Adjusting for the Confounding Effects of Treatment Switching-The BREAK-3 Trial: Dabrafenib Versus Dacarbazine.

BACKGROUND: Patients with previously untreated BRAF V600E mutation-positive melanoma in BREAK-3 showed a median overall survival (OS) of 18.2 months for dabrafenib versus 15.6 months for dacarbazine (hazard ratio [HR], 0.76; 95% confidence interval, 0.48-1.21). Because patients receiving dacarbazine were allowed to switch to dabrafenib at disease progression, we attempted to adjust for the confounding effects on OS. MATERIALS AND METHODS: Rank preserving structural failure time models (RPSFTMs) and the iterative parameter estimation (IPE) algorithm were used. Two analyses, "treatment group" (assumes treatment effect could continue until death) and "on-treatment observed" (assumes treatment effect disappears with discontinuation), were used to test the assumptions around the durability of the treatment effect. RESULTS: A total of 36 of 63 patients (57%) receiving dacarbazine switched to dabrafenib. The adjusted OS HRs ranged from 0.50 to 0.55, depending on the analysis. The RPSFTM and IPE "treatment group" and "on-treatment observed" analyses performed similarly well. CONCLUSION: RPSFTM and IPE analyses resulted in point estimates for the OS HR that indicate a substantial increase in the treatment effect compared with the unadjusted OS HR of 0.76. The results are uncertain because of the assumptions associated with the adjustment methods. The confidence intervals continued to cross 1.00; thus, the adjusted estimates did not provide statistically significant evidence of a treatment benefit on survival. However, it is clear that a standard intention-to-treat analysis will be confounded in the presence of treatment switching-a reliance on unadjusted analyses could lead to inappropriate practice. Adjustment analyses provide useful additional information on the estimated treatment effects to inform decision making. IMPLICATIONS FOR PRACTICE: Treatment switching is common in oncology trials, and the implications of this for the interpretation of the clinical effectiveness and cost-effectiveness of the novel treatment are important to consider. If patients who switch treatments benefit from the experimental treatment and a standard intention-to-treat analysis is conducted, the overall survival advantage associated with the new treatment could be underestimated. The present study applied established statistical methods to adjust for treatment switching in a trial that compared dabrafenib and dacarbazine for metastatic melanoma. The results showed that this led to a substantially increased estimate of the overall survival treatment effect associated with dabrafenib.

Radiotherapy plus chemotherapy with or without surgical resection for stage III non-small-cell lung cancer: a phase III randomised controlled trial.

BACKGROUND: Results from phase II studies in patients with stage IIIA non-small-cell lung cancer with ipsilateral mediastinal nodal metastases (N2) have shown the feasibility of resection after concurrent chemotherapy and radiotherapy with promising rates of survival. We therefore did this phase III trial to compare concurrent chemotherapy and radiotherapy followed by resection with standard concurrent chemotherapy and definitive radiotherapy without resection. METHODS: Patients with stage T1-3pN2M0 non-small-cell lung cancer were randomly assigned in a 1:1 ratio to concurrent induction chemotherapy (two cycles of cisplatin [50 mg/m(2) on days 1, 8, 29, and 36] and etoposide [50 mg/m(2) on days 1-5 and 29-33]) plus radiotherapy (45 Gy) in multiple academic and community hospitals. If no progression, patients in group 1 underwent resection and those in group 2 continued radiotherapy uninterrupted up to 61 Gy. Two additional cycles of cisplatin and etoposide were given in both groups. The primary endpoint was overall survival (OS). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00002550. FINDINGS: 202 patients (median age 59 years, range 31-77) were assigned to group 1 and 194 (61 years, 32-78) to group 2. Median OS was 23.6 months (IQR 9.0-not reached) in group 1 versus 22.2 months (9.4-52.7) in group 2 (hazard ratio [HR] 0.87 [0.70-1.10]; p=0.24). Number of patients alive at 5 years was 37 (point estimate 27%) in group 1 and 24 (point estimate 20%) in group 2 (odds ratio 0.63 [0.36-1.10]; p=0.10). With N0 status at thoracotomy, the median OS was 34.4 months (IQR 15.7-not reached; 19 [point estimate 41%] patients alive at 5 years). Progression-free survival (PFS) was better in group 1 than in group 2, median 12.8 months (5.3-42.2) vs 10.5 months (4.8-20.6), HR 0.77 [0.62-0.96]; p=0.017); the number of patients without disease progression at 5 years was 32 (point estimate 22%) versus 13 (point estimate 11%), respectively. Neutropenia and oesophagitis were the main grade 3 or 4 toxicities associated with chemotherapy plus radiotherapy in group 1 (77 [38%] and 20 [10%], respectively) and group 2 (80 [41%] and 44 [23%], respectively). In group 1, 16 (8%) deaths were treatment related versus four (2%) in group 2. In an exploratory analysis, OS was improved for patients who underwent lobectomy, but not pneumonectomy, versus chemotherapy plus radiotherapy. INTERPRETATION: Chemotherapy plus radiotherapy with or without resection (preferably lobectomy) are options for patients with stage IIIA(N2) non-small-cell lung cancer. FUNDING: National Cancer Institute, Canadian Cancer Society, and National Cancer Institute of Canada.

Increasing tumor volume is predictive of poor overall and progression-free survival: secondary analysis of the Radiation Therapy Oncology Group 93-11 phase I-II radiation dose-escalation study in patients with inoperable non-small-cell lung cancer.

PURPOSE: Patients with non-small-cell lung cancer (NSCLC) in the Radiation Therapy Oncology Group (RTOG) 93-11 trial received radiation doses of 70.9, 77.4, 83.8, or 90.3 Gy. The locoregional control and survival rates were similar among the various dose levels. We investigated the effect of the gross tumor volume (GTV) on the outcome. METHODS AND MATERIALS: The GTV was defined as the sum of the volumes of the primary tumor and involved lymph nodes. The tumor response, median survival time (MST), and progression-free survival (PFS) were analyzed separately for smaller (< or =45 cm(3)) vs. larger (>45 cm(3)) tumors. RESULTS: The distribution of the GTV was as follows: < or =45 cm(3) in 79 (49%) and >45 cm(3) in 82 (51%) of 161 patients. The median GTV was 47.3 cm(3). N0 status and female gender were associated with better tumor responses. Patients with smaller (< or =45 cm(3)) tumors achieved a longer MST and better PFS than did patients with larger (>45 cm(3)) tumors (29.7 vs. 13.3 months, p < 0.0001; and 15.8 vs. 8.3 months, p < 0.0001, respectively). Increasing the radiation dose had no effect on the MST or PFS. On multivariate analysis, only a smaller GTV was a significant prognostic factor for improved MST and PFS (hazard ratio [HR], 2.12, p = 0.0002; and HR, 2.0, p = 0.0002, respectively). The GTV as a continuous variable was also significantly associated with the MST and PFS (HR, 1.59, p < 0.0001; and HR, 1.39, p < 0.0001, respectively). CONCLUSIONS: Radiation dose escalation up to 90.3 Gy did not result in improved MST or PFS. The tumor responses were greater in node-negative patients and women. An increasing GTV was strongly associated with decreased MST and PFS. Future radiotherapy trials patients might need to use stratification by tumor volume.

Effect of amifostine on response rates in locally advanced non-small-cell lung cancer patients treated on randomized controlled trials: a meta-analysis.

PURPOSE: Amifostine can reduce the cytotoxic effects of chemotherapy and radiotherapy in patients with locally advanced non-small-cell lung cancer, but concerns remain regarding its possible tumor-protective effects. Studies with sufficient statistical power to address this question are lacking. METHODS AND MATERIALS: We performed a meta-analysis of all published clinical trials involving locally advanced non-small-cell lung cancer patients treated with radiotherapy with or without chemotherapy, who had been randomized to treatment with amifostine vs. no amifostine or placebo. Random effects estimates of the relative risk of overall, partial, and complete response were obtained. RESULTS: Seven randomized trials involving 601 patients were identified. Response rate data were available for six studies (552 patients). The pooled relative risk (RR) estimate was 1.07 (95% confidence interval, 0.97-1.18; p = 0.18), 1.21 (95% confidence interval, 0.83-1.78; p = 0.33), and 0.99 (95% confidence interval, 0.78-1.26; p = 0.95) for overall, complete, and partial response, respectively (a RR >1 indicates improvement in response with amifostine compared with the control arm). The results were similar after sensitivity analyses. No evidence was found of treatment effect heterogeneity across the studies. CONCLUSIONS: Amifostine has no effect on tumor response in patients with locally advanced non-small-cell lung cancer treated with radiotherapy with or without chemotherapy.

Effect of pilocarpine during radiation therapy: results of RTOG 97-09, a phase III randomized study in head and neck cancer patients.

Radiation therapy is an important curative modality in the treatment of patients with head and neck cancer. However, radiation-induced changes in the oral cavity, such as xerostomia and mucositis, are among the most debilitating treatment sequelae experienced by patients undergoing radiation therapy, and attempts at ameliorating these side effects have been poor at best. Pilocarpine has been approved for post-radiation xerostomia, and the effect of its use during radiation therapy on salivary flow, xerostomia, mucositis, and quality of life (QOL) was assessed in a phase III study conducted by the Radiation Therapy Oncology Group (RTOG 97-09). In total, 245 evaluable patients were randomized to pilocarpine or placebo. Selected patients were required to have > or = 50% of the volume of the major salivary glands receive > or = 50Gy; to agree to provide stimulated and unstimulated samples of saliva (measured in g) before treatment, at the end of treatment, and 3 and 6 months after completion of radiation therapy; and to complete the University of Washington Head and Neck Symptom Scale. Following the completion of radiation therapy, the average unstimulated salivary flow was statistically greater in the pilocarpine group, whereas no difference was noted following parotid stimulation. There was no effect on the amelioration of mucositis. The results of the QOL scales did not reveal any significant difference between the pilocarpine and placebo groups with regard to xerostomia and mucositis. The significant difference in unstimulated salivary flow supports the concomitant use of oral pilocarpine to decrease radiation-associated xerostomia. However, the absent correlation between improved salivary flow and QOL scores is of some concern (though not a new finding) and may be related to the existence of comorbidities and the lack of effect on mucositis.

Effect of overall treatment time on outcomes after concurrent chemoradiation for locally advanced non-small-cell lung carcinoma: analysis of the Radiation Therapy Oncology Group (RTOG) experience.

PURPOSE: To determine whether overall treatment time affects outcomes after definitive concurrent chemoradiotherapy for locally advanced non-small-cell lung carcinoma (NSCLC). METHODS AND MATERIALS: Data were analyzed from 3 prospective Radiation Therapy Oncology Group trials (RTOG 91-06, 92-04, and 94-10) in which immediate concurrent chemoradiation (cisplatin-based) was the primary therapy for good-performance status Stage III (and selected inoperable Stage II) NSCLC. "Short" overall treatment time (per protocol) was defined as completing treatment within 5 days of plan; other patients were considered to have had "prolonged" treatment time (protocol violation); treatment time was also analyzed as a continuous variable in a multivariate model. Actuarial analysis was performed for overall survival, progression-free survival, freedom from local-regional progression, and toxicity. RESULTS: A total of 474 patients were analyzed. Median follow-up for surviving patients was 6.1 years. Treatment time was delivered per protocol in 387 (82%), whereas 87 patients (18%) had a prolonged treatment time. Long treatment time was significantly associated with severe acute esophagitis. Median survival was slightly better in patients completing treatment on time (19.5 months vs. 14.8 months), but this did not reach statistical significance (p = 0.15) in the univariate analysis. However, in the multivariate analysis of treatment time as a continuous variable, prolonged treatment time was significantly associated with poorer survival (p = 0.02), indicating a 2% increase in the risk of death for each day of prolongation in therapy. Histology (squamous fared worse) and performance status were also significant in the multivariate model. CONCLUSIONS: This retrospective analysis demonstrates a correlation between prolonged overall radiotherapy treatment time and survival in patients with locally advanced NSCLC, even when concurrent chemotherapy is used. Further study of novel radiation-chemotherapy dose/fractionation regimens is warranted.

Phase I study of thoracic radiation dose escalation with concurrent chemotherapy for patients with limited small-cell lung cancer: Report of Radiation Therapy Oncology Group (RTOG) protocol 97-12.

PURPOSE: The purpose of RTOG 97-12 was to determine the maximum tolerated dose (MTD) of thoracic radiation therapy (RT) with concurrent chemotherapy for patients with limited-stage small-cell lung cancer. PATIENTS AND METHODS: Sixty-four patients received four cycles of cisplatin (60 mg/m(2) i.v.) and etoposide (120 mg/m(2) i.v. Days 1-3) (PE), with concurrent thoracic RT starting on Day 1. Thoracic RT was given during the first two cycles with 1.8 Gy/fraction daily to the clinical target volume, followed by thoracic RT to the gross tumor volume b.i.d. for the last 3, 5, 7, 9, or 11 treatment days (total dose 50.4, 54.0, 57.6, 61.2, or 64.8 Gy, respectively). The MTD was based on the dose that produced Grades 3-4 nonhematologic toxicity (mainly esophagitis and pneumonitis) in greater than 50% of patients. RESULTS: After the first 8 patients were enrolled in Arm 1, administration of etoposide was changed from 120 mg/m(2) i.v. on Days 2 and 3 of each cycle to 240 mg/m(2) p.o. for patient convenience as outpatients. Total thoracic RT doses from 50.4 Gy to 61.2 Gy over 5 weeks given with PE were well tolerated. Three of the first 5 patients in the 64.8 Gy arm developed Grade 3 acute esophagitis; the MTD was determined to be 61.2 Gy. Fifty-four (87%) of the 62 evaluable patients achieved a complete (68%) or partial (19%) tumor response. The 18-month survival was 25% for patients receiving 50.4 Gy and 82% for those receiving 61.2 Gy. CONCLUSIONS: The MTD for this accelerated thoracic RT regimen with concurrent PE was 61.2 Gy over 5 weeks.

