Aging is the physiologic change that occurs over time. In humans, this change occurs at different rates and are related to lifestyle, environment and genetics. It can be challenging to differentiate ...normal aging from disease. In the oral cavity, with increasing age the teeth demonstrate wearing of the enamel, chipping and fracture lines, and a darker color. The pulp chamber and canals are reduced in size as a result of the deposition of secondary dentin. Coronal or root caries, however, represent disease. A limited amount of periodontal attachment loss occurs in association with aging, usually manifesting as recession on the buccal surface of teeth. Severe periodontitis occurs in 10.5–12% of the population, with the peak incidence being observed at 35–40 years of age. Changes to the mucosal tissue that occur with age include reduced wound‐healing capacity. However, environmental factors, such as smoking, dramatically increase the risk of mucosal pathology. Reduced salivary gland function is often seen in association with medication usage, as well as with disorders such as diabetes mellitus. Both medication use and chronic disorders are more common in older adults. Masticatory function is of particular importance for older adults. Maintenance of a nutritionally complete diet is important for avoiding sarcopenia and the frailty syndrome. Successful oral aging is associated with adequate function and comfort. A reduced, but functional, dentition of 20 teeth in occlusion has been proposed as a measure of successful oral aging. Healthy oral aging is important to healthy aging from both biological and social perspectives.
Many factors contribute to human tooth loss, including oral hygiene practices, trauma, smoking, health status, socio‐economic status and individual preferences. Loss of teeth impairs quality‐of‐life ...measures, including the eating of most foods that require full masticatory function. A recent study of centenarians found that at age 65–74 years, those who lived to be 100 had a lower rate of edentulism than did younger members of their birth cohort at ages 65–74 years. Oral health was consistent with compression of morbidity toward the end of life. This article explores the hypothesis that factors associated with oral disease and noncommunicable diseases may increase the risk of tooth loss and lead to diminished longevity as a result of multifactorial interactions. It specifically addresses two critical questions. The first is: ‘Can we conclude that the number of teeth in aging humans can affect longevity and life expectancy?’ The answer is yes. The second is: ‘Is tooth loss a predictor of shortened longevity?’ Again, the answer is yes. Edentulism and partial edentulism are discussed as a disability, and how the philosophy/belief systems of dental providers and patients toward retaining teeth influences the outcome of tooth loss is also examined. Osteoporosis and cognitive impairment provide examples of modifying risk factors.
A greater understanding of the biology of tumor recurrence should improve adjuvant treatment decision making. We conducted a validation study of the 12-gene recurrence score (RS), a quantitative ...assay integrating stromal response and cell cycle gene expression, in tumor specimens from patients enrolled onto Cancer and Leukemia Group B (CALGB) 9581.
CALGB 9581 randomly assigned 1,713 patients with stage II colon cancer to treatment with edrecolomab or observation and found no survival difference. The analysis reported here included all patients with available tissue and recurrence (n = 162) and a random (approximately 1:3) selection of nonrecurring patients. RS was assessed in 690 formalin-fixed paraffin-embedded tumor samples with quantitative reverse transcriptase polymerase chain reaction by using prespecified genes and a previously validated algorithm. Association of RS and recurrence was analyzed by weighted Cox proportional hazards regression.
Continuous RS was significantly associated with risk of recurrence (P = .013) as was mismatch repair (MMR) gene deficiency (P = .044). In multivariate analyses, RS was the strongest predictor of recurrence (P = .004), independent of T stage, MMR, number of nodes examined, grade, and lymphovascular invasion. In T3 MMR-intact (MMR-I) patients, prespecified low and high RS groups had average 5-year recurrence risks of 13% (95% CI, 10% to 16%) and 21% (95% CI, 16% to 26%), respectively.
The 12-gene RS predicts recurrence in stage II colon cancer in CALGB 9581. This is consistent with the importance of stromal response and cell cycle gene expression in colon tumor recurrence. RS appears to be most discerning for patients with T3 MMR-I tumors, although markers such as grade and lymphovascular invasion did not add value in this subset of patients.
