Use of letrozole after aromatase inhibitor-based therapy in postmenopausal breast cancer (NRG Oncology/NSABP B-42): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: The optimal duration of extended therapy with aromatase inhibitors in patients with postmenopausal breast cancer is unknown. In the NSABP B-42 study, we aimed to determine whether extended letrozole treatment improves disease-free survival after 5 years of aromatase inhibitor-based therapy in women with postmenopausal breast cancer. METHODS: This randomised, double-blind, placebo-controlled, phase 3 trial was done in 158 centres in the USA, Canada, and Ireland. Postmenopausal women with stage I-IIIA hormone receptor-positive breast cancer, who were disease-free after about 5 years of treatment with an aromatase inhibitor or tamoxifen followed by an aromatase inhibitor, were randomly assigned (1:1) to receive 5 years of letrozole (2·5 mg orally per day) or placebo. Randomisation was stratified by pathological node status, previous tamoxifen use, and lowest bone mineral density T score in the lumbosacral spine, total hip, or femoral neck. The primary endpoint was disease-free survival, defined as time from randomisation to breast cancer recurrence, second primary malignancy, or death, and was analysed by intention to treat. To adjust for previous interim analyses, the two-sided statistical significance level for disease-free survival was set at 0·0418. This study is registered with ClinicalTrials.gov, number NCT00382070, is active, and is no longer enrolling patients. FINDINGS: Between Sept 28, 2006, and Jan 6, 2010, 3966 patients were randomly assigned to receive letrozole (n=1983) or placebo (n=1983). Follow-up information was available for 3903 patients for the analyses of disease-free survival. Median follow-up was 6·9 years (IQR 6·1-7·5). Letrozole treatment did not significantly improve disease-free survival (339 disease-free survival events were reported in the placebo group and 292 disease-free survival events were reported in the letrozole group; hazard ratio 0·85, 95% CI 0·73-0·999; p=0·048). 7-year disease-free survival estimate was 81·3% (95% CI 79·3-83·1) in the placebo group and 84·7% (82·9-86·4) in the letrozole group. The most common grade 3 adverse events were arthralgia (47 [2%] of 1933 patients in the placebo group vs 50 [3%] of 1941 patients in the letrozole group) and back pain (44 [2%] vs 38 [2%]). The most common grade 4 adverse event in the placebo group was thromboembolic event (eight [<1%]) and the most common grade 4 adverse events in the letrozole group were urinary tract infection, hypokalaemia, and left ventricular systolic dysfunction (four [<1%] each). INTERPRETATION: After 5 years of aromatase inhibitor-based therapy, 5 years of letrozole therapy did not significantly prolong disease-free survival compared with placebo. Careful assessment of potential risks and benefits is required before recommending extended letrozole therapy to patients with early-stage breast cancer. FUNDING: National Cancer Institute, Korea Health Technology R&D Project, Novartis.

Phase III trial assessing bevacizumab in stages II and III carcinoma of the colon: results of NSABP protocol C-08.

PURPOSE: The National Surgical Adjuvant Breast and Bowel Project C-08 trial was designed to investigate the safety and efficacy of adding bevacizumab to modified FOLFOX6 (mFOLFOX6; ie, infusional/bolus fluorouracil, leucovorin, and oxaliplatin) for the adjuvant treatment of patients with stages II to III colon cancer. METHODS: Patients received mFOLFOX6 every 2 weeks for 26 weeks alone or modified as FOLFOX6 + bevacizumab (5 mg/kg every 2 weeks for 52 weeks [ie, experimental group]). The primary end point was disease-free survival (DFS). RESULTS: Among 2,672 analyzed patients, demographic factors were well balanced by treatment. With a median follow-up of 35.6 months, the addition of bevacizumab to mFOLFOX6 did not result in an overall significant increase in DFS (hazard ratio [HR], 0.89; 95% CI, 0.76 to 1.04; P = .15). The point estimates for 3-year DFS for the overall population were 77.4% and 75.5% for the experimental and control arms, respectively. For patients with stages II and III diseases, these same estimates were 87.4% and 84.7%, respectively, for stage II and 74.2% and 72.4%, respectively, for stage III. Exploratory analyses found that the effect of bevacizumab on DFS was different before and after a 15-month landmark (time-by-treatment interaction P value < .0001). Bevacizumab had a strong effect before the landmark (HR, 0.61; 95% CI, 0.48 to 0.78; P < .001) but no significant effect after (HR, 1.22; 95% CI, 0.98 to 1.52; P = .076). CONCLUSION: Bevacizumab for 1 year with mFOLFOX6 does not significantly prolong DFS in stages II and III colon cancer. However, a significant but transient effect during bevacizumab exposure was observed in the experimental arm. We postulate that this observation reflects a biologic effect during bevacizumab exposure. Given the lack of improvement in DFS, the use of bevacizumab cannot be recommended for use in the adjuvant treatment of patients with colon cancer.

