Generalizability of Tau and Amyloid Plasma Biomarkers in Alzheimer's Disease Cohorts of Diverse Genetic Ancestries

Introduction

Plasma phosphorylated threonine-181 of Tau and amyloid beta are biomarkers for differential diagnosis and preclinical detection of Alzheimer disease (AD). Given differences in AD risk across diverse populations, generalizability of existing biomarker data is not assured.

Methods

In 2,086 individuals of diverse genetic ancestries (African American, Caribbean Hispanic, and Peruvians) we measured plasma pTau-181 and Aβ42/Aβ40. Differences in biomarkers between cohorts and clinical diagnosis groups and the potential discriminative performance of the two biomarkers were assessed.

Results

pTau-181 and Aβ42/Aβ40 were consistent across cohorts. Higher levels of pTau181 were associated with AD while Aβ42/Aβ40 had minimal differences. Correspondingly, pTau-181 had greater predictive value than Aβ42/Aβ40, however, the area under the curve differed between cohorts.

Discussion

pTau-181 as a plasma biomarker for clinical AD is generalizable across genetic ancestries, but predictive value may differ. Combining genomic and biomarker data from diverse individuals will increase understanding of genetic risk and refine clinical diagnoses.

The FDA-approved compound, pramipexole and the clinical-stage investigational drug, dexpramipexole, reverse chronic allodynia from sciatic nerve damage in mice, and alter IL-1β and IL-10 expression from immune cell culture

During the onset of neuropathic pain from a variety of etiologies, nociceptors become hypersensitized, releasing neurotransmitters and other factors from centrally-projecting nerve terminals within the dorsal spinal cord. Consequently, glial cells (astrocytes and microglia) in the spinal cord are activated and mediate the release of proinflammatory cytokines that act to enhance pain transmission and sensitize mechanical non-nociceptive fibers which ultimately results in light touch hypersensitivity, clinically observed as allodynia. Pramipexole, a D2/D3 preferring agonist, is FDA-approved for the treatment of Parkinson's disease and demonstrates efficacy in animal models of inflammatory pain. The clinical-stage investigational drug, R(+) enantiomer of pramipexole, dexpramipexole, is virtually devoid of D2/D3 agonist actions and is efficacious in animal models of inflammatory and neuropathic pain. The current experiments focus on the application of a mouse model of sciatic nerve neuropathy, chronic constriction injury (CCI), that leads to allodynia and is previously characterized to generate spinal glial activation with consequent release IL-1β. We hypothesized that both pramipexole and dexpramipexole reverse CCI-induced chronic neuropathy in mice, and in human monocyte cell culture studies (THP-1 cells), pramipexole prevents IL-1β production. Additionally, we hypothesized that in rat primary splenocyte culture, dexpramixole increases mRNA for the anti-inflammatory and pleiotropic cytokine, interleukin-10 (IL-10). Results show that following intravenous pramipexole or dexpramipexole, a profound decrease in allodynia was observed by 1 hr, with allodynia returning 24 hr post-injection. Pramipexole significantly blunted IL-1β protein production from stimulated human monocytes and dexpramipexole induced elevated IL-10 mRNA expression from rat splenocytes. The data support that clinically-approved compounds like pramipexole and dexpramipexole support their application as anti-inflammatory agents to mitigate chronic neuropathy, and provide a blueprint for future, multifaceted approaches for opioid-independent neuropathic pain treatment.

P3707CHA2DS2 VASC score as predictor of the incidence of stroke in patients with stable coronary artery disease and sinus rhythm in the long-term follow-up

Background

Cerebral vascular disease and coronary artery disease (CAD) share risk factors. Our aim was to study CHA2DS2VASC score as predictor of stroke incidence in a sample of patients with sinus ryhtm and stable CAD (sCAD) during long term follow-up.

Methods

The CICCOR registry (“Chronic ischaemic heart disease in Cordoba”) is a prospective monocentric cohort study. Between February 2000 and January 2004 all patients with sCAD who attended two outpatient cardiology clinics in a city of the South of Spain were recruited. We analyzed the relationship between baseline CHA2DS2VASC score and the incidence of stroke in a sample of patients with sCAD without atrial fibrillation during long term follow-up. Patients without sinus rythm were excluded.

Results

1268 patients with sCAD were recruited (median age 68±10 years, 73% male). 69 patients showed atrial fibrillation and were excluded. The median follow-up was 11.2 years (maximum follow-up of 17 years). During this period, only 2 patients were lost, and 136 patients (11.5% of the sample) suffered stroke. Baseline mean CHA2DS2 VASC score was 3.21. Most patients showed CHA2DS2 VASC score lower than 4 (81.4% of the sample). Higher CHA2DS2 VASC score at baseline was associated with higher risk of suffering stroke during follow-up (Hazard Ratio = 1.31 (1.16–1.48); p<0.001). Mean results are shown in the table.

Table 1 No stroke (n=1063) Stroke (n=136) Hazard ratio (CI 95%) p Sex male (%) 777 (88.8) 98 (11.2) High blood pressure (%) 561 (86.6) 86 (13.3) Diabetes mellitus (%) 317 (86.4) 50 (13.6) 75 years and older (%) 205 (83.7) 40 (16.3) Mean CHADS VASC score 3.17 3.55 1.31 (1.16–1.48) <0.001 CHADS VASC score higher than 4 (%) 185 (84.1) 35 (15.9) 2.00 (1.33–3.01) 0.001

Stroke incidence according to CHADSVASC

Conclusion

Higher CHA2DS2 VASC score was significantly associated with higher stroke incidence during long term follow-up in this real-world sample of patients with sCAD in sinus rythm.

Urinary stress incontinence and other maternal outcomes 2 years after caesarean or vaginal birth for twin pregnancy: a multicentre randomised trial

OBJECTIVE

Does planned caesarean compared with planned vaginal birth lower the risk of problematic urinary stress, faecal, or flatal incontinence?

DESIGN

Women between 32^0/7 and 38^6/7 weeks of gestation with a twin pregnancy were randomised to planned caesarean or planned vaginal birth.

SETTING

The trial took place at 106 centres in 25 countries.

POPULATION

A total of 2305 of the 2804 women enrolled in the study completed questionnaires at 2 years (82.2% follow-up): 1155 in the planned caesarean group and 1150 in the planned vaginal birth group.

METHODS

A structured self-administered questionnaire completed at 2 years postpartum.

MAIN OUTCOME MEASURES

The primary maternal outcome of the Twin Birth Study was problematic urinary stress, or fecal, or flatal incontinence at 2 years RESULTS: Women in the planned caesarean group had lower problematic urinary stress incontinence rates compared with women in the planned vaginal birth group [93/1147 (8.11%) versus 140/1143 (12.25%); odds ratio, 0.63; 95% confidence interval, 0.47-0.83; P = 0.001]. Among those with problematic urinary stress incontinence, quality of life (measured using the Incontinence Impact Questionnaire, IIQ-7) was not different for planned caesarean versus planned vaginal birth groups [mean (SD): 18.4 (21.0) versus 19.1 (21.5); P = 0.82]. There were no differences in problematic faecal or flatal incontinence, or in other maternal outcomes.

CONCLUSIONS

Among women with a twin pregnancy and no prior history of urinary stress incontinence, a management strategy of planned caesarean compared with planned vaginal birth reduces the risk of problematic urinary stress incontinence at 2 years postpartum. Our findings show that the prevalence but not the severity of urinary stress incontinence was associated with mode of birth.

FUNDING

Canadian Institutes of Health Research (CIHR) (grant no. MCT-63164).

TWEETABLE ABSTRACT

For women with twins, planned caesarean compared with planned vaginal birth is associated with decreased prevalence but not severity of urinary stress incontinence at 2 years.

Impact of treatment in long-term survival patients with follicular lymphoma: A Spanish Lymphoma Oncology Group registry

BACKGROUND

Follicular lymphoma is the second most common non-Hodgkin lymphoma in the United States and Europe. However, most of the prospective randomized studies have very little follow-up compared to the long natural history of the disease. The primary aim of this study was to investigate the long-term survival of our series of patients with follicular lymphoma.

PATIENTS AND METHODS

A total of 1074 patients with newly diagnosed FL were enrolled. Patients diagnosed were prospectively enrolled from 1980 to 2013.

RESULTS

Median follow-up was 54.9 months and median overall survival is over 20 years in our series. We analyzed the patients who are still alive beyond 10 years from diagnosis in order to fully assess the prognostic factors that condition this group. Out of 166 patients who are still alive after more than 10 years of follow-up, 118 of them (73%) are free of evident clinical disease. Variables significantly associated with survival at 10 years were stage < II (p <0.03), age < 60 years (p <0.0001), low FLIPI (p <0.002), normal β2 microglobulin (p <0.005), no B symptoms upon diagnosis (p <0.02), Performance Status 0-1 (p <0.03) and treatment with anthracyclines and rituximab (p <0.001), or rituximab (p <0.0001).

