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1.
BMC Cancer ; 18(1): 64, 2018 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-29321047

RESUMEN

BACKGROUND: Prostate cancer is the most commonly diagnosed cancer in north-American men. Few dietary or lifestyle interventions have been tested to prevent prostate cancer progression. Omega-3 fatty acid supplementation represents a promising intervention for prostate cancer patients. The aim of the study is to evaluate the effects of long-chain omega-3 polyunsaturated fatty acids (LCn3), more precisely eicosapentaenoic acid monoacylglyceride (MAG-EPA) supplementation, on prostate cancer proliferation, inflammation mediators and quality of life among men who will undergo radical prostatectomy. METHODS/DESIGN: We propose a phase IIb, randomized, double-blind placebo-controlled trial of MAG-EPA supplementation for 130 men who will undergo radical prostatectomy as treatment for a prostate cancer of Gleason score ≥ 7 in an academic cancer center in Quebec City. Participants will be randomized to 6 capsules of 625 mg of fish oil (MAG-EPA) per capsule containing 500 mg of EPA daily or to identically looking capsules of high oleic acid sunflower oil (HOSO) as placebo. The intervention begins 4 to 10 weeks prior to radical prostatectomy (baseline) and continues for one year after surgery. The primary endpoint is the proliferative index (Ki-67) measured in prostate cancer cells at radical prostatectomy. A secondary endpoint includes prostate tissue levels of inflammatory mediators (cytokines and proteins) at time of radical prostatectomy. Changes in blood levels of inflammatory mediators, relative to baseline levels, at time of radical prostatectomy and 12 months after radical prostatectomy will also be evaluated. Secondary endpoints also include important aspects of psychosocial functioning and quality of life such as depression, anxiety, sleep disturbances, fatigue, cognitive complaints and prostate cancer-specific quality of life domains. The changes in these outcomes, relative to baseline levels, will be evaluated at 3, 6, 9 and 12 months after radical prostatectomy. DISCUSSION: The results from this trial will provide crucial information to clarify the role of omega-3 supplementation on prostate cancer proliferation, inflammation and quality of life. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02333435. Registered on December 17, 2014. Last updated September 6, 2016.


Asunto(s)
Ácidos Grasos Omega-3/administración & dosificación , Inflamación/dietoterapia , Neoplasias de la Próstata/dietoterapia , Neoplasias de la Próstata/cirugía , Adulto , Anciano , Proliferación Celular/efectos de los fármacos , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Ácidos Grasos Omega-3/efectos adversos , Humanos , Inflamación/patología , Inflamación/cirugía , Masculino , Persona de Mediana Edad , Terapia Nutricional/métodos , Prostatectomía , Neoplasias de la Próstata/patología , Resultado del Tratamiento
2.
Br J Nutr ; 113(8): 1319-29, 2015 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-25826598

RESUMEN

Dietary supplements (DS) may influence cancer prognosis. Their use in cancer patients has been described in the United States, but data are largely lacking in Europe and notably in France. The present study's objectives were (1) to assess DS use and its sociodemographic, lifestyle, and dietary correlates in a large sample of French cancer survivors; (2) to evaluate the involvement of physicians in such DS use; and (3) to assess the extent of potentially harmful practices. Data were collected by self-administered web-based questionnaires among participants of the NutriNet-Santé cohort. Data on DS use was available for 1081 cancer survivors. DS users were compared to non-users with unconditional logistic regressions. DS use was reported by 62% of women and 29% of men. Vitamins D, B6, C and Mg were the most frequently consumed nutrients. 14% of cancer survivors initiated DS use after diagnosis. For 35% of the DS consumed, subjects did not inform their attending physician. DS use was associated with a healthier lifestyle (normal weight, never smoking and better diet) and substantially contributed to nutrient intake. 18% of DS users had potentially harmful DS use practices, such as the simultaneous use of vitamin E and anticoagulant/antiplatelet agents, the use of ß-carotene and smoking or the use of phyto-oestrogens in hormone-dependent cancer patients. The present study suggests that DS use is widespread among cancer survivors, a large amount of that use is performed without any medical supervision and a substantial proportion of that use involves potentially harmful practices. Physicians should be encouraged to more routinely discuss DS use with their cancer patients.


