Cetuximab for the treatment of colorectal cancer

BACKGROUND

Cetuximab, an IgG1 chimeric monoclonal antibody against epidermal growth factor receptor (EGFR), has activity against colorectal cancers that express EGFR.

METHODS

From December 2003 to August 2005, 572 patients who had colorectal cancer expressing immunohistochemically detectable EGFR and who had been previously treated with a fluoropyrimidine, irinotecan, and oxaliplatin or had contraindications to treatment with these drugs underwent randomization to an initial dose of 400 mg of cetuximab per square meter of body-surface area followed by a weekly infusion of 250 mg per square meter plus best supportive care (287 patients) or best supportive care alone (285 patients). The primary end point was overall survival.

RESULTS

In comparison with best supportive care alone, cetuximab treatment was associated with a significant improvement in overall survival (hazard ratio for death, 0.77; 95% confidence interval [CI], 0.64 to 0.92; P=0.005) and in progression-free survival (hazard ratio for disease progression or death, 0.68; 95% CI, 0.57 to 0.80; P<0.001). These benefits were robust after adjustment in a multivariable Cox proportional-hazards model. The median overall survival was 6.1 months in the cetuximab group and 4.6 months in the group assigned to supportive care alone. Partial responses occurred in 23 patients (8.0%) in the cetuximab group but in none in the group assigned to supportive care alone (P<0.001); the disease was stable in an additional 31.4% of patients assigned to cetuximab and in 10.9% of patients assigned to supportive care alone (P<0.001). Quality of life was better preserved in the cetuximab group, with less deterioration in physical function and global health status scores (both P<0.05). Cetuximab treatment was associated with a characteristic rash; a rash of grade 2 or higher was strongly associated with improved survival (hazard ratio for death, 0.33; 95% CI, 0.22 to 0.50; P<0.001). The incidence of any adverse event of grade 3 or higher was 78.5% in the cetuximab group and 59.1% in the group assigned to supportive care alone (P<0.001).

CONCLUSIONS

Cetuximab improves overall survival and progression-free survival and preserves quality-of-life measures in patients with colorectal cancer in whom other treatments have failed. (ClinicalTrials.gov number, NCT00079066 [ClinicalTrials.gov].).

ESMO Consensus Guidelines for management of patients with colon and rectal cancer. a personalized approach to clinical decision making

Colorectal cancer (CRC) is the most common tumour type in both sexes combined in Western countries. Although screening programmes including the implementation of faecal occult blood test and colonoscopy might be able to reduce mortality by removing precursor lesions and by making diagnosis at an earlier stage, the burden of disease and mortality is still high. Improvement of diagnostic and treatment options increased staging accuracy, functional outcome for early stages as well as survival. Although high quality surgery is still the mainstay of curative treatment, the management of CRC must be a multi-modal approach performed by an experienced multi-disciplinary expert team. Optimal choice of the individual treatment modality according to disease localization and extent, tumour biology and patient factors is able to maintain quality of life, enables long-term survival and even cure in selected patients by a combination of chemotherapy and surgery. Treatment decisions must be based on the available evidence, which has been the basis for this consensus conference-based guideline delivering a clear proposal for diagnostic and treatment measures in each stage of rectal and colon cancer and the individual clinical situations. This ESMO guideline is recommended to be used as the basis for treatment and management decisions.

Capecitabine plus oxaliplatin compared with fluorouracil and folinic acid as adjuvant therapy for stage III colon cancer

PURPOSE

This multicenter, randomized trial compared capecitabine plus oxaliplatin (XELOX) with bolus fluorouracil (FU) and folinic acid (FA) as adjuvant therapy for patients with stage III colon cancer.

PATIENTS AND METHODS

Patients who had undergone curative resection were randomly assigned to XELOX (oxaliplatin 130 mg/m(2) on day 1 plus capecitabine 1,000 mg/m(2) twice daily on days 1 to 14 every 3 weeks for 24 weeks) or a standard bolus FU/FA adjuvant regimen (Mayo Clinic for 24 weeks or Roswell Park for 32 weeks). The primary study end point was disease-free survival (DFS).