CONCLUSIONS

A longer follow-up and a large series demonstrated a substantial population of patients with follicular lymphoma free of disease for more than 10 years.

High BIM mRNA levels are associated with longer survival in advanced gastric cancer

Chemotherapy drugs, including 5-fluorouracil (5-FU), oxaliplatin and docetaxel, are commonly used in the treatment of gastric cancer (GC). Apoptosis-relevant genes may be associated with drug resistance. In the present study, the messenger RNA (mRNA) expression levels of B-cell lymphoma 2 interacting mediator of cell death (BIM), astrocyte elevated gene-1 (AEG-1) and AXL receptor tyrosine kinase (AXL) were investigated in 131 advanced GC samples, and the expression levels of these genes were correlated with patients' overall survival (OS). All 131 patients received first-line FOLFOX combination chemotherapy with folinic acid and 5-FU, in which 56 patients were further treated with second-line docetaxel-based chemotherapy. A correlation between the mRNA expression levels of BIM and AEG-1 was observed (r_s=0.30; P=0.002). There was no association between the mRNA expression levels of any of the individual genes analyzed and OS in patients only receiving first-line FOLFOX chemotherapy. In a subgroup of patients receiving docetaxel-based second-line chemotherapy, those with high or intermediate levels of BIM exhibited a median OS of 18.2 months [95% confidence interval (CI), 12.8-23.6], compared with 9.6 months (95% CI, 8.9-10.3) in patients with low BIM levels (P=0.008). However, there was no correlation between the mRNA expression levels of AEG-1 or AXL and OS. The risk of mortality was higher in patients with low BIM mRNA levels than in those with high or intermediate BIM mRNA levels (hazard ratio, 2.61; 95% CI, 1.21-5.62; P=0.010). Therefore, BIM may be considered as a biomarker to identify whether patients could benefit from docetaxel-based second-line chemotherapy in GC.

Tobacco Cessation in Economically Disadvantaged Dominican Republic Communities: Who are the Ex-Users?

INTRODUCTION

Tobacco use and harm continue to increase in low- and middle income countries (LMICs) globally. Smoking cessation is the most effective means of reducing morbidity and mortality from tobacco use. Increasing the prevalence of ex-users is an indicator of population cessation.

AIMS

This study provides the first examination of factors associated with ex-tobacco use status in the Dominican Republic (DR), a LMIC in the Latin America and Caribbean region.

METHODS

Baseline surveillance was conducted for 1177 randomly selected households in 7 economically disadvantaged DR communities (total N=2680 adult household members).

RESULTS

Ex-user prevalence was 10.6% (1.0%-18.5% across communities), 14.8% were current users (9.1-20.4), and quit ratios were 41.7% (9.7%-52.7%). Among ever-users, females (OR 2.02, 95% CI 1.41, 2.90), older adults (45-64: OR 1.75, 95% CI 1.12, 2.74; 65+: OR 2.09, 95% CI 1.29, 3.39), and those who could read/write (OR 1.64, 95% CI 1.08, 2.50), had health conditions (OR 1.63, 95% CI 1.11, 2.41), and lived with ex-users (OR 1.70, 95% CI 1.12, 2.58) were over 60% to two times as likely to be ex-users. Those from remote communities (OR 0.52, 95% CI 0.36, 0.74), using chewed tobacco (OR 0.14, 95% CI 0.04, 0.48) and living with tobacco users (OR 0.55, 95% CI 0.37, 0.81) were less likely to be ex-users.

CONCLUSIONS

Ex-user prevalence and quit ratios were lower than for high income countries. Implementing broad tobacco control measures, combined with clinically targeting vulnerable groups, may increase tobacco cessation to most effectively reduce this public health crisis.

Maternal outcomes at 3 months after planned caesarean section versus planned vaginal birth for twin pregnancies in the Twin Birth Study: a randomised controlled trial

OBJECTIVE

To compare outcomes at 3 months post partum for women randomised to give birth by planned caesarean section (CS) or by planned vaginal birth (VB) in the Twin Birth Study (TBS).

DESIGN

We invited women in the TBS to complete a 3-month follow-up questionnaire.

SETTING

Two thousand and eight hundred and four women from 25 countries.

POPULATION

Two thousand and five hundred and seventy women (92% response rate).

METHODS

Women randomised between 13 December 2003 and 4 April 2011 in the TBS completed a questionnaire and outcomes were compared using an intention-to-treat approach.

MAIN OUTCOME AND MEASURES

Breastfeeding, quality of life, depression, fatigue and urinary incontinence.

RESULTS

We found no clinically important differences between groups in any outcome. In the planned CS versus planned VB groups, breastfeeding at any time after birth was reported by 84.4% versus 86.4% (P = 0.13); the mean physical and mental Short Form (36) Health Survey (SF-36) quality of life scores were 51.8 versus 51.6 (P = 0.65) and 46.7 versus 46.0 (P = 0.09), respectively; the mean Multidimensional Assessment of Fatigue score was 20.3 versus 20.8 (P = 0.14); the frequency of probable depression on the Edinburgh Postnatal Depression Scale was 14.0% versus 14.8% (P = 0.57); the rate of problematic urinary incontinence was 5.5% versus 6.4% (P = 0.31); and the mean Incontinence Impact Questionnaire-7 score was 20.5 versus 20.4 (P = 0.99). Partner relationships, including painful intercourse, were similar between the groups.

CONCLUSION

For women with twin pregnancies randomised to planned CS compared with planned VB, outcomes at 3 months post partum did not differ. The mode of birth was not associated with problematic urinary incontinence or urinary incontinence that affected the quality of life. Contrary to previous studies, breastfeeding at 3 months was not increased with planned VB.

TWEETABLE ABSTRACT

Planned mode of birth for twins doesn't affect maternal depression, wellbeing, incontinence or breastfeeding.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies

BACKGROUND

In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients.

PATIENTS AND METHODS

Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS).

RESULTS

Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82).

CONCLUSION

Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches.

TRIAL REGISTRATION

NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

Differential effect of MMSET mRNA levels on survival to first-line FOLFOX and second-line docetaxel in gastric cancer

Background:

Breast cancer susceptibility gene 1 (BRCA1) expression differentially affects outcome to platinum- and taxane-based chemotherapy. Mediator of DNA damage checkpoint protein 1 (MDC1), p53-binding protein 1 (53BP1), multiple myeloma SET domain (MMSET) and ubiquitin-conjugating enzyme 9 (UBC9) are involved in DNA repair and could modify the BRCA1 predictive model.

Methods:

Mediator of DNA damage checkpoint protein 1, 53BP1, MMSET and UBC9 mRNA were assessed in gastric tumours from patients in whom BRCA1 levels had previously been determined.

Results:

In vitro chemosensitivity assay, MMSET levels were higher in docetaxel-sensitive samples. In a separate cohort, survival was longer in those with low MMSET (12.3 vs 8.8 months; P=0.04) or UBC9 (12.4 vs 8.8 months; P=0.01) in patients receiving only folinic acid, fluorouracil (5-FU) and oxaliplatin (FOLFOX). Conversely, among patients receiving second-line docetaxel, longer survival was associated with high MMSET (19.1 vs 13.9 months; P=0.003). Patients with high MMSET and BRCA1 attained a median survival of 36.6 months, compared with 13.9 months for those with high BRCA1 and low MMSET (P=0.003). In the multivariate analyses, low MMSET (hazard ratio (HR), 0.59; P=0.04) and low UBC9 (HR, 0.52; P=0.01) levels were markers of longer survival to first-line FOLFOX, whereas palliative surgery (HR, 2.47; P=0.005), low BRCA1 (HR, 3.17; P=0.001) and low MMSET (HR, 2.52; P=0.004) levels were markers of shorter survival to second-line docetaxel.

Conclusions:

Breast cancer susceptibility gene 1, MMSET and UBC9 can be useful for customising chemotherapy in gastric cancer patients.