Asunto(s)
Suplementos Dietéticos , Neoplasias/terapia , Adolescente , Adulto , Anciano , Estudios de Cohortes , Dieta , Femenino , Francia , Humanos , Estilo de Vida , Modelos Logísticos , Masculino , Persona de Mediana Edad , Pronóstico , Encuestas y Cuestionarios , Sobrevivientes , Vitamina E/metabolismo , Adulto Joven , beta Caroteno
3.
Gynecol Oncol ; 131(2): 357-61, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23988418

RESUMEN

OBJECTIVES: A two-stage, single-arm, phase II study was conducted to assess the effectiveness and safety of an epigallocatechin gallate (EGCG)-enriched tea drink, the double-brewed green tea (DBGT), as a maintenance treatment in women with advanced stage serous or endometrioid ovarian cancer (clinicaltrials.gov, NCT00721890). METHODS: Eligible women had FIGO stage III-IV serous or endometrioid ovarian cancer. They had to undergo complete response after debulking surgery followed by 6 to 8 cycles of platinum/taxane chemotherapy at the Centre Hospitalier Universitaire de Québec. They all had to drink the DBGT, 500 mL daily until recurrence or during a follow-up of 18 months. The primary endpoint was the absence of recurrence at 18 months. Statistical analyses were done according to the principle of intention to treat. Using a two-stage design, the first stage consisted of 16 enrolled patients. At the end of the follow-up, if 7 or fewer patients were free of recurrence, the trial stopped. Otherwise, accrual would continue to a total of 46 patients. RESULTS: During the first stage of the study, only 5 of the 16 women remained free of recurrence 18 months after complete response. Accordingly, the clinical trial was terminated. Women's adherence to DBGT was high (median daily intake during intervention, 98.1%, interquartile range: 89.7-100%), but 6 women discontinued the intervention before the end of their follow-up. No severe toxicity was reported. CONCLUSIONS: DBGT supplementation does not appear to be a promising maintenance intervention in women with advanced stage ovarian cancer after standard treatment.


Asunto(s)
Catequina/análogos & derivados , Neoplasias Ováricas/tratamiento farmacológico , , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma Endometrioide/tratamiento farmacológico , Carcinoma Endometrioide/patología , Carcinoma Endometrioide/cirugía , Catequina/administración & dosificación , Catequina/efectos adversos , Terapia Combinada , Cistadenocarcinoma Seroso/tratamiento farmacológico , Cistadenocarcinoma Seroso/patología , Cistadenocarcinoma Seroso/cirugía , Supervivencia sin Enfermedad , Femenino , Humanos , Quimioterapia de Mantención , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Compuestos Organoplatinos/administración & dosificación , Neoplasias Ováricas/patología , Neoplasias Ováricas/cirugía , Taxoides/administración & dosificación
4.
Gynecol Oncol ; 126(3): 491-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22564714

RESUMEN

OBJECTIVE: This systematic review was conducted to examine the effects of green tea or green tea components on the prevention and progression of epithelial ovarian cancer. METHODS: Using Medline, EMBASE and SciVerse (last researched: July 2011), we retrieved 22 articles including 5 epidemiological studies. RESULTS: In epithelial ovarian cancer cell lines, green tea and green tea components have been shown to downregulate the expression of proteins involved in inflammation, cell signalization, cell motility and angiogenesis. Green tea and green tea components would induce apoptosis and could potentiate the effects of cisplatin, a chemotherapeutic agent. In human observational studies, significant associations between green tea intake and both decreased ovarian cancer occurrence and better prognosis were reported. CONCLUSIONS: Available literature suggests potential molecular targets for green tea in ovarian cancer treatment and also provides data supporting the clinical evaluation of the role of green tea or green tea components in ovarian cancer prevention and treatment.