RESULTS

The intention-to-treat population comprised 1,886 patients; 944 patients were randomly assigned to XELOX and 942 to FU/FA (Mayo Clinic, n = 664; Roswell Park, n = 278). After 57 months of follow-up for the primary analysis, 295 patients (31.3%) in the XELOX group had relapsed, developed a new primary colon cancer, or died compared with 353 patients (37.5%) in the FU/FA group (hazard ratio [HR] for DFS, 0.80; 95% CI, 0.69 to 0.93; P = .0045). The 3-year DFS rate was 70.9% with XELOX and 66.5% with FU/FA. The HR for overall survival (OS) for XELOX compared to FU/FA was 0.87 (95% CI, 0.72 to 1.05; P = .1486). The 5-year OS for XELOX and FU/FA were 77.6% and 74.2%, respectively. Follow-up is ongoing. Preplanned multivariate and subgroup analyses supported the robustness of these findings.

CONCLUSION

The addition of oxaliplatin to capecitabine improves DFS in patients with stage III colon cancer. XELOX is an additional adjuvant treatment option for these patients.

HER2 screening data from ToGA: targeting HER2 in gastric and gastroesophageal junction cancer

BACKGROUND

In the Trastuzumab for GAstric cancer (ToGA) study, trastuzumab plus chemotherapy improved median overall survival by 2.7 months in patients with human epidermal growth factor receptor 2 (HER2)-positive [immunohistochemistry (IHC) 3+/fluorescence in situ hybridization-positive] gastric/gastroesophageal junction cancer compared with chemotherapy alone (hazard ratio 0.74). Post hoc exploratory analyses in patients expressing higher HER2 levels (IHC 2+/fluorescence in situ hybridization-positive or IHC 3+) demonstrated a 4.2-month improvement in median overall survival with trastuzumab (hazard ratio 0.65). The ToGA study provides the largest screening dataset available on HER2 overexpression/amplification in this indication. We further analyzed correlation(s) of HER2 overexpression/amplification with clinical and epidemiological factors.

METHODS

HER2-positivity was analyzed by histological subtype, tumor location, geographic region, and specimen type. Exploratory efficacy analyses were performed.

RESULTS

The HER2-positivity rate was 22.1 % across analyzed tumor samples. Rates were similar between European and Asian patients (23.6 % vs. 23.9 %), but higher in intestinal- vs. diffuse-type (31.8 % vs. 6.1 %), and gastroesophageal junction cancer versus gastric tumors (32.2 % vs. 21.4 %). Across all IHC scores, variability in HER2 staining (≤30 % stained cells) was observed in almost 50 % of cases, with increasing rates in lower IHC categories, and did not affect treatment outcome. The polysomy rate was 4 %.

CONCLUSIONS

HER2 expression varies by tumor location and type. All patients with advanced gastric or gastroesophageal junction cancer should be tested for HER2 status, preferably using IHC initially. Due to the unique characteristics of gastric cancer, specific testing/scoring guidelines should be adhered to.

Prospective randomized trial comparing mitomycin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) With epirubicin, cisplatin, and PVI 5-FU in advanced esophagogastric cancer

PURPOSE

We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous-infusion fluorouracil (PVI 5-FU) (ECF) with the combination of mitomycin, cisplatin, and PVI 5-FU (MCF) in previously untreated patients with advanced esophagogastric cancer.

PATIENTS AND METHODS

Five hundred eighty patients with adenocarcinoma, squamous carcinoma, or undifferentiated carcinoma were randomized to receive either ECF (epirubicin 50 mg/m(2) every 3 weeks, cisplatin 60 mg/m(2) every 3 weeks and PVI 5-FU 200 mg/m(2)/d) or MCF (mitomycin 7 mg/m(2) every 6 weeks, cisplatin 60 mg/m(2) every 3 weeks, and PVI 5-FU 300 mg/m(2)/d) and analyzed for survival, response, toxicity, and quality of life (QOL).

