Estimating number of events from the Kaplan-Meier curve for incorporation in a literature-based meta-analysis: what you don't see you can't get!

In literature-based meta-analyses of time-to-event data, the number of events in the treated and control groups together with the total number of patients randomized to the two treatment arms are often used as summary statistics. If interest is in mortality at a specified moment in time, the number of events can, in most cases, only be obtained from the Kaplan-Meier curve. The estimated number of events, however, is typically larger than the true number of events.

Long-term results of a randomized trial comparing breast-conserving therapy with mastectomy: European Organization for Research and Treatment of Cancer 10801 trial.

Background: Breast-conserving therapy (BCT) has been shown to be as effective as mastectomy in the treatment of tumors 2 cm or smaller. However, evidence of its efficacy, over the long term, in patients with tumors larger than 2 cm is limited. From May 1980 to May 1986, the European Organization for Research and Treatment of Cancer carried out a randomized, multicenter trial comparing BCT with modified radical mastectomy for patients with tumors up to 5 cm.

The role of meta-analyses in assessing cancer treatments.

The results of individual phase III cancer clinical trials are often inconclusive due to the overly optimistic size of treatment differences that are sought. Increased power and precision can generally be obtained if the data from several different trials studying the same or similar questions are analysed together. Individual patient data meta-analyses, which combine together the quantitative results from all properly randomised studies, provide an overall estimate of the size of treatment differences.

Treatment of superficial bladder tumors: achievements and needs. The EORTC Genitourinary Group.

Objective: The therapeutic objectives in the initial treatment of superficial tumors are to remove completely the tumor, to assess the need for further therapy and to plan the follow-up.

Methods/results: The EORTC Genitourinary Group assessed the percentage of patients with recurrence at 3 months (3RR) after complete resection of all visible lesions taking into account the institution, the number of tumors at presentation and the year of treatment. The 3RR was considered for 18 institutions.

Radiotherapy in breast-conserving treatment for ductal carcinoma in situ: first results of the EORTC randomised phase III trial 10853. EORTC Breast Cancer Cooperative Group and EORTC Radiotherapy Group.

Background: Ductal carcinoma in situ (DCIS) of the breast is a disorder that has become more common since it may manifest as microcalcifications that can be detected by screening mammography. Since selected women with invasive cancer can be treated safely with breast conservation therapy it is paradoxical that total mastectomy has remained the standard treatment for DCIS. We did a randomised phase III clinical trial to investigate the role of radiotherapy after complete local excision of DCIS.

Paclitaxel versus doxorubicin as first-line single-agent chemotherapy for metastatic breast cancer: a European Organization for Research and Treatment of Cancer Randomized Study with cross-over.

Purpose: To compare the efficacy of paclitaxel versus doxorubicin given as single agents in first-line therapy of advanced breast cancer (primary end point, progression-free survival ¿PFS) and to explore the degree of cross-resistance between the two agents.

Patients And Methods: Three hundred thirty-one patients were randomized to receive either paclitaxel 200 mg/m(2), 3-hour infusion every 3 weeks, or doxorubicin 75 mg/m(2), intravenous bolus every 3 weeks. Seven courses were planned unless progression or unacceptable toxicity occurred before the seven courses were finished.

Radical nephrectomy with and without lymph node dissection: preliminary results of the EORTC randomized phase III protocol 30881. EORTC Genitourinary Group.

Objective: The authors present demographic and surgical data from a randomized phase III trial, instituted by the EORTC Genitourinary Group in 1988, the aim of which was to assess whether complete lymph node dissection in conjunction with radical nephrectomy for renal cell cancer is more effective than radical nephrectomy alone.

Methods: Before surgery, the renal cell carcinoma was staged and judged to be nonmetastatic and resectable. The patients were randomized prior to surgery into those having radical nephrectomy combined with complete lymph node dissection or into those having radical nephrectomy alone.

Orchiectomy and orchiectomy plus mitomycin C for metastatic prostate cancer in patients with poor prognosis: the final results of a European Organization for Research in Cancer Therapy Genitourinary Group Trial.

Purpose: The outcome of patients with symptomatic metastatic prostate cancer is poor and improved treatment regimens are urgently needed. Theoretically, the combination of orchiectomy and chemotherapy could reduce androgen sensitive and insensitive cells in the prostate. This European Organization for Research in Cancer Therapy Genitourinary Group randomized, multicenter phase III trial demonstrates the outcome of orchiectomy alone versus orchiectomy followed by intravenous mitomycin C.

Significance of bladder biopsies in Ta,T1 bladder tumors: a report from the EORTC Genito-Urinary Tract Cancer Cooperative Group. EORTC-GU Group Superficial Bladder Committee.

Objectives: We investigated to what extent biopsies of normal-appearing urothelium taken from patients with Ta,T1 bladder cancer showed malignant disease: carcinoma in situ, or papillary tumor. We also investigated biopsies underlying the papillary tumor, adjacent to the tumor, and from suspicious-appearing mucosa.

Methods: In EORTC protocol 30863 (low-risk tumors), 393 patients underwent a biopsy of normal-appearing urothelium.

Impact of the treating institution on survival of patients with "poor-prognosis" metastatic nonseminoma. European Organization for Research and Treatment of Cancer Genito-Urinary Tract Cancer Collaborative Group and the Medical Research Council Testicular Cancer Working Party.

Background: Because metastatic nonseminomatous germ cell cancer is a rare but treatable cancer, we have explored whether there is an association between the experience of the treating institution with this disease and the long-term clinical outcome of the patients, particularly patients with a poor prognosis.

Methods: We analyzed data on 380 patients treated in one of 49 institutions participating in the European Organization for Research and Treatment of Cancer/ Medical Research Council randomized trial of four cycles of bleomycin-etoposide-cisplatin followed by two cycles of etoposide-cisplatin versus three cycles of bleomycin-vincristine-cisplatin followed by three cycles of etoposide-ifosfamide-cisplatin-bleomycin, both treatment regimens given with or without filgrastim (granulocyte colony-stimulating factor). Institutions were divided into four groups based on the total number of patients entered in the trial.

Sample size estimation in phase III cancer clinical trials.

This paper deals with the basic principles involved in sample size calculation of phase III cancer clinical trials. It illustrates the concepts and factors determining the sample size. Various examples of phase III cancer clinical trials are provided and the sample size is calculated taking into account the assumptions made.

Statistical considerations of chemoprevention clinical trials in prostate cancer.

The design and analysis of chemoprevention trials in prostate cancer is more complicated than that of an ordinary treatment efficacy trial. The following issues must be taken into account when designing prospective randomized chemoprevention trials: (1) The choice of the primary endpoint: biopsy-proven prostate cancer or mortality from prostate cancer? The choice of the endpoint has a major impact on the design of the trial, its overall duration, and the number of patients required. (2) The sample size calculation which depends on the event rate in the control group, the size of the difference to be detected, the size of the type I and type II errors, the non-adherence and crossover rates, and the duration of patient entry and follow-up.

Prognosis after treatment for loco-regional recurrence after mastectomy or breast conserving therapy in two randomised trials (EORTC 10801 and DBCG-82TM). EORTC Breast Cancer Cooperative Group and the Danish Breast Cancer Cooperative Group.

The aim of this study was to investigate and compare the prognosis after treatment for loco-regional recurrences (LR) after (modified) radical mastectomy (MRM) or breast conserving therapy (BCT), in terms of overall survival and time to subsequent LR, in patients originally treated in two European randomised trials. In EORTC trial 10801 and DBCG trial 82-TM, 1,807 patients with stage I and II breast cancer were randomised to receive MRM or BCT from 1980 to 1989. All patients with a LR in these trials were analysed for survival and time to subsequent LR after salvage treatment.

An EORTC international multicenter randomized trial (EORTC number 19923) comparing two dosages of liposomal amphotericin B for treatment of invasive aspergillosis.

This is the first completed prospective randomized clinical efficacy trial of antifungals in the treatment of invasive aspergillosis (IA) and the first to compare the clinical efficacy of two dosages of liposomal amphotericin B (L-AmB) for IA in neutropenic patients with cancer or those undergoing bone marrow transplantation. Eighty-seven of 120 patients were eligible and evaluable. Clinical responses were documented for 26 (64%) of 41 patients receiving 1 mg/(kg.

An EORTC multicentre prospective survey of invasive aspergillosis in haematological patients: diagnosis and therapeutic outcome. EORTC Invasive Fungal Infections Cooperative Group.

Objectives: The EORTC Invasive Fungal Infections Cooperative Group (IFICG) conducted a prospective survey by questionnaire of all cases of invasive aspergillosis (IA) in cancer patients to ascertain current diagnostic and therapeutic approaches.

Methods: All members of the IFICG were asked prospectively to complete a detailed questionnaire for each IA case identified in their institution over a 12-month period.

Results: One hundred and thirty questionnaires were returned.

Serum alpha-fetoprotein surge after the initiation of chemotherapy for non-seminomatous testicular cancer has an adverse prognostic significance.

It has been recognized that the tumour markers alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG) may show a transient elevation after the initiation of chemotherapy in non-seminomatous testicular cancer. We investigated the prognostic importance of these so-called marker surges in a cohort of patients treated with cisplatin combination chemotherapy between 1983 and 1991. A total of 669 patients were studied.

Four cycles of BEP vs four cycles of VIP in patients with intermediate-prognosis metastatic testicular non-seminoma: a randomized study of the EORTC Genitourinary Tract Cancer Cooperative Group. European Organization for Research and Treatment of Cancer.

We investigated the efficacy and toxicity of induction chemotherapy with cisplatin and etoposide with either bleomycin or ifosfamide in patients with intermediate-prognosis testicular non-seminoma. A total of 84 eligible patients were randomized to receive four cycles of etoposide, ifosfamide, cisplatin (VIP), or four cycles of bleomycin, etoposide, cisplatin (BEP). Intermediate prognosis was defined as any of the following: lymph node metastases 5-10 cm in diameter, lung metastases more than four in number or > 3 cm, HCG 5000-50,000 IU l(-1), AFP > 1000 IU l(-1).

Long-term follow-up of an EORTC randomized prospective trial comparing intravesical bacille Calmette-Guérin-RIVM and mitomycin C in superficial bladder cancer. EORTC GU Group and the Dutch South East Cooperative Urological Group. European Organisation for Research and Treatment of Cancer Genito-Urinary Tract Cancer Collaborative Group.

Objectives: To determine long-term efficacy of intravesical mitomycin C (MMC) versus bacille Calmette-Guérin (BCG) in patients with superficial bladder cancer with regard to recurrences and progression.

Methods: Patients with superficial bladder cancer (pTa, pT1, pTis) were treated with intravesical MMC (30 mg, weekly for 4 weeks, and thereafter monthly for 5 months) or BCG (weekly for 6 weeks).

Results: Three hundred forty-four patients were eligible (171 in the BCG group, 173 in the MMC group).

Doxorubicin vs epirubicin, report of a second-line randomized phase II/III study in advanced breast cancer. EORTC Breast Cancer Cooperative Group.

The EORTC Breast Cancer Cooperative Group carried out a randomized trial to compare doxorubicin with epirubicin as second-line chemotherapy in patients with metastatic breast cancer. Two hundred and fifty-nine patients with at least one site of metastatic disease entered this trial, of whom 232 patients were eligible. Treatment consisted of doxorubicin 75 mg m(-2) or epirubicin 90 mg m(-2) i.