The predictive role of integrated BRCA1 and HERC2 mRNA expression in advanced non-small cell lung cancer (NSCLC) patients (p) treated with platinum-based first-line chemotherapy

11078

Background: The use of cis- or carboplatin is the backbone of first-line treatment for advanced NSCLC p, and currently no molecular markers of platinum sensitivity are used in routine clinical practice. Preclinical data and retrospective analyses have shown that high BRCA1 expression is associated with resistance to platinum. HERC2 is an E3 ubiquitin ligase promoting DNA repair by interacting with the E3 ubiquitin ligase RNF8 to facilitate the assembly of the RNF8-UBC13 complex, leading to the recruitment of BRCA1 and other DNA repair components responsible for double-strand break repair. Methods: We retrospectively analyzed 71 tumor samples from advanced NSCLC p treated with cis- or carboplatin plus gemcitabine or pemetrexed in the first-line setting. BRCA1 and HERC2 mRNA levels were determined by real-time PCR and categorized using medians as cut-off points. Results: Overall survival (OS) for all 71 p was 10.7 months (m), and progression free survival (PFS) was 7.2 m. Expression of both genes was successfully analyzed in 53 p (74. 6%). Neither gene as a single variable influenced outcome. However, the joint effect of BRCA1 and HERC2 was significant for predictive modeling. Among 30 p with low BRCA1 levels, OS was 15.3 m and PFS was 7.4 m in the 21 p with low HERC2 levels, compared to 7.4 m and 5.9 m, respectively, in the 9 p with high HERC2 levels (OS, P=0.008; PFS, P=0.01). The multivariate analyses identified the combination of low BRCA1 and low HERC2 expression as predictive of longer OS and PFS. In contrast, high levels of either gene were associated with an increased risk of death (HR=3.7, P=0.004) and of progression (HR=1.4, P=0.03). Conclusions: The integrated analysis of multiple DNA repair components can improve available predictive models in NSCLC. BRCA1 and HERC2 low expression levels can predict improved outcome to first-line platinum-based chemotherapy.

F-box and WD repeat domain-containing 7 (FBXW7) mRNA and outcome in biliary tract cancer

e14521

Background: Thestandard treatment for biliary tract cancer is gemcitabine plus platinum, but median progression-free survival (PFS) is only 5-8 months (m) (Valle et al, NEJM 2010). Gene expression or somatic mutations may influence the clinical phenotype, which will affect decisions on individualized treatment. Methods: We retrospectively analyzed tissue blocks from 54 advanced or metastatic cholangiocarcinoma, gallbladder or ampulllary cancer patients (p) treated with single-agent gemcitabine or gemcitabine plus carboplatin or cisplatin. Using RT-PCR, we analyzed the mRNA expression levels of oncogenes, tumor suppressors and DNA repair genes (BRCA1, RRM1, AEG-1, RAP80, SPINK1 and FBXW7) and correlated results with PFS, overall survival (OS) and response. In addition, FBXW7 hotspot mutations were assessed. Results: p characteristics: 72% females; median age, 60 (40-87). Only FBXW7 expression correlated with PFS and OS. When FBXW7 levels were dichotomized at the median value, PFS was 4.2 m for p with low levels vs 12.6 m for p with high levels (p=0.02). When FBXW7 expression was divided by terciles, PFS was 4.9 m for p in the lowest tercile, 7.6 for p in the intermediate tercile, and 26.9 m for p in the highest tercile (p=0.08). OS was 6.2 m for p in the lowest tercile, 8 m for p in the intermediate tercile, and not reached for p in the highest tercile. No other significant correlation was observed between expression levels of the other genes examined and PFS or OS. Only AEG-1 expression correlated with response (p=0.05). No FBXW7 hotspot mutations were detected. Conclusions: Although we did not find the FBXW7 hotspot mutations previously described in biliary tract cancer, FBXW7 mRNA expression significantly influenced PFS and OS. A separate cohort of p is being analyzed to validate the prognostic role of FBXW7.

Prognostic value of “angiogenic” risk score in early-stage NSCLC

10594

Background: Angiogenesis is a key mechanism in tumor growth and dissemination mainly regulated by VEGF family members. We analyze the expression of 11 angiogenic genes in a cohort of resectable NSCLC patients and correlate them with clinico-pathological variables and prognosis. Methods: RNA was obtained from tumor and normal lung specimens from 175 NSCLC patients. RT-PCR was performed to assess the expression of HIF1-A, PIGF, VEGFA, VEGFB, VEGFC, VEGFD, VEGFR1, VEGFR2, VEGFR3, NRP1 and NRP2. Relative expression was normalized by an endogenous gene (GUS) using the Pfaffl formulae. Differences were considered statistically significant at p<0.05. Results: We found that tumor samples had a significant higher expression of PIGF and lower expression of VEGFD, VEGFR2, and VEGFR3 compared with normal tissue (2.76X, 0.035X, 0.417X and 0.426X, respectively). The group of patients with higher expression levels of VEGFA or PlGF had a significantly reduced TTP (p=0.024 and p=0.027, respectively) and OS (p=0.055 and p=0.048, respectively) whereas those patients with values of VEGFB or VEGFD below the median had reduced TTP (p=0.020 and p=0.135, respectively) and OS (p=0.003 and p=0.089, respectively). The multivariate Cox regression analysis revealed that VEGFA, VEGFB and PlGF were independent prognostic markers for TTP and OS and based on these results we generated an “angiogenic” risk score model. TTP and OS were significantly different among the low, medium and high risk score patients (Table). Conclusions: VEGF family members are master control genes of the angiogenic process and have a crucial role in the prognostic of the disease. We found differences in the expression of four genes between tumor and normal lung samples. An “angiogenic” risk score (based on the expression of PlGF, VEGF-A and VEGF-B) significantly predicts OS and TTP in our cohort of early-stage NSCLC patients. Validation in an independent cohort is needed. Supported by grants PS09-01149 and RD06/0020/1024 from ISCIII. [Table: see text]

Association of p53 mutations with progression-free survival (PFS) and overall survival (OS) in EGFR-mutated non-small cell lung cancer (NSCLC) patients (p) treated with erlotinib

e18143

Background: Advanced NSCLC p with EGFR mutations have a median PFS of 14 months (m) and OS of 27 m when treated with erlotinib. In NSCLC cell lines, tyrosine kinase inhibitors (TKIs) induce p53 translocation from the cytoplasm to the nucleus and subsequent upregulation of Fas and caspase activation leading to apoptosis, but this mechanism was defective in p53-null cells. We tested whether TP53 mutations influence outcome to erlotinib in EGFR-mutated p. Expression levels of the p53 repressor MDM2 were also examined. Methods: We assessed p53 status in pretreatment paraffin-embedded tumor samples from 93 erlotinib-treated, EGFR-mutated advanced NSCLC p. Mutations in exons 5, 6, 7 and 8 were screened by High Resolution Melting analysis followed by sequencing of the amplified products with non-wild-type (wt) melt curves. All mutant samples were re-confirmed by standard PCR and sequencing. Expression levels of MDM2 mRNA were determined by quantitative RT-PCR. Results: Mutations in exons 5-8 of TP53 were detected in 26 of 93 p (28%). We found an unusually high frequency of in-frame and frameshift deletions (23% of mutations), indicating that the spectrum of p53 mutations might be different in EGFR-mutated NSCLC. Mutations were less frequent in p with ECOG PS >2 and more frequent in p with the T790M mutation. OS was 15 m in the 16 p with missense mutations 31 m in p with wt p53 and not reached in p with non-missense mutations (P=0.04). PFS was 9 m for 14 p with mutations in one of the p53 DNA binding motifs (DBMs), compared to 19 m for wt p and 27 m for p with non-DBM mutations. MDM2 mRNA levels were significantly lower in tumors with p53 mutations, especially in DBM mutations. In the case of wt p, high MDM2 expression correlated with longer PFS and OS in p with wt p53. Conclusions: TP53 mutations co-exist with EGFR mutations in a significant number of p; missense mutations correlate with shorter OS and mutations in DBMs correlate with shorter PFS. This finding paves the way for the possibility of combining erlotinib with a drug restoring p53 function in those p harboring certain types of mutations in the TP53 gene.

High mRNA expression of LMO4, a BRCA1 downregulator, correlates with better prognosis in erlotinib-treated non-small cell lung cancer (NSCLC) patients (p) with EGFR mutations

e18137

Background: Advanced NSCLC p with EGFR activating mutations show an impressive progression-free survival (PFS) to erlotinib. The co-existence of the EGFR T790M mutation, in conjunction with high BRCA1 mRNA levels, affected PFS to erlotinib (Rosell et al. CCR 2011). LMO4 is a negative regulator of BRCA1 function in sporadic breast cancers, and CtIP can bind to BRCA1 and LMO4. We have assessed the expression of CtIP, LMO4 and BRCA1 and examined the impact of CtIP and LMO4 levels on outcome. Methods: mRNA expression of LMO4 and CtIP was examined by RT-PCR in the original pretreatment tumor biopsies of 81 NSCLC p with sensitive EGFR mutations. Results: Expression of BRCA1 and LMO4 was successfully assessed in 55 p: median age, 68; 61.8% female; 98.2% Caucasian; 63.6% never-smokers; 81.8% ECOG PS <2; 80% adenocarcinoma; 14.5% BAC; 4.5% LCC; 94.5% stage IV; 63.6% exon 19 deletion; 36.4% L858R mutation; 36.4% T790M; 83.1% showed clinical benefit to erlotinib (CR/PR/SD). BRCA1 expression was correlated with that of CtIP (r=0.31; P=0.01) and LMO4 (r=0.32; P=0.02). There was no correlation between CtIP and LMO4 (r=0.09; P=0.49). PFS for p with high LMO4 levels was not reached while it was 13 months (m) for p with low levels (P=0.006). Overall survival (OS) was not reached for p with high levels of LMO4 and was 31 m for p with low levels (P=0.17). No differences in PFS or OS were observed according to CtIP levels. When BRCA1 and LMO4 expression was analyzed together, PFS was not reached for p with low BRCA1 and high LMO4 levels and was 19 m for p with low levels of both genes (P=0.04). PFS was 8 m for p with high BRCA1 and low LMO4 levels and 18 m for p with high levels of both genes (P=0.03). In the multivariate analysis, BRCA1 and LMO4 expression emerged as markers of PFS (Table). Conclusions: BRCA1 and LMO4 mRNA expression can predict PFS to erlotinib in p with EGFR mutations and could be useful in the development of new therapeutic strategies. [Table: see text]