RESULTS

The overall response rate was 42.4% (95% confidence interval [CI], 37% to 48%) with ECF and 44.1% (95% CI, 38% to 50%) with MCF (P =.692). Toxicity was tolerable, and there were only two toxic deaths. ECF resulted in more grade 3/4 neutropenia and grade 2 alopecia, but MCF caused more thrombocytopenia and plantar-palmar erythema. Median survival was 9.4 months with ECF and 8.7 months with MCF (P =.315); at 1 year, 40.2% (95% CI, 34% to 46%) of ECF and 32.7% (95% CI, 27% to 38%) of MCF patients were alive. Median failure-free survival was 7 months with both regimens. Global QOL scores were better with ECF at 3 and 6 months.

CONCLUSION

This study confirms response, survival, and QOL benefits of ECF observed in a previous randomized study. The equivalent efficacy of MCF was demonstrated, but QOL was superior with ECF. ECF remains one of the reference treatments for advanced esophagogastric cancer.

Directional selection and the evolution of breeding date in birds

In many bird species, those pairs that breed earlier in the season have higher reproductive success than those that breed later. Since breeding date is known to be heritable, it is unclear why it does not evolve to an earlier time. Under assumptions outlined by Fisher, a model is developed that shows how breeding date may have considerable additive genetic variance, appear to be under directional selection, and yet not evolve. These results provide a general explanation for a persistent correlation of fitness with a variety of traits in natural populations.

Silent MRI infarcts and the risk of future stroke: the cardiovascular health study

BACKGROUND

Silent infarcts are commonly discovered on cranial MRI in the elderly.

OBJECTIVE

To examine the association between risk of stroke and presence of silent infarcts, alone and in combination with other stroke risk factors.

METHODS

Participants (3,324) in the Cardiovascular Health Study (CHS) without a history of stroke underwent cranial MRI scans between 1992 and 1994. Silent infarcts were defined as focal lesions greater than 3 mm that were hyperintense on T2 images and, if subcortical, hypointense on T1 images. Incident strokes were identified and classified over an average follow-up of 4 years. The authors evaluated the risk of subsequent symptomatic stroke and how it was modified by other potential stroke risk factors among those with silent infarcts.

RESULTS

Approximately 28% of CHS participants had evidence of silent infarcts (n = 923). The incidence of stroke was 18.7 per 1,000 person-years in those with silent infarcts (n = 67) compared with 9.5 per 1,000 person-years in the absence of silent infarcts. The adjusted relative risk of incident stroke increased with multiple (more than one) silent infarcts (hazard ratio 1.9 [1.2 to 2.8]). Higher values of diastolic and systolic blood pressure, common and internal carotid wall thickness, and the presence of atrial fibrillation were associated with an increased risk of strokes in those with silent infarcts (n = 53 strokes).

CONCLUSION

The presence of silent cerebral infarcts on MRI is an independent predictor of the risk of symptomatic stroke over a 4-year follow- up in older individuals without a clinical history of stroke.

Serial circulating tumour DNA analysis during multimodality treatment of locally advanced rectal cancer: a prospective biomarker study

OBJECTIVE

For patients with locally advanced rectal cancer (LARC), adjuvant chemotherapy selection following surgery remains a major clinical dilemma. Here, we investigated the ability of circulating tumour DNA (ctDNA) to improve risk stratification in patients with LARC.

DESIGN

We enrolled patients with LARC (T3/T4 and/or N+) planned for neoadjuvant chemoradiotherapy. Plasma samples were collected pretreatment, postchemoradiotherapy and 4-10 weeks after surgery. Somatic mutations in individual patient's tumour were identified via massively parallel sequencing of 15 genes commonly mutated in colorectal cancer. We then designed personalised assays to quantify ctDNA in plasma samples. Patients received adjuvant therapy at clinician discretion, blinded to the ctDNA results.

RESULTS

We analysed 462 serial plasma samples from 159 patients. ctDNA was detectable in 77%, 8.3% and 12% of pretreatment, postchemoradiotherapy and postsurgery plasma samples. Significantly worse recurrence-free survival was seen if ctDNA was detectable after chemoradiotherapy (HR 6.6; P<0.001) or after surgery (HR 13.0; P<0.001). The estimated 3-year recurrence-free survival was 33% for the postoperative ctDNA-positive patients and 87% for the postoperative ctDNA-negative patients. Postoperative ctDNA detection was predictive of recurrence irrespective of adjuvant chemotherapy use (chemotherapy: HR 10.0; P<0.001; without chemotherapy: HR 22.0; P<0.001). Postoperative ctDNA status remained an independent predictor of recurrence-free survival after adjusting for known clinicopathological risk factors (HR 6.0; P<0.001).

