Identification of hypermethylated tumor suppressor genes in body fluids is an appealing strategy for the noninvasive detection of colorectal cancer. Here we examined the role of N-Myc downstream-regulated gene 4 (NDRG4) as a novel tumor suppressor and biomarker in colorectal cancer.
NDRG4 promoter methylation was analyzed in human colorectal cancer cell lines, colorectal tissue, and noncancerous colon mucosa by using methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing. NDRG4 mRNA and protein expression were studied using real-time–PCR and immunohistochemistry, respectively. Tumor suppressor functions of NDRG4 were examined by colony formation, cell proliferation, and migration and invasion assays in colorectal cancer cell lines that were stably transfected with an NDRG4 expression construct. Quantitative methylation-specific PCR was used to examine the utility of NDRG4 promoter methylation as a biomarker in fecal DNA from 75 colorectal cancer patients and 75 control subjects. All P values are two-sided.
The prevalence of NDRG4 promoter methylation in two independent series of colorectal cancers was 86% (71/83) and 70% (128/184) compared with 4% (2/48) in noncancerous colon mucosa (P < .001). NDRG4 mRNA and protein expression were decreased in colorectal cancer tissue compared with noncancerous colon mucosa. NDRG4 overexpression in colorectal cancer cell lines suppressed colony formation (P = .014), cell proliferation (P < .001), and invasion (P < .001). NDRG4 promoter methylation analysis in fecal DNA from a training set of colorectal cancer patients and control subjects yielded a sensitivity of 61% (95% confidence interval [CI] = 43% to 79%) and a specificity of 93% (95% CI = 90% to 97%). An independent test set of colorectal cancer patients and control subjects yielded a sensitivity of 53% (95% CI = 39% to 67%) and a specificity of 100% (95% CI = 86% to 100%).
NDRG4 is a candidate tumor suppressor gene in colorectal cancer whose expression is frequently inactivated by promoter methylation. NDRG4 promoter methylation is a potential biomarker for the noninvasive detection of colorectal cancer in stool samples.
Information on clinically verified stroke and transient ischemic attack (TIA) following Hodgkin lymphoma is scarce. We quantified the long-term risk of cerebrovascular disease associated with the use of radiotherapy and chemotherapy in survivors of Hodgkin lymphoma and explored potential pathogenic mechanisms.
We performed a retrospective cohort study among 2201 five-year survivors of Hodgkin lymphoma treated before age 51 between 1965 and 1995. We compared incidence rates of clinically verified stroke and TIA with those in the general population. We used multivariable Cox regression techniques to study treatment-related factors and other risk factors. All statistical tests were two-sided.
After a median follow-up of 17.5 years, 96 patients developed cerebrovascular disease (55 strokes, 31 TIAs, and 10 with both TIA and stroke; median age = 52 years). Most ischemic events were from large-artery atherosclerosis (36%) or cardioembolisms (24%). The standardized incidence ratio for stroke was 2.2 (95% confidence interval [CI] = 1.7 to 2.8), and for TIA, it was 3.1 (95% CI = 2.2 to 4.2). The risks remained elevated, compared with those in the general population, after prolonged follow-up. The cumulative incidence of ischemic stroke or TIA 30 years after Hodgkin lymphoma treatment was 7% (95% CI = 5% to 8%). Radiation to the neck and mediastinum was an independent risk factor for ischemic cerebrovascular disease (hazard ratio = 2.5, 95% CI = 1.1 to 5.6 vs without radiotherapy). Treatment with chemotherapy was not associated with an increased risk. Hypertension, diabetes mellitus, and hypercholesterolemia were associated with the occurrence of ischemic cerebrovascular disease, whereas smoking and overweight were not.
Patients treated for Hodgkin lymphoma experience a substantially increased risk of stroke and TIA, associated with radiation to the neck and mediastinum. Physicians should consider appropriate risk-reducing strategies.
Merkel cell carcinoma is a rare malignancy of the skin. Integration of Merkel cell polyomavirus (MCPyV) DNA to the tumor genome is frequent in these cancers. The clinical consequences of MCPyV infection are unknown.