Sensory peripheral neuropathy is a common and sometimes debilitating toxicity associated with paclitaxel therapy. This study aims to identify genetic risk factors for the development of this ...toxicity.
A prospective pharmacogenetic analysis of patients with primary breast cancer, randomized to the paclitaxel arm of CALGB 40101, was used to identify genetic predictors of the onset and severity of sensory peripheral neuropathy. A genome-wide association study in 855 subjects of European ancestry was conducted and findings were replicated in additional European (n = 154) and African American (n = 117) subjects.
A single nucleotide polymorphism in FGD4 was associated with the onset of sensory peripheral neuropathy in the discovery cohort rs10771973; HR, 1.57; 95% confidence interval (CI), 1.30-1.91; P = 2.6 × 10(-6) and in a European (HR, 1.72; 95% CI, 1.06-2.80; P = 0.013) and African American (HR, 1.93; 95% CI, 1.13-3.28; P = 6.7 × 10(-3)) replication cohort. There is also evidence that markers in additional genes, including EPHA5 (rs7349683) and FZD3 (rs10771973), were associated with the onset or severity of paclitaxel-induced sensory peripheral neuropathy.
A genome-wide association study has identified novel genetic markers of paclitaxel-induced sensory peripheral neuropathy, including a common polymorphism in FGD4, a congenital peripheral neuropathy gene. These findings suggest that genetic variation may contribute to variation in development of this toxicity. Validation of these findings may allow for the identification of patients at increased risk of peripheral neuropathy and inform the use of an alternative to paclitaxel and/or the clinical management of this toxicity.
Purpose Tumor overexpression of cyclooxygenase-2 (COX-2) has been associated with worse outcome in non-small-cell lung cancer (NSCLC). In Cancer and Leukemia Group B (CALGB) 30203, we found that the ...selective COX-2 inhibitor celecoxib in addition to chemotherapy in advanced NSCLC improved progression-free and overall survival in patients with moderate to high COX-2 expression by immunohistochemistry (IHC). CALGB 30801 (Alliance) was designed to prospectively confirm that finding. Patients and Methods Patients with NSCLC (stage IIIB with pleural effusion or stage IV according to American Joint Committee on Cancer sixth edition criteria) were preregistered, and biopsy specimens were analyzed for COX-2 by IHC. Patients with COX-2 expression ≥ 2, performance status of 0 to 2, and normal organ function were eligible. Chemotherapy was determined by histology: carboplatin plus pemetrexed for nonsquamous NSCLC and carboplatin plus gemcitabine for squamous histology. Patients were randomly assigned to celecoxib (400 mg twice per day; arm A) or placebo (arm B). The primary objective was to demonstrate improvement in progression-free survival in patients with COX-2 index ≥ 4 with hazard ratio of 0.645 with approximately 85% power at two-sided significance level of .05. Results The study was halted for futility after 312 of the planned 322 patients with COX-2 index ≥ 2 were randomly assigned. There were no significant differences between the groups (hazard ratio, 1.046 for COX-2 ≥ 4). Subset analyses evaluating histology, chemotherapy regimen, and incremental COX-2 expression did not demonstrate any advantage for COX-2 inhibition. Elevation of baseline urinary metabolite of prostaglandin E2, indicating activation of the COX-2 pathway, was a negative prognostic factor. Values above the third quartile may have been a predictive factor. Conclusion COX-2 expression by IHC failed to select patients who could benefit from selective COX-2 inhibition. Urinary metabolite of prostaglandin E2 may be able to identify patients who could benefit from COX-2 inhibition.
To assess pathologic complete response (pCR), clinical response, feasibility, safety, and potential predictors of response to preoperative trastuzumab plus vinorelbine in patients with operable, ...human epidermal growth factor receptor 2 (HER2)-positive breast cancer.
Forty-eight patients received preoperative trastuzumab and vinorelbine weekly for 12 weeks. Single and multigene biomarker studies were done in an attempt to identify predictors of response.
