Prévention

Comportements individuels

A partir d'une revue systématique de la littérature publiée jusqu'en octobre 2011 (20 études), cette étude évalue l'effet de l'activité physique sur la densité mammaire

Physical activity and mammographic breast density: a systematic review
• Breast Cancer Research and Treatment, sous presse, 2012 (résumé)

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A partir d'une revue systématique de la littérature publiée jusqu'en octobre 2011 (20 études), cette étude évalue l'effet de l'activité physique sur la densité mammaire

“Physical activity and mammographic breast density: a systematic review”

• Yaghjyan, Lusine;Colditz, Graham;Wolin, Kathleen

Studies show a protective relationship between physical activity and breast cancer risk across the life course from menarche to postmenopausal years. Mammographic breast density is a known and strong breast cancer risk factor. Whether the association of physical activity with breast cancer risk is mediated through mammographic breast density is poorly understood. This systematic review summarizes published studies that investigated the association between physical activity and mammographic breast density and discusses the methodological issues that need to be addressed. We included in this review studies that were published before October 31, 2011 that were accessible in full-text format and were published in English. We identified 20 studies through the PubMed Central, BioMed Central, Embase, and Scopus and using the search terms “physical activity and breast density” and “exercise and breast density” as well as through manual searches of the bibliographies of the articles ...

Mots clés : Sein; Prévention (Comportements individuels)

A partir des données d'une enquête en ligne et d'une étude de cohorte menées respectivement auprès de 2 649 et 3 658 adultes en 2010, cette étude évalue, en fonction de leur statut tabagique et de leurs caractéristiques socio-démographiques, le taux d'utilisation des cigarettes électroniques ainsi que le degré de sensibilisation au produit et aux risques liés au tabac

e-Cigarette Awareness, Use, and Harm Perceptions in US Adults
• American Journal of Public Health, pp. e1-e9, 2012 (résumé)

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A partir des données d'une enquête en ligne et d'une étude de cohorte menées respectivement auprès de 2 649 et 3 658 adultes en 2010, cette étude évalue, en fonction de leur statut tabagique et de leurs caractéristiques socio-démographiques, le taux d'utilisation des cigarettes électroniques ainsi que le degré de sensibilisation au produit et aux risques liés au tabac

“e-Cigarette Awareness, Use, and Harm Perceptions in US Adults”

• Pearson, Jennifer L.;Richardson, Amanda;Niaura, Raymond S.;Vallone, Donna M.;Abrams, David B.

Objectives. We estimated e-cigarette (electronic nicotine delivery system) awareness, use, and harm perceptions among US adults. Methods. We drew data from 2 surveys conducted in 2010: a national online study (n = 2649) and the Legacy Longitudinal Smoker Cohort (n = 3658). We used multivariable models to examine e-cigarette awareness, use, and harm perceptions. Results. In the online survey, 40.2% (95% confidence interval [CI] = 37.3, 43.1) had heard of e-cigarettes, with awareness highest among current smokers. Utilization was higher among current smokers (11.4%; 95% CI = 9.3, 14.0) than in the total population (3.4%; 95% CI = 2.6, 4.2), with 2.0% (95% CI = 1.0, 3.8) of former smokers and 0.5% (95% CI = 0.16, 1.4) of never-smokers ever using e-cigarettes. In both surveys, non-Hispanic Whites, current smokers, young adults, and those with at least a high-school diploma were most likely to perceive e-cigarettes as less harmful than regular cigarettes. Conclusions. Awareness ...

Mots clés : Cancer (général); Prévention (Comportements individuels)

A partir des données d'une étude de cohorte incluant 2 607 adultes âgés de 20 à 28 ans, cette étude américaine analyse, en fonction de leurs caractéristiques socio-démographiques, leur degré de sensibilisation au snus (tabac à priser), leur utilisation de ce produit et leurs perceptions vis-à-vis des risques associés à sa consommation

Awareness, perceptions and use of snus among young adults from the upper Midwest region of the USA
• Tobacco Control, sous presse, 2012 (résumé)

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A partir des données d'une étude de cohorte incluant 2 607 adultes âgés de 20 à 28 ans, cette étude américaine analyse, en fonction de leurs caractéristiques socio-démographiques, leur degré de sensibilisation au snus (tabac à priser), leur utilisation de ce produit et leurs perceptions vis-à-vis des risques associés à sa consommation

“Awareness, perceptions and use of snus among young adults from the upper Midwest region of the USA”

• Choi, Kelvin;Forster, Jean

Background Since its introduction in 2006, snus has been aggressively marketed by tobacco companies. However, little is known about the awareness, perceptions and use of snus among young adults after Camel and Marlboro snus were sold nationwide in 2010.Methods Data were collected from 2607 young adults (ages 20–28) who participated in the Minnesota Adolescent Community Cohort Study in 2010–2011. Data include awareness of snus, ever and past 30-day use, perceived potential of snus as a quit aid, and perceived harmfulness and addictiveness of snus relative to cigarettes. The authors assessed the associations between these outcome variables and socio-demographic characteristics.Results Overall, 64.8% of participants were aware of snus, 14.5% ever used snus and 3.2% used snus in the past 30 days. Men and participants who smoked >100 cigarettes in their lifetime were associated with these three outcomes (p<0.05). Among those who were aware of snus, 16.3% agreed snus can help people ...

