Holly J. Wolf

Promoter Hypermethylation of Multiple Genes in Sputum Precedes Lung Cancer Incidence in a High-Risk Cohort

A sensitive screening approach for lung cancer could markedly reduce the high mortality rate for this disease. Previous studies have shown that methylation of gene promoters is present in exfoliated cells within sputum prior to lung cancer diagnosis. The purpose of the current study is to conduct a nested case-control study of incident lung cancer cases from an extremely high-risk cohort for evaluating promoter methylation of 14 genes in sputum. Controls (n = 92) were cohort members matched to cases (n = 98) by gender, age, and month of enrollment. The comparison of proximal sputum collected within 18 months to >18 months prior to diagnosis showed that the prevalence for methylation of gene promoters increased as the time to lung cancer diagnosis decreased. Six of 14 genes were associated with a >50% increased lung cancer risk. The concomitant methylation of three or more of these six genes was associated with a 6.5-fold increased risk and a sensitivity and specificity of 64%. This is the first study to prospectively examine a large panel of genes for their ability to predict lung cancer and shows the promise of gene promoter hypermethylation in sputum as a molecular marker for identifying people at high risk for cancer incidence.

The Impact of Socioeconomic Status on Survival After Cancer in the United States : Findings From the National Program of Cancer Registries Patterns of Care Study

Understanding the ways in which socioeconomic status (SES) affects mortality is important for defining strategies to eliminate the unequal burden of cancer by race and ethnicity in the United States.

Defining a Gene Promoter Methylation Signature in Sputum for Lung Cancer Risk Assessment

Purpose: To evaluate the methylation state of 31 genes in sputum as biomarkers in an expanded nested, case–control study from the Colorado cohort, and to assess the replication of results from the most promising genes in an independent case–control study of asymptomatic patients with stage I lung cancer from New Mexico. Experimental Design: Cases and controls from Colorado and New Mexico were interrogated for methylation of up to 31 genes using nested, methylation-specific PCR. Individual genes and methylation indices were used to assess the association between methylation and lung cancer with logistic regression modeling. Results: Seventeen genes with ORs of 1.4 to 3.6 were identified and selected for replication in the New Mexico study. Overall, the direction of effects seen in New Mexico was similar to Colorado with the largest increase in case discrimination (ORs, 3.2–4.2) seen for the PAX5α, GATA5, and SULF2 genes. Receiver operating characteristic (ROC) curves generated from seven-gene panels from Colorado and New Mexico studies showed prediction accuracy of 71% and 77%, respectively. A 22-fold increase in lung cancer risk was seen for a subset of New Mexico cases with five or more genes methylated. Sequence variants associated with lung cancer did not improve the accuracy of this gene methylation panel. Conclusions: These studies have identified and replicated a panel of methylated genes whose integration with other promising biomarkers could initially identify the highest risk smokers for computed tomographic screening for early detection of lung cancer. Clin Cancer Res; 18(12); 3387–95. ©2012 AACR.

Breast cancer survival in the US and Europe: A CONCORD high-resolution study.

Breast cancer survival is reportedly higher in the US than in Europe. The first worldwide study (CONCORD) found wide international differences in age‐standardized survival. The aim of this study is to explain these survival differences. Population‐based data on stage at diagnosis, diagnostic procedures, treatment and follow‐up were collected for about 20,000 women diagnosed with breast cancer aged 15–99 years during 1996–98 in 7 US states and 12 European countries. Age‐standardized net survival and the excess hazard of death up to 5 years after diagnosis were estimated by jurisdiction (registry, country, European region), age and stage with flexible parametric models. Breast cancers were generally less advanced in the US than in Europe. Stage also varied less between US states than between European jurisdictions. Early, node‐negative tumors were more frequent in the US (39%) than in Europe (32%), while locally advanced tumors were twice as frequent in Europe (8%), and metastatic tumors of similar frequency (5–6%). Net survival in Northern, Western and Southern Europe (81–84%) was similar to that in the US (84%), but lower in Eastern Europe (69%). For the first 3 years after diagnosis the mean excess hazard was higher in Eastern Europe than elsewhere: the difference was most marked for women aged 70–99 years, and mainly confined to women with locally advanced or metastatic tumors. Differences in breast cancer survival between Europe and the US in the late 1990s were mainly explained by lower survival in Eastern Europe, where low healthcare expenditure may have constrained the quality of treatment.

