Evaluation of the Value of Attribution in the Interpretation of Adverse Event Data: A North Central Cancer Treatment Group and American College of Surgeons Oncology Group Investigation
Purpose In March 1998, Common Toxicity Criteria (CTC) version 2.0 introduced the collection of attribution of adverse events (AEs) to study drug. We investigate whether attribution adds value to the interpretation of AE data. Patients and Methods Patients in the placebo arm of two phase III trials—North Central Cancer Treatment Group Trial 97-24-51 (carboxyamino-triazole v placebo in advanced non–small-cell lung cancer) and American College of Surgeons Oncology Group Trial Z9001 (imatinib mesylate v placebo after resection of primary gastrointestinal stromal tumors)—were studied. Attribution was categorized as unrelated (not related or unlikely) and related (possible, probable, or definite). Results In total, 398 patients (84 from Trial 97-24-51 and 314 from Trial Z9001) and 7,736 AEs were included; 47% and 50% of the placebo-arm AEs, respectively, were reported as related. When the same AE was reported in the same patient on multiple visits, the attribution category changed at least once 36% and 31% of the time. AE type and sex (Trial Z9001) and AE type and performance status (Trial 97-24-51) were associated with a higher likelihood of AEs being deemed related. Conclusion Nearly 50% of AEs were reported as attributed to study drug on the placebo arm of two randomized clinical trials. These data provide strong evidence that AE attribution is difficult to determine, unreliable, and of questionable value in interpreting AE data in randomized clinical trials.
Evaluation of the Optimal Number of Lesions Needed for Tumor Evaluation Using the Response Evaluation Criteria in Solid Tumors: A North Central Cancer Treatment Group Investigation
Purpose In February 2000, the criteria for measuring tumor shrinkage as an indicator of antitumor activity were redefined by the Response Evaluation Criteria in Solid Tumors (RECIST). This resulted in simplifying bidimensional to unidimensional measurement of lesions. Under RECIST, all lesions, up to 10, must be measured. Scanning and measuring multiple lesions is costly, time-consuming, and a disincentive to participation in clinical trials. We investigated whether fewer than 10 lesions can be measured without compromising the accuracy of assessing a regimen's activity. Patients and Methods Thirty-two North Central Cancer Treatment Group trials including 2,374 patients were analyzed. Twelve studies were conducted before RECIST; 20 were conducted post-RECIST. Agreement between objective status by cycle, confirmed response, overall response rate, and time to progression (TTP) was evaluated based on all 10 versus the largest one through five lesions. Results The median number of lesions reported on RECIST trials did not differ from pre-RECIST trials (median = 2.0). One lesion at baseline was reported in 49% of patients, two lesions in 28% of patients, three lesions in 12% of patients, four lesions in 6% of patients, and five lesions in 5% of patients in post-RECIST trials. Utilizing the largest two lesions produced excellent concordance with that using all lesions for all end points. In no trial did the overall response rate differ by more than 3% when two versus all lesions were considered. Evaluating more than two lesions did not significantly improve agreement. Conclusion Based on these trials, the assessment of more than two lesions did not alter the conclusions regarding a treatment's efficacy as judged by response rate or TTP.
Results of a Phase II Study of High-Dose Thoracic Radiation Therapy With Concurrent Cisplatin and Etoposide in Limited-Stage Small-Cell Lung Cancer (NCCTG 95-20-53)
Purpose To evaluate the outcome of patients with limited-stage small-cell lung cancer (L-SCLC) treated with cisplatin and etoposide (PE), early prophylactic cranial irradiation (PCI), and high-dose twice-daily thoracic radiotherapy (bid RT). Patients and Methods A total of 76 assessable patients were treated on this phase II trial, which included six cycles of PE. PCI (25 Gy/10 fractions) was delivered during cycle 3 to responding patients. Cycles 4 and 5 included concurrent chemotherapy and thoracic RT (30 Gy/20 bid fractions, a 2-week break, and another 30 Gy/20 bid fractions). Results Of the 76 assessable patients, 74 patients (97%) suffered grade 3 or greater (3+) toxicity and 61 patients (80%) had grade 4 or greater (4+) toxicity. Of these adverse events, grade 3+ hematologic toxicity occurred in 72 patients (95%), and grade 3+ nonhematologic toxicity occurred in 55 patients (72%). Only one (2%) of the 61 patients who received PCI experienced treatment failure in the brain. The 5-year survival rate of the 76 assessable patients was 24% (median, 20 months). The 5-year survival rate of the 64 patients who received thoracic RT was 29% (median, 22 months). The 5-year cumulative incidence of in-field treatment failure was 34%. Conclusion This regimen included a high total dose of bid TRT, which resulted in a favorable 5-year survival rate. Local failure remains a problem that will require additional investigation. Newer technology should allow the safe administration of greater doses of RT, which should improve patient outcome. Data from eight trials were combined to demonstrate a relationship between RT dose fractionation and 5-year survival.