Mots clés : Cancer (général); Prévention (Comportements individuels)

Nutrition et prévention

A partir d'entretiens auprès de 132 837 hommes et femmes, cette étude chinoise évalue l'association entre la consommation de vitamines, d'origine alimentaire ou en supplémentation, et le risque de cancer du foie (267 cas dont 149 hommes)

Vitamin Intake and Liver Cancer Risk: A Report From Two Cohort Studies in China
• Journal of the National Cancer Institute, sous presse, 2012 (résumé)

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A partir d'entretiens auprès de 132 837 hommes et femmes, cette étude chinoise évalue l'association entre la consommation de vitamines, d'origine alimentaire ou en supplémentation, et le risque de cancer du foie (267 cas dont 149 hommes)

“Vitamin Intake and Liver Cancer Risk: A Report From Two Cohort Studies in China”

• Zhang, Wei;Shu, Xiao-Ou;Li, Honglan;Yang, Gong;Cai, Hui;Ji, Bu-Tian;Gao, Jing;Gao, Yu-Tang;Zheng, Wei;Xiang, Yong-Bing

Background Epidemiologic studies on the relationship between vitamin intake and liver cancer risk are sparse and inconsistent. Methods : We evaluated vitamin intake from diet and supplements and risk of liver cancer in 132 837 women and men from China who were recruited into the Shanghai Women’s Health Study from 1997 to 2000 or the Shanghai Men’s Health Study from 2002 to 2006. In-person interviews, using a validated food-frequency questionnaire, were conducted to collect data on dietary habits. Follow-up consisted of in-person surveys and record linkage. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazard models with adjustment for potential confounders to compare liver cancer risk among participants with high vs low vitamin intake. All statistical tests were two-sided. Results After excluding the first 2 years of follow-up, 267 participants (including 118 women and 149 men) developed liver cancer during an average of 10.9 (Shanghai Women’s ...
Vitamin E May Lower Liver Cancer Risk
• Journal of the National Cancer Institute, sous presse, 2012 (communiqué de presse)

Détails

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A partir d'entretiens auprès de 132 837 hommes et femmes, cette étude chinoise évalue l'association entre la consommation de vitamines, d'origine alimentaire ou en supplémentation, et le risque de cancer du foie (267 cas dont 149 hommes)

“Vitamin E May Lower Liver Cancer Risk”

Mots clés : Foie; Prévention (Nutrition et prévention)

Chimioprévention

A partir d'une revue de la littérature publiée jusqu'en janvier 2012 (13 études de cohorte,11 études cas-témoins ; nombre de participants : supérieur à 2,4 millions), cette méta-analyse évalue l'association entre l'utilisation de statines et le risque de cancer du sein (76 759 cas)

Statin use and risk of breast cancer: a meta-analysis of observational studies
• Breast Cancer Research and Treatment, sous presse, 2012 (résumé)

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A partir d'une revue de la littérature publiée jusqu'en janvier 2012 (13 études de cohorte,11 études cas-témoins ; nombre de participants : supérieur à 2,4 millions), cette méta-analyse évalue l'association entre l'utilisation de statines et le risque de cancer du sein (76 759 cas)

“Statin use and risk of breast cancer: a meta-analysis of observational studies”

• Undela, Krishna;Srikanth, Vallakatla;Bansal, Dipika

Emerging evidence suggests that statins’ may decrease the risk of cancers. However, available evidence on breast cancer is conflicting. We, therefore, examined the association between statin use and risk of breast cancer by conducting a detailed meta-analysis of all observational studies published regarding this subject. PubMed database and bibliographies of retrieved articles were searched for epidemiological studies published up to January 2012, investigating the relationship between statin use and breast cancer. Before meta-analysis, the studies were evaluated for publication bias and heterogeneity. Combined relative risk (RR) and 95 % confidence interval (CI) were calculated using a random-effects model (DerSimonian and Laird method). Subgroup analyses, sensitivity analysis, and cumulative meta-analysis were also performed. A total of 24 (13 cohort and 11 case–control) studies involving more than 2.4 million participants, including 76,759 breast cancer cases contributed to ...