Asunto(s)
Catequina/análogos & derivados , Neoplasias Glandulares y Epiteliales/epidemiología , Neoplasias Glandulares y Epiteliales/prevención & control , Neoplasias Ováricas/epidemiología , Neoplasias Ováricas/prevención & control , Sustancias Protectoras/farmacología , , Animales , Apoptosis/efectos de los fármacos , Carcinoma Epitelial de Ovario , Catequina/farmacología , Catequina/uso terapéutico , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Femenino , Humanos , Incidencia , Neoplasias Glandulares y Epiteliales/tratamiento farmacológico , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Sustancias Protectoras/uso terapéutico
5.
Int J Radiat Oncol Biol Phys ; 82(4): 1454-62, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21640495

RESUMEN

PURPOSE: Radiation therapy (RT) causes acute and late toxicities that affect various organs and functions. In a large cohort of patients treated with RT for localized head and neck cancer (HNC), we prospectively assessed the occurrence of RT-induced acute and late toxicities and identified characteristics that predicted these toxicities. METHODS AND MATERIALS: We conducted a randomized trial among 540 patients treated with RT for localized HNC to assess whether vitamin E supplementation could improve disease outcomes. Adverse effects of RT were assessed using the Radiation Therapy Oncology Group Acute Radiation Morbidity Criteria during RT and one month after RT, and the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme at six and 12 months after RT. The most severe adverse effect among the organs/tissues was selected as an overall measure of either acute or late toxicity. Grade 3 and 4 toxicities were considered as severe. Stepwise multivariate logistic regression models were used to identify all independent predictors (p < 0.05) of acute or late toxicity and to estimate odds ratios (OR) for severe toxicity with their 95% confidence intervals (CI). RESULTS: Grade 3 or 4 toxicity was observed in 23% and 4% of patients, respectively, for acute and late toxicity. Four independent predictors of severe acute toxicity were identified: sex (female vs. male: OR = 1.72, 95% confidence interval [CI]: 1.06-2.80), Karnofsky Performance Status (OR = 0.67 for a 10-point increment, 95% CI: 0.52-0.88), body mass index (above 25 vs. below: OR = 1.88, 95% CI: 1.22-2.90), TNM stage (Stage II vs. I: OR = 1.91, 95% CI: 1.25-2.92). Two independent predictors were found for severe late toxicity: female sex (OR = 3.96, 95% CI: 1.41-11.08) and weight loss during RT (OR = 1.26 for a 1 kg increment, 95% CI: 1.12-1.41). CONCLUSIONS: Knowledge of these predictors easily collected in a clinical setting could help tailoring therapies to reduce toxicities among patients treated with RT for HNC.


Asunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Traumatismos por Radiación/etiología , Enfermedad Aguda , Índice de Masa Corporal , Intervalos de Confianza , Método Doble Ciego , Femenino , Neoplasias de Cabeza y Cuello/patología , Humanos , Estado de Ejecución de Karnofsky , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Oportunidad Relativa , Estudios Prospectivos , Quebec , Traumatismos por Radiación/diagnóstico , Factores Sexuales , Vitamina E/uso terapéutico , Vitaminas/administración & dosificación , Vitaminas/efectos adversos , Pérdida de Peso , beta Caroteno/administración & dosificación , beta Caroteno/efectos adversos
6.
Int J Cancer ; 128(7): 1741-6, 2011 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-20533282

