Christopher J. O’Callaghan

BACKGROUND: Among patients with metastatic pancreatic cancer, combination chemotherapy with fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) leads to longer overall survival than gemcitabine therapy. We compared the efficacy and safety of a modified FOLFIRINOX regimen with gemcitabine as adjuvant therapy in patients with resected pancreatic cancer. METHODS: We randomly assigned 493 patients with resected pancreatic ductal adenocarcinoma to receive a modified FOLFIRINOX regimen (oxaliplatin [85 mg per square meter of body-surface area], irinotecan [180 mg per square meter, reduced to 150 mg per square meter after a protocol-specified safety analysis], leucovorin [400 mg per square meter], and fluorouracil [2400 mg per square meter] every 2 weeks) or gemcitabine (1000 mg per square meter on days 1, 8, and 15 every 4 weeks) for 24 weeks. The primary end point was disease-free survival. Secondary end points included overall survival and safety. RESULTS: At a median follow-up of 33.6 months, the median disease-free survival was 21.6 months in the modified-FOLFIRINOX group and 12.8 months in the gemcitabine group (stratified hazard ratio for cancer-related event, second cancer, or death, 0.58; 95% confidence interval [CI], 0.46 to 0.73; P<0.001). The disease-free survival rate at 3 years was 39.7% in the modified-FOLFIRINOX group and 21.4% in the gemcitabine group. The median overall survival was 54.4 months in the modified-FOLFIRINOX group and 35.0 months in the gemcitabine group (stratified hazard ratio for death, 0.64; 95% CI, 0.48 to 0.86; P=0.003). The overall survival rate at 3 years was 63.4% in the modified-FOLFIRINOX group and 48.6% in the gemcitabine group. Adverse events of grade 3 or 4 occurred in 75.9% of the patients in the modified-FOLFIRINOX group and in 52.9% of those in the gemcitabine group. One patient in the gemcitabine group died from toxic effects (interstitial pneumonitis). CONCLUSIONS: Adjuvant therapy with a modified FOLFIRINOX regimen led to significantly longer survival than gemcitabine among patients with resected pancreatic cancer, at the expense of a higher incidence of toxic effects. (Funded by R&D Unicancer and others; ClinicalTrials.gov number, NCT01526135 ; EudraCT number, 2011-002026-52 .).

BACKGROUND: Glioblastoma is associated with a poor prognosis in the elderly. Survival has been shown to increase among patients 70 years of age or younger when temozolomide chemotherapy is added to standard radiotherapy (60 Gy over a period of 6 weeks). In elderly patients, more convenient shorter courses of radiotherapy are commonly used, but the benefit of adding temozolomide to a shorter course of radiotherapy is unknown. METHODS: We conducted a trial involving patients 65 years of age or older with newly diagnosed glioblastoma. Patients were randomly assigned to receive either radiotherapy alone (40 Gy in 15 fractions) or radiotherapy with concomitant and adjuvant temozolomide. RESULTS: -methylguanine-DNA methyltransferase (MGMT) status, the median overall survival was 13.5 months with radiotherapy plus temozolomide and 7.7 months with radiotherapy alone (hazard ratio for death, 0.53; 95% CI, 0.38 to 0.73; P<0.001). Among 189 patients with unmethylated MGMT status, the median overall survival was 10.0 months with radiotherapy plus temozolomide and 7.9 months with radiotherapy alone (hazard ratio for death, 0.75; 95% CI, 0.56 to 1.01; P=0.055; P=0.08 for interaction). Quality of life was similar in the two trial groups. CONCLUSIONS: In elderly patients with glioblastoma, the addition of temozolomide to short-course radiotherapy resulted in longer survival than short-course radiotherapy alone. (Funded by the Canadian Cancer Society Research Institute and others; ClinicalTrials.gov number, NCT00482677 .).

PURPOSE: A traditional end point for colon adjuvant clinical trials is overall survival (OS), with 5 years demonstrating adequate follow-up. A shorter-term end point providing convincing evidence to allow treatment comparisons could significantly speed the translation of advances into practice. METHODS: Individual patient data were pooled from 18 randomized phase III colon cancer adjuvant clinical trials. Trials included 43 arms, with a pooled sample size of 20,898 patients. The primary hypothesis was that disease-free survival (DFS), with 3 years of follow-up, is an appropriate primary end point to replace OS with 5 years of follow-up. RESULTS: The recurrence rates for years 1 through 5 were 12%, 14%, 8%, 5%, and 3%, respectively. Median time from recurrence to death was 12 months. Eighty percent of recurrences were in the first 3 years; 91% of patients with recurrence by 3 years died before 5 years. Correlation between 3-year DFS and 5-year OS was 0.89. Comparing control versus experimental arms within each trial, the correlation between hazard ratios for DFS and OS was 0.92. Within-trial log-rank testing using both DFS and OS provided the same conclusion in 23 (92%) of 25 cases. Formal measures of surrogacy were satisfied. CONCLUSION: In patients treated on phase III adjuvant colon clinical trials, DFS and OS are highly correlated, both within patients and across trials. These results suggest that DFS after 3 years of median follow-up is an appropriate end point for adjuvant colon cancer clinical trials of fluorouracil-based regimens, although marginally significant DFS improvements may not translate into significant OS benefits.

BACKGROUND: Trastuzumab, a humanized anti-HER2 antibody, increases the clinical benefit of first-line chemotherapy in patients with metastatic breast cancers that overexpress HER2. We characterized interactions between trastuzumab and chemotherapeutic agents commonly used in the treatment of breast cancer. METHODS: Multiple drug effect/combination index isobologram analysis was used to study the efficacy of chemotherapeutic drug plus trastuzumab combinations tested against four HER2-overexpressing breast cancer cell lines (SK-BR-3, BT-474, MDA-MB-361, and MDA-MB-453). Combination index values were derived from parameters of the median effect plots, and statistical tests were used to determine whether the mean combination index values at multiple effect levels were statistically significantly different from a combination index value of 1.0. Values less than 1.0 indicate synergistic interactions, values greater than 1.0 indicate antagonistic interactions, and values equal to 1.0 indicate additive interactions. RESULTS: At a wide range of clinically achievable drug concentrations, synergistic interactions were observed in all four breast cancer cell lines for trastuzumab plus carboplatin (mean combination index values ranged from 0.32 [P<.001] to 0.53 [P<.001]), 4-hydroxycyclophosphamide (mean combination index values ranged from 0.38 [P<.001] to 0.73 [P =.010]), docetaxel (mean combination index values ranged from 0.30 [P<.001] to 0.62 [P<.001]), and vinorelbine (mean combination index values ranged from 0.24 [P<.001] to 0.78 [P<.034]). Additive interactions were observed in all four cell lines with trastuzumab plus doxorubicin, epirubicin, and paclitaxel. Interactions between trastuzumab and gemcitabine were synergistic at low concentrations of gemcitabine and antagonistic at high concentrations. A synergistic interaction was observed with a three-drug combination of docetaxel plus carboplatin plus trastuzumab in SK-BR-3 cells (mean combination index value = 0.09; P<.001). CONCLUSION: Consistent synergistic interactions of trastuzumab plus carboplatin, 4-hydroxycyclophosphamide, docetaxel, or vinorelbine across a wide range of clinically relevant concentrations in HER2-overexpressing breast cancer cells indicate that these are rational combinations to test in human clinical trials.

BACKGROUND: Intermittent androgen deprivation for prostate-specific antigen (PSA) elevation after radiotherapy may improve quality of life and delay hormone resistance. We assessed overall survival with intermittent versus continuous androgen deprivation in a noninferiority randomized trial. METHODS: We enrolled patients with a PSA level greater than 3 ng per milliliter more than 1 year after primary or salvage radiotherapy for localized prostate cancer. Intermittent treatment was provided in 8-month cycles, with nontreatment periods determined according to the PSA level. The primary end point was overall survival. Secondary end points included quality of life, time to castration-resistant disease, and duration of nontreatment intervals. RESULTS: Of 1386 enrolled patients, 690 were randomly assigned to intermittent therapy and 696 to continuous therapy. Median follow-up was 6.9 years. There were no significant between-group differences in adverse events. In the intermittent-therapy group, full testosterone recovery occurred in 35% of patients, and testosterone recovery to the trial-entry threshold occurred in 79%. Intermittent therapy provided potential benefits with respect to physical function, fatigue, urinary problems, hot flashes, libido, and erectile function. There were 268 deaths in the intermittent-therapy group and 256 in the continuous-therapy group. Median overall survival was 8.8 years in the intermittent-therapy group versus 9.1 years in the continuous-therapy group (hazard ratio for death, 1.02; 95% confidence interval, 0.86 to 1.21). The estimated 7-year cumulative rates of disease-related death were 18% and 15% in the two groups, respectively (P=0.24). CONCLUSIONS: Intermittent androgen deprivation was noninferior to continuous therapy with respect to overall survival. Some quality-of-life factors improved with intermittent therapy. (Funded by the Canadian Cancer Society Research Institute and others; ClinicalTrials.gov number, NCT00003653.).