We analyzed formalin-fixed paraffin-embedded Merkel cell carcinoma tissue samples from 114 of 207 patients diagnosed with Merkel cell carcinoma in Finland from 1979 to 2004 for the presence of MCPyV DNA with the use of polymerase chain reaction (PCR), quantitative PCR, and DNA sequencing and examined associations between tumor MCPyV DNA status and histopathologic factors and survival. The median follow-up time after Merkel cell carcinoma diagnosis for subjects who were alive was 9.9 years (range = 4.9–21.9 years). All P values are two-sided.
MCPyV DNA was present in 91 carcinomas (79.8%). Compared with MCPyV DNA–negative cancers, MCPyV DNA–positive cancers were more often located in a limb (40.7% vs 8.7%, P = .015) and less frequent in patients who had regional nodal metastases at diagnosis (6.6% vs 21.7%, P = .043). Patients with MCPyV DNA–positive tumors had better overall survival than those with MCPyV DNA–negative tumors (5-year survival: 45.0% vs 13.0%, respectively; P < .001, two-sided log-rank test).
MCPyV infection is associated with clinical outcomes in patients with Merkel cell carcinoma. These findings lend support to the hypothesis that viral infection is frequently associated with the pathogenesis of Merkel cell carcinoma.
Adult survivors of childhood central nervous system (CNS) malignancies are at high risk for long-term morbidity and late mortality. However, patterns of late mortality, the long-term risks of subsequent neoplasms and debilitating medical conditions, and sociodemographic outcomes have not been comprehensively characterized for individual diagnostic and treatment groups.
We collected information on treatment, mortality, chronic medical conditions, and neurocognitive functioning of adult 5-year survivors of CNS malignancies diagnosed between 1970 and 1986 within the Childhood Cancer Survivor Study. Using competing risk framework, we calculated cumulative mortality according to cause of death and cumulative incidence of subsequent neoplasms according to exposure and dose of cranial radiation therapy (RT). Neurocognitive impairment and socioeconomic outcomes were assessed with respect to dose of CNS radiotherapy to specific brain regions. Cumulative incidence of chronic medical conditions was compared between survivors and siblings using Cox regression models. All tests of statistical significance were two-sided.
Among all eligible 5-year survivors (n = 2821), cumulative late mortality at 30 years was 25.8% (95% confidence interval [CI] = 23.4% to 28.3%), due primarily to recurrence and/or progression of primary disease. Patients who received cranial RT of 50 Gy or more (n = 813) had a cumulative incidence of a subsequent neoplasm within the CNS of 7.1% (95% CI = 4.5% to 9.6%) at 25 years from diagnosis compared with 1.0% (95% CI = 0% to 2.3%) for patients who had no RT. Survivors had higher risk than siblings of developing new endocrine, neurological, or sensory complications 5 or more years after diagnosis. Neurocognitive impairment was high and proportional to radiation dose for specific tumor types. There was a dose-dependent association between RT to the frontal and/or temporal lobes and lower rates of employment, and marriage.
Survivors of childhood CNS malignancies are at high risk for late mortality and for developing subsequent neoplasms and chronic medical conditions. Care providers should be informed of these risks so they can provide risk-directed care and develop screening guidelines.
Adding genotypes from seven single-nucleotide polymorphisms (SNPs), which had previously been associated with breast cancer, to the National Cancer Institute's Breast Cancer Risk Assessment Tool (BCRAT) increases the area under the receiver operating characteristic curve from 0.607 to 0.632.
Criteria that are based on four clinical or public health applications were used to compare BCRAT with BCRATplus7, which includes the seven genotypes. Criteria included number of expected life-threatening events for the decision to take tamoxifen, expected decision losses (in units of the loss from giving a mammogram to a woman without detectable breast cancer) for the decision to have a mammogram, rates of risk reclassification, and number of lives saved by risk-based allocation of screening mammography. For all calculations, the following assumptions were made: Hardy–Weinberg equilibrium, linkage equilibrium across SNPs, additive effects of alleles at each locus, no interactions on the logistic scale among SNPs or with factors in BCRAT, and independence of SNPs from factors in BCRAT.