RESUMEN

Low pretreatment vitamin D status has been associated with worsened disease outcomes in patients with cancer at various sites. Its prognostic significance in head and neck cancer (HNC) patients has not been studied. Patients with HNC who participated in a randomized trial were evaluated for: (i) total intake of vitamin D from diet and supplements using a validated food frequency questionnaire (all trial participants, n = 540) and (ii) pretreatment serum 25-hydroxyvitamin D through a radioimmunoassay (n = 522). The association of dietary/serum measures of vitamin D status with HNC recurrence, second primary cancer (SPC) incidence, and overall mortality was evaluated using multivariate Cox proportional hazard models. There was no significant association between dietary or serum vitamin D measures and the three HNC outcomes. The hazard ratios (HRs) comparing the highest with the lowest quartile of dietary/supplemental vitamin D intake were 1.10 (95% confidence interval (CI): 0.66-1.84) for recurrence, 1.05 (95% CI: 0.63-1.74) for SPC, and 1.27 (95% CI: 0.87-1.84) for overall mortality. HRs comparing the uppermost to the lowest quartile of serum 25-hydroxyvitamin D levels were 1.12 (95% CI: 0.65-1.93) for recurrence, 0.72 (95% CI: 0.40-1.30) for SPC, and 0.85 (95% CI: 0.57-1.28) for overall mortality. There was no effect modification by cancer stage, season of initial treatment, or trial arm. Among patients with HNC, vitamin D status before treatment does not influence disease outcomes. Our results contrast with those from most published studies, which suggest prognostic significance of vitamin D status in cancer patients at least in subgroups.


Asunto(s)
Suplementos Dietéticos , Neoplasias de Cabeza y Cuello/sangre , Vitamina D/análogos & derivados , Anciano , Dieta , Femenino , Neoplasias de Cabeza y Cuello/diagnóstico , Neoplasias de Cabeza y Cuello/terapia , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Modelos de Riesgos Proporcionales , Radioterapia/métodos , Recurrencia , Encuestas y Cuestionarios , Resultado del Tratamiento , Vitamina D/sangre
7.
Psychooncology ; 18(12): 1300-10, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19165757

RESUMEN

OBJECTIVE: Palliative care (PC) nurses experience several recurrent organizational, professional, and individual challenges. To address existential and emotional demands, the meaning-centered intervention was recently developed. The intervention applied didactic and process-oriented strategies, including guided reflections, experiential exercises, and education based on themes of Viktor Frankl's logotherapy. The objective of this study was to test its efficiency to improve job satisfaction and quality of life in PC nurses from three regional districts in Quebec Province, Canada. METHODS: A randomized waiting-list group design was conducted, intervention group (n=56) versus waiting-list group (n=53). Job satisfaction, perception of benefits of working in PC, and spiritual and emotional quality of life were measured at pre-, posttest, and 3-month follow-up. RESULTS: The PC nurses in the experimental group reported more perceived benefits of working in PC after the intervention and at follow-up. Spiritual and emotional quality of life remained, however, unaffected by the intervention. CONCLUSIONS: To explain null findings, theoretical and methodological challenges, related to existential interventions, such as choice of outcomes, and selection bias (participants recruited were healthy workers) are discussed. Future directions and strategies to deal with those issues are proposed.


Asunto(s)
Adaptación Psicológica , Agotamiento Profesional/terapia , Existencialismo , Satisfacción en el Trabajo , Enfermería Oncológica , Cuidados Paliativos/psicología , Psicoterapia de Grupo/métodos , Calidad de Vida/psicología , Adulto , Agotamiento Profesional/psicología , Emociones , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Quebec , Espiritualidad , Trastornos de Estrés Traumático/psicología , Trastornos de Estrés Traumático/terapia
8.
Int J Cancer ; 122(7): 1679-83, 2008 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-18059031