Mots clés : Sein; Prévention (Chimioprévention)

Menée in vitro et à l'aide d'un modèle murin, cette étude identifie un mécanisme par lequel le pioglitazone, un antidiabétique oral agoniste de PPARγ, pourrait réduire le risque de cancer du sein hormono-dépendant chez les femmes obèses ménopausées

Pioglitazone, a PPARγ agonist, Suppresses CYP19 Transcription: Evidence for Involvement of 15-Hydroxyprostaglandin Dehydrogenase and BRCA1
• Cancer Prevention Research, sous presse, 2012 (résumé)

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Menée in vitro et à l'aide d'un modèle murin, cette étude identifie un mécanisme par lequel le pioglitazone, un antidiabétique oral agoniste de PPARγ, pourrait réduire le risque de cancer du sein hormono-dépendant chez les femmes obèses ménopausées

“Pioglitazone, a PPARγ agonist, Suppresses CYP19 Transcription: Evidence for Involvement of 15-Hydroxyprostaglandin Dehydrogenase and BRCA1”

• Subbaramaiah, Kotha;Howe, Louise R.;Zhou, Xi Kathy;Yang, Peiying;Hudis, Clifford A.;Kopelovich, Levy;Dannenberg, Andrew J.

Estrogen synthesis is catalyzed by cytochrome P450 aromatase, which is encoded by the CYP19 gene. In obese postmenopausal women, increased aromatase activity in white adipose tissue is believed to contribute to hormone-dependent breast cancer. Prostaglandin E2 (PGE2)stimulates the cAMP→protein kinase A (PKA) pathway leading to increased CYP19 transcription and elevated aromatase activity in inflamed white adipose tissue. 15-hydroxyprostaglandin dehydrogenase (15-PGDH) plays a major role in the catabolism of PGE2. Here we investigated the mechanism by which pioglitazone, a ligand of the nuclear receptor peroxisome proliferator activated receptor γ (PPARγ), suppressed aromatase expression. Treatment of human preadipocytes with pioglitazone suppressed Snail, a repressive transcription factor, resulting in elevated levels of 15-PGDH and reduced levels of PGE2 in the culture medium. Pioglitazone also inhibited cAMP→PKA signaling leading to reduced interaction between phosphorylated ...

Mots clés : Sein; Prévention (Chimioprévention)

Menée in vitro et à l'aide de modèles murins, cette étude identifie le mécanisme par lequel la taxifoline, un flavonoïde d'origine végétale, inhibe la carcinogenèse de la peau induite par les ultraviolets

Taxifolin suppresses UV-induced skin carcinogenesis by targeting EGFR and PI3-K
• Cancer Prevention Research, sous presse, 2012 (résumé)

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Menée in vitro et à l'aide de modèles murins, cette étude identifie le mécanisme par lequel la taxifoline, un flavonoïde d'origine végétale, inhibe la carcinogenèse de la peau induite par les ultraviolets

“Taxifolin suppresses UV-induced skin carcinogenesis by targeting EGFR and PI3-K”

• Oi, Naomi;Chen, Hanyong;Kim, Myoung Ok;Lubet, Ronald A.;Bode, Ann M.;Dong, Zigang

Skin cancer is one of the most commonly diagnosed cancers in United States. Taxifolin reportedly exerts multiple biological effects but the molecular mechanisms and direct target(s) of taxifolin in skin cancer chemoprevention are still unknown. In silico computer screening and kinase profiling results suggest that the epidermal growth factor receptor (EGFR), phosphatidyl inositol 3-kinase (PI3-K) and Src are potential targets for taxifolin. Pull-down assay results showed that EGFR, PI3-K and Src directly interacted with taxifolin in vitro, whereas taxifolin bound to EGFR and PI3-K but not to Src in cells. ATP-competition and in vitro kinase assay data revealed that taxifolin interacted with EGFR and PI3-K at the ATP binding pocket and inhibit their kinase activities. Western blot analysis showed that taxifolin suppressed UVB-induced phosphorylation of EGFR and Akt, and subsequently suppressed their signaling pathways in JB6 P+ mouse skin epidermal cells. Expression levels and promoter ...

Mots clés : Peau (hors mélanome); Prévention (Chimioprévention)

Cet article passe en revue les études concernant le rôle du facteur de transcription NRF2 dans la chimioprévention des cancers et livre une analyse critique de leurs résultats contradictoires

NRF2 and cancer: the good, the bad and the importance of context
• Nature Reviews Cancer, sous presse, 2012 (résumé)

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Cet article passe en revue les études concernant le rôle du facteur de transcription NRF2 dans la chimioprévention des cancers et livre une analyse critique de leurs résultats contradictoires

“NRF2 and cancer: the good, the bad and the importance of context”

• Sporn, Michael B.;Liby, Karen T.