Colorectal cancer survival in the USA and Europe: a CONCORD high-resolution study

Objectives To assess the extent to which stage at diagnosis and adherence to treatment guidelines may explain the persistent differences in colorectal cancer survival between the USA and Europe. Design A high-resolution study using detailed clinical data on Dukes’ stage, diagnostic procedures, treatment and follow-up, collected directly from medical records by trained abstractors under a single protocol, with standardised quality control and central statistical analysis. Setting and participants 21 population-based registries in seven US states and nine European countries provided data for random samples comprising 12 523 adults (15–99 years) diagnosed with colorectal cancer during 1996–1998. Outcome measures Logistic regression models were used to compare adherence to ‘standard care’ in the USA and Europe. Net survival and excess risk of death were estimated with flexible parametric models. Results The proportion of Dukes’ A and B tumours was similar in the USA and Europe, while that of Dukes’ C was more frequent in the USA (38% vs 21%) and of Dukes’ D more frequent in Europe (22% vs 10%). Resection with curative intent was more frequent in the USA (85% vs 75%). Elderly patients (75–99 years) were 70–90% less likely to receive radiotherapy and chemotherapy. Age-standardised 5-year net survival was similar in the USA (58%) and Northern and Western Europe (54–56%) and lowest in Eastern Europe (42%). The mean excess hazard up to 5 years after diagnosis was highest in Eastern Europe, especially among elderly patients and those with Dukes’ D tumours. Conclusions The wide differences in colorectal cancer survival between Europe and the USA in the late 1990s are probably attributable to earlier stage and more extensive use of surgery and adjuvant treatment in the USA. Elderly patients with colorectal cancer received surgery, chemotherapy or radiotherapy less often than younger patients, despite evidence that they could also have benefited.

The Detection of Chromosomal Aneusomy by Fluorescence In situ Hybridization in Sputum Predicts Lung Cancer Incidence

Lung cancer usually is disseminated (advanced) and has a poor prognosis at diagnosis. Current and former smokers are at a high risk for lung cancer and are candidates for prevention and early detection strategies. Sputum is a potential source of biomarkers that might determine either lung cancer risk or the presence of early lung cancer, but no current sputum test is sufficiently sensitive and specific for effective screening. We used fluorescence in situ hybridization (FISH) to measure chromosomal aneusomy (CA) in sputum samples collected prospectively from 100 incident lung cancer cases and 96 controls (matched on age, gender, and date of collection) nested within an ongoing high-risk cohort. The CA-FISH assay was aimed at four DNA targets: epidermal growth factor receptor, MYC, 5p15, and CEP 6. The sensitivity of a positive CA-FISH assay (abnormal for two or more of the four markers) for lung cancer was substantially higher for samples collected within 18 months (76% sensitivity) than for samples collected more than 18 months (31%) before lung cancer diagnosis. Sensitivity was higher for squamous cell cancers (94%) than for other histologic types (69%). CA-FISH specificity based on samples collected within 18 months before diagnosis was 88%. The adjusted odds ratio (OR) of lung cancer for specimens collected within 18 months before a cancer diagnosis was higher for the CA-FISH assay [OR, 29.9; 95% confidence interval (95% CI), 9.5-94.1] than for previously studied ORs of cytologic atypia (OR, 1.8; 95% CI, 1.3-2.6) and gene promoter methylation (OR, 6.5; 95% CI, 1.2-35.5). Whether CA-FISH is an indicator of extreme risk for incident lung cancer or detects exfoliated cancer cells is unknown. The apparent promise of CA-FISH in sputum for assessing lung cancer risk and/or for lung cancer early detection now needs to be validated in a clinical screening trial. Cancer Prev Res; 3(4); 447–53. ©2010 AACR.

Recurrent genomic gains in preinvasive lesions as a biomarker of risk for lung cancer.

Lung carcinoma development is accompanied by field changes that may have diagnostic significance. We have previously shown the importance of chromosomal aneusomy in lung cancer progression. Here, we tested whether genomic gains in six specific loci, TP63 on 3q28, EGFR on 7p12, MYC on 8q24, 5p15.2, and centromeric regions for chromosomes 3 (CEP3) and 6 (CEP6), may provide further value in the prediction of lung cancer. Bronchial biopsy specimens were obtained by LIFE bronchoscopy from 70 subjects (27 with prevalent lung cancers and 43 individuals without lung cancer). Twenty six biopsies were read as moderate dysplasia, 21 as severe dysplasia and 23 as carcinoma in situ (CIS). Four-micron paraffin sections were submitted to a 4-target FISH assay (LAVysion, Abbott Molecular) and reprobed for TP63 and CEP 3 sequences. Spot counts were obtained in 30–50 nuclei per specimen for each probe. Increased gene copy number in 4 of the 6 probes was associated with increased risk of being diagnosed with lung cancer both in unadjusted analyses (odds ratio = 11, p<0.05) and adjusted for histology grade (odds ratio = 17, p<0.05). The most informative 4 probes were TP63, MYC, CEP3 and CEP6. The combination of these 4 probes offered a sensitivity of 82% for lung cancer and a specificity of 58%. These results indicate that specific cytogenetic alterations present in preinvasive lung lesions are closely associated with the diagnosis of lung cancer and may therefore have value in assessing lung cancer risk.

Bronchial Epithelial Ki-67 Index Is Related to Histology, Smoking, and Gender, but Not Lung Cancer or Chronic Obstructive Pulmonary Disease

Purpose: To determine whether increased bronchial epithelial proliferation is associated with histology, smoking status, gender, age, chronic obstructive pulmonary disease (COPD), or lung cancer. Experimental Design: Cross-sectional study of 113 subjects undergoing white light and autofluorescence bronchoscopy: 27 never smokers; 27 current or ex-smokers with normal spirometry; 31 current or ex-smokers with COPD; and 28 current, ex-, or never smokers with lung cancer. Ki-67 expresssion was determined by immunohistochemistry on all evaluable biopsy sites without carcinoma. Relationships between Ki-67 index (percentage of epithelial cells expressing Ki-67), demographic variables, smoking, histology, and the presence of COPD and/or lung cancer were determined. Results: Results for both maximal and mean Ki-67 index are similar, so only the former are reported. Average maximal Ki-67 index was higher in current smokers than either ex-smokers or never smokers (48.0% versus 30.6% versus 22.6%; P < 0.001). Males had higher Ki-67 index than females (39.9% versus 23.6%; P < 0.001). Compared with subjects without disease (Ki-67 index = 30.0%), maximal Ki-67 index was not significantly elevated (P = 0.44) in subjects with either lung cancer (Ki-67 = 39.1%) or COPD (Ki-67 = 38.9%). Conclusions: Smoking status, bronchial histology, and gender were significantly associated with Ki-67 index. No increase in Ki-67 index was found in the nonmalignant epithelium of patients with lung cancer or COPD. Although Ki-67 index may provide insight into the short-term effects of chemoprevention agents on cell proliferation, its lack of association with lung cancer or COPD raises question regarding its utility as a lung cancer risk biomarker. (Cancer Epidemiol Biomarkers Prev 2007;16(11):2425–31)

Sputum Cytologic Atypia Predicts Incident Lung Cancer: Defining Latency and Histologic Specificity

Background: There is a need for early detection methods for lung cancer. Radiologic imaging may be more sensitive for peripheral cancers than for cancers arising in the central airways, from which bronchial epithelial cells are exfoliated into the sputum. Methods: Sputum samples were collected at baseline and periodically thereafter in a cohort of smokers and former smokers with chronic obstructive lung disease. The association between cytologic atypia and incident lung cancer was assessed by hazard ratios (HR; 95% confidence intervals) using Cox regression and by odds ratios (95% confidence intervals) using logistic regression, adjusting for potential confounding factors. Results: We observed 174 incident lung cancers in a cohort of 2,521 people over 9,869 person-years of observation. Risk for incident lung cancer was increased among those with cytologic atypia graded as moderate or worse (adjusted HR, 2.37; 1.68-3.34). The association between sputum atypia and lung cancer incidence was greatest for those sputum samples collected 5 months or less before the diagnosis of lung cancer (odds ratio, 10.32; 5.34-19.97). The association was substantially stronger for squamous cell lung cancers (HR, 5.13; 2.89-9.10) than for adenocarcinomas (HR, 1.85; 0.94-3.65). Conclusion: Cytologic atypia is a marker for increased lung cancer risk. These cytologic changes seem to arise from late events that are most apparent for cancers arising in the central respiratory airways. Whether cytologic atypia might complement radiologic imaging in a combined approach to lung cancer, early detection requires additional evaluation of those two methods used together. (Cancer Epidemiol Biomarkers Prev 2008;17(1):158–63)

Genome-Wide Significant Association Between a Sequence Variant at 15q15.2 and Lung Cancer Risk

Genome-wide association studies (GWAS) have identified 3 genomic regions, at 15q24-25.1, 5p15.33, and 6p21.33, which associate with the risk of lung cancer. Large meta-analyses of GWA data have failed to find additional associations of genome-wide significance. In this study, we sought to confirm 7 variants with suggestive association to lung cancer (P < 10(-5)) in a recently published meta-analysis. In a GWA dataset of 1,447 lung cancer cases and 36,256 controls in Iceland, 3 correlated variants on 15q15.2 (rs504417, rs11853991, and rs748404) showed a significant association with lung cancer, whereas rs4254535 on 2p14, rs1530057 on 3p24.1, rs6438347 on 3q13.31, and rs1926203 on 10q23.31 did not. The most significant variant, rs748404, was genotyped in an additional 1,299 lung cancer cases and 4,102 controls from the Netherlands, Spain, and the United States and the results combined with published GWAS data. In this analysis, the T allele of rs748404 reached genome-wide significance (OR = 1.15, P = 1.1 × 10(-9)). Another variant at the same locus, rs12050604, showed association with lung cancer (OR = 1.09, 3.6 × 10(-6)) and remained significant after adjustment for rs748404 and vice versa. rs748404 is located 140 kb centromeric of the TP53BP1 gene that has been implicated in lung cancer risk. Two fully correlated, nonsynonymous coding variants in TP53BP1, rs2602141 (Q1136K) and rs560191 (E353D) showed association with lung cancer in our sample set; however, this association did not remain significant after adjustment for rs748404. Our data show that 1 or more lung cancer risk variants of genome-wide significance and distinct from the coding variants in TP53BP1 are located at 15q15.2.