BRCA1, RAP80, and AEG-1 mRNA expression in resectable muscle-invasive bladder cancer (MIBC) patients (p) treated with neoadjuvant cisplatin-based chemotherapy

4579

Background: Cystectomy remains the standard treatment in MIBC and only a minority of p are treated with neoadjuvant chemotherapy, suggesting that predictive markers of chemotherapy outcome are needed. Low BRCA1 mRNA expression is associated with an improvement in survival in bladder cancer p treated with cisplatin-based chemotherapy. However, BRCA1 function can be modulated by other DNA repair genes. RAP80 is required for the accumulation of BRCA1 to sites of DNA breaks, and cells depleted of RAP80 exhibit hypersensitivity to irradiation. AEG-1 can induce BRCA1 expression and cause chemoresistance. Methods: Paraffin-embedded pre-treatment tumor samples were collected by transurethral resection from 65 p with resectable MIBC stage T2-4N0M0 treated with neoadjuvant cisplatin-based chemotherapy. Gene expression levels of BRCA1, RAP80 and AEG-1 were quantified by real-time quantitative PCR. Expression levels were divided into terciles and correlated with median survival (MS). Results: 33 p were treated with cisplatin, methotrexate and vinblastine (CMV) and 32 p with cisplatin and gemcitabine. Chemotherapy was followed by cystectomy in 60 p. Overall MS was not reached and 5-year survival was 51%. MS was 45 months (m) and 5-year survival was 27% in 21 p with high BRCA1 mRNA levels vs 168 m and 59% in 44 p with low and intermediate levels (p=0.05). MS was 50 m in 15 p with high AEG-1 levels, 45 m in 15 p with intermediate levels, and was not reached in 18 p with low levels, although these differences were not statistically significant (p=0.3). No differences in MS were observed according to RAP80 mRNA levels. Conclusions: BRCA1 can be a useful marker to predict the efficacy of neoadjuvant chemotherapy. Cisplatin-based chemotherapy should be recommended in p with low/intermediate BRCA1 expression. Further studies with larger numbers of p are warranted to elucidate the role of AEG-1 in this setting.

Measuring transcripts of components of the BRCA1 DNA repair pathway, components of the hippo-YAP pathway, β-TrCP, HER2, AEG-1, EZH2 and other genes in advanced gastric cancer

4068

Background: The primary goal of this study was to classify gastric cancer in two different sub-groups. We speculated that HER2-positive gastric cancers could be regulated by β-TrCP, while tumors unaffected by β-TrCP activation could be more dependent on the Hippo-YAP signaling pathway, in which TAZ increases the expression of AXL. Gastric cancer can overexpress AEG-1 and EZH2. The relationship between EZH2 and the Hippo-YAP pathway was explored in this study. We also explored BRCA1 complexes, including upstream components, such as 53BP1 and MMSET. Methods: Paraffin-embedded samples were collected from 132 advanced gastric cancer patients (p) treated with first-line FOLFOX, 58 of whom received second-line docetaxel-based treatment. Gene expression levels of HER2, β-TrCP, TAZ, AXL, EZH2, AEG-1, BRCA1, and genes involved in DNA repair pathways (RAP80, PIAS1, PIAS4, MDC1, 53BP1, MMSET, and UBC9) were quantified by real-time PCR. BIM, IDO, and SPINK1 were also examined. Results: A close correlation was found for the majority of the genes, for example, BRCA1-MMSET (rho=0.28; P=0.002) and AXL-TAZ (rho=0.58; P>0.001). Median overall survival (OS) was 12.5 months (m). Among the 58 p receiving second-line docetaxel, in p with high levels of BRCA1, OS was 24.9 m, while it was 19.1 m in p with intermediate levels and 9.5 m in p with low levels (P=0.009). OS was 28.6 in p with high levels of MMSET, 13.8 in p with intermediate levels and 12.3 in p with low levels (P=0.001). In the multivariate analysis, only BRCA1 was a significant marker for OS (Table). Conclusions: The study showed the predictive value of BRCA1, which could be useful for customizing chemotherapy with or without docetaxel. In addition, MMSET requires further study since it is involved in DNA repair upstream of BRCA1. [Table: see text]

DNA repair components modulating the function of breast cancer susceptibility gene 1 (BRCA1) in advanced non-small cell lung cancer (NSCLC) patients (p) treated with platinum-based chemotherapy

e18130

Background: The standard first-line treatment for advanced NSCLC p with wild-type epidermal growth factor receptor (EGFR) is platinum-based chemotherapy, but median overall survival (OS) is about 12 months, with great heterogeneity in terms of efficacy and tolerability. Low BRCA1 mRNA expression has been correlated with sensitivity to cisplatin, but BRCA1 function is modulated by other DNA repair components. For example, AEG1 can induce BRCA1 expression, and CASPASE 3 cleaves the mediator of DNA damage checkpoint 1 (MDC1) preventing the activation of the DDR pathway Methods: Paraffin-embedded samples were collected from 115 advanced NSCLC p treated with first-line platinum-based chemotherapy (not including taxanes and vinca alkaloids). Samples were screened for EGFR, KRAS and p53 mutations, and gene expression levels of BRCA1, RAP80, AEG1, MDC1, CASPASE 3, 53BP1, MMSET, PIAS4, UBC9, UBC13, NPM1 and HERC2 were quantified by real-time PCR. Results: Gene expression levels were significantly higher in squamous tumors, and the correlation among genes confirmed the biological model. Median OS was 11 months and median progression free survival (PFS) was 7.1 months. In p with low levels of both BRCA1 and RAP80, PFS was 12 months and OS was not reached, while in p with high level of both genes, PFS was 5.1 months and OS was 6.2 months and in p with other combinations, PFS was 7.4 months and OS was 10.9 months (P=0.02). Increased levels of AEG1 increased the risk of death (HR: 1.3; P=0.01) and of progression (HR: 1.2; P=0.04). When CASPASE 3 levels were divided into tertiles, intermediate levels were associated with improved PFS (P=0.005) and OS (P=0.05). The multivariate analysis confirmed the role of BRCA1 (P=0.02) and CASPASE 3 (P=0.008). Conclusions: The study showed the predictive value of combined BRCA1 and RAP80 mRNA levels. In addition, AEG1 and CASPASE 3 have emerged as potential predictive markers.

MCPH1 (BRIT1) and outcome to erlotinib in non-small cell lung cancer (NSCLC) patients (p) harboring EGFR mutations

e18131

Background: Progression-free survival (PFS) in EGFR-mutant NSCLC p treated with erlotinib can range from a few months (m) to more than two years, but genetic influences on the duration of response remain unclear. The cytotoxic effect of erlotinib has been related to several proteins that regulate DNA damage response (eg, BRCA1, BRCA2). MCPH1 contains 3 BRCT domains which are conserved in important molecules involved in DNA damage signaling, including BRCA1, MDC1 and 53BP1. MCPH1 binds to BRCA2 and regulates the localization of BRCA2 and Rad51 at sites of DNA damage. MCPH1 also regulates the ATP-dependent SWI-SNF chromatin remodeling complex during DNA repair. Methods: We used the NanoString nCounter gene expression system, which captures and counts individual mRNA transcripts, to analyze the expression of 44 selected genes, many of which are involved in DNA damage response, in 55 erlotinib-treated NSCLC p. We identified MCPH1 and correlated expression levels with clinical outcomes. Results: p characteristics: 16 males, 39 females (70.9%); 39 never-smokers (70.9%), 12 former smokers, 4 current smokers; 34 with EGFR deletion in exon 19 (61.8%), 21 with L858R mutation (38.2%). PFS was not reached for patients with high MCPH1, while it was 19 m for those with intermediate levels and 9 m for those with low levels (P=0.01). Median survival was 31 m for p with high levels, not reached for p with intermediate levels and 17 m for p with low levels (P=0.004). Conclusions: The enhanced effect of erlotinib in the presence of elevated MCPH1 could be due to the fact that MCPH1 can interfere with the function of MDC1 and 53BP1. The role of MCPH1 merits validation as a predictive marker of erlotinib response.

