Sharlene Gill

Phase III Trial of Bevacizumab in Combination With Gemcitabine and Erlotinib in Patients With Metastatic Pancreatic Cancer

PURPOSE Treatment with gemcitabine provides modest benefits in patients with metastatic pancreatic cancer. The addition of erlotinib to gemcitabine shows a small but significant improvement in overall survival (OS) versus gemcitabine alone. Phase II results for bevacizumab plus gemcitabine provided the rationale for a phase III trial of gemcitabine-erlotinib plus bevacizumab or placebo. PATIENTS AND METHODS Patients with metastatic pancreatic adenocarcinoma were randomly assigned to receive gemcitabine (1,000 mg/m(2)/week), erlotinib (100 mg/day), and bevacizumab (5 mg/kg every 2 weeks) or gemcitabine, erlotinib, and placebo in this double-blind, phase III trial. Primary end point was OS; secondary end points included progression-free survival (PFS), disease control rate, and safety. RESULTS A total of 301 patients were randomly assigned to the placebo group and 306 to the bevacizumab group. Median OS was 7.1 and 6.0 months in the bevacizumab and placebo arms, respectively (hazard ratio [HR], 0.89; 95% CI, 0.74 to 1.07; P = .2087); this difference was not statistically significant. Adding bevacizumab to gemcitabine-erlotinib significantly improved PFS (HR, 0.73; 95% CI, 0.61 to 0.86; P = .0002). Treatment with bevacizumab plus gemcitabine-erlotinib was well tolerated: safety data did not differ from previously described safety profiles for individual drugs. CONCLUSION The primary objective was not met. The addition of bevacizumab to gemcitabine-erlotinib did not lead to a statistically significant improvement in OS in patients with metastatic pancreatic cancer. PFS, however, was significantly longer in the bevacizumab group compared with placebo. No unexpected safety events were observed from adding bevacizumab to gemcitabine-erlotinib.

Effect of oxaliplatin, fluorouracil, and leucovorin with or without cetuximab on survival among patients with resected stage III colon cancer: a randomized trial.

CONTEXT Leucovorin, fluorouracil, and oxaliplatin (FOLFOX) is the standard adjuvant therapy for resected stage III colon cancer. Adding cetuximab to FOLFOX benefits patients with metastatic wild-type KRAS but not mutated KRAS colon cancer. OBJECTIVE To assess the potential benefit of cetuximab added to the modified sixth version of the FOLFOX regimen (mFOLFOX6) in patients with resected stage III wild-type KRAS colon cancer. DESIGN, SETTING, AND PARTICIPANTS A randomized trial of 2686 patients aged 18 years or older at multiple institutions across North America enrolled following resection and informed consent between February 10, 2004, and November 25, 2009. The primary randomized comparison was 12 biweekly cycles of mFOLFOX6 with and without cetuximab. KRAS mutation status was centrally determined. The trial was halted after a planned interim analysis of 48% of predicted events (246/515) occurring in 1863 (of 2070 planned) patients with tumors having wild-type KRAS. A total of 717 patients with mutated KRAS and 106 with indeterminate KRAS were accrued. The 2070 patients with wild-type KRAS provided 90% power to detect a hazard ratio (HR) of 1.33 (2-sided α = .05), with planned interim efficacy analyses after 25%, 50%, and 75% of expected relapses. MAIN OUTCOME MEASURES Disease-free survival in patients with wild-type KRAS mutations. Secondary end points included overall survival and toxicity. RESULTS Median (range) follow-up was 28 (0-68) months. The trial demonstrated no benefit when adding cetuximab. Three-year disease-free survival for mFOLFOX6 alone was 74.6% vs 71.5% with the addition of cetuximab (HR, 1.21; 95% CI, 0.98-1.49; P = .08) in patients with wild-type KRAS, and 67.1% vs 65.0% (HR, 1.12; 95% CI, 0.86-1.46; P = .38) in patients with mutated KRAS, with no significant benefit in any subgroups assessed. Among all patients, grade 3 or higher adverse events (72.5% vs 52.3%; odds ratio [OR], 2.4; 95% CI, 2.1-2.8; P < .001) and failure to complete 12 cycles (33% vs 23%; OR, 1.6; 95% CI, 1.4-1.9; P < .001) were significantly higher with cetuximab. Increased toxicity and greater detrimental differences in all outcomes were observed in patients aged 70 years or older. CONCLUSION Among patients with stage III resected colon cancer, the use of cetuximab with adjuvant mFOLFOX6 compared with mFOLFOX6 alone did not result in improved disease-free survival. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00079274.

Asian Ethnicity–Related Differences in Gastric Cancer Presentation and Outcome Among Patients Treated at a Canadian Cancer Center

PURPOSE Differences in stage-stratified survival have been reported between Asian and Western populations with gastric cancer. This study examines differences in presentation and outcomes among Asian and non-Asian patients evaluated and treated at a Canadian institution. PATIENTS AND METHODS We reviewed 2,043 patients (159 Asians and 1,884 non-Asians) with gastric adenocarcinoma treated between 1978 and 1997. Overall survival was examined by the Kaplan-Meier method, and multivariable analysis by Cox proportional hazards was used to identify whether Asian ethnicity had independent prognostic significance for survival. RESULTS Median survival was 13.1 months for Asians and 11.1 months for non-Asians (P =.0016). Asian patients were younger and had a greater proportion of signet ring cell histology but were less likely to have proximal disease. Signet ring cell histology did not adversely affect survival. By multivariable analysis, proximal location, poor differentiation, and extent of disease were independently associated with worse survival. Survival was improved with curative resection, palliative resection, and palliative chemotherapy. Asian ethnicity was not independently associated with survival (hazard ratio, 0.89; 95% confidence interval, 0.74 to 1.08). Although a similar proportion of patients underwent curative resection, an interaction was observed between Asian ethnicity and efficacy of resection, with Asians achieving a greater benefit as compared with non-Asians even when adjusted for age and location. CONCLUSION The disparity between Eastern and Western gastric cancer survival is not explained by the hypothesis of ethnicity-related differences in tumor biology. Although it is not an independent predictor of survival, Asian ethnicity is associated with distinct characteristics at presentation and more favorable outcomes after curative surgery.

Phase 2 trial of linifanib (ABT-869) in patients with unresectable or metastatic hepatocellular carcinoma

The efficacy and safety of linifanib (ABT‐869), a selective inhibitor of vascular endothelial growth factor and platelet‐derived growth factor receptor tyrosine kinases, were assessed in this phase 2, single‐arm, open‐label, multicenter trial.

Chemotherapy regimens for advanced pancreatic cancer: a systematic review and network meta-analysis

BackgroundAdvanced pancreatic cancer confers poor prognosis and treatment advancement has been slow. Recent randomized clinical trials (RCTs) have demonstrated survival benefits for combination therapy compared to gemcitabine alone. However, the comparative benefits and harms of available combination chemotherapy treatments are not clear. We therefore conducted a systematic review and Bayesian network meta-analysis to assess the comparative safety and efficacy of chemotherapy regimens for the treatment of advanced pancreatic cancer.MethodsMEDLINE, PubMed, EMBASE, Cochrane Central Registry of Clinical trials and abstracts from major scientific meetings were searched for RCTs published from 2002 to 2013. Key outcomes were overall survival (OS), progression free survival (PFS), and safety including grade 3–4 febrile neutropenia, neutropenia, vomiting, diarrhea, fatigue and sensory neuropathy. Bayesian network meta-analyses were conducted to calculate survival and safety outcomes using gemcitabine (GEM) as the reference comparator. Effect estimates and 95% credible intervals were calculated for each comparison. Mean ranks and the probability of being best were obtained for each treatment analyzed in the network meta-analysis.ResultsThe search identified 23 studies involving 19 different treatment regimens and 9,989 patients. FOLFIRINOX, GEM/cisplatin/epirubicin/5FU (PEFG), GEM/NAB-paclitaxel (NAB-P), GEM/erlotinib+/-bevacizumab, GEM/capecitabine, and GEM/oxaliplatin were associated with statistically significant improvements in OS and PFS relative to gemcitabine alone and several other treatments. They were amongst the top ranked for survival outcomes amongst other treatments included. No significant differences were found for other combination chemotherapy treatments. Effect estimates from indirect comparisons matched closely to estimates derived from pairwise comparisons. Overall, combination therapies had greater risk for evaluated grade 3–4 toxicities over gemcitabine alone.ConclusionsIn the absence of head-to-head comparisons, we performed a mixed-treatment analysis to achieve high-quality information on the effectiveness and safety of each treatment. This study suggests that some combination therapies may offer greater benefits in the treatment of advanced pancreatic cancer than others. To more fully elucidate the comparative benefits and harms of different combination chemotherapy regimens, rigorously conducted comparative studies, or network meta-analysis of patient-level data are required.