Should Elderly Non–Small-Cell Lung Cancer Patients Be Offered Elderly-Specific Trials? Results of a Pooled Analysis From the North Central Cancer Treatment Group
Purpose To answer the question, “should elderly non–small-cell lung cancer patients be offered elderly-specific trials?” Patients and Methods The North Central Cancer Treatment Group (NCCTG) performed a pooled analysis of elderly patients who participated in elderly-specific trials (required age ≥ 65 years) and age-unspecified trials (required age ≥ 18 years). Between 1998 and 2000, all NCCTG non–small-cell lung cancer (NSCLC) patients with incurable cancer, age ≥ 65 years, and receiving first-line chemotherapy were included. A total of 118 elderly patients participated in elderly-specific trials, and 108, in age-unspecified trials. Demographics and outcomes were compared based on trial type. Results The median age of elderly patients in elderly-specific trials was greater: median (range): 73 years (65 to 87) and 70 years (65 to 85), respectively (P < .001), as was the percentage older than 80 years: 17% and 3%, respectively (P = .0008). Median survival times were 232 and 302 days, respectively (P = .08). After adjustment for baseline age, Eastern Cooperative Oncology Group performance score, cancer stage, and body mass index, this survival difference was not statistically significant (hazard ratio = 1.25; P = .16). Grade 3 or worse nonhematologic adverse event rates were greater in age-unspecified trials (81% v 57%, respectively; P < .001), as were grade 3 or worse hematologic events (68% v 10%, respectively; P < .001). Conclusion Elderly patients in NSCLC elderly-specific trials suffered lower rates of severe adverse events with no statistically significant differences in survival. It seems that elderly-specific trials are providing quality care and helping to define optimal cancer therapy in the elderly, particularly among the “oldest of the old.”
Randomized Phase II Trial of Three Schedules of Pemetrexed and Gemcitabine As Front-Line Therapy for Advanced Non–Small-Cell Lung Cancer
Purpose A randomized three-arm phase II study was undertaken to evaluate the optimum administration schedule of pemetrexed and gemcitabine in chemotherapy-naïve patients with non–small-cell lung cancer. Patients and Methods Patients were randomly assigned to three schedules of pemetrexed 500 mg/m2 plus gemcitabine 1,250 mg/m2, separated by a 90-minute interval, on a 21-day cycle as follows: schedule A, pemetrexed followed by gemcitabine on day 1 and gemcitabine on day 8; schedule B, gemcitabine followed by pemetrexed on day 1 and gemcitabine on day 8; and schedule C, gemcitabine on day 1 and pemetrexed followed by gemcitabine on day 8. Results One hundred fifty-two eligible patients (schedule A, n = 59; schedule B, n = 31, and schedule C, n = 62) received a median of five (schedule A), two (schedule B), and four (schedule C) treatment cycles. Overall, 66% of patients experienced grade 3 or 4 neutropenia. Common grade 3 and 4 nonhematologic toxicities were dyspnea (11%), fatigue (16%), and transaminase elevation (9%). Schedule A seemed less toxic compared with schedule C (grade 3 or 4 events: 86% v 94%, respectively; P = .19; grade 4 events: 39% v 48%, respectively; P = .30). Schedule B was closed at interim analysis for inferior efficacy. Schedule A, with a confirmed response rate of 31% (95% CI, 20% to 45%), met the protocol-defined efficacy criteria, whereas schedule C, with a confirmed response rate of 16.1% (95% CI, 11% to 34%), did not. Median survival time and time to progression were 11.4 and 4.4 months, respectively, with no observable difference between the arms. Conclusion Pemetrexed and gemcitabine administered as outlined for schedule A met the protocol-defined efficacy criteria, was less toxic compared with the other treatment schedules, and should be further evaluated.