The log-rank test is perhaps the most commonly used nonparametric method for comparing two survival curves and yields maximum power under proportional hazards alternatives. While the assumption of ...proportional hazards is often reasonable, it need not hold. Several authors have therefore developed versatile tests using combinations of weighted log-rank statistics that are more sensitive to nonproportional hazards. Fleming and Harrington (1991, Counting Processes and Survival Analysis, Wiley) consider the family of Gρ statistics and their supremum versions, while Lee (1996, Biometrics 52: 721-725) and Lee (2007, Computational Statistics and Data Analysis 51: 6557-6564) propose tests based on the more extended Gρ,γ family. In this article, I consider Zm = max(|Z1|, |Z2|, |Z3|), where Z1, Z2, and Z3 are z statistics obtained from G0,0, G1,0, and G0,1 tests, respectively. G0,0 corresponds to the log-rank test, while G1,0 and G0,1 are more sensitive to early and late-difference alternatives. I conduct a simulation study to compare the performance of Zm with the log-rank test, the more optimally weighted test, and Lee's (2007) tests, under the null hypothesis, proportional hazards, early difference, and late-difference alternatives. Results indicate that the method based on Zm maintains the type I error rate, provides increased power relative to the log-rank test under early difference and late-difference alternatives, and entails only a small to moderate power loss compared with the more optimally chosen test. I apply the procedure to two datasets reported in the literature, both of which exhibit nonproportional hazards. Versatile tests such as Zm may be useful in clinical trial settings where there is concern that the treatment effect may not conform to the proportional hazards assumption. I also describe the syntax for a Stata command, verswlr, to implement the method.
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Progression free survival as a primary endpoint for comparative trials does not fully capture the therapeutic risk/benefit ratio. Additionally, summarization of the treatment effect via a hazard ...ratio is problematic when the proportional hazards assumption is violated. Restricted mean survival time metrics may address these challenges but have other limitations.
In men with a detectable prostate-specific antigen (PSA) level after prostatectomy for prostate cancer, salvage prostate bed radiotherapy (PBRT) results in about 70% of patients being free of ...progression at 5 years. A three-group randomised trial was designed to determine whether incremental gains in patient outcomes can be achieved by adding either 4–6 months of short-term androgen deprivation therapy (ADT) to PBRT, or both short-term ADT and pelvic lymph node radiotherapy (PLNRT) to PBRT.
The international, multicentre, randomised, controlled SPPORT trial was done at 283 radiation oncology cancer treatment centres in the USA, Canada, and Israel. Eligible patients (aged ≥18 years) were those who after prostatectomy for adenocarcinoma of the prostate had a persistently detectable or an initially undetectable and rising PSA of between 0·1 and 2·0 ng/mL. Patients with and without lymphadenectomy (N0/Nx) were eligible if there was no clinical or pathological evidence of lymph node involvement. Other eligibility criteria included pT2 or pT3 disease, prostatectomy Gleason score of 9 or less, and a Zubrod performance status of 0–1. Eligible patients were randomly assigned to receive PBRT alone at a dose of 64·8–70·2 Gy at 1·8 Gy per fraction daily (group 1), PBRT plus short-term ADT (group 2), or PLNRT (45 Gy at 1·8 Gy per fraction, and then a volume reduction made to the planning target volume for the remaining 19·8–25 ·2 Gy) plus PBRT plus short-term ADT (group 3). The primary endpoint was freedom from progression, in which progression was defined as biochemical failure according to the Phoenix definition (PSA ≥2 ng/mL over the nadir PSA), clinical failure (local, regional, or distant), or death from any cause. A planned interim analysis of 1191 patents with minimum potential follow-up time of 5 years applied a Haybittle-Peto boundary of p<0·001 (one sided) for comparison of 5-year freedom from progression rates between the treatment groups. This trial is registered with ClinicalTrials.gov, NCT00567580. The primary objectives of the trial have been completed, although long-term follow-up is continuing.