Erlotinib versus standard chemotherapy as first-line treatment for European patients with advanced EGFR mutation-positive non-small-cell lung cancer (EURTAC): a multicentre, open-label, randomised phase 3 trial

BACKGROUND

Erlotinib has been shown to improve progression-free survival compared with chemotherapy when given as first-line treatment for Asian patients with non-small-cell lung cancer (NSCLC) with activating EGFR mutations. We aimed to assess the safety and efficacy of erlotinib compared with standard chemotherapy for first-line treatment of European patients with advanced EGFR-mutation positive NSCLC.

METHODS

We undertook the open-label, randomised phase 3 EURTAC trial at 42 hospitals in France, Italy, and Spain. Eligible participants were adults (> 18 years) with NSCLC and EGFR mutations (exon 19 deletion or L858R mutation in exon 21) with no history of chemotherapy for metastatic disease (neoadjuvant or adjuvant chemotherapy ending ≥ 6 months before study entry was allowed). We randomly allocated participants (1:1) according to a computer-generated allocation schedule to receive oral erlotinib 150 mg per day or 3 week cycles of standard intravenous chemotherapy of cisplatin 75 mg/m(2) on day 1 plus docetaxel (75 mg/m(2) on day 1) or gemcitabine (1250 mg/m(2) on days 1 and 8). Carboplatin (AUC 6 with docetaxel 75 mg/m(2) or AUC 5 with gemcitabine 1000 mg/m(2)) was allowed in patients unable to have cisplatin. Patients were stratified by EGFR mutation type and Eastern Cooperative Oncology Group performance status (0 vs 1 vs 2). The primary endpoint was progression-free survival (PFS) in the intention-to-treat population. We assessed safety in all patients who received study drug (≥ 1 dose). This study is registered with ClinicalTrials.gov, number NCT00446225.

FINDINGS

Between Feb 15, 2007, and Jan 4, 2011, 174 patients with EGFR mutations were enrolled. One patient received treatment before randomisation and was thus withdrawn from the study; of the remaining patients, 86 were randomly assigned to receive erlotinib and 87 to receive standard chemotherapy. The preplanned interim analysis showed that the study met its primary endpoint; enrolment was halted, and full evaluation of the results was recommended. At data cutoff (Jan 26, 2011), median PFS was 9·7 months (95% CI 8·4-12·3) in the erlotinib group, compared with 5·2 months (4·5-5·8) in the standard chemotherapy group (hazard ratio 0·37, 95% CI 0·25-0·54; p < 0·0001). Main grade 3 or 4 toxicities were rash (11 [13%] of 84 patients given erlotinib vs none of 82 patients in the chemotherapy group), neutropenia (none vs 18 [22%]), anaemia (one [1%] vs three [4%]), and increased amino-transferase concentrations (two [2%] vs 0). Five (6%) patients on erlotinib had treatment-related severe adverse events compared with 16 patients (20%) on chemotherapy. One patient in the erlotinib group and two in the standard chemotherapy group died from treatment-related causes.

INTERPRETATION

Our findings strengthen the rationale for routine baseline tissue-based assessment of EGFR mutations in patients with NSCLC and for treatment of mutation-positive patients with EGFR tyrosine-kinase inhibitors.

FUNDING

Spanish Lung Cancer Group, Roche Farma, Hoffmann-La Roche, and Red Temática de Investigacion Cooperativa en Cancer.

Abstract 4110: NanoString multiple target profiling identifies AEG-1 as an essential predictor of erlotinib outcome in EGFR-mutant non-small cell lung cancer (NSCLC)

Background: Low BRCA1 mRNA expression significantly prolongs progression-free survival (PFS) to erlotinib in EGFR-mutant NSCLC patients (p). In order to explore other genes potentially involved in erlotinib resistance, we used NanoString, an integrated digital technology, to examine expression levels of 48 genes in a single reaction. Several genes involved in homologous recombination repair were included in the 48-gene assessment, including the E3 ubiquitin ligases RNF8, RNF168 and RAP80.

Methods: CodeSets (Reporter and Capture probe sets) for 48 genes were custom-designed by NanoString Technologies. 100ng of total RNA for each sample was mixed with the reagents and hybridized at 65° overnight. Samples were processed and analyzed with the nCounter Prep Station (NanoString Technologies). Data analysis was performed adjusting the expression values according to positive control values and normalizing the data according to housekeeping genes.

Results: In 43 EGFR-mutant NSCLC p treated with erlotinib, response rate was 67.6%, PFS was 16 months (m), median survival (MS) was 29 m. Three genes were significantly associated with PFS: PIAS1, DBC1 and AEG-1. Median PFS was not reached in p with low levels of AEG-1, while it was 18 m for p with intermediate levels and 5 m for p with high levels (P=0.002). In the multivariate analysis, the hazard ratio for high levels of AEG-1 was 14 (P&lt;0.001).

Conclusions: AEG-1 activates the NF-κB and PI3K/Akt pathways, induces the transcription factor LSF, which upregulates TS, ALDH3A1 and Met, conferring resistance to several cytotoxic drugs. AEG-1 mRNA expression predicts outcome to erlotinib-treated EGFR-mutant NSCLC p and could have important implications for the optimal management of NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4110. doi:10.1158/1538-7445.AM2011-4110

Abstract 4112: De novo EGFR T790M mutation modifies outcome to second-line erlotinib in non-small cell lung cancer (NSCLC) according to metastatic site and upfront chemotherapy

EGFR T790M mutation is associated with shorter progression-free survival (PFS) (12 months [m] vs 18 m; P=0.02). We hypothesized that the site of metastases (mets) and/or prior chemotherapy could also influence outcome in these p.

Methods: The T790M mutation was assessed in 129 advanced NSCLC p by TaqMan assay in the presence of a peptide-nucleic acid designed to inhibit the amplification of the wild-type allele.

Results: De novo T790M mutations were identified in 35% (45 of 129) of EGFR-mutant p before receiving erlotinib. The T790M mutation was detected more frequently in p with bone mets (35.6% vs 16.7%; P=0.03). PFS was 20 m for 58 p with a deletion in EGFR exon 19 (del 19) but without the T790M mutation vs 12 m for 23 p with both del 19 and the T790M mutation (P=0.03), but with no difference in MS between these two groups (31 m vs 29 m; P=0.56). PFS was 15 m for 26 p with the L858R mutation but without the T790M mutation vs 16 m for 22 p with both the L858R and T790M mutations (P=0.83), with no difference in MS between these two groups (27 m vs 21 m; P=0.81). When p with T790M were divided according to the presence of brain mets, PFS was 1 m for 4 p with brain mets vs 13 m for 41 p without brain mets (P=0.002), while MS was 6 m for p with brain mets vs 36 m for those without (P=0.009). No effect on PFS or MS was observed in p with the T790M mutation according to lung, liver, pleura or bone mets. In the multivariate analysis, the presence of the T790M mutation did not increase the risk of short MS (HR, 1.3; P=0.49), while having received prior chemotherapy was associated with longer MS (HR, 0.48; P=0.02).

Conclusions: The de novo T790M mutation is a marker for poor prognosis in p with brain mets. Upfront chemotherapy can play a role in the management of NSCLC p with the de novo T790M mutation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4112. doi:10.1158/1538-7445.AM2011-4112

Pretreatment EGFR T790M mutation and BRCA1 mRNA expression in erlotinib-treated advanced non-small-cell lung cancer patients with EGFR mutations

PURPOSE

Advanced non-small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations (deletion in exon 19 or L858R) show an impressive progression-free survival of 14 months when treated with erlotinib. However, the presence of EGFR mutations can only imperfectly predict outcome. We hypothesized that progression-free survival could be influenced both by the pretreatment EGFR T790M mutation and by components of DNA repair pathways.

EXPERIMENTAL DESIGN

We assessed the T790M mutation in pretreatment diagnostic specimens from 129 erlotinib-treated advanced NSCLC patients with EGFR mutations. The expression of eight genes and two proteins involved in DNA repair and four receptor tyrosine kinases was also examined.

RESULTS

The EGFR T790M mutation was observed in 45 of 129 patients (35%). Progression-free survival was 12 months in patients with and 18 months in patients without the T790M mutation (P = 0.05). Progression-free survival was 27 months in patients with low BRCA1 mRNA levels, 18 months in those with intermediate levels, and 10 months in those with high levels (P = 0.02). In the multivariate analysis, the presence of the T790M mutation (HR, 4.35; P = 0.001), intermediate BRCA1 levels (HR, 8.19; P < 0.0001), and high BRCA1 levels (HR, 8.46; P < 0.0001) emerged as markers of shorter progression-free survival.

CONCLUSIONS

Low BRCA1 levels neutralized the negative effect of the T790M mutation and were associated with longer progression-free survival to erlotinib. We advocate baseline assessment of the T790M mutation and BRCA1 expression to predict outcome and provide alternative individualized treatment to patients based on T790M mutations and BRCA1 expression.

First-line therapy and methylation status of CHFR in serum influence outcome to chemotherapy versus EGFR tyrosine kinase inhibitors as second-line therapy in stage IV non-small-cell lung cancer patients

The potential differential effect of first-line treatment and molecular mechanisms on survival to second-line chemotherapy or EGFR tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC) has not been fully investigated. In particular, CHFR is frequently methylated in NSCLC and may influence outcome. We analyzed the outcome of second-line chemotherapy or EGFR TKIs in 179 of 366 patients who had been treated in an ERCC1 mRNA-based customized cisplatin trial and correlated the results with CHFR methylation status. CHFR methylation in circulating DNA was examined by methylation-specific assay. A panel of seven human EGFR wild-type NSCLC cell lines was characterized for their sensitivity to sequential treatment with cisplatin and erlotinib, and the results were correlated with CHFR. Patients who had received first-line docetaxel/cisplatin attained an overall survival of 19.2 months when treated with second-line EGFR TKIs, in comparison with 10.7 months when treated with second-line chemotherapy (P = 0.0002). However, for patients who had received first-line docetaxel/gemcitabine, overall survival was 14.8 months with EGFR TKIs and 10.8 months with chemotherapy (P = 0.29). For patients with unmethylated CHFR overall survival to EGFR TKIs was 21.4 months, and 11.2 months for those with treated with chemotherapy (P = 0.0001). In the only lung tumor cell line not expressing CHFR, pretreatment with cisplatin was antagonistic to erlotinib, while it was synergistic in the other six lines. Second-line EGFR TKIs improved survival in patients receiving first-line cisplatin-based treatment. Unmethylated CHFR predicts increased survival to EGFR TKIs.

Screening for epidermal growth factor receptor mutations in lung cancer

BACKGROUND

Activating mutations in the epidermal growth factor receptor gene (EGFR) confer hypersensitivity to the tyrosine kinase inhibitors gefitinib and erlotinib in patients with advanced non-small-cell lung cancer. We evaluated the feasibility of large-scale screening for EGFR mutations in such patients and analyzed the association between the mutations and the outcome of erlotinib treatment.

METHODS

From April 2005 through November 2008, lung cancers from 2105 patients in 129 institutions in Spain were screened for EGFR mutations. The analysis was performed in a central laboratory. Patients with tumors carrying EGFR mutations were eligible for erlotinib treatment.

RESULTS

EGFR mutations were found in 350 of 2105 patients (16.6%). Mutations were more frequent in women (69.7%), in patients who had never smoked (66.6%), and in those with adenocarcinomas (80.9%) (P<0.001 for all comparisons). The mutations were deletions in exon 19 (62.2%) and L858R (37.8%). Median progression-free survival and overall survival for 217 patients who received erlotinib were 14 months and 27 months, respectively. The adjusted hazard ratios for the duration of progression-free survival were 2.94 for men (P<0.001); 1.92 for the presence of the L858R mutation, as compared with a deletion in exon 19 (P=0.02); and 1.68 for the presence of the L858R mutation in paired serum DNA, as compared with the absence of the mutation (P=0.02). The most common adverse events were mild rashes and diarrhea; grade 3 cutaneous toxic effects were recorded in 16 patients (7.4%) and grade 3 diarrhea in 8 patients (3.7%).

CONCLUSIONS

Large-scale screening of patients with lung cancer for EGFR mutations is feasible and can have a role in decisions about treatment.

Customized treatment in non-small-cell lung cancer based on EGFR mutations and BRCA1 mRNA expression

BACKGROUND

Median survival is 10 months and 2-year survival is 20% in metastatic non-small-cell lung cancer (NSCLC) treated with platinum-based chemotherapy. A small fraction of non-squamous cell lung cancers harbor EGFR mutations, with improved outcome to gefitinib and erlotinib. Experimental evidence suggests that BRCA1 overexpression enhances sensitivity to docetaxel and resistance to cisplatin. RAP80 and Abraxas are interacting proteins that form complexes with BRCA1 and could modulate the effect of BRCA1. In order to further examine the effect of EGFR mutations and BRCA1 mRNA levels on outcome in advanced NSCLC, we performed a prospective non-randomized phase II clinical trial, testing the hypothesis that customized therapy would confer improved outcome over non-customized therapy. In an exploratory analysis, we also examined the effect of RAP80 and Abraxas mRNA levels.

METHODOLOGY/PRINCIPAL FINDINGS

We treated 123 metastatic non-squamous cell lung carcinoma patients using a customized approach. RNA and DNA were isolated from microdissected specimens from paraffin-embedded tumor tissue. Patients with EGFR mutations received erlotinib, and those without EGFR mutations received chemotherapy with or without cisplatin based on their BRCA1 mRNA levels: low, cisplatin plus gemcitabine; intermediate, cisplatin plus docetaxel; high, docetaxel alone. An exploratory analysis examined RAP80 and Abraxas expression. Median survival exceeded 28 months for 12 patients with EGFR mutations, and was 11 months for 38 patients with low BRCA1, 9 months for 40 patients with intermediate BRCA1, and 11 months for 33 patients with high BRCA1. Two-year survival was 73.3%, 41.2%, 15.6% and 0%, respectively. Median survival was influenced by RAP80 expression in the three BRCA1 groups. For example, for patients with both low BRCA1 and low RAP80, median survival exceeded 26 months. RAP80 was a significant factor for survival in patients treated according to BRCA1 levels (hazard ratio, 1.3 [95% CI, 1-1.7]; P = 0.05).

CONCLUSIONS/SIGNIFICANCE

Chemotherapy customized according to BRCA1 expression levels is associated with excellent median and 2-year survival for some subsets of NSCLC patients , and RAP80 could play a crucial modulating effect on this model of customized chemotherapy.

TRIAL REGISTRATION

(ClinicalTrials.gov) NCT00883480.

Tumor BRCA1, RRM1 and RRM2 mRNA expression levels and clinical response to first-line gemcitabine plus docetaxel in non-small-cell lung cancer patients

BACKGROUND

Overexpression of RRM1 and RRM2 has been associated with gemcitabine resistance. BRCA1 overexpression increases sensitivity to paclitaxel and docetaxel. We have retrospectively examined the effect of RRM1, RRM2 and BRCA1 expression on outcome to gemcitabine plus docetaxel in advanced non-small-cell lung cancer (NSCLC) patients.

METHODOLOGY AND PRINCIPAL FINDINGS

Tumor samples were collected from 102 chemotherapy-naïve advanced NSCLC patients treated with gemcitabine plus docetaxel as part of a randomized trial. RRM1, RRM2 and BRCA1 mRNA levels were assessed by quantitative PCR and correlated with response, time to progression and survival. As BRCA1 levels increased, the probability of response increased (Odds Ratio [OR], 1.09: p = 0.01) and the risk of progression decreased (hazard ratio [HR], 0.99; p = 0.36). As RRM1 and RRM2 levels increased, the probability of response decreased (RRM1: OR, 0.97; p = 0.82; RRM2: OR, 0.94; p<0.0001) and the risk of progression increased (RRM1: HR, 1.02; p = 0.001; RRM2: HR, 1.005; p = 0.01). An interaction observed between BRCA1 and RRM1 allowed patients to be classified in three risk groups according to combinations of gene expression levels, with times to progression of 10.13, 4.17 and 2.30 months (p = 0.001). Low BRCA1 expression was the only factor significantly associated with longer time to progression in 31 patients receiving cisplatin-based second-line therapy.

CONCLUSIONS

The mRNA expression of BRCA1, RRM1 and RRM2 is potentially a useful tool for selecting NSCLC patients for individualized chemotherapy and warrants further investigation in prospective studies.

Detailed mtDNA genotypes permit a reassessment of the settlement and population structure of the Andaman Islands

The population genetics of the Indian subcontinent is central to understanding early human prehistory due to its strategic location on the proposed corridor of human movement from Africa to Australia during the late Pleistocene. Previous genetic research using mtDNA has emphasized the relative isolation of the late Pleistocene colonizers, and the physically isolated Andaman Island populations of Island South-East Asia remain the source of claims supporting an early split between the populations that formed the patchy settlement pattern along the coast of the Indian Ocean. Using whole-genome sequencing, combined with multiplexed SNP typing, this study investigates the deep structure of mtDNA haplogroups M31 and M32 in India and the Andaman Islands. The identification of a so far unnoticed rare polymorphism shared between these two lineages suggests that they are actually sister groups within a single haplogroup, M31'32. The enhanced resolution of M31 allows for the inference of a more recent colonization of the Andaman Islands than previously suggested, but cannot reject the very early peopling scenario. We further demonstrate a widespread overlap of mtDNA and cultural markers between the two major language groups of the Andaman archipelago. Given the "completeness" of the genealogy based on whole genome sequences, and the multiple scenarios for the peopling of the Andaman Islands sustained by this inferred genealogy, our study hints that further mtDNA based phylogeographic studies are unlikely to unequivocally support any one of these possibilities.

ERCC1 mRNA levels and survival of advanced gastric cancer patients treated with a modified FOLFOX regimen

Molecular markers involved in DNA repair can help to predict survival in gastric cancer patients treated with 5-FU plus platinum chemotherapy. Excision repair cross-complementing 1 (ERCC1) and thymidylate synthase (TS) mRNA expression levels were assessed in advanced gastric cancer tumour samples using real-time quantitative PCR in 76 patients treated with a modified FOLFOX (biweekly oxaliplatin plus 5-FU and folinic acid) regimen. Median survival time in patients with low ERCC1 levels was significantly longer than in those with high levels (15.8 vs 6.2 months; P<0.0001). Patients with high TS levels had longer survival than those with low levels (12.2 vs 10.1 months; P=0.01). Forty-eight patients with low ERCC1 and high TS levels had a median survival of 16.1 months (P<0.0001). The hazard ratio for patients with high ERCC1 expression was 9.4 (P<0.0001). In patients with high mRNA levels of ERCC1, alternative chemotherapy regimens should be considered.

BRCA1: a novel prognostic factor in resected non-small-cell lung cancer

BACKGROUND

Although early-stage non-small-cell lung cancer (NSCLC) is considered a potentially curable disease following complete resection, patients have a wide spectrum of survival according to stage (IB, II, IIIA). Within each stage, gene expression profiles can identify patients with a higher risk of recurrence. We hypothesized that altered mRNA expression in nine genes could help to predict disease outcome: excision repair cross-complementing 1 (ERCC1), myeloid zinc finger 1 (MZF1) and Twist1 (which regulate N-cadherin expression), ribonucleotide reductase subunit M1 (RRM1), thioredoxin-1 (TRX1), tyrosyl-DNA phosphodiesterase (Tdp1), nuclear factor of activated T cells (NFAT), BRCA1, and the human homolog of yeast budding uninhibited by benzimidazole (BubR1).

METHODOLOGY AND PRINCIPAL FINDINGS

We performed real-time quantitative polymerase chain reaction (RT-QPCR) in frozen lung cancer tissue specimens from 126 chemonaive NSCLC patients who had undergone surgical resection and evaluated the association between gene expression levels and survival. For validation, we used paraffin-embedded specimens from 58 other NSCLC patients. A strong inter-gene correlation was observed between expression levels of all genes except NFAT. A Cox proportional hazards model indicated that along with disease stage, BRCA1 mRNA expression significantly correlated with overall survival (hazard ratio [HR], 1.98 [95% confidence interval (CI), 1.11-6]; P = 0.02). In the independent cohort of 58 patients, BRCA1 mRNA expression also significantly correlated with survival (HR, 2.4 [95%CI, 1.01-5.92]; P = 0.04).

CONCLUSIONS

Overexpression of BRCA1 mRNA was strongly associated with poor survival in NSCLC patients, and the validation of this finding in an independent data set further strengthened this association. Since BRCA1 mRNA expression has previously been linked to differential sensitivity to cisplatin and antimicrotubule drugs, BRCA1 mRNA expression may provide additional information for customizing adjuvant antimicrotubule-based chemotherapy, especially in stage IB, where the role of adjuvant chemotherapy has not been clearly demonstrated.

Setting the benchmark for tailoring treatment with EGFR tyrosine kinase inhibitors

Overexpression and mutational activation of the epidermal growth factor receptor (EGFR) is involved in tumor development and progression in non-small-cell lung cancer (NSCLC). Somatic mutations in the EGFR kinase domain confer high sensitivity to tyrosine kinase inhibitors (TKIs). The two most frequent mutations are the exon 19 deletion and the exon 21 L858R. Distinct EGFR mutations differ in their effect on response and survival to TKIs. We have examined EGFR mutations in more than 1800 stage IV NSCLCs for erlotinib customization as both first- and second-line treatment. EGFR mutations cluster in never-smokers, women and adenocarcinomas, as has been described in multiple retrospective studies. The overall frequency of EGFR mutations in our study was 15% and the response in first- and second-line treatment was 84%. Overall, progression-free survival was 13 months and median survival has not been reached. However, patients with exon 19 deletions showed a significantly longer progression-free survival than those harboring L858R mutations. Despite abundant molecular evidence on the role of EGFR mutations, there is still no general agreement as to their predictive value. To clarify this important issue, the Spanish Lung Cancer Group has opened a Phase III trial comparing erlotinib with chemotherapy in stage IV NSCLC patients with EGFR mutations. This study is open to other European institutions.

Customizing Cisplatin Based on Quantitative Excision Repair Cross-Complementing 1 mRNA Expression: A Phase III Trial in Non–Small-Cell Lung Cancer

Purpose

Although current treatment options for metastatic non–small-cell lung cancer (NSCLC) rely on cisplatin-based chemotherapy, individualized approaches to therapy may improve response or reduce unnecessary toxicity. Excision repair cross-complementing 1 (ERCC1) has been associated with cisplatin resistance. We hypothesized that assigning cisplatin based on pretreatment ERCC1 mRNA levels would improve response.

Patients and Methods

From August 2001 to October 2005, 444 stage IV NSCLC patients were enrolled. RNA was isolated from pretreatment biopsies, and quantitative real-time reverse transcriptase PCR assays were performed to determine ERCC1 mRNA expression. Patients were randomly assigned in a 1:2 ratio to either the control or genotypic arm before ERCC1 assessment. Patients in the control arm received docetaxel plus cisplatin. In the genotypic arm, patients with low ERCC1 levels received docetaxel plus cisplatin, and those with high levels received docetaxel plus gemcitabine. The primary end point was the overall objective response rate.

Results

Of 444 patients enrolled, 78 (17.6%) went off study before receiving one cycle of chemotherapy, mainly due to insufficient tumor tissue for ERCC1 mRNA assessment. Of the remaining 346 patients assessable for response, objective response was attained by 53 patients (39.3%) in the control arm and 107 patients (50.7%) in the genotypic arm (P = .02).

Conclusion

Assessment of ERCC1 mRNA expression in patient tumor tissue is feasible in the clinical setting and predicts response to docetaxel and cisplatin. Additional studies are warranted to optimize methodologies for ERCC1 analysis in small tumor samples and to refine a multibiomarker profile predictive of patient outcome.

Typing of multiple single-nucleotide polymorphisms using ribonuclease cleavage of DNA/RNA chimeric single-base extension primers and detection by MALDI-TOF mass spectrometry

A novel single-base extension (SBE) assay using cleavable and noncleavable SBE primers in the same reaction mix is described. The cleavable SBE primers consisted of deoxyribonucleotides and one ribonucleotide (hereafter denoted chimeric primers), whereas the noncleavable SBE primers consisted of only deoxyribonucleotides (hereafter denoted standard primers). Biotin-labeled ddNTPs were used in the SBE reaction, and the SBE products were purified using the monomeric avidin triethylamine purification protocol, ensuring that only primers extended with a biotin-ddNTP in the 3'-end were isolated. A ribonuclease mix was developed to specifically cleave the chimeric primers, irrespective of the base of the ribonucleotide, whereas standard primers without a ribonucleotide were unaffected by the ribonuclease treatment. The SBE products were analyzed in linear mode using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. The cleaved SBE products were detected in the 2000-5500 m/z range, and the noncleaved SBE products were detected in the 5500-10 000 m/z range. The method was validated by typing 17 Y chromosome single-nucleotide polymorphisms in 100 males with a 17-plex SBE package containing 9 chimeric primers and 8 standard primers.

Polymorphisms in DNA repair genes modulate survival in cisplatin/gemcitabine-treated non-small-cell lung cancer patients

BACKGROUND

Impaired DNA repair capacity may favorably affect survival in cisplatin/gemcitabine-treated non-small-cell lung cancer (NSCLC) patients. We investigated the association of survival with genetic polymorphisms in X-ray repair cross-complementing group 1 and group 3 (XRCC3), xeroderma pigmentosum group D (XPD), excision repair cross-complementing group 1, ligase IV, ribonucleotide reductase, TP53, cyclooxygenase-2, interleukin-6, peroxisome proliferator-activated receptor gamma, epidermal growth factor, methylene-tetra-hydrofolate reductase and methionine synthase.

PATIENTS AND METHODS

One hundred and thirty-five stage IV or IIIB (with malignant pleural effusion) NSCLC patients treated with cisplatin/gemcitabine from different hospitals of the Spanish Lung Cancer Group were genotyped for 14 different polymorphisms in 13 genes. Polymorphisms were detected by the TaqMan method, using genomic DNA extracted from baseline blood samples.