Obstacles to residents' conducting research and predictors of publication.

Internal medicine residents at one school identified barriers to and predictors of publishing their research. Insufficient time was the key obstacle to completing research. Residents with previous research experience, senior residents, and men were more likely to publish.

Isolated Loss of PMS2 Expression in Colorectal Cancers: Frequency, Patient Age, and Familial Aggregation

Purpose: Most colorectal cancers that have high levels of microsatellite instability (MSI-H) show loss of immunohistochemical expression of proteins that participate in the DNA mismatch repair process, most often involving MLH1 and MSH2. Less commonly, a third DNA mismatch repair protein, MSH6, may also be lost as the primary event. Rarely, tumors with MSI-H show normal expression of these three proteins. The genetic deficiency leading to the MSI-H phenotype in such cases is unknown. PMS2 is another member of the DNA mismatch repair complex. Its expression is generally lost in tumors with MLH1 loss of expression. Rarely, there is selective loss of PMS2 expression. We sought to describe the frequency and clinical correlates of selective loss of expression of PMS2 with the MSI-H tumor phenotype. Experimental Design: Two thousand seven hundred nineteen colorectal cancers from both clinic- and research-based ascertainment were studied. Tumor MSI testing and immunohistochemistry for MLH1, MSH2, MSH6, and PMS2 were conducted. Medical records were abstracted for age at diagnosis, gender, colorectal cancer site, and family history. Results: Five hundred thirty-five of the 2,719 tumors were MSI-H. Of these, 93% showed loss of expression of MLH1, MSH2, and/or MSH6. Thirty-eight showed normal expression for these proteins. PMS2 immunohistochemical staining was successful in 32 of 38 of these tumors. Of the 32, 23 showed selective loss of expression of PMS2. This was associated with young age of diagnosis and right-sided location but not with a striking family history of cancer. Conclusions: Overall, 97% of the MSI-H tumors showed loss of expression for one or more of these four mismatch repair proteins. Selective loss of expression of PMS2 was present in 72% of cases in which colorectal cancers had an MSI-H phenotype but no alteration of expression of MLH1, MSH2, and MSH6. The underlying mechanism involved cannot be determined from this study but could involve point mutations in other DNA mismatch repair genes with retention of immunohistochemical expression, somatic inactivation of PMS2, or germ line mutation of PMS2.

Validation of predictive models for germline mutations in DNA mismatch repair genes in colorectal cancer

Lynch syndrome is defined by the presence of germline mutations in mismatch repair (MMR) genes. Several models have been recently devised that predict mutation carrier status (Myriad Genetics, Wijnen, Barnetson, PREMM and MMRpro models). Families at moderate‐high risk for harboring a Lynch‐associated mutation, referred to the BC Cancer Agency (BCCA) Hereditary Cancer Program (HCP), underwent mutation analysis, immunohistochemistry and/or microsatellite testing. Seventy‐two tested cases were included. Twenty‐five patients were mutation positive (34.7%) and 47 were mutation negative (65.3%). Nineteen of 43 patients who were both microsatellite stable and normal on immunohistochemistry for MLH1 and MSH2 were also genotyped for mutations in these genes; all 19 were negative for MMR gene mutations. Model‐derived probabilities of harboring a MMR gene mutation in the proband were calculated and compared to observed results. The area under the ROC curves were 0.75 (95%CI; 0.63–0.87), 0.86 (0.7–0.96), 0.89 (0.82–0.97), 0.89 (0.81–0.98) and 0.93 (0.86–0.99) for the Myriad, Barnetson, Wijnen, MMRpro and PREMM models, respectively. The Amsterdam II criteria had a sensitivity and specificity of 0.76 and 0.74, respectively, in this cohort. The PREMM model demonstrated the best performance for predicting carrier status based on the positive likelihood ratios at the >10%, >20% and >30% probability thresholds. In this referred cohort, the PREMM model had the most favorable concordance index and predictive performance for carrier status based on the positive LR. These prediction models (PREMM, MMRPro and Wijnen) may soon replace the Amsterdam II and revised Bethesda criteria as a prescreening tool for Lynch mutations.

PANCREOX: A Randomized Phase III Study of Fluorouracil/Leucovorin With or Without Oxaliplatin for Second-Line Advanced Pancreatic Cancer in Patients Who Have Received Gemcitabine-Based Chemotherapy.

Purpose The standard of care for second-line therapy in patients with advanced pancreatic cancer after gemcitabine-based therapy is not clearly defined. The CONKO-003 phase III study reported a survival benefit with second-line fluorouracil (FU) and oxaliplatin using the oxaliplatin, folinic acid, and FU (OFF) regimen. 1 PANCREOX was a phase III multicenter trial to evaluate the benefit of FU and oxaliplatin administered as modified FOLFOX6 (mFOLFOX6; infusional fluorouracil, leucovorin, and oxaliplatin) versus infusional FU/leucovorin (LV) in this setting. Patients and Methods Patients with confirmed advanced pancreatic cancer who were previously treated with gemcitabine therapy and with an Eastern Cooperative Oncology Group performance status of 0-2 were eligible. A total of 108 patients were randomly assigned to receive biweekly mFOLFOX6 or infusional FU/LV until progression. Progression-free survival (PFS) was the primary end point. Results Baseline patient characteristics were similar in both arms. No difference was observed in PFS (median, 3.1 months v 2.9 months; P = .99). Overall survival (OS) was inferior in patients assigned to mFOLFOX6 (median, 6.1 months v 9.9 months; P = .02). Increased toxicity was observed with the addition of oxaliplatin, with grade 3/4 adverse events occurring in 63% of patients who received mFOLFOX6 and 11% of those who received FU/LV. More patients in the mFOLFOX6 arm withdrew from study due to adverse events than in the FU/LV arm (20% v 2%), whereas the use of postprogression therapy was significantly higher in the FU/LV arm (25% v 7%; P = .015). No significant differences were observed in time to deterioration on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 global health scale. Conclusion No benefit was observed with the addition of oxaliplatin, administered as mFOLFOX6, versus infusional FU/LV in patients with advanced pancreatic cancer previously treated with first-line gemcitabine.

Adjuvant chemotherapy for stage III colon cancer: does timing matter?

BACKGROUND: Clinical trials commonly mandate that adjuvant chemotherapy for colon cancer should commence within 8 weeks (56 days) of surgery. OBJECTIVE: We investigated the consequences of the timing of adjuvant chemotherapy for stage III colon cancer. PATIENTS AND METHODS: This is a retrospective review of all patients with newly diagnosed stage III colon cancer who received adjuvant chemotherapy in 2 provincial centers in 1999 and 2000. The impact of time to adjuvant chemotherapy on overall survival and relapse-free survival was analyzed by the use of univariate and multivariate Cox modeling, adjusting for prognostic factors. RESULTS: Three hundred forty-five subjects were included. Median time to adjuvant chemotherapy was 50 days (range, 20–242 days); in 111 (32.2%) patients, it was beyond 56 days. On univariate analysis, time >56 days was nonsignificantly associated with a hazard ratio of death of 1.31 (P = .12). Similar results were seen for relapse-free survival. Planned exploratory analysis suggests that the commencement of adjuvant chemotherapy up to 10 weeks postsurgery still confers a benefit. CONCLUSIONS: Delaying adjuvant chemotherapy in stage III colon cancer beyond 8 to 10 weeks postsurgery appears to be associated with diminished benefit.