Between March 31, 2008, and March 30, 2015, 1792 eligible patients were enrolled and randomly assigned to the three treatment groups (592 to group 1 PBRT alone, 602 to group 2 PBRT plus short-term ADT, and 598 to group 3 PLNRT plus PBRT plus short-term ADT). 76 patients subsequently found to be ineligible were excluded from the analyses; thus, the evaluable patient population comprised 1716 patients. At the interim analysis (n=1191 patients; data cutoff May 23, 2018), the Haybittle-Peto boundary for 5-year freedom from progression was exceeded when group 1 was compared with group 3 (difference 17·9%, SE 2·9%; p<0·0001). The difference between groups 2 and 3 did not exceed the boundary (p=0·0063). With additional follow-up beyond the interim analysis (the final planned analysis; data cutoff May 26, 2021), at a median follow-up among survivors of 8·2 years (IQR 6·6–9·4), the 5-year freedom from progression rates in all 1716 eligible patients were 70·9% (95% CI 67·0–74·9) in group 1, 81·3% (78·0–84·6) in group 2, and 87·4% (84·7–90·2) in group 3. Per protocol criteria, freedom from progression in group 3 was superior to groups 1 and 2. Acute (≤3 months after radiotherapy) grade 2 or worse adverse events were significantly more common in group 3 (246 44% of 563 patients) than in group 2 (201 36% of 563; p=0·0034), which, in turn, were more common than in group 1 (98 18% of 547; p<0·0001). Similar findings were observed for grade 3 or worse adverse events. However, late toxicity (>3 months after radiotherapy) did not differ significantly between the groups, apart from more late grade 2 or worse blood or bone marrow events in group 3 versus group 2 (one-sided p=0·0060) attributable to the addition of PLNRT in this group.
The results of this randomised trial establish the benefit of adding short-term ADT to PBRT to prevent progression in prostate cancer. To our knowledge, these are the first such findings to show that extending salvage radiotherapy to treat the pelvic lymph nodes when combined with short-term ADT results in meaningful reductions in progression after prostatectomy in patients with prostate cancer.
National Cancer Institute.
The PI3K/Akt/mTOR (PAM) axis is constitutively activated in multiple lymphoma subtypes and is a promising therapeutic target. The mTOR inhibitor temsirolimus (TEM) and the immunomodulatory agent ...lenalidomide (LEN) have overlapping effects within the PAM axis with synergistic potential. This multicenter phase I/II study evaluated combination therapy with TEM/LEN in patients with relapsed and refractory lymphomas. Primary endpoints of the phase II study were rates of complete (CR) and overall response (ORR). There were 18 patients in the phase I dose-finding study, and TEM 25 mg weekly and LEN 20 mg on day 1 through day 21 every 28 days was established as the recommended phase II dose. An additional 93 patients were enrolled in the phase II component with three cohorts: diffuse large B-cell lymphoma (DLBCL, n=39), follicular lymphoma (FL, n=15), and an exploratory cohort of other lymphoma histologies with classical Hodgkin lymphoma (cHL) comprising the majority (n=39 total, n=20 with cHL). Patients were heavily pretreated with a median of four (range, 1-14) prior therapies and one-third with relapse following autologous stem cell transplantation (ASCT); patients with cHL had a median of six prior therapies. The FL cohort was closed prematurely due to slow accrual. ORR were 26% (13% CR) and 64% (18% CR) for the DLBCL and exploratory cohorts, respectively. ORR for cHL patients in the exploratory cohort, most of whom had relapsed after both brentuximab vedotin and ASCT, was 80% (35% CR). Eight cHL patients (40%) proceeded to allogeneic transplantation after TEM/LEN therapy. Grade ≥3 hematologic adverse events (AE) were common. Three grade 5 AE occurred. Combination therapy with TEM/LEN was feasible and demonstrated encouraging activity in heavily-pretreated lymphomas, particularly in relapsed/refractory cHL (clinicaltrials gov. Identifier: NCT01076543).
Gemcitabine plus cisplatin is active in malignant mesothelioma (MM), although single-arm phase II trials have reported variable outcomes. Vascular endothelial growth factor (VEGF) inhibitors have ...activity against MM in preclinical models. We added the anti-VEGF antibody bevacizumab to gemcitabine/cisplatin in a multicenter, double-blind, placebo-controlled randomized phase II trial in patients with previously untreated, unresectable MM.
Eligible patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 and no thrombosis, bleeding, or major blood vessel invasion. The primary end point was progression-free survival (PFS). Patients were stratified by ECOG performance status (0 v 1) and histologic subtype (epithelial v other). Patients received gemcitabine 1,250 mg/m(2) on days 1 and 8 every 21 days, cisplatin 75 mg/m(2) every 21 days, and bevacizumab 15 mg/kg or placebo every 21 days for six cycles, and then bevacizumab or placebo every 21 days until progression.
One hundred fifteen patients were enrolled at 11 sites; 108 patients were evaluable. Median PFS time was 6.9 months for the bevacizumab arm and 6.0 months for the placebo arm (P = .88). Median overall survival (OS) times were 15.6 and 14.7 months in the bevacizumab and placebo arms, respectively (P = .91). Partial response rates were similar (24.5% for bevacizumab v 21.8% for placebo; P = .74). A higher pretreatment plasma VEGF concentration (n = 56) was associated with shorter PFS (P = .02) and OS (P = .0066), independent of treatment arm. There were no statistically significant differences in toxicity of grade 3 or greater.