Eight of 40 (20%) patients achieved pCR (95% confidence interval, 9-36%). Of 9 additional patients recruited for protocol-defined toxicity analysis, 8 were evaluable; 42 of 48 (88%) patients had clinical response (16 patients, clinical complete response; 26 patients, clinical partial response). T(1) tumors more frequently exhibited clinical complete response (P = 0.05) and showed a trend to exhibit pCR (P = 0.07). Five (13%) patients experienced grade 1 cardiac dysfunction during preoperative treatment. Neither HER2 nor estrogen receptor status changed significantly after exposure to trastuzumab and vinorelbine. RNA profiling identified three top-level clusters by unsupervised analysis. Tumors with extremes of response pCR (n = 3) versus nonresponse (n = 3) fell into separate groups by hierarchical clustering. No predictive genes were identified in pCR tumors. Nonresponding tumors were more likely to be T(4) stage (P = 0.02) and express basal markers (P < 0.00001), growth factors, and growth factor receptors. Insulin-like growth factor-I receptor membrane expression was associated with a lower response rate (50% versus 97%; P = 0.001).
Preoperative trastuzumab plus vinorelbine is active and well tolerated in patients with HER2-positive, operable, stage II/III breast cancer. HER2-overexpressing tumors with a basal-like phenotype, or with expression of insulin-like growth factor-I receptor and other proteins involved in growth factor pathways, are more likely to be resistant to this regimen.
Microtubule targeting agents (MTAs) are anticancer therapies commonly prescribed for breast cancer and other solid tumors. Sensory peripheral neuropathy (PN) is the major dose‐limiting toxicity for ...MTAs and can limit clinical efficacy. The current pharmacogenomic study aimed to identify genetic variations that explain patient susceptibility and drive mechanisms underlying development of MTA‐induced PN. A meta‐analysis of genomewide association studies (GWAS) from two clinical cohorts treated with MTAs (Cancer and Leukemia Group B (CALGB) 40502 and CALGB 40101) was conducted using a Cox regression model with cumulative dose to first instance of grade 2 or higher PN. Summary statistics from a GWAS of European subjects (n = 469) in CALGB 40502 that estimated cause‐specific risk of PN were meta‐analyzed with those from a previously published GWAS of European ancestry (n = 855) from CALGB 40101 that estimated the risk of PN. Novel single nucleotide polymorphisms in an enhancer region downstream of sphingosine‐1‐phosphate receptor 1 (S1PR1 encoding S1PR1; e.g., rs74497159, βCALGB 40101 per allele log hazard ratio (95% confidence interval (CI)) = 0.591 (0.254–0.928), βCALGB 40502 per allele log hazard ratio (95% CI) = 0.693 (0.334–1.053); PMETA = 3.62 × 10−7) were the most highly ranked associations based on P values with risk of developing grade 2 and higher PN. In silico functional analysis identified multiple regulatory elements and potential enhancer activity for S1PR1 within this genomic region. Inhibition of S1PR1 function in induced pluripotent stem cell‐derived human sensory neurons shows partial protection against paclitaxel‐induced neurite damage. These pharmacogenetic findings further support ongoing clinical evaluations to target S1PR1 as a therapeutic strategy for prevention and/or treatment of MTA‐induced neuropathy.
CALGB80303 was a phase III trial of 602 patients with locally advanced or metastatic pancreatic cancer comparing gemcitabine/bevacizumab versus gemcitabine/placebo. The study found no benefit in any ...outcome from the addition of bevacizumab to gemcitabine. Blood samples were collected and multiple angiogenic factors were evaluated and then correlated with clinical outcome in general (prognostic markers) and with benefit specifically from bevacizumab treatment (predictive markers).
Plasma samples were analyzed via a novel multiplex ELISA platform for 31 factors related to tumor growth, angiogenesis, and inflammation. Baseline values for these factors were correlated with overall survival (OS) using univariate Cox proportional hazard regression models and multivariable Cox regression models with leave-one-out cross validation. Predictive markers were identified using a treatment by marker interaction term in the Cox model.
Baseline plasma was available from 328 patients. Univariate prognostic markers for OS were identified including: Ang2, CRP, ICAM-1, IGFBP-1, TSP-2 (all P < 0.001). These prognostic factors were found to be highly significant, even after adjustment for known clinical factors. Additional modeling approaches yielded prognostic signatures from multivariable Cox regression. The gemcitabine/bevacizumab signature consisted of IGFBP-1, interleukin-6, PDGF-AA, PDGF-BB, TSP-2; whereas the gemcitabine/placebo signature consisted of CRP, IGFBP-1, PAI-1, PDGF-AA, P-selectin (both P < 0.0001). Finally, three potential predictive markers of bevacizumab efficacy were identified: VEGF-D (P < 0.01), SDF1 (P < 0.05), and Ang2 (P < 0.05).
This study identified strong prognostic markers for pancreatic cancer patients. Predictive marker analysis indicated that plasma levels of VEGF-D, Ang2, and SDF1 significantly predicted for benefit or lack of benefit from bevacizumab in this population.
The African American (AA) population displays a 1.6 to 3‐fold higher incidence of thrombosis and stroke mortality compared with European Americans (EAs). Current antiplatelet therapies target the ...ADP‐mediated signaling pathway, which displays significant pharmacogenetic variation for platelet reactivity. The focus of this study was to define underlying population differences in platelet function in an effort to identify novel molecular targets for future antiplatelet therapy. We performed deep coverage RNA‐Seq to compare gene expression levels in platelets derived from a cohort of healthy volunteers defined by ancestry determination. We identified > 13,000 expressed platelet genes of which 480 were significantly differentially expressed genes (DEGs) between AAs and EAs. DEGs encoding proteins known or predicted to modulate platelet aggregation, morphology, or platelet count were upregulated in AA platelets. Numerous G‐protein coupled receptors, ion channels, and pro‐inflammatory cytokines not previously associated with platelet function were likewise differentially expressed. Many of the signaling proteins represent potential pharmacologic targets of intervention. Notably, we confirmed the differential expression of cytokines IL32 and PROK2 in an independent cohort by quantitative real‐time polymerase chain reaction, and provide functional validation of the opposing actions of these two cytokines on collagen‐induced AA platelet aggregation. Using Genotype‐Tissue Expression whole blood data, we identified 516 expression quantitative trait locuses with Fst values > 0.25, suggesting that population‐differentiated alleles may contribute to differences in gene expression. This study identifies gene expression differences at the population level that may affect platelet function and serve as potential biomarkers to identify cardiovascular disease risk. Additionally, our analysis uncovers candidate novel druggable targets for future antiplatelet therapies.
Conventional staging methods are inadequate to identify patients with stage II colon cancer (CC) who are at high risk of recurrence after surgery with curative intent. ColDx is a gene expression, ...microarray-based assay shown to be independently prognostic for recurrence-free interval (RFI) and overall survival in CC. The objective of this study was to further validate ColDx using formalin-fixed, paraffin-embedded specimens collected as part of the Alliance phase III trial, C9581.
C9581 evaluated edrecolomab versus observation in patients with stage II CC and reported no survival benefit. Under an initial case-cohort sampling design, a randomly selected subcohort (RS) comprised 514 patients from 901 eligible patients with available tissue. Forty-nine additional patients with recurrence events were included in the analysis. Final analysis comprised 393 patients: 360 RS (58 events) and 33 non-RS events. Risk status was determined for each patient by ColDx. The Self-Prentice method was used to test the association between the resulting ColDx risk score and RFI adjusting for standard prognostic variables.
Fifty-five percent of patients (216 of 393) were classified as high risk. After adjustment for prognostic variables that included mismatch repair (MMR) deficiency, ColDx high-risk patients exhibited significantly worse RFI (multivariable hazard ratio, 2.13; 95% CI, 1.3 to 3.5; P < .01). Age and MMR status were marginally significant. RFI at 5 years for patients classified as high risk was 82% (95% CI, 79% to 85%), compared with 91% (95% CI, 89% to 93%) for patients classified as low risk.
ColDx is associated with RFI in the C9581 subsample in the presence of other prognostic factors, including MMR deficiency. ColDx could be incorporated with the traditional clinical markers of risk to refine patient prognosis.
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