CONCLUSION

Postoperative ctDNA analysis stratifies patients with LARC into subsets that are either at very high or at low risk of recurrence, independent of conventional clinicopathological risk factors. ctDNA analysis could potentially be used to guide patient selection for adjuvant chemotherapy.

Correlated evolution and independent contrasts

The use of the independent contrast method in comparative tests is studied. It is assumed that: (i) the traits under investigation are subject to natural selection; (ii) closely related species are similar because they share many characteristics of their niche, inherited from a common ancestor; and (iii) the current adaptive significance of the traits is the focus of investigation. The main objection to the use of species values in this case is that third variables which are shared by closely related species confound the relationship between the focal traits. In this paper, I argue that third variables are largely not controlled by the contrast methods, which are designed to estimate correlated evolution. To the extent that third variables also show correlated evolution, the true relationship among the traits of interest will remain obscured. Although the independent contrast method does not resolve the influence of third traits it does, in principle, provide a greater resolution than the use of the species mean values. However, its validity depends on the applicability of an evolutionary model which has a substantial stochastic component. To illustrate the consequences of relaxing this assumption I consider an alternative model of an adaptive radiation, where species come to fill a fixed niche space. Under this model, the expected value for the contrast correlation differs from that for the species correlation. The two correlations differ because contrasts reflect the historical pattern of diversification among species, whereas the species values describe the present-day relationships among the species. If the latter is of interest, I suggest that assessing significance based on the species correlations can be justified, providing that attention is paid to the role of potentially confounding third traits. Often, differences between contrast and species correlations may be biologically informative, reflecting changes in correlations between traits as an adaptive radiation proceeds; contrasts may be particularly useful as a means of investigating past history, rather than current utility of traits.

Honesty, perception and population divergence in sexually selected traits

We investigate the evolution of female preference for one and two male ornaments, to address two issues in sexual selection: (i) what factors affect the evolution of female preferences; and (ii) how do preferences diverge between isolated populations, leading to speciation? We assume that the male traits are costly indicators of male condition ('handicaps'), and that females benefit directly from a high-condition mate. We find that optimal female preference for a single male trait equals (benefit of condition) x (detectability of male trait) x (honesty of male trait)/(costliness of preference). With two male traits to choose from, females should prefer the one with greatest honesty x detectability, and ignore the second. These results highlight the role of perception in the evolution of both male ornaments and female preferences, and provide a theoretical illustration of 'sensory drive'. They confirm that a less honest male trait can displace a more honest trait if its detectability is sufficiently high. Environmental differences can drive evolutionary divergence between populations in both the male trait and female preference. Even small differences between habitats in detectability of male traits can trigger dramatic change in the female preference. Finally, populations may drift apart in arbitrary directions if choice of different male traits yields equivalent benefits to females.

Phase III trial of capecitabine plus oxaliplatin as adjuvant therapy for stage III colon cancer: a planned safety analysis in 1,864 patients

PURPOSE

To report the results of a planned safety analysis from a phase III trial comparing capecitabine plus oxaliplatin (XELOX) with bolus fluorouracil/leucovorin (FU/LV) as adjuvant therapy for stage III colon cancer.

PATIENTS AND METHODS

Patients with stage III colon carcinoma were randomly assigned to receive either XELOX (intravenous oxaliplatin plus oral capecitabine; 3-week cycle for eight cycles) or standard intravenous bolus FU/LV administered as the Mayo Clinic (Mayo; Rochester, MN) or Roswell Park (RP; Buffalo, NY) regimen for a similar length of time. A total of 1,886 patients were randomly assigned.