Recommendations for capture, validation and summarisation of data from studies using RECIST.

Response Evaluation Criteria in Solid Tumors (RECIST) is commonly used in oncology clinical trials and provides a standard approach for the assessment of treatment. However, data capture, validation and summarisation are complex. This article focuses on managing solid tumour lesion and response assessment data from capture through summarisation. Conventions for capturing lesion data, as well as considerations for data validation and summarisation, are provided. Recommendations are based on a review of data capture forms (including data items and instructions), data validation practices and algorithms for data summarisation across solid tumour studies at a single company. The intent of the authors is to share our experiences at GSK in the spirit of harmonisation by transparently describing our decisions and methods.

Phase II proof-of-concept study of pazopanib monotherapy in treatment-naive patients with stage I/II resectable non-small-cell lung cancer.

PURPOSE: Patients with early-stage, resectable, non-small-cell lung cancer (NSCLC) are at risk for recurrent disease, and 5-year survival rates do not exceed 75%. Angiogenesis inhibitors have shown clinical activity in patients with late-stage NSCLC, raising the possibility that targeting the vascular endothelial growth factor pathway in earlier-stage disease may be beneficial. This proof-of-concept study examined safety and efficacy of short-term, preoperative pazopanib monotherapy in patients with operable stage I/II NSCLC. PATIENTS AND METHODS: Patients scheduled for resection received oral pazopanib 800 mg/d for 2 to 6 weeks preoperatively. Tumor response was measured by high-resolution computed tomography, permitting estimation of change in tumor volume and diameter. Gene-expression profiling was performed on 77 pre- and post-treatment lung samples from 34 patients. RESULTS: Of 35 patients enrolled, 33 (94%) had clinical stage I NSCLC and two (6%) had clinical stage II NSCLC. Median treatment duration was 16 days (range, 3 to 29 days). Thirty patients (86%) achieved tumor-volume reduction after pazopanib treatment. Two patients achieved tumor-volume reduction > or = 50%, and three patients had partial response according to Response Evaluation Criteria in Solid Tumors. Pazopanib was generally well tolerated. The most common adverse events included grade 2 hypertension, diarrhea, and fatigue. One patient developed pulmonary embolism 11 days after surgery. Several pazopanib target genes and other angiogenic factors were dysregulated post-treatment. CONCLUSION: Short-duration pazopanib was generally well tolerated and demonstrated single-agent activity in patients with early-stage NSCLC. Several target genes were dysregulated after pazopanib treatment, validating target-specific response and indicating a persistent pazopanib effect on lung cancer tissue. Further clinical evaluation of pazopanib in NSCLC is planned.

Phase III Trial of an emulsion containing trolamine for the prevention of radiation dermatitis in patients with advanced squamous cell carcinoma of the head and neck: results of Radiation Therapy Oncology Group Trial 99-13.

PURPOSE: This multicentered phase III trial was designed to compare an emulsion containing trolamine against the usual supportive care within each participating institution for patients with head and neck cancer undergoing radiation therapy. PATIENTS AND METHODS: Patients with biopsy-proven squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx were randomly assigned to one of the following treatments: prophylactic trolamine emulsion, interventional trolamine emulsion, or declared institutional preference. The primary outcome was the reduction in grade 2 or higher skin toxicity, as per National Cancer Institute Common Toxicity Criteria version 2.0. Secondary outcomes included patient-reported quality of life (QOL). RESULTS: From October 2000 to April 2002, 547 patients from 51 institutions were entered onto the trial. The average age was 59 years. Patients were predominately male (79%) and most continued to use tobacco products (52%). The rates of grade 2 or higher radiation dermatitis were 79%, 77%, and 79% in the prophylactic, interventional, and institutional preference arms of the study, respectively. No significant differences in QOL were found. CONCLUSION: The results of this trial demonstrate no advantage for the use of trolamine in reducing the incidence of grade 2 or higher radiation dermatitis or improving patient-reported QOL. The use of 15 different local standards of care highlights the need to continue research that will result in evidence-based recommendations to reduce the burden of radiation dermatitis.