Citations

Abstract Background The multicentre ALaCaRT and ACOSOG Z6051 randomized trials were unable to demonstrate non-inferiority of laparoscopic versus open surgery for rectal cancer with respect to a composite pathology metric indicating successful resection. Neither trial was individually powered to detect differences in long-term recurrence or survival. This planned meta-analysis determined long-term oncological outcomes of laparoscopic versus open proctectomy for rectal adenocarcinoma. Methods This prospective meta-analysis included individual patient data from patients with cT1–3 N0–2 M0 rectal adenocarcinoma enrolled in the ALaCaRT and ACOSOG Z6051 trials. Pathologically successful resection was defined as complete or near-complete total mesorectal excision, a clear circumferential resection margin (CRM; > 1 mm), and a clear distal resection margin (> 1 mm). The non-inferiority margin for disease-free survival (DFS) was an absolute difference of 5% at least 3 years after surgery. Results The combined data set included 935 patients (65.6% men, mean age 60.7 years, mean body mass index 26.7 kg/m2) randomized to open (457 patients) or laparoscopic (478 patients) proctectomy. Pathologically successful resection was lower in the laparoscopic than open group (85.1% versus 89.9%, respectively; pooled estimate 4.6% difference; 95% confidence interval (c.i.) −8.6% to −0.5%). The median follow-up was 60.2 (interquartile range 49.9–61.1) months. Three-year DFS was 75.2% (95% c.i. 71.1% to 79.2%) and 76.5% (95% c.i. 72.5% to 80.6%) for the laparoscopic and open groups, respectively (pooled estimate difference −1.5%; 95% c.i. −7.2% to 4.2%). Non-inferiority of laparoscopic surgery was not demonstrated because the lower one-sided 95% c.i. (−6.3% to 100%) crossed −5%. Three-year locoregional recurrence was higher in laparoscopic than open group (5.4% (95% c.i. 3.3% to 7.5%) versus 2.0% (95% c.i. 0.7% to 3.4%), respectively; pooled estimate 3.1% difference (95% c.i. 0.6% to 5.6%)). A clear CRM was the most significant and only pathological predictor of both DFS (P < 0.0001) and overall survival (P < 0.0001). Conclusion Laparoscopic proctectomy led to a lower rate of pathologically successful resection and a higher rate of locoregional recurrence at 3 years. The possibility of subsequent poorer DFS or overall survival rate requires further evaluation, because this analysis was not specifically powered for these endpoints.

Abstract PARP inhibition can enhance the efficacy of temozolomide and prolong survival in orthotopic glioblastoma (GBM) xenografts. The aim of this study was to evaluate the combination of the PARP inhibitor rucaparib with temozolomide and to correlate pharmacokinetic and pharmacodynamic studies with efficacy in patient-derived GBM xenograft models. The combination of rucaparib with temozolomide was highly effective in vitro in short-term explant cultures derived from GBM12, and, similarly, the combination of rucaparib and temozolomide (dosed for 5 days every 28 days for 3 cycles) significantly prolonged the time to tumor regrowth by 40% in heterotopic xenografts. In contrast, the addition of rucaparib had no impact on the efficacy of temozolomide in GBM12 or GBM39 orthotopic models. Using Madin-Darby canine kidney (MDCK) II cells stably expressing murine BCRP1 or human MDR1, cell accumulation studies demonstrated that rucaparib is transported by both transporters. Consistent with the influence of these efflux pumps on central nervous system drug distribution, Mdr1a/b−/−Bcrp1−/− knockout mice had a significantly higher brain to plasma ratio for rucaparib (1.61 ± 0.25) than wild-type mice (0.11 ± 0.08). A pharmacokinetic and pharmacodynamic evaluation after a single dose confirmed limited accumulation of rucaparib in the brain is associated with substantial residual PARP enzymatic activity. Similarly, matrix-assisted laser desorption/ionization mass spectrometric imaging demonstrated significantly enhanced accumulation of drug in flank tumor compared with normal brain or orthotopic tumors. Collectively, these results suggest that limited drug delivery into brain tumors may significantly limit the efficacy of rucaparib combined with temozolomide in GBM. Mol Cancer Ther; 14(12); 2735–43. ©2015 AACR.

Purpose: Radioimmunotherapy (RIT) with yttrium-90 (90Y)-labeled anti-CD20 antibody (90Y ibritumomab tiuxetan; Zevalin, IDEC Pharmaceuticals Corporation, San Diego, CA) has a high rate of tumor response in patients with relapsed or refractory, low-grade, follicular, or transformed B-cell non-Hodgkin’s lymphoma (NHL). This study presents the safety data from 349 patients in five studies of outpatient treatment with 90Y ibritumomab tiuxetan. Patients and Methods: Patients received rituximab 250 mg/m2 on days 1 and 8, and either 0.4 mCi/kg (15 MBq/kg) or 0.3 mCi/kg (11 MBq/kg) of 90Y ibritumomab tiuxetan on day 8 (maximum dose, 32 mCi). Patients were observed for up to 4 years after therapy or until progressive disease. Results: Infusion-related toxicities were typically grade 1 or 2 and were associated with rituximab. No significant organ toxicity was noted. Toxicity was primarily hematologic, with nadir counts occurring at 7 to 9 weeks and lasting approximately 1 to 4 weeks depending on the method of calculation. After the 0.4-mCi/kg dose, grade 4 neutropenia, thrombocytopenia, and anemia occurred in 30%, 10%, and 3% of patients, respectively, and after the 0.3-mCi/kg dose, these grade 4 toxicities occurred in 35%, 14%, and 8% of patients, respectively. The risk of hematologic toxicity increased with degree of baseline bone marrow involvement with NHL. Seven percent of patients were hospitalized with infection (3% with neutropenia) and 2% had grade 3 or 4 bleeding events. Myelodysplasia or acute myelogenous leukemia was reported in five patients (1%) 8 to 34 months after treatment. Conclusion: Single-dose 90Y ibritumomab tiuxetan RIT has an acceptable safety profile in relapsed NHL patients with less than 25% lymphoma marrow involvement, adequate marrow reserve, platelets greater than 100,000 cells/μL, and neutrophils greater than 1,500 cells/μL.

Mildly thrombocytopenic patients with relapsed or refractory low-grade non-Hodgkin lymphoma (NHL) have an increased risk of chemotherapy-induced myelosuppression following treatment. The safety and efficacy of radioimmunotherapy with a reduced dose of90Y ibritumomab tiuxetan (0.3 mCi/kg [11 MBq/kg]; maximum 32 mCi [1.2 GBq]) was evaluated in 30 patients with mild thrombocytopenia (100-149 × 109 platelets/L) who had advanced, relapsed or refractory, low-grade, follicular, or transformed B-cell NHL. The ibritumomab tiuxetan regimen included an infusion of rituximab (250 mg/m2) and injection of 111In ibritumomab tiuxetan (5 mCi [185 MBq]) for dosimetry evaluation, followed 1 week later with rituximab (250 mg/m2) and90Y ibritumomab tiuxetan (0.3 mCi/kg [11 MBq/kg]). Patients (median age, 61 years; 90% stage III/IV at study entry; 83% follicular lymphoma; and 67% with bone marrow involvement) had a median of 2 prior therapy regimens (range, 1-9). Estimated radiation-absorbed doses were well below the study-defined maximum allowable for all 30 patients. With the use of the International Workshop criteria for NHL response assessment, the overall response rate was 83% (37% complete response, 6.7% complete response unconfirmed, and 40% partial response). Kaplan-Meier estimated median time to progression (TTP) was 9.4 months (range, 1.7-24.6). In responders, Kaplan-Meier estimated median TTP was 12.6 months (range, 4.9-24.6), with 35% of data censored. Toxicity was primarily hematologic, transient, and reversible. The incidence of grade 4 neutropenia, thrombocytopenia, and anemia was 33%, 13%, and 3%, respectively. Reduced-dose ibritumomab tiuxetan is safe and well tolerated and has significant clinical activity in this patient population.