RESULTS

The safety population comprised 1,864 patients, of whom 938 received XELOX and 926 received FU/LV. Most treatment-related adverse events (AEs) occurred at similar rates in both treatment arms. However, patients receiving XELOX experienced less all-grade diarrhea, alopecia, and more neurosensory toxicity, vomiting, and hand-foot syndrome than those patients receiving FU/LV. Compared with Mayo, XELOX showed fewer grade 3/4 hematologic AE and more grade 3/4 gastrointestinal AE. Compared with RP, XELOX showed less grade 3/4 gastrointestinal AE and more grade 3/4 hematologic AE. As expected grade 3/4 neurosensory toxicity and grade 3 hand-foot syndrome were higher with XELOX. Treatment-related mortality within 28 days from the last study dose was 0.6% in the XELOX group and 0.6% in the FU/LV group.

CONCLUSION

XELOX has a manageable tolerability profile in the adjuvant setting. Efficacy data will be available within the next 24 months.

Capecitabine Plus Oxaliplatin Compared With Fluorouracil/Folinic Acid As Adjuvant Therapy for Stage III Colon Cancer: Final Results of the NO16968 Randomized Controlled Phase III Trial

PURPOSE

To report the final efficacy findings and biomarker analysis from the NO16968 trial comparing bolus fluorouracil/folinic acid (FU/FA) with capecitabine plus oxaliplatin (XELOX) in resected stage III colon cancer.

PATIENTS AND METHODS

After curative resection, patients were randomly assigned to receive XELOX, as oxaliplatin 130 mg/m(2) on day 1 and capecitabine 1,000 mg/m(2) twice daily on days 1 to 14 every 3 weeks, or bolus FU/FA, as the Mayo Clinic or Roswell Park regimens, for 6 months. The primary end point was disease-free survival (DFS). Secondary end points included overall survival (OS).

RESULTS

The intention-to-treat population comprised 1,886 patients (XELOX, n = 944; FU/FA, n = 942). Seven-year DFS rates were 63% and 56% in the XELOX and FU/FA groups, respectively (hazard ratio [HR], 0.80; 95% CI, 0.69 to 0.93; P = .004). Seven-year OS rates were 73% and 67% in the XELOX and FU/FA groups, respectively (HR, 0.83; 95% CI, 0.70 to 0.99; P = .04). A total of 68% and 77% of patients who experienced relapse or a new colorectal cancer in the XELOX and FU/FA groups, respectively, received drug treatment for metastatic disease. Four hundred ninety-eight patients consented to the biomarker analysis: 242 in the XELOX group and 256 in the FU/FA group. Low tumor expression of dihydropyrimidine dehydrogenase may be predictive for XELOX efficacy; in the XELOX group, for high versus low dihydropyrimidine dehydrogenase expression levels, DFS HR was 2.45 (95% CI, 1.55 to 3.86; P < .001), and OS HR was 2.75 (95% CI, 1.65 to 4.59; P < .001). In the FU/FA group, no statistically significant associations were observed between any tumor biomarker and outcomes.

CONCLUSION

XELOX improved OS compared with bolus FU/FA in patients with resected stage III colon cancer after a median follow-up of almost 7 years. XELOX should be considered a standard adjuvant treatment option in patients with stage III disease. Tumoral dihydropyrimidine dehydrogenase expression is a promising predictive, and potentially, highly clinically relevant, biomarker for XELOX efficacy requiring further prospective evaluation.

Evolution of ecological differences in the Old World leaf warblers

Sympatric species that belong to the same ecological guild usually differ in their behaviour and morphology, and these differences are often interpreted as adaptations to having to make use of different resources. Evidence supporting this interpretation comes from association between ecology and morphology among species, in which an a priori functional relationship is reasonable. But one problem with such comparisons is that members of a guild may be closely related, so the more closely related species can share a greater similarity in their morphology and ecology simply as a result of the lingering legacy of a common ancestor. In principle, the importance of historical legacy can be evaluated from phylogenetic relationships and times since divergence for all species, but this is rarely possible because these data are not available. Here we use a phylogeny for eight sympatric species of warbler in the genus Phylloscopus, based on their mitochondrial DNA sequences, to remove the effects of historical legacy. Without these effects, we find strong support for adaptive interpretations of among-species variation in habitat selection, prey-size choice and feeding method. Ecological variation along any of these three niche axes is associated with predictable morphological variation. We also find evidence for historical legacy in that more closely related species are often more similar behaviourally and morphologically. This paradoxical result can be reconciled because the most closely related species tend to differ along only one niche axis, habitat choice. In contrast, the evolution of prey-size choice and feeding method occurred rapidly and early in the diversification of this group. Once a new ecological zone was occupied, subsequent morphological change along these niche axes was limited, accounting for the similarity of closely related species.