Initial safety report of NSABP C-08: A randomized phase III study of modified FOLFOX6 with or without bevacizumab for the adjuvant treatment of patients with stage II or III colon cancer.

PURPOSE: The National Surgical Adjuvant Breast and Bowel Project C-08 trial was designed to investigate the safety and effectiveness of adding bevacizumab to modified infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) 6 regimen for the adjuvant treatment of patients with stage II or III colon cancer. We present safety information in advance of the planned analysis of efficacy. PATIENTS AND METHODS: Among 2,710 randomly assigned patients, demographic factors were balanced. Patients received modified FOLFOX6 every 2 weeks x 12 or modified FOLFOX6 plus bevacizumab (5 mg/kg every 2 weeks x 26, experimental group). RESULTS: Overall rates of grade 4 or 5 toxicities were nearly identical in the FOLFOX6 and FOLFOX6 plus bevacizumab arms (15.2% and 15.0%, respectively). Six-month mortality rates were 0.96% and 0.90% for the control and experimental groups, respectively. Grade 3+ toxicities that occurred more often in the experimental arm versus control arm included hypertension (12% v 1.8%, respectively), wound complications (abdominal incisional hernia or infusion port dehiscence/inflammation; 1.7% v 0.3%, respectively), pain (11.1% v 6.3%, respectively), and proteinuria (2.7% v 0.8%, respectively). Grade 2+ neuropathy was increased in the experimental arm versus the control arm (grade 2, 33% v 29%, respectively; grade 3, 16% v 14%, respectively; and grade 4, < 1% each). In the experimental arm versus control arm, significantly less thrombocytopenia (1.4% v 3.4%, respectively) and fewer allergic reactions (3.1% v 4.7%, respectively) were observed. Advanced age was associated with a significantly greater rate of grade 4 and 5 toxicities regardless of treatment. CONCLUSION: Bevacizumab with modified FOLFOX6 is well tolerated in the surgical adjuvant setting in these patients. No significant increase in GI perforation, hemorrhage, arterial or venous thrombotic events, or death with the addition of bevacizumab to modified FOLFOX6 has been observed. Follow-up for potential delayed adverse effects and efficacy is ongoing.

Severe enteropathy among patients with stage II/III colon cancer treated on a randomized trial of bolus 5-fluorouracil/leucovorin plus or minus oxaliplatin: a prospective analysis.

BACKGROUND: Cases of severe gastrointestinal toxicity were monitored prospectively during NSABP C-07, a randomized clinical trial of adjuvant therapy for patients with stage II/III colon cancer. METHODS: Patients were treated with weekly bolus 5-fluorouracil (5-FU) and leucovorin (FL; "Roswell Park Regimen") or the same regimen plus oxaliplatin (FLOX). RESULTS: Of 1857 patients, 79 (4.3%) developed a syndrome of bowel wall injury (BWI, small or large) characterized by hospitalization for the management of severe diarrhea or dehydration and radiographic or endoscopic evidence of bowel wall thickening or ulceration. Fifty-one (64.6%) of these adverse events occurred in patients treated with FLOX and 28 (35.4%) in those treated with FL (P < .01). Enteric sepsis (ES), characterized by grade 3 or greater diarrhea and grade 4 neutropenia with or without proven bacteremia occurred in 22 patients treated with FLOX, versus 8 in those treated with FL (P = .01). Patients >60 years were at higher risk for BWI after treatment with FLOX (6.7%) versus treatment with FL (2.9%, P < .01). Female patients had a higher incidence of BWI with FLOX (9.1%) than with FL (3.9%, P < .01). Severe gastrointestinal toxicity usually occurred during the third or fourth week on the first cycle of therapy, required hospitalization, and was managed with fluids, antidiarrheals, and antibiotics. There were 5 deaths (0.3%) due to enteropathy, 2 related to ES and 3 related to both BWI and ES. Seventy-one percent of patients resumed treatment with FL after recovery. CONCLUSIONS: Patients treated with adjuvant FL should be closely monitored for diarrhea and aggressively managed, especially if oxaliplatin has been added to the regimen. Society.

Neurotoxicity from oxaliplatin combined with weekly bolus fluorouracil and leucovorin as surgical adjuvant chemotherapy for stage II and III colon cancer: NSABP C-07.

