin, paclitaxel or treosulfan). Imatinib mesylate showed low inhibition (IndexSUM>300) across the range of concentrations tested in this study, with few tumors exhibiting increasing inhibition with increased drug concentration. The median IC90 values for cutaneous and uveal melanoma and ovarian carcinoma were 13.2 micromol/l (4.0-294.3 micromol/l), 12.0 micromol/l (2.0-285.4 micromol/l) and 7.71 micromol/l (6.51-11.02 micromol/l), respectively. Imatinib mesylate potentiated the effect of different cytotoxics in 9% (5/54) of cases and had a negative effect in 13% (7/54) of cases, with no effect in the remainder. No correlation of effect was noted with c-kit, platelet-derived growth factor receptor-alpha or platelet-derived growth factor receptor-beta expression, assessed by immunohistochemistry. The signaling pathways mediated by activation of c-kit or platelet-derived growth factor receptor may act as antiapoptotic survival signals in some cancers and inhibition of these pathways may potentiate the activity of some cytotoxic drugs by inhibiting the survival signal. Growth inhibition, however, may reduce the efficacy of cytotoxic drugs, which tend to target proliferating cells preferentially, and clinical effects are therefore difficult to predict.

Cancer cell adaptation to chemotherapy.

BACKGROUND: Tumor resistance to chemotherapy may be present at the beginning of treatment, develop during treatment, or become apparent on re-treatment of the patient. The mechanisms involved are usually inferred from experiments with cell lines, as studies in tumor-derived cells are difficult. Studies of human tumors show that cells adapt to chemotherapy, but it has been largely assumed that clonal selection leads to the resistance of recurrent tumors. METHODS: Cells derived from 47 tumors of breast, ovarian, esophageal, and colorectal origin and 16 paired esophageal biopsies were exposed to anticancer agents (cisplatin; 5-fluorouracil; epirubicin; doxorubicin; paclitaxel; irinotecan and topotecan) in short-term cell culture (6 days). Real-time quantitative PCR was used to measure up- or down-regulation of 16 different resistance/target genes, and when tissue was available, immunohistochemistry was used to assess the protein levels. RESULTS: In 8/16 paired esophageal biopsies, there was an increase in the expression of multi-drug resistance gene 1 (MDR1) following epirubicin + cisplatin + 5-fluorouracil (ECF) chemotherapy and this was accompanied by increased expression of the MDR-1 encoded protein, P-gp. Following exposure to doxorubicin in vitro, 13/14 breast carcinomas and 9/12 ovarian carcinomas showed >2-fold down-regulation of topoisomerase IIalpha (TOPOIIalpha). Exposure to topotecan in vitro, resulted in >4-fold down-regulation of TOPOIIalpha in 6/7 colorectal tumors and 8/10 ovarian tumors. CONCLUSION: This study suggests that up-regulation of resistance genes or down-regulation in target genes may occur rapidly in human solid tumors, within days of the start of treatment, and that similar changes are present in pre- and post-chemotherapy biopsy material. The molecular processes used by each tumor appear to be linked to the drug used, but there is also heterogeneity between individual tumors, even those with the same histological type, in the pattern and magnitude of response to the same drugs. Adaptation to chemotherapy may explain why prediction of resistance mechanisms is difficult on the basis of tumor type alone or individual markers, and suggests that more complex predictive methods are required to improve the response rates to chemotherapy.

Outcome of ATP-based tumor chemosensitivity assay directed chemotherapy in heavily pre-treated recurrent ovarian carcinoma.