Many studies of chemopreventive drugs have suggested that their beneficial effects on suppression of carcinogenesis and many other chronic diseases are mediated through activation of the transcription factor NFE2-related factor 2 (NRF2). More recently, genetic analyses of human tumours have indicated that NRF2 may conversely be oncogenic and cause resistance to chemotherapy. It is therefore controversial whether the activation, or alternatively the inhibition, of NRF2 is a useful strategy for the prevention or treatment of cancer. This Opinion article aims to rationalize these conflicting perspectives by critiquing the context dependence of NRF2 functions and the experimental methods behind these conflicting data.

Mots clés : Cancer (général); Prévention (Chimioprévention)

Menée sur un modèle murin ayant été exposé à une dose non mortelle de rayonnements ionisants, cette étude montre qu'une supplémentation en tempol, un antioxydant, peut réduire le risque de cancer induit par les rayonnements et augmenter la survie

The Antioxidant Tempol Reduces Carcinogenesis and Enhances Survival in Mice when Administered After Non-Lethal Total Body Radiation
• Cancer Research, sous presse, 2012 (résumé)

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Menée sur un modèle murin ayant été exposé à une dose non mortelle de rayonnements ionisants, cette étude montre qu'une supplémentation en tempol, un antioxydant, peut réduire le risque de cancer induit par les rayonnements et augmenter la survie

“The Antioxidant Tempol Reduces Carcinogenesis and Enhances Survival in Mice when Administered After Non-Lethal Total Body Radiation”

• Mitchell, James B.;Anver, Miriam R.;Sowers, Anastasia;Rosenberg, Philip S;Figueroa, Maria;Thetford, Angela;Krishna, Murali C;Albert, Paul S.;Cook, John A.

There is significant interest in the development of agents that can ameliorate radiation damage after exposure to radiation has occurred. Here we report that chronic supplementation of the antioxidant Tempol in the diet of mice can reduce body weight without toxicity, decrease cancer, and extend survival when administered after non-lethal total body radiation (TBI). These effects were apparent in two different strains of mice (C3H, CBA) exposed to TBI (3 Gy). Notably, delaying administration of the Tempol diet 1 month after TBI could also enhance survival. Tempol reduced the incidence of hematopoietic neoplasms (lymphomas) in both strains; whereas, both the onset and incidence of non-hematopoietic neoplasms were reduced in CBA mice. These results encourage further study of Tempol as a chemopreventive, to reduce the incidence of radiation-induced second malignancies after a course of definitive radiation therapy. Tempol may also find applications to reduce the risk of cancers in ...

Mots clés : Cancer (général); Prévention (Chimioprévention)

Menée in vitro et à l'aide d'une xénogreffe de cancer du poumon, cette étude évalue l'intérêt d'un système d'implant polymère multicouche à libération prolongée de substances actives pour la chimioprévention des cancers

Multi-layer polymeric implants for sustained release of chemopreventives
• Cancer Letters, sous presse, 2012 (résumé)

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Menée in vitro et à l'aide d'une xénogreffe de cancer du poumon, cette étude évalue l'intérêt d'un système d'implant polymère multicouche à libération prolongée de substances actives pour la chimioprévention des cancers

“Multi-layer polymeric implants for sustained release of chemopreventives”

• Aqil, Farrukh;Jeyabalan, Jeyaprakash;Kausar, Hina;Bansal, Shyam S.;Sharma, Ram J.;Singh, Inder P.;Vadhanam, Manicka V.;Gupta, Ramesh C.

Poor oral bioavailability limits the use of many chemopreventives in the prevention and treatment of cancer. To overcome this limitation, we report on an improvised implant formulation (“coated” implants) using curcumin, individual curcuminoids, withaferin A and oltipraz. This method involves the coating of blank polycaprolactone implants with 20-40 layers of 10-20% polycaprolactone solution in dichloromethane containing 0.5-2% of the test agent. The in vitro release showed that while oltipraz was released with almost zero-order kinetics over eight weeks, curcumin, individual curcuminoids and withaferin A were released with some initial burst. The in vivo release was determined by grafting implants subcutaneously in A/J mice. When delivered by coated implants, oltipraz significantly diminished lung DNA adducts in mice treated with dibenzo[a,l]pyrene compared with sham treatment (28±7 versus 54±17 adducts/109 nucleotides). Withaferin A also diminished DNA adducts, but it was ...