PURPOSE: The randomized, multicenter, phase III protocol C-07 compared the efficacy of adjuvant bolus fluorouracil and leucovorin (FULV) versus FULV with oxaliplatin (FLOX) in stage II or III colon cancer. Definitive analysis revealed an increase in 4-year disease-free survival from 67.0% to 73.2% in favor of FLOX. This study compares neurotoxicity between the treatments. PATIENTS AND METHODS: Neurotoxicity was recorded for all patients using standard adverse event reporting. Patients at select institutions completed a neurotoxicity questionnaire through 18 months of follow-up. RESULTS: A total of 2,492 patients enrolled onto C-07 and 400 patients enrolled onto the patient-reported substudy. Mean patient-reported neurotoxicity was higher with oxaliplatin throughout the 18 months of study (P < .0001). During therapy, patients receiving oxaliplatin experienced significantly more hand/foot toxicity (eg, "quite a bit" of cold-induced hand/foot pain 26% FLOX v 2.6% FULV) and overall weakness (eg, moderate weakness in 27.4% FLOX v 16.2% FULV). At 18 months, hand neuropathy had diminished, but patients who received oxaliplatin experienced continued foot discomfort (eg, moderate foot numbness and tingling for 22.1% FLOX v 4.6% FULV). Observer-reported neurotoxicity was low grade and primarily neurosensory rather than neuromotor. Sixty-eight percent in the FLOX group v 8% in the FULV group had neurotoxicity at their first on-treatment assessment. Time to resolution was significantly longer for those receiving oxaliplatin, and continued beyond 2 years for more than 10% in the oxaliplatin group. CONCLUSION: Oxaliplatin causes significant neurotoxicity. It is experienced primarily in the hands during therapy and in the feet during follow-up. In a minority of patients the neurotoxicity is long lasting.

Oxaliplatin combined with weekly bolus fluorouracil and leucovorin as surgical adjuvant chemotherapy for stage II and III colon cancer: results from NSABP C-07.

PURPOSE: This phase III clinical trial evaluated the impact on disease-free survival (DFS) of adding oxaliplatin to bolus weekly fluorouracil (FU) combined with leucovorin as surgical adjuvant therapy for stage II and III colon cancer. PATIENTS AND METHODS: Patients who had undergone a potentially curative resection were randomly assigned to either FU 500 mg/m2 intravenous (IV) bolus weekly for 6 weeks plus leucovorin 500 mg/m2 IV weekly for 6 weeks during each 8-week cycle for three cycles (FULV), or the same FULV regimen with oxaliplatin 85 mg/m2 IV administered on weeks 1, 3, and 5 of each 8-week cycle for three cycles (FLOX). RESULTS: A total of 2,407 patients (96.6%) of the 2,492 patients randomly assigned were eligible. Median follow-up for patients still alive is 42.5 months. The hazard ratio (FLOX v FULV) is 0.80 (95% CI, 0.69 to 0.93), a 20% risk reduction in favor of FLOX (P < .004). The 3- and 4-year disease-free survival (DFS) rates were 71.8% and 67.0% for FULV and 76.1% and 73.2% for FLOX, respectively. Grade 3 neurosensory toxicity was noted in 8.2% of patients receiving FLOX and in 0.7% of those receiving FULV (P < .001). Hospitalization for diarrhea associated with bowel wall thickening occurred in 5.5% of the patients receiving FLOX and in 3.0% of the patients receiving FULV (P < .01). A total of 1.2% of patients died as a result of any cause within 60 days of receiving chemotherapy, with no significant difference between regimens. CONCLUSION: The addition of oxaliplatin to weekly FULV significantly improved DFS in patients with stage II and III colon cancer. FLOX can be recommended as an effective option in clinical practice.

Oral uracil and tegafur plus leucovorin compared with intravenous fluorouracil and leucovorin in stage II and III carcinoma of the colon: results from National Surgical Adjuvant Breast and Bowel Project Protocol C-06.

PURPOSE: The primary aim of this study was to compare the relative efficacy of oral uracil and tegafur (UFT) plus leucovorin (LV) with the efficacy of weekly intravenous fluorouracil (FU) plus LV in prolonging disease-free survival (DFS) and overall survival (OS) after primary surgery for colon carcinoma. PATIENTS AND METHODS: Between February 1997 and March 1999, 1,608 patients with stage II and III carcinoma of the colon were randomly assigned to receive either oral UFT+LV or intravenous FU+LV. RESULTS: Of the total patients, 47% had stage II colon cancer, and 53% had stage III colon cancer. Median follow-up time was 62.3 months. The estimated hazard ratio (HR) for OS of patients who received UFT+LV versus that of patients who received FU+LV was 1.014 (95% CI, 0.825 to 1.246). The estimated HR for DFS was 1.004 (95% CI, 0.847 to 1.190). Cox proportional hazards model analyses with regard to age (< 60 v > or = 60 years), stage, or number of involved nodes (none v one to three v > or = four nodes) revealed no interaction with OS or DFS. Toxicity was similar in the two groups. In the UFT+LV arm, 38.2% of patients experienced any grade 3 or 4 toxic event compared with 37.8% of patients in the FU+LV arm. Primary quality-of-life end points did not differ between the two regimens, although convenience of care analysis favored UFT+LV. CONCLUSION: UFT+LV achieved similar DFS and OS when compared with an intravenous, weekly, bolus FU+LV regimen. The two regimens were equitoxic and generally well tolerated.