Improvements in expected numbers of life-threatening events were only 0.07% and 0.81% for deciding whether to take tamoxifen to prevent breast cancer for women aged 50–59 and 40–49 years, respectively. For deciding whether to recommend screening mammograms to women aged 50–54 years, the reduction in expected losses was 0.86% if the ideal breast cancer prevalence threshold for recommending mammography was that of women aged 50–54 years. Cross-classification of risks indicated that some women classified by BCRAT would have different classifications with BCRATplus7, which might be useful if BCRATplus7 was well calibrated. Improvements from BCRATplus7 were small for risk-based allocation of mammograms under costs constraints.
The gains from BCRATplus7 are small in the applications examined. Models with SNPs, such as BCRATplus7, have not been validated for calibration in independent cohort data. Additional studies are needed to validate a model with SNPs and justify its use.
Pancreatic cancer outcomes vary considerably among hospitals. Assessing pancreatic cancer care by using quality indicators could help reduce this variability. However, valid quality indicators are not currently available for pancreatic cancer management, and a composite assessment of the quality of pancreatic cancer care in the United States has not been done.
Potential quality indicators were identified from the literature, consensus guidelines, and interviews with experts. A panel of 20 pancreatic cancer experts ranked potential quality indicators for validity based on the RAND/UCLA Appropriateness Methodology. The rankings were rated as valid (high or moderate validity) or not valid. Adherence with valid indicators at both the patient and the hospital levels and a composite measure of adherence at the hospital level were assessed using data from the National Cancer Data Base (2004–2005) for 49 065 patients treated at 1134 hospitals. Summary statistics were calculated for each individual candidate quality indicator to assess the median ranking and distribution.
Of the 50 potential quality indicators identified, 43 were rated as valid (29 as high and 14 as moderate validity). Of the 43 valid indicators, 11 (25.6%) assessed structural factors, 19 (44.2%) assessed clinical processes of care, four (9.3%) assessed treatment appropriateness, four (9.3%) assessed efficiency, and five (11.6%) assessed outcomes. Patient-level adherence with individual indicators ranged from 49.6% to 97.2%, whereas hospital-level adherence with individual indicators ranged from 6.8% to 99.9%. Of the 10 component indicators (contributing 1 point each) that were used to develop the composite score, most hospitals were adherent with fewer than half of the indicators (median score = 4; interquartile range = 3–5).
Based on the quality indicators developed in this study, there is considerable variability in the quality of pancreatic cancer care in the United States. Hospitals can use these indicators to evaluate the pancreatic cancer care they provide and to identify potential quality improvement opportunities.
The impact of cancer on health-related quality of life (HRQOL) is poorly understood because of the lack of baseline HRQOL status before cancer diagnosis. To our knowledge, this is the first population-based study to quantify the nature and extent of HRQOL changes from before to after cancer diagnosis for nine types of cancer patients and to compare their health with individuals without cancer.
The Surveillance, Epidemiology, and End Results cancer registry data were linked with the Medicare Health Outcomes Survey (MHOS) data; data were collected from Medicare beneficiaries who were aged 65 years and older from 1998 through 2003. Cancer patients (n = 1432; with prostate, breast, colorectal, lung, bladder, endometrial, or kidney cancers; melanoma; or non-Hodgkin lymphoma [NHL]) were selected whose first cancer diagnosis occurred between their baseline and follow-up MHOS assessments. Control subjects without cancer (n = 7160) were matched to cancer patients by use of propensity scores that were estimated from demographics and comorbid medical conditions. Analysis of covariance models were used to estimate changes in HRQOL as assessed with the Medical Outcomes Study Short Form-36 survey (mean score = 50, SD = 10). All statistical tests were two-sided.
Patients with all cancer types (except melanoma and endometrial cancer) reported statistically significant declines in physical health (mean scores: prostate cancer = –3.4, 95% confidence interval [CI] = –2.5 to –4.2; breast cancer = –3.5, 95% CI = –2.5 to –4.5; bladder cancer = –4.3, 95% CI = –2.5 to –6.1; colorectal cancer = –4.4, 95% CI = –3.3 to –5.5; kidney cancer = –5.7, 95% CI = –3.2 to –8.2; NHL = –6.7, 95% CI = –4.4 to –9.1; and lung cancer = –7.5, 95% CI = –5.9 to –9.2) compared with the control subjects (mean score = –1.8, 95% CI = –1.6 to –2.0) (all P < .05). However, only lung (mean score = –5.4, 95% CI = –3.5 to –7.2), colorectal (mean score = –3.5, 95% CI = –2.2 to –4.7), and prostate (mean score = –2.8, 95% CI = –1.8 to –3.7) cancer patients showed statistically significant decreases in mental health relative to the mean change of the control subjects (mean score = –1.2, 95% CI = –0.9 to –1.4) (all P < .05).
These findings provide validation of the specific deleterious effects of cancer on HRQOL and an evidence base for future research and clinical interventions aimed at understanding and remediating these effects.
Appearance of autoantibodies and clinical manifestations of autoimmunity in melanoma patients treated with adjuvant interferon (IFN)-2b was reported to be associated with improved prognosis. We assessed the association of the appearance of autoantibodies after initiation of treatment with recurrence-free interval in two randomized trials that compared intermediate doses of IFN with observation for the treatment of melanoma patients.
Serum levels of anticardiolipin, antithyroglobulin, and antinuclear antibodies were determined using enzyme-linked immunosorbent assays in 187 and 356 patients in the European Organization for Research and Treatment of Cancer (EORTC) 18952 and Nordic IFN trials, respectively, immediately before and up to 3 years after random assignment. The association of the presence of at least one of the three autoantibodies with risk of recurrence was assessed by three Cox models in patients negative for all three autoantibodies at baseline (125 from the EORTC 18952 trial and 230 from the Nordic IFN trial): 1) a model that considered appearance of autoantibodies as a time-independent variable, 2) one that considered a patient autoantibody positive once a positive test for an autoantibody was obtained, and 3) a model in which the status of the patient was defined by the most recent autoantibody test. All statistical tests were two-sided.
When treated as a time-independent variable (model 1), appearance of autoantibodies was associated with improved relapse-free interval in both trials (EORTC 18952, hazard ratio [HR] = 0.41, 95% confidence interval [CI] = 0.25 to 0.68, P < .001; and Nordic IFN, HR = 0.51, 95% CI = 0.34 to 0.76, P < .001). However, on correction for guarantee-time bias, the association was weaker and not statistically significant (model 2: EORTC 18952, HR = 0.81, 95% CI = 0.46 to 1.40, P = .44; and Nordic IFN, HR = 0.85, 95% CI = 0.55 to 1.30, P = .45; model 3: EORTC 18952, HR = 1.05, 95% CI = 0.59 to 1.87, P = .88; and Nordic IFN, HR = 0.78, 95% CI = 0.49 to 1.24, P = .30).
In two randomized trials of IFN for the treatment of melanoma patients, appearance of autoantibodies was not strongly associated with improved relapse-free interval when correction was made for guarantee-time bias.
Although many tools for the assessment of prostate cancer risk have been published, most are designed to predict only biochemical recurrence, usually after a single specified treatment. We assessed the accuracy of the Cancer of the Prostate Risk Assessment (CAPRA) score, which was validated previously to predict pathological and biochemical outcomes after radical prostatectomy, to predict metastases, prostate cancer–specific mortality, and all-cause mortality.
We studied 10 627 men with clinically localized prostate cancer in the Cancer of the Prostate Strategic Urologic Research Endeavor registry, who underwent primary radical prostatectomy, radiation therapy (external beam or interstitial), androgen deprivation monotherapy, or watchful waiting/active surveillance, and had at least 6 months of follow-up after treatment. CAPRA scores were calculated at diagnosis from the prostate-specific antigen level, Gleason score, percentage of biopsy cores that were positive for cancer, clinical tumor stage, and age at diagnosis. Survival was studied with Kaplan–Meier analyses. Associations between increasing CAPRA scores and bone metastasis, cancer-specific mortality, and all-cause mortality were examined by use of proportional hazards regression, with adjustment for primary treatment; for all-cause mortality, the analysis also included adjustment for age and comorbidity. Accuracy of the CAPRA score was assessed with the concordance (c)-index.
Among the 10 627 patients, 311 (2.9%) men developed bone metastases, 251 (2.4%) died of prostate cancer, and 1582 (14.9%) died of other causes. Each single-point increase in the CAPRA score was associated with increased bone metastases (hazard ratio [HR] for bone metastases = 1.47, 95% confidence interval [CI] = 1.39 to 1.56), cancer-specific mortality (HR for prostate cancer death = 1.39, 95% CI = 1.31 to 1.48), and all-cause mortality (HR for death = 1.13, 95% CI = 1.10 to 1.16). The CAPRA score was accurate for predicting metastases (c-index = 0.78), cancer-specific mortality (c-index = 0.80), and all-cause mortality (c-index = 0.71).
In a large cohort of patients with clinically localized prostate cancer who were managed with one of five primary modalities, the CAPRA score predicted clinical prostate cancer endpoints with good accuracy. These results support the value of the CAPRA score as a risk assessment and stratification tool for both research studies and clinical practice.
Vaccination with minor capsid protein L2 induces antibodies that cross-neutralize diverse papillomavirus types. However, neutralizing antibody titers against the papillomavirus type from which the L2 vaccine was derived are generally higher than the titers against heterologous types, which could limit effectiveness against heterologous types. We hypothesized that vaccination with concatenated multitype L2 fusion proteins derived from known cross-protective epitopes of several divergent human papillomavirus (HPV) types might enhance immunity across clinically relevant HPV genotypes.
Antibody responses of mice (n = 120) and rabbits (n = 23) to vaccination with HPV-16 amino-terminal L2 polypeptides or multitype L2 fusion proteins, namely, 11-200 x 3 (HPV types 6, 16, 18), 11-88 x 5 (HPV types 1, 5, 6, 16, 18), or 17-36 x 22 (five cutaneous, two mucosal low-risk, and 15 oncogenic types), that were formulated alone or in GPI-0100, alum, or 1018 ISS adjuvants were compared with vaccination with L1 virus-like particles (VLPs), including Gardasil, a licensed quadrivalent HPV L1 vaccine, and a negative control. Mice were challenged with HPV-16 pseudovirions 4 months after vaccination. Statistical tests were two-sided.
The HPV-16 L2 polypeptides generated robust HPV-16–neutralizing antibody responses, albeit lower than those to HPV-16 L1 VLPs, and lower responses against other HPVs. In contrast, vaccination with the multitype L2 fusion proteins 11-200 x 3 and 11-88 x 5 induced high serum neutralizing antibody titers against all heterologous HPVs tested. 11-200 x 3 formulated in GPI-0100 adjuvant or alum with 1018 ISS protected mice against HPV-16 challenge (reduction in HPV-16 infection vs phosphate-buffered saline control, P < .001) 4 months after vaccination as well as HPV-16 L1 VLPs, but 11-200 x 3 alone or formulated with either alum or 1018 ISS was less effective (reduction in HPV-16 infection, P < .001).
Concatenated multitype L2 proteins in adjuvant have potential as pan-oncogenic HPV vaccines.
Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified human oncoprotein that stabilizes the c-Myc (MYC) protein. However, the clinical relevance of CIP2A to human cancers had not been demonstrated, but the mechanism of its regulation and its clinical role in cancer were completely unknown.
Tissue microarrays consisting of 223 gastric adenocarcinoma specimens were evaluated for the presence of CIP2A using immunohistochemistry, and the association of CIP2A expression with survival was assessed using Kaplan–Meier analysis. The effects of MYC and CIP2A on each other's expression and on cell proliferation were investigated in several gastric cancer cell lines using small interfering RNAs to CIP2A and MYC and immunoblotting. To further evaluate the role of MYC in CIP2A regulation, an inhibitor of MYC dimerization, 10058-F4, and an inducible MycER model were used.
Expression of CIP2A protein was associated with reduced overall survival for gastric cancer patients with tumors 5 cm or smaller, with a 10-year overall survival in the CIP2A-immunopositive group of 8.1% as compared with 37.6% in the CIP2A-negative group (difference = 29.5%, 95% confidence interval = 12.5% to 46.5%, P = .001). In gastric cancer cell lines, CIP2A depletion led to decreased proliferation and anchorage-independent growth of the cells, as well as to reduced stability and expression of MYC protein. Interestingly, MYC depletion led to reduced expression of CIP2A mRNA and protein. Moreover, experiments with an MYC inhibitor and activator suggested that MYC directly promotes CIP2A gene expression. Finally, CIP2A and MYC immunopositivities were associated in gastric cancer specimens (P = .021).
CIP2A immunopositivity is a predictor of survival for some subgroups of gastric cancer patients. CIP2A and MYC appear to be regulated in a positive feedback loop, wherein they promote each other's expression and gastric cancer cell proliferation.
The pattern of cancer in long-term survivors from childhood cancer has not been investigated comprehensively.
We obtained a cohort of 47 697 children and adolescents aged 0–19 years with cancer as defined by the country-wide cancer registries of Denmark, Finland, Iceland, Norway, and Sweden during 1943–2005. Cohort members were followed through age 79 years for subsequent primary cancers notified to the registries, and the age-specific risk pattern of the survivors was compared with that of the national populations using country and sex standardized incidence ratios (SIRs). We used a multiplicative Poisson regression model to estimate relative risk of cancer for attained age, with adjustment for calendar period and age at diagnosis of primary cancer. We also calculated excess absolute risk (EAR) attributable to status as childhood cancer survivor and determined the cumulative incidence of second primary cancer as a function of attained age for three subcohorts defined by period of treatment for childhood cancer.
A total of 1180 asynchronous second primary cancers were observed in 1088 persons, yielding an overall SIR of 3.3 (95% confidence interval = 3.1 to 3.5). The relative risk was statistically significantly increased in all age groups, even for cohort members approaching 70 years of age. The EAR for second primary cancer among survivors increased gradually from one additional case per 1000 person-years of observation in early life to six additional cases per 1000 person-years in the age group 60–69 years. For children treated in the prechemotherapy era (1943–1959), the cumulative risk for a second primary cancer reached 18%, 34%, and 48% at ages 60, 70, and 80 years, respectively. The age-specific incidence rates were highest for cohort members treated in the era of intensive, multiple-agent chemotherapy (1975–2005).
Survivors of childhood cancer have a persistent excess risk for a second primary cancer throughout their lives, accompanied by continuous changes in the risk of cancers at specific sites.
Interpretive performance of screening mammography varies substantially by facility, but performance of diagnostic interpretation has not been studied.
Facilities performing diagnostic mammography within three registries of the Breast Cancer Surveillance Consortium were surveyed about their structure, organization, and interpretive processes. Performance measurements (false-positive rate, sensitivity, and likelihood of cancer among women referred for biopsy [positive predictive value of biopsy recommendation {PPV2}]) from January 1, 1998, through December 31, 2005, were prospectively measured. Logistic regression and receiver operating characteristic (ROC) curve analyses, adjusted for patient and radiologist characteristics, were used to assess the association between facility characteristics and interpretive performance. All statistical tests were two-sided.
Forty-five of the 53 facilities completed a facility survey (85% response rate), and 32 of the 45 facilities performed diagnostic mammography. The analyses included 28 100 diagnostic mammograms performed as an evaluation of a breast problem, and data were available for 118 radiologists who interpreted diagnostic mammograms at the facilities. Performance measurements demonstrated statistically significant interpretive variability among facilities (sensitivity, P = .006; false-positive rate, P < .001; and PPV2, P < .001) in unadjusted analyses. However, after adjustment for patient and radiologist characteristics, only false-positive rate variation remained statistically significant and facility traits associated with performance measures changed (false-positive rate = 6.5%, 95% confidence interval [CI] = 5.5% to 7.4%; sensitivity = 73.5%, 95% CI = 67.1% to 79.9%; and PPV2 = 33.8%, 95% CI = 29.1% to 38.5%). Facilities reporting that concern about malpractice had moderately or greatly increased diagnostic examination recommendations at the facility had a higher false-positive rate (odds ratio [OR] = 1.48, 95% CI = 1.09 to 2.01) and a non–statistically significantly higher sensitivity (OR = 1.74, 95% CI = 0.94 to 3.23). Facilities offering specialized interventional services had a non–statistically significantly higher false-positive rate (OR = 1.97, 95% CI = 0.94 to 4.1). No characteristics were associated with overall accuracy by ROC curve analyses.
Variation in diagnostic mammography interpretation exists across facilities. Failure to adjust for patient characteristics when comparing facility performance could lead to erroneous conclusions. Malpractice concerns are associated with interpretive performance.