PET imaging of cortical S2 serotonin receptors after stroke: lateralized changes and relationship to depression

Patients with right-hemisphere strokes (N = 9) more than 1 year after injury had greater cortical binding of (3-N-[11C]methyl)spiperone than a similar group of patients with left-hemisphere strokes (N = 8) or normal control subjects (N = 17). The higher S2 serotonin receptor binding occurred in uninjured regions of the right parietal and temporal cortex. The ratio of binding in the ipsilateral to contralateral cortex showed a significant negative correlation with severity of depression scores in the left temporal cortex. These findings suggest that the biochemical response of the brain may be different depending on which hemisphere is injured and that some depressions may be a consequence of the failure to upregulate serotonin receptors after stroke.

Medium-throughput Drug Screening of Patient-derived Organoids from Colorectal Peritoneal Metastases to Direct Personalized Therapy

PURPOSE

Patients with colorectal cancer with peritoneal metastases (CRPMs) have limited treatment options and the lowest colorectal cancer survival rates. We aimed to determine whether organoid testing could help guide precision treatment for patients with CRPMs, as the clinical utility of prospective, functional drug screening including nonstandard agents is unknown.

EXPERIMENTAL DESIGN

CRPM organoids (peritonoids) isolated from patients underwent parallel next-generation sequencing and medium-throughput drug panel testing ex vivo to identify specific drug sensitivities for each patient. We measured the utility of such a service including: success of peritonoid generation, time to cultivate peritonoids, reproducibility of the medium-throughput drug testing, and documented changes to clinical therapy as a result of the testing.

RESULTS

Peritonoids were successfully generated and validated from 68% (19/28) of patients undergoing standard care. Genomic and drug profiling was completed within 8 weeks and a formal report ranking drug sensitivities was provided to the medical oncology team upon failure of standard care treatment. This resulted in a treatment change for two patients, one of whom had a partial response despite previously progressing on multiple rounds of standard care chemotherapy. The barrier to implementing this technology in Australia is the need for drug access and funding for off-label indications.

CONCLUSIONS

Our approach is feasible, reproducible, and can guide novel therapeutic choices in this poor prognosis cohort, where new treatment options are urgently needed. This platform is relevant to many solid organ malignancies.

Phase 1 clinical trial of the novel proteasome inhibitor marizomib with the histone deacetylase inhibitor vorinostat in patients with melanoma, pancreatic and lung cancer based on in vitro assessments of the combination

PURPOSE

Combining proteasome and histone deacetylase (HDAC) inhibition has been seen to provide synergistic anti-tumor activity, with complementary effects on a number of signaling pathways. The novel bi-cyclic structure of marizomib with its unique proteasome inhibition, toxicology and efficacy profiles, suggested utility in combining it with an HDAC inhibitor such as vorinostat. Thus, in this study in vitro studies assessed the potential utility of combining marizomib and vorinostat, followed by a clinical trial with the objectives of assessing the recommended phase 2 dose (RP2D), pharmacokinetics (PK), pharmacodynamics (PD), safety and preliminary anti-tumor activity of the combination in patients.

EXPERIMENTAL DESIGN

Combinations of marizomib and vorinostat were assessed in vitro. Subsequently, in a Phase 1 clinical trial patients with melanoma, pancreatic carcinoma or Non-small Cell Lung Cancer (NSCLC) were given escalating doses of weekly marizomib in combination with vorinostat 300 mg daily for 16 days in 28 day cycles. In addition to standard safety studies, proteasome inhibition and pharmacokinetics were assayed.

RESULTS

Marked synergy of marizomib and vorinostat was seen in tumor cell lines derived from patients with NSCLC, melanoma and pancreatic carcinoma. In the clinical trial, 22 patients were enrolled. Increased toxicity was not seen with the combination. Co-administration did not appear to affect the PK or PD of either drug in comparison to historical data. Although no responses were demonstrated using RECIST criteria, 61% of evaluable patients demonstrated stable disease with 39% having decreases in tumor measurements.

CONCLUSIONS

Treatment of multiple tumor cell lines with marizomib and vorinostat resulted in a highly synergistic antitumor activity. The combination of full dose marizomib with vorinostat is tolerable in patients with safety findings consistent with either drug alone.

Traditional risk factors and ischemic stroke in young adults: the Baltimore-Washington Cooperative Young Stroke Study

OBJECTIVE

To determine the association of hypertension, diabetes, and cigarette smoking with incidence of ischemic stroke in young adults.

DESIGN

Case-control study.

SETTING

Population-based sample of cases and controls.

SUBJECTS

The study included 296 cases of incident ischemic stroke among black and white adults aged 18 to 44 years in central Maryland counties from the Baltimore-Washington Cooperative Young Stroke Study and 1220 black and white adults aged 18 to 44 years from the Maryland Behavioral Risk Factor Survey, a telephone survey of a random sample of the same region, to serve as controls.

MAIN OUTCOME MEASURES

Logistic regression models were developed to determine the age-adjusted odds ratios for each risk factor. Population-attributable risk percent were computed based on the odds ratios and prevalence of each risk factor.

RESULTS

The age-adjusted odds ratios (95% confidence intervals) for white men (WM), white women (WW), black men (BM), and black women (BW) were as follows: current cigarette smoking: WM, 2.0 (1.1-3.8), WW, 2.1 (1.1-4.3), BM, 3.3 (1.6-6.6), and BW, 2.2 (1.3-3.9); history of diabetes mellitus: WM, 22.9 (5.8-89.6), WW, 6.2 (1.9-20.2), BM, 4.2 (0.8-21.9), and BW, 3.3 (1.4-7.7); and history of hypertension: WM, 1.6 (0.7-3.2), WW, 2.5 (1.1-5.9), BM, 3.8 (1.8-7.9), and BW, 4.2 (2.4-7.5). The population-attributable risk percent (95% confidence intervals) were as follows: current cigarette smoking: WM, 22.6 (3.1-38.2), WW, 17.2 (4.0-34.0), BM, 40.5 (23.1-54.0), and BW, 29.1 (13.5-41.9); history of diabetes mellitus: WM, 19.0 (8.2-28.5), WW, 15.8 (3.8-26.3), BM, 13.2 (5.3-20.4), and BW, 22.1 (12.5-30.7); and history of hypertension: WM, 21.7 (6.2-34.6), WW, 21.3 (5.4-34.5), BM, 53.5 (39.0-64.4), and BW, 50.5 (37.1-61.1).

CONCLUSIONS

Hypertension, diabetes mellitus, and current cigarette smoking are important risk factors in a biracial young adult population. Cigarette smoking and hypertension, the 2 most modifiable risk factors, were particularly important risk factors in young blacks.

13C/31P NMR studies on the mechanism of insulin resistance in obesity

The mechanism of insulin resistance in obesity was examined in ten obese (BMI 33 +/- 1 kg/m2) and nine lean (BMI 22 +/- 1 kg/m2) Caucasian women during a hyperglycemic-hyperinsulinemic clamp using 13C and 31P nuclear magnetic resonance (NMR) spectroscopy to measure rates of muscle glycogen synthesis and intramuscular glucose-6-phosphate (G-6-P) concentrations. Under similar steady-state plasma concentrations of glucose (approximately 11 mmol/l) and insulin (approximately 340 pmol/l), rates of muscle glycogen synthesis were reduced approximately 70% in the obese subjects (52 +/- 8 micromol/[l muscle-min]) as compared with the rates in the lean subjects (176 +/- 22 micromol/[l muscle-min]; P < 0.0001). Basal concentrations of intramuscular G-6-P were similar in the obese and lean subjects; but during the clamp, G-6-P failed to increase in the obese group (deltaG-6-P obese 0.044 +/- 0.011 vs. lean 0.117 +/- 0.011 mmol/l muscle; P < 0.001), reflecting decreased muscle glucose transport and/or phosphorylation activity. We conclude that insulin resistance in obesity can be mostly attributed to impairment of insulin-stimulated muscle glycogen synthesis due to a defect in glucose transport and/or phosphorylation activity.

The survival outcome of patients with metastatic colorectal cancer based on the site of metastases and the impact of molecular markers and site of primary cancer on metastatic pattern

BACKGROUND

Pattern of spread in patients with metastatic colorectal cancer (mCRC) is variable and may reflect different biology in subsets of patients. This is a retrospective study to explore the outcome of patients with mCRC based on their site of metastasis at diagnosis and to explore the association between tumor characteristics [KRAS/RAS, BRAF, mismatch repair (MMR) status, site of primary] and the site of metastasis.

METHODS

Patients from two Australian databases were divided into six groups based on site of metastasis at time of diagnosis of metastatic disease; lung-only, liver-only, lymph node-only or any patients with brain, bone or peritoneal metastases. Primary endpoint was overall survival (OS) of each cohort compared with the rest of the population. A Mantel-Haenszel chi-squared test used to explore the association between site of metastasis and selected tumor characteristics.

RESULTS

Five thousand nine hundred and sixty-seven patients were included. In a univariate analysis, median OS was significantly higher when metastases were limited to lung or liver and shorter for those with brain, bone or peritoneal metastases (p < .001) in both datasets. BRAF mutation was strongly associated with peritoneal metastases (relative risk = 1.8, p < .001) with lower incidence of lung (RR = 0.3, p = .004) and liver (RR = 0.7, p = .005) limited metastases. Lung-only metastases were more frequent with KRAS/RAS mutation (RR = 1.4, p = .007). Left colon tumors were associated with bone (RR = 1.6, p < .001) and lung-only metastases (RR = 2.3, p = .001) while peritoneal spread was less frequent compared with right colon tumors (RR = 0.6, p < .001). Rectal cancer was associated with brain, bone and lung metastases (RR = 1.7; p = .002, 1.7; p < .001, 2.0; p < .001). Liver-only metastases were less frequent in deficient MMR tumors (RR = 0.7, p = .01).

CONCLUSION

Survival duration with mCRC is related to the site of metastases with lung limited disease showing a more favorable survival outcome compared to other single metastatic site disease. The BRAF mutation and primary rectal cancer were associated with poor prognostic metastatic sites.

Survival differences in patients with metastatic colorectal cancer and with single site metastatic disease at initial presentation: results from South Australian clinical registry for advanced colorectal cancer

BACKGROUND

Colorectal cancer is the third most common cancer in Australia. The median overall survival for metastatic colorectal cancer is nearly 2 years. However, there may be survival differences based on site of metastatic disease.

METHODS

Data was collected from the South Australian Registry for Advanced Colorectal Cancer. A total of 1207 patients with single site metastatic disease at initial diagnosis were subclassified into 6 subgroups: liver only (n = 780), pelvic only (n = 148), lung only (n = 142), lymph node only (n = 95), bone only (n = 32), and brain only (n = 10). Univariate and multivariate parametric survival analyses were performed.

RESULTS

Median overall survival was 20.3 months for the whole group. The overall survival for lung-only metastases group was 41.1 months followed by liver- and pelvic-only disease groups (22.8 and 23.8 months, respectively). Patients with isolated bone-only and brain-only metastases had poor overall survival (5.1 and 5.7 months, respectively). On multivariate analysis, prognosis was superior for the lung-only group.

CONCLUSIONS

Lung only group had the longest median overall survival. Bone and brain sites had a poor outlook. Site of metastatic disease at initial presentation may be prognostic.

Infarcts of the inferior division of the right middle cerebral artery: mirror image of Wernicke's aphasia

We searched the Stroke Data Bank and personal files to find patients with CT-documented infarcts in the territory of the inferior division of the right middle cerebral artery. The most common findings among the 10 patients were left hemianopia, left visual neglect, and constructional apraxia (4 of 5 tested). Five patients had an agitated confusional state that was characterized by hyperactivity, restlessness, and easy distractibility. Motor and sensory abnormalities were not severe or persistent. The most common cause was cardiogenic embolism.