The addition of bevacizumab to gemcitabine/cisplatin in this trial did not significantly improve PFS or OS in patients with advanced MM.
Patients were eligible for the SPPORT trial1 with a prostate-specific antigen (PSA) concentration of 0·1 ng/mL because these patients have a greater than 98% risk of their disease progressing ...biochemically.2 The trial was designed and took place when the availability of newer PET tracers for prostate cancer was limited, so we anticipated questions related to the management of patients for whom PET scans show no evidence of metastatic disease (including in the pelvic lymph nodes), especially those with other features (eg, more than ten lymph nodes removed at prostatectomy3) that potentially predict reduced benefit from the addition of pelvic lymph node radiotherapy (PLNRT). The randomised phase 3 POP-RT trial4 staged 85% of high-risk patients using prostate-specific membrane antigen PET scans before primary prostate radiotherapy, and found that the addition of prophylactic PLNRT significantly reduced biochemical failure and distant metastasis. Fabio Turco and colleagues raise another interesting hypothesis as an extension of the SPPORT trial results: that low tumour burden metastatic castrate-sensitive prostate cancer would benefit not only from treating the primary tumour in the prostate and the oligometastatic sites with radiotherapy, but also from the administration of PLNRT.
Induction chemotherapy (IC) before radiotherapy lowers distant failure (DF) rates in locally advanced squamous cell carcinoma of the head and neck (SCCHN). The goal of this phase III trial was to ...determine whether IC before chemoradiotherapy (CRT) further improves survival compared with CRT alone in patients with N2 or N3 disease.
Treatment-naive patients with nonmetastatic N2 or N3 SCCHN were randomly assigned to CRT alone (CRT arm; docetaxel, fluorouracil, and hydroxyurea plus radiotherapy 0.15 Gy twice per day every other week) versus two 21-day cycles of IC (docetaxel 75 mg/m(2) on day 1, cisplatin 75 mg/m(2) on day 1, and fluorouracil 750 mg/m(2) on days 1 to 5) followed by the same CRT regimen (IC + CRT arm). The primary end point was overall survival (OS). Secondary end points included DF-free survival, failure pattern, and recurrence-free survival (RFS).
A total of 285 patients were randomly assigned. The most common grade 3 to 4 toxicities during IC were febrile neutropenia (11%) and mucositis (9%); during CRT (both arms combined), they were mucositis (49%), dermatitis (21%), and leukopenia (18%). Serious adverse events were more common in the IC arm (47% v 28%; P = .002). With a minimum follow-up of 30 months, there were no statistically significant differences in OS (hazard ratio, 0.91; 95% CI, 0.59 to 1.41), RFS, or DF-free survival.
IC did not translate into improved OS compared with CRT alone. However, the study was underpowered because it did not meet the planned accrual target, and OS was higher than predicted in both arms. IC cannot be recommended routinely in patients with N2 or N3 locally advanced SCCHN.
BACKGROUNDWe previously demonstrated the safety of stereotactic body radiotherapy followed by pembrolizumab (SBRT+P) in patients with advanced solid tumors. This phase I clinical trial was expanded ...to study the safety of partial tumor irradiation (partial-Rx). We assessed irradiated local failure (LF) and clinical outcomes with correlations to biomarkers including CD8+ T cell radiomics score (RS) and circulating cytokines.METHODSPatients received SBRT to 2-4 metastases and pembrolizumab for up to 7 days after SBRT. Tumors measuring up to 65 cc received the full radiation dose (complete-Rx), whereas tumors measuring more than 65 cc received partial-Rx. Landmark analysis was used to assess the relationship between tumor response and overall survival (OS). Multivariable analysis was performed for RS and circulating cytokines.RESULTSIn the combined (expansion plus original) cohort, 97 patients (219 metastases) were analyzed and received SBRT+P. Forty-six (47%) patients received at least 1 partial-Rx treatment. There were 7 (7.2%)dose-limiting toxicities (DLTs). 1-year LF was 7.6% overall, and 13.3% and 5.4% for partial-Rx and complete-Rx tumors, respectively (HR 2.32, 95% CI 0.90-5.97, P = 0.08). The overall, unirradiated, and irradiated objective response rates were 22%, 12%, and 34%, respectively. Irradiated tumor response to SBRT+P was associated with prolonged OS; 1-year OS was 71% (responders), 42% (mixed-responders), and 0% (nonresponders) (P < 0.01). High-RS was significantly associated with improved LF, progression-free survival (PFS), and OS. Elevated circulating IL-8 was independently associated with inferior PFS and OS.CONCLUSIONSBRT+P is safe in patients with large, advanced solid tumors. Additional studies are warranted to assess noninferiority of complete versus partial irradiation of tumors in the setting of immunotherapy.TRIAL REGISTRATIONClinicaltrials.gov NCT02608385FUNDINGMerck Investigator Studies Program; Hillman Fellows for Innovative Cancer Research Program; NIH grants UM1CA186690-06, P50CA254865-01A1, P30CA047904-32, and R01DE031729-01A1.
Background The primary objective of phase II cancer clinical trials is to determine whether a new regimen has sufficient activity to warrant further study, with activity generally defined as tumor ...shrinkage. However, oncology drug development has been limited by high rates of failure (lack of efficacy) in subsequent phase III testing. This high failure rate may reflect the process by which antineoplastic agents are usually evaluated in phase II trials, i.e., via single-arm studies in which the primary efficacy measure is the proportion of patients who achieve a complete or partial response to the treatment. This design may efficiently eliminate truly ineffective therapy but may not reliably indicate whether subsequent phase III testing is warranted. Methods We describe the design of a randomized phase II clinical trial of sorafenib in combination with erlotinib for the treatment of patients with non–small-cell lung cancer using change in tumor size, measured on a continuous scale, as the primary outcome variable. For the purpose of determining the sample size of the trial, we made assumptions as to the likely magnitude of treatment effect and the variability in tumor size changes based on data from four previous trials using these agents. Results The study design includes two different dosage arms and a placebo group with a total sample size of 150 patients and is powered to detect a modest reduction in the mean tumor size burden in the high-dose sorafenib arm compared with a slight increase in the placebo group. Conclusions Clinical trial designs that treat change in tumor size as a continuous variable rather than categorizing the changes are feasible, and by inclusion of a prospective control group they offer advantages over conventional single-arm trials.
Summary Background Epidermal growth factor receptor (EGFR) is a validated target in squamous-cell carcinoma of the head and neck, but in patients with recurrent or metastatic disease, EGFR targeting ...agents have displayed modest efficacy. Vascular endothelial growth factor (VEGF)-mediated angiogenesis has been implicated as a mechanism of resistance to anti-EGFR therapy. In this multi-institutional phase I/II study we combined an EGFR inhibitor, erlotinib, with an anti-VEGF antibody, bevacizumab. Methods Between April 15, 2003, and Jan 27, 2005, patients with recurrent or metastatic squamous-cell carcinoma of the head and neck were enrolled from seven centres in the USA and were given erlotinib (150 mg daily) and bevacizumab in escalating dose cohorts. The primary objectives in the phase I and II sections, respectively, were to establish the maximum tolerated dose and dose-limiting toxicity of bevacizumab when administered with erlotinib and to establish the proportion of objective responses and time to disease progression. Pretreatment serum and tissues were collected and analysed by enzyme-linked immunosorbent assay and immunofluorescence quantitative laser analysis, respectively. This study was registered with ClinicalTrials.gov , number NCT00055913. Findings In the phase I section of the trial, ten patients were enrolled in three successive cohorts with no dose-limiting toxic effects noted. 46 patients were enrolled in the phase II section of the trial (including three patients from the phase I section) on the highest dose of bevacizumab (15 mg/kg every 3 weeks). Two additional patients were accrued beyond the protocol-stipulated 46, leaving a total of 48 patients for the phase II assessment. The most common toxic effects of any grade were rash and diarrhoea (41 and 16 of 48 patients, respectively). Three patients had serious bleeding events of grade 3 or higher. Seven patients had a response, with four showing a complete response allowing rejection of the null hypothesis. Median time of overall survival and progression-free survival (PFS) were 7·1 months (95% CI 5·7–9·0) and 4·1 months (2·8–4·4), respectively. Higher ratios of tumour-cell phosphorylated VEGF receptor-2 (pVEGFR2) over total VEGFR2 and endothelial-cell pEGFR over total EGFR in pretreatment biopsies were associated with complete response (0·704 vs 0·386, p=0·036 and 0·949 vs 0·332, p=0·036, respectively) and tumour shrinkage (p=0·007 and p=0·008, respectively) in a subset of 11 patients with available tissue. Interpretation The combination of erlotinib and bevacizumab is well tolerated in recurrent or metastatic squamous-cell carcinoma of the head and neck. A few patients seem to derive a sustained benefit and complete responses were associated with expression of putative targets in pretreatment tumour tissue. Funding National Cancer Institute, National Institutes of Health, Bethesda, MD, USA (grant number N01-CM-17102) and the University of Chicago Cancer Research Center, Chicago, IL, USA (grant number P30 CA14599).
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