RESUMEN

There has been concern that the efficacy of radiation therapy may be reduced when patients smoke or take antioxidant vitamins during treatment. Cancer prevention trials with beta carotene supplements documented adverse effects only among smokers. We conducted a randomized trial with alpha tocopherol (400 IU/day) and beta carotene (30 mg/day) supplements among 540 head and neck cancer (HNC) patients treated by radiation therapy. We examined whether smoking during radiation therapy modified the effects of the supplementation on HNC recurrence and on mortality. During the follow-up, 119 patients had a HNC recurrence and 179 died. Cox models were used to test the interaction between smoking and supplementation and to estimate the hazard ratios (HR) for HNC recurrence and death associated with the supplementation. Cigarette smoking either before or after radiation therapy did not modify the effects of the supplementation. In contrast, the interactions between supplementation and cigarette smoking during radiation therapy were statistically significant for HNC recurrence (p = 0.03), all-cause mortality (p = 0.02) and mortality from the initial HNC (p = 0.04). Among cigarette smokers, the HR were 2.41 (95% CI: 1.25-4.64) for recurrence, 2.26 (95% CI: 1.29-3.97) for all-cause mortality and 3.38 (95% CI: 1.11-10.34) for HNC mortality. All corresponding HR among nonsmokers were close to 1. These results could best be explained by the hypothesis that the combined exposures reduced the efficacy of radiation therapy. Particular attention should be devoted to prevent patients from both smoking and taking antioxidant supplements during radiation therapy.


Asunto(s)
Antioxidantes/efectos adversos , Suplementos Dietéticos/efectos adversos , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/radioterapia , Recurrencia Local de Neoplasia/mortalidad , Fumar/efectos adversos , Vitaminas/efectos adversos , Adulto , Anciano , Antioxidantes/administración & dosificación , Femenino , Estudios de Seguimiento , Neoplasias de Cabeza y Cuello/etiología , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/etiología , Recurrencia Local de Neoplasia/prevención & control , Oportunidad Relativa , Modelos de Riesgos Proporcionales , Radioterapia Adyuvante , Resultado del Tratamiento , Vitaminas/administración & dosificación
9.
Cancer Detect Prev ; 31(4): 323-31, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17935908

RESUMEN

BACKGROUND: A study was conducted to identify determinants of diagnostic delay in order to develop strategies to reduce the waiting time for breast cancer diagnosis. METHODS: A cohort of 696 women diagnosed with early breast cancer was recruited in two radiation oncology centers of Quebec, Canada, in 2002-2003. A structured questionnaire was administered to identify potential determinants of diagnostic delay. Dates for all of the breast procedures were extracted from medical records. "Diagnostic delay" was defined as a time interval of more than 5 weeks between the first breast specific procedure and the final diagnostic procedure. A logistic regression model was used to estimate adjusted odds ratios (OR) of diagnostic delay and their 95% confidence intervals (CI). RESULTS: The two main determinants of diagnostic delay were the medical indication for the breast investigation and the scheduling of the diagnostic procedures. Compared to screened women, those referred because of clinical findings had an OR of diagnostic delay of 0.34 (95% CI=0.22-0.54). Women who underwent breast procedures during visits on at least four separate days had an OR of 6.31 (95% CI=3.85-10.34) compared to those who completed their investigation during visits on at most two separate days. Women who had complementary procedures the day of the first procedure were less likely to experience a diagnostic delay (OR=0.51, 95% CI=0.31-0.82). Finally, diagnostic delay was also significantly associated with the interpretation of the first diagnostic procedure, type of final diagnostic procedure, size of tumor, and family income. CONCLUSIONS: This study suggests that a promising strategy for reducing the waiting time for breast cancer diagnosis is to better integrate the services during the investigation period.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Anciano , Estudios de Cohortes , Continuidad de la Atención al Paciente , Prestación Integrada de Atención de Salud , Femenino , Humanos , Persona de Mediana Edad , Quebec , Análisis de Regresión , Encuestas y Cuestionarios , Factores de Tiempo
10.
Nutr Cancer ; 59(1): 29-35, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17927499