RESULTS

Median survival was significantly increased in patients harboring XRCC3 241 MetMet: 16 months versus 10 months for patients with ThrMet and 14 months for those with ThrThr (P = 0.01). The risk of death ratio was significantly lower for MetMet than for ThrMet patients (hazard ratio, 0.43; P = 0.01). In the multivariate Cox model, XRCC3 241 remained an independent prognostic factor (hazard ratio: XRCC3 241 MetMet, 0.44; P = 0.01), and XPD 751 and XRCC1 399 also emerged as significant prognostic factors (hazard ratios: XPD 751 LysGln, 0.46, P = 0.03; XRCC1 399 ArgGln, 0.61, P = 0.04). No other association was observed between genotype and survival.

CONCLUSION

XRCC3 241 MetMet is an independent determinant of favorable survival in NSCLC patients treated with cisplatin/gemcitabine. A simple molecular assay to determine the XRCC3 241 genotype can be useful for customizing chemotherapy.

beta-Catenin, Nf-kappaB and FAS protein expression are independent events in head and neck cancer: study of their association with clinical parameters

In spite of much effort, no good markers have yet been found for predicting prognosis or response to therapy in advanced head and neck squamous cell carcinoma (HNSCCs) patients. beta-catenin, a protein involved in the cytoskeleton, cell-cell adhesion and gene transcription, is a factor associated with tumour progression. Recently, an interaction has been reported between beta-catenin, and NF-kappaB coupled with an inverse association of beta-catenin, and FAS (CD95/APO-1) protein expression in breast and colorectal tumours. To confirm these observations and to test their clinical impact in HNSCCs we have evaluated the expression of beta-catenin, NF-kappaB and FAS proteins. We used tissue microarrays to simultaneously analyse the levels of these proteins immunohistochemically in 118 HNSCCs. Among the 113 tumours evaluable for beta-catenin, increased and decreased levels were detected in 41 (36%) and 62 (55%) of the tumours, respectively. beta-catenin, protein staining was mainly membranous but 10 tumours (9%) showed the clear presence of protein in the cytoplasm, and none in the nucleus. Moreover, 81% of the tumours had decreased FAS protein expression, indicating that loss of FAS protein is a common feature of HNSCCs. Abnormal or nuclear NF-kappaB staining was observed in 24% of the tumours. No association was detected between the expression levels of the proteins evaluated. Regarding clinical associations, tumours from the hypopharynx had significantly lower levels of beta-catenin expression than those from other locations (P<0.05). Moreover, our data revealed that patients whose tumours had low levels of beta-catenin protein expression had decreased survival probability (24.8 months vs. NR, P=0.03) and reduced response to therapy (15.4 vs. 43 months; P=0.01) compared with patients whose tumours had high levels of beta-catenin. Taken together, our observations indicate that beta-catenin, NF-kappaB and FAS expression are independent events during HNSCC development and that levels of beta-catenin protein may identify subsets of advanced HNSCCs patients with different prognosis and response to therapy capabilities.

Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor are associated with improved survival in gefitinib-treated chemorefractory lung adenocarcinomas

PURPOSE

Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) confer a strong sensitivity to gefitinib, a selective tyrosine kinase inhibitor of EGFR.

EXPERIMENTAL DESIGN

We examined EGFR mutations at exons 18, 19, and 21 in tumor tissue from 68 gefitinib-treated, chemorefractory, advanced non-small cell lung cancer patients from the United States, Europe, and Asia and in a highly gefitinib-sensitive non-small cell lung cancer cell line and correlated their presence with response and survival. In addition, in a subgroup of 28 patients for whom the remaining tumor tissue was available, we examined the relationship among EGFR mutations, CA repeats in intron 1 of EGFR, EGFR and caveolin-1 mRNA levels, and increased EGFR gene copy numbers.

RESULTS

Seventeen patients had EGFR mutations, all of which were in lung adenocarcinomas. Radiographic response was observed in 16 of 17 (94.1%) patients harboring EGFR mutations, in contrast with 6 of 51 (12.6%) with wild-type EGFR (P < 0.0001). Probability of response increased significantly in never smokers, patients receiving a greater number of prior chemotherapy regimens, Asians, and younger patients. Median survival was not reached for patients with EGFR mutations and was 9.9 months for those with wild-type EGFR (P = 0.001). EGFR mutations tended to be associated with increased numbers of CA repeats and increased EGFR gene copy numbers but not with EGFR and caveolin-1 mRNA overexpression (P = not significant).

CONCLUSIONS

The presence of EGFR mutations is a major determinant of gefitinib response, and targeting EGFR should be considered in preference to chemotherapy as first-line treatment in lung adenocarcinomas that have demonstrable EGFR mutations.

Mutations in the tyrosine kinase domain of the EGFR gene associated with gefitinib response in non-small-cell lung cancer

The potential relevance of epidermal growth factor receptor (EGFR) mutations to non-small-cell lung cancer treatment has recently been identified. We have examined the presence of EGFR mutations in Japanese and Spanish gefitinib-treated non-small-cell lung cancer patients. A total of 34 gefitinib-treated patients were screened, 18 from Japan and 16 from Spain. Laser capture microdissection was performed for the accurate procurement of tumor cells. EGFR exons 18, 19 and 21 were amplified from genomic DNA by means of PCR, and the samples were then subjected to bi-directional automatic sequencing. EGFR somatic mutations in the tyrosine kinase domain were found in 8 of 34 patients (23.5%). Gefitinib response was observed in 7 of 8 patients (87.5%) with EGFR mutations and in 3 of 24 (12.5%) with wild-type EGFR (P=0.0003). Five deletion mutations were clustered in the region spanning codons 746 to 750 (ELREA) within exon 19. Three additional tumors had amino acid substitutions within exon 18, at codons 718 and 719. Logistic regression analysis showed that response was primarily linked to the presence of EGFR mutations and secondarily linked to female gender, non-smoker status and a greater number of prior chemotherapy regimens. The presence of EGFR mutations is a major determinant of gefitinib response, and EGFR tyrosine kinase inhibitors should be tested in clinical trials of first-line treatment of lung adenocarcinomas harboring EGFR mutations.

MALDI-TOF mass spectrometric detection of multiplex single base extended primers. A study of 17 y-chromosome single-nucleotide polymorphisms

One of the most promising techniques for typing of multiple single-nucleotide polymorphism (SNP) is detection of single base extension primers (SBE) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We present a new MALDI-TOF MS protocol for typing of multiple SNPs in a single reaction. Biotin-labeled ddNTPs were used in the SBE reaction and solid phase-bound monomeric avidin was used as capturing/purification scheme allowing the exclusive release of the SBE products under gentle conditions using 5% triethylamine. We dubbed this method monomeric avidin triethylamine purification. The biotin-labeled ddNTPs contained linkers with different masses ensuring a clear separation of the alleles even for SBE primers with a mass of 10 300 Da. Furthermore, only 25-350 fmol of SBE primers were necessary in order to obtain reproducible MALDI-TOF spectra. Similar signal intensities were obtained in the 5500-10 300 m/z mass range by increasing the concentration of the longer SBE primers in the reaction. To validate the technique, 17 Y-chromosome SNPs were analyzed in 200 males. The precision and accuracy of the mass determination were analyzed by parametric statistic, and the potential use of MALDI-TOF MS for SNP typing is discussed.

Epidermal growth factor receptor activating mutations in Spanish gefitinib-treated non-small-cell lung cancer patients

BACKGROUND

North American and Japanese non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) activation via tyrosine kinase (TK) mutations respond dramatically to gefitinib treatment. To date, however, the frequency and effect of EGFR TK mutations have not been examined in European patients.

PATIENTS AND METHODS

Eighty-three Spanish advanced NSCLC patients who had progressed after chemotherapy, were treated with compassionate use of gefitinib. Patients were selected on the basis of available tumor tissue. Tumor genomic DNA was retrieved from paraffin-embedded tissue obtained by laser capture microdissection. EGFR mutations in exons 19 and 21 were examined by direct sequencing.

RESULTS

EGFR mutations were found in 10 of 83 (12%) of patients. All mutations were found in adenocarcinomas, more frequently in females (P=0.007) and non-smokers (P=0.01). Response was observed in 60% of patients with mutations and 8.8% of patients with wild-type EGFR (P=0.001). Time to progression for patients with mutations was 12.3 months, compared with 3.6 months for patients with wild-type EGFR (P=0.002). Median survival was 13 months for patients with mutations and 4.9 months for those with wild-type EGFR (P=0.02).

CONCLUSIONS

EGFR TK mutational analysis is a novel predictive test for selecting lung adenocarcinoma patients for targeted therapy with EGFR TK inhibitors.