RESUMO
Cell-mediated immune suppression may play an important role in lung carcinogenesis. We investigated the associations for circulating levels of tryptophan, kynurenine, kynurenine:tryptophan ratio (KTR), quinolinic acid (QA) and neopterin as markers of immune regulation and inflammation with lung cancer risk in 5,364 smoking-matched case-control pairs from 20 prospective cohorts included in the international Lung Cancer Cohort Consortium. All biomarkers were quantified by mass spectrometry-based methods in serum/plasma samples collected on average 6 years before lung cancer diagnosis. Odds ratios (ORs) and 95% confidence intervals (CIs) for lung cancer associated with individual biomarkers were calculated using conditional logistic regression with adjustment for circulating cotinine. Compared to the lowest quintile, the highest quintiles of kynurenine, KTR, QA and neopterin were associated with a 20-30% higher risk, and tryptophan with a 15% lower risk of lung cancer (all ptrend < 0.05). The strongest associations were seen for current smokers, where the adjusted ORs (95% CIs) of lung cancer for the highest quintile of KTR, QA and neopterin were 1.42 (1.15-1.75), 1.42 (1.14-1.76) and 1.45 (1.13-1.86), respectively. A stronger association was also seen for KTR and QA with risk of lung squamous cell carcinoma followed by adenocarcinoma, and for lung cancer diagnosed within the first 2 years after blood draw. This study demonstrated that components of the tryptophan-kynurenine pathway with immunomodulatory effects are associated with risk of lung cancer overall, especially for current smokers. Further research is needed to evaluate the role of these biomarkers in lung carcinogenesis and progression.
Assuntos
Adenocarcinoma de Pulmão/diagnóstico , Biomarcadores Tumorais/sangue , Carcinoma de Células Grandes/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Inflamação/complicações , Neoplasias Pulmonares/diagnóstico , Carcinoma de Pequenas Células do Pulmão/diagnóstico , Adenocarcinoma de Pulmão/sangue , Adenocarcinoma de Pulmão/etiologia , Adulto , Idoso , Carcinoma de Células Grandes/sangue , Carcinoma de Células Grandes/etiologia , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/etiologia , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Inflamação/sangue , Inflamação/imunologia , Cinurenina/sangue , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/etiologia , Masculino , Pessoa de Meia-Idade , Neopterina/sangue , Prognóstico , Estudos Prospectivos , Fatores de Risco , Carcinoma de Pequenas Células do Pulmão/sangue , Carcinoma de Pequenas Células do Pulmão/etiologia , Triptofano/sangueRESUMO
BACKGROUND: Prospective cohort studies contribute importantly to understanding the role of lifestyle, genetic, and other factors in chronic disease etiology. METHODS: The American Cancer Society (ACS) recruited a new prospective cohort study, Cancer Prevention Study 3 (CPS-3), between 2006 and 2013 from 35 states and Puerto Rico. Enrollment took place primarily at ACS community events and at community enrollment "drives." At enrollment sites, participants completed a brief survey that included an informed consent, identifying information necessary for follow-up, and key exposure information. They also provided a waist measure and a nonfasting blood sample. Most participants also completed a more comprehensive baseline survey at home that included extensive medical, lifestyle, and other information. Participants will be followed for incident cancers through linkage with state cancer registries and for cause-specific mortality through linkage with the National Death Index. RESULTS: In total, 303,682 participants were enrolled. Of these, 254,650 completed the baseline survey and are considered "fully" enrolled; they will be sent repeat surveys periodically for at least the next 20 years to update exposure information. The remaining participants (n = 49,032) will not be asked to update exposure information but will be followed for outcomes. Twenty-three percent of participants were men, 17.3% reported a race or ethnicity other than "white," and the median age at enrollment was 47 years. CONCLUSIONS: CPS-3 will be a valuable resource for studies of cancer and other outcomes because of its size; its diversity with respect to age, ethnicity, and geography; and the availability of blood samples and detailed questionnaire information collected over time. Cancer 2017;123:2014-2024. © 2017 American Cancer Society.
Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Dieta/estatística & dados numéricos , Detecção Precoce de Câncer/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Exercício Físico , Estilo de Vida , Neoplasias/epidemiologia , Fumar/epidemiologia , Adulto , Idoso , American Cancer Society , Índice de Massa Corporal , Estudos de Coortes , Anticoncepcionais Orais Hormonais/uso terapêutico , Escolaridade , Terapia de Reposição de Estrogênios/estatística & dados numéricos , Feminino , Frutas , Humanos , Masculino , Estado Civil , Pessoa de Meia-Idade , Estudos Prospectivos , Porto Rico/epidemiologia , Carne Vermelha , Fatores de Risco , Inquéritos e Questionários , Estados Unidos/epidemiologia , Verduras , Circunferência da CinturaRESUMO
Fumonisins are a family of toxic and carcinogenic mycotoxins produced by Fusarium verticillioides (formerly Fusarium moniliforme), a common fungal contaminant of maize. Fumonisins inhibit ceramide synthase, causing accumulation of bioactive intermediates of sphingolipid metabolism (sphinganine and other sphingoid bases and derivatives) as well as depletion of complex sphingolipids, which interferes with the function of some membrane proteins, including the folate-binding protein (human folate receptor alpha). Fumonisin causes neural tube and craniofacial defects in mouse embryos in culture. Many of these effects are prevented by supplemental folic acid. Recent studies in LMBc mice found that fumonisin exposure in utero increases the frequency of developmental defects and administration of folate or a complex sphingolipid is preventive. High incidences of neural tube defects (NTD) occur in some regions of the world where substantial consumption of fumonisins has been documented or plausibly suggested (Guatemala, South Africa, and China); furthermore, a recent study of NTD in border counties of Texas found a significant association between NTD and consumption of tortillas during the first trimester. Hence, we propose that fumonisins are potential risk factors for NTD, craniofacial anomalies, and other birth defects arising from neural crest cells because of their apparent interference with folate utilization.