BACKGROUND: We wished to evaluate the clinical response following ATP-Tumor Chemosensitivity Assay (ATP-TCA) directed salvage chemotherapy in a series of UK patients with advanced ovarian cancer. The results are compared with that of a similar assay used in a different country in terms of evaluability and clinical endpoints. METHODS: From November 1998 to November 2001, 46 patients with pre-treated, advanced ovarian cancer were given a total of 56 courses of chemotherapy based on in-vitro ATP-TCA responses obtained from fresh tumor samples or ascites. Forty-four patients were evaluable for results. Of these, 18 patients had clinically platinum resistant disease (relapse < 6 months after first course of chemotherapy). There was evidence of cisplatin resistance in 31 patients from their first ATP-TCA. Response to treatment was assessed by radiology, clinical assessment and tumor marker level (CA 125). RESULTS: The overall response rate was 59% (33/56) per course of chemotherapy, including 12 complete responses, 21 partial responses, 6 with stable disease, and 15 with progressive disease. Two patients were not evaluable for response having received just one cycle of chemotherapy: if these were excluded the response rate is 61%. Fifteen patients are still alive. Median progression free survival (PFS) was 6.6 months per course of chemotherapy; median overall survival (OAS) for each patient following the start of TCA-directed therapy was 10.4 months (95% confidence interval 7.9-12.8 months). CONCLUSION: The results show similar response rates to previous studies using ATP-TCA directed therapy in recurrent ovarian cancer. The assay shows high evaluability and this study adds weight to the reproducibility of results from different centres.

Prospective, randomized, double-blind, placebo-controlled trial of marimastat after response to first-line chemotherapy in patients with small-cell lung cancer: a trial of the National Cancer Institute of Canada-Clinical Trials Group and the European Organization for Research and Treatment of Cancer.

PURPOSE: Increased expression of metalloproteinases is associated with poor prognosis in small-cell lung cancer (SCLC). This trial was undertaken to determine whether adjuvant treatment with the metalloproteinase inhibitor marimastat could prolong survival in responding patients with SCLC after chemotherapy. PATIENTS AND METHODS: SCLC patients in complete or partial remission were eligible. They were stratified by radiotherapy (early, late, or none), stage (extensive or limited), response (complete or partial), and cooperative group (National Cancer Institute of Canada-Clinical Trials Group or European Organization for Research and Treatment of Cancer). They were randomized to receive marimastat 10 mg or placebo orally bid for up to 2 years. RESULTS: There were 532 eligible patients (266 marimastat and 266 placebo). Stage was limited for 279 patients (52%) and extensive for 253 (48%). Best response to induction therapy was complete remission for 176 patients (33%), partial remission for 341 (64%), and 15 patients (3%) had undergone surgical resection. The median time to progression for marimastat patients was 4.3 months compared with 4.4 months for placebo patients (P =.81). Median survivals for marimastat and placebo patients were 9.3 months and 9.7 months, respectively (P =.90) Toxicity was generally limited to musculoskeletal symptoms (18% grade 3/4 for marimastat). Dose modifications for musculoskeletal toxicity were required in 90 patients (33%) on the marimastat arm, and 87 (32%) permanently stopped marimastat because of toxicity. Patients on marimastat had significantly poorer quality of life at 3 and 6 months. CONCLUSION: Treatment with marimastat after induction therapy for SCLC did not result in improved survival and had a negative impact on quality of life.

Use of an ATP-based chemosensitivity assay to design new combinations of high-concentration doxorubicin with other drugs for recurrent ovarian cancer.

Liposomal doxorubicin (Caelyx/Doxil) has been shown to be active in around 20% of recurrent ovarian cancers. As yet, there is little clinical data on combinations of existing agents with liposomal doxorubicin, despite considerable clinical experience with soluble doxorubicin in combination. In this study, we have used an ATP-based tumor chemosensitivity assay to determine the relative efficacy of high concentrations of doxorubicin tested in combination with cisplatin, treosulfan, 5-fluorouracil (5-FU) or vinorelbine against cells obtained from recurrent ovarian tumor tissue. The results show little enhancement of the efficacy of high concentrations of doxorubicin by 5-FU, cisplatin, or treosulfan. However, vinorelbine+liposomal doxorubicin showed additive inhibition, and this combination is worthy of further testing in clinical trials.