RESUMEN

There is a debate concerning the effects of antioxidant vitamins during radiation therapy: Can they reduce the adverse effects of therapy without reducing treatment efficacy? We examined whether dietary and plasma beta carotene and alpha tocopherol were related to severe acute adverse effects of radiation therapy and to cancer local recurrence. We conducted a prospective study of 540 head and neck cancer patients treated by radiation therapy. Dietary intakes of beta carotene and alpha tocopherol were measured by a validated food frequency questionnaire and plasma levels were determined. Acute adverse effects of radiation therapy and local recurrence were documented. A higher beta carotene dietary intake was associated with fewer severe acute adverse effects: odds ratio (OR) = 0.61 [95% confidence interval (CI) = 0.40-0.93]. There was a tendency for a similar effect for plasma beta carotene: OR = 0.73 (95% CI = 0.48-1.11). Participants with higher plasma beta carotene had a significantly lower rate of local recurrence (hazard ratio = 0.67; 95% CI = 0.45-0.99). Alpha tocopherol was not related to severe adverse effects or to cancer recurrence. This study suggests that a higher usual dietary beta carotene intake can reduce the occurrence of severe adverse effects of radiation therapy and decrease local cancer recurrence.


Asunto(s)
Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Traumatismos por Radiación/prevención & control , alfa-Tocoferol/sangre , alfa-Tocoferol/uso terapéutico , beta Caroteno/sangre , beta Caroteno/uso terapéutico , Antioxidantes/metabolismo , Antioxidantes/uso terapéutico , Intervalos de Confianza , Dieta , Suplementos Dietéticos , Método Doble Ciego , Femenino , Neoplasias de Cabeza y Cuello/sangre , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/tratamiento farmacológico , Oportunidad Relativa , Estudios Prospectivos , Encuestas y Cuestionarios
11.
Can J Urol ; 13(5): 3255-60, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17076947

RESUMEN

PURPOSE: Prostatic intraepithelial neoplasia (PIN) is considered as a precursor lesion for adenocarcinoma of the prostate. Most data supporting this relationship comes from the short-term follow-up of patients with repeated biopsies. We report a study in which patients were followed-up for 11 years to assess the relationships between the presence of high grade PIN, low grade PIN, and atypical adenomatous hyperplasia (AAH) and the subsequent occurrence of prostate cancer. MATERIALS AND METHODS: For 601 men treated by TURP in 1990-1993, prostate specimens were reviewed to assess the presence of high grade PIN, low grade PIN, and AAH. Incidental carcinoma was observed in 67 men. Follow-up of the 534 men without incidental prostate cancer was conducted until December 2003 and 24 new prostate cancers were diagnosed. Multivariate regression models were used to assess the relationships between PIN and AAH and prostate cancer on both cross-sectional and prospective data. RESULTS: High grade PIN (odds ratio (OR) = 6.16, 95% confidence interval (CI): 3.28-11.58), low grade PIN (OR = 3.06, 95% CI: 1.45-6.46), and AAH (OR = 2.06, 95% CI: 1.00-4.29) were significantly associated with incidental prostate cancer. In the prospective study, only high grade PIN was associated with a statistically significant increased risk of prostate cancer: hazard ratio = 3.12, 95% CI: 1.15-8.49. CONCLUSION: Although high grade PIN, low grade PIN, and AAH were all associated with incidental prostate cancer, the long-term prospective study showed that only high grade PIN was a significant determinant of the subsequent occurrence of prostate cancer.


Asunto(s)
Adenocarcinoma/etiología , Hiperplasia Prostática/patología , Neoplasia Intraepitelial Prostática/patología , Neoplasias de la Próstata/etiología , Anciano , Estudios de Seguimiento , Humanos , Masculino , Oportunidad Relativa , Hiperplasia Prostática/complicaciones , Hiperplasia Prostática/cirugía , Neoplasia Intraepitelial Prostática/complicaciones , Resección Transuretral de la Próstata
12.
Int J Cancer ; 119(9): 2221-4, 2006 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-16841333

RESUMEN

There has been concern that long-term supplