Evolution of the randomized controlled trial in oncology over three decades. High-dose therapy improves progression-free survival and survival in relapsed follicular non-Hodgkin's lymphoma: results from the randomized European CUP trial. Adjuvant therapy in large bowel adenocarcinoma: long-term results of a Southwest Oncology Group Study. First isolated locoregional recurrence following mastectomy for breast cancer: results of a phase III multicenter study comparing systemic treatment with observation after excision and radiation. Swiss Group for Clinical Cancer Research.
The randomized controlled trial (RCT) is the gold standard for establishing new therapies in clinical oncology. Here we document changes with time in design, sponsorship, and outcomes of oncology RCTs.
                Reports of RCTs evaluating systemic therapy for breast, colorectal (CRC), and non-small-cell lung cancer (NSCLC) published 1975 to 2004 in six major journals were reviewed. Two authors abstracted data regarding trial design, results, and conclusions. Conclusions of authors were graded using a 7-point Likert scale. For each study the effect size for the primary end point was converted to a summary measure.
                A total of 321 eligible RCTs were included (48% breast, 24% CRC, 28% NSCLC). Over time, the number and size of RCTs increased considerably. For-profit/mixed sponsorship increased substantially during the study period (4% to 57%; P < .001). There was increasing use of time-to-event measures (39% to 78%) and decreasing use of response rate (54% to 14%) as primary end point (P < .001). Effect size remained stable over the study period. Authors have become more likely to strongly endorse the experimental arm (P = .017). A significant P value for the primary end point and industry sponsorship were each independently associated with endorsement of the experimental agent (odds ratio [OR] = 19.6, 95% CI, 8.9 to 43.1, and OR = 3.5, 95% CI, 1.6 to 7.5, respectively).
                RCTs in oncology have become larger and are more likely to be sponsored by industry. Authors of modern RCTs are more likely to strongly endorse novel therapies. For-profit sponsorship and statistically significant results are independently associated with endorsement of the experimental arm. To determine, in a randomized clinical trial, whether high-dose therapy (HDT) followed by autologous stem-cell transplantation is more effective than standard treatment with regard to progression-free survival (PFS) and overall survival (OS) in patients with relapsed follicular non-Hodgkin's lymphoma; and to assess the additional value of B-cell purging of the stem-cell graft with regards to PFS and OS.
                Patients received three cycles of chemotherapy. Responding patients with limited bone marrow infiltration were eligible for random assignment to three further cycles of chemotherapy (C), unpurged HDT (U), or purged HDT (P).
                Between August 1993 and April 1997, 140 patients were registered from 36 centers internationally, and 89 were randomly assigned. Reasons for not randomizing included patient refusal, early progression, or death on induction therapy. With a 69-month median follow-up, the log-rank P value for PFS and OS were.0037 and.079, respectively. For PFS, the hazard ratios (95% CIs) for U versus C, P versus C, and P versus U were 0.33 (0.16 to 0.70), 0.38 (0.19 to 0.79), and 1.02 (0.51 to 2.05), respectively. The hazard ratio (95% CI) for C versus U + P was 0.30 (0.15 to 0.61). Hazard ratios (95% CIs) for OS were 0.43 (0.18 to 1.06), 0.43 (0.18 to 1.02), and 0.72 (0.32 to 1.63). For C versus U + P, the hazard ratio (95% CI) was 0.40 (0.18 to 0.89). Kaplan-Meier estimates (95% CIs) of 2-year PFS for C, U, and P were 26% (8% to 44%), 58% (37% to 79%), and 55% (34% to 75%), respectively. OS at 4 years for C, U, and P are 46% (25% to 67%), 71% (52% to 91%), and 77% (60% to 95%) respectively.
                HDT significantly improves PFS and OS. There is no clear evidence of benefit through purging. The Southwest Oncology Group (SWOG) colorectal adjuvant study 7510 went through two phases. From 1975 to 1977, 309 patients were randomized to chemotherapy alone or the same chemotherapy plus immunotherapy. From 1977 until 1980, 317 patients were randomized among the same two therapy programs and a control group. With a minimum follow-up in either phase of greater than 7 years, data are now mature. They show no difference in relapse-free survival (RFS) nor overall survival (OS) in either the two-way phase or in the three-way phase. There is no indication, except possibly in one very small subset, that the addition of immunotherapy to chemotherapy provides an improvement in OS or in RFS. Using data from patients accrued after randomization to the control group, we fail to find evidence that either chemotherapy alone or chemoimmunotherapy improves OS or RFS when contrasted to outcomes obtained by patients on the control arm. In fact, we have significant evidence, at the P = .016 level, that chemotherapy does not improve OS by at least 50%; we also have significant evidence, at the P = .011 level, that chemoimmunotherapy will not improve OS by at least 25%. No evidence of efficacy was demonstrated for either treatment regimen, even though enough therapy was given to result in significant toxicities. Acute toxicity was at least moderate, but not fatal, in 75% of patients. Recognizable delayed toxicity included rare cases of fatal renal failure and acute leukemia. We performed a randomized phase III multicenter study to compare systemic treatment versus no treatment after complete excision and radiotherapy for isolated first locoregional recurrence in patients with breast cancer.
                One hundred sixty-seven good-risk patients with an estrogen receptor (ER+) positive recurrence or, in case of unknown receptor status, a disease-free interval (DFI) of greater than 12 months and < or = three recurrent tumor nodules each < or = 3 cm in diameter were entered onto the study. They were randomized to observation subsequent to local treatment or to receive tamoxifen (TAM) until disease progression. Seventy-nine percent of the patients were postmenopausal.
                The median observation period for the entire study population was 6.3 years. The median disease-free survival (DFS) duration was 26 months for observation and 82 months for TAM patients (P = .007). This was mainly due to the reduction of further local recurrences, whereas the occurrence of early distant metastases was delayed. A multivariate analysis identified DFI and treatment with TAM as significant prognostic factors for DFS. The 5-year overall survival (OS) rates were 76% and 74%, respectively (P = .77). DFI was also a prognostic factor for OS.
                Systemic therapy with TAM after isolated locoregional recurrence of breast cancer significantly increased 5-year DFS rates from 36% to 59% compared with observation alone and prolonged median DFS by more than 4.5 years in patients with ER+ tumors or in the case of unknown ER status with a DFI of greater than 12 months and minimal tumor burden. Treatment with TAM currently has no significant impact on OS, but the median survival duration of the study population has not yet been reached.
We found no evidence that the systemic interventions for untreated patients with AIDS-related NHL provide superior clinical effectiveness for improving OS, DSF, and tumour response rate; however, this conclusion is based on four RCTs with limited sample size and variable quality. More adequately powered RCTs that have low risk of bias are necessary to determine the real benefit or harm of interventions to treat this population. Overall survival (OS), DFS, and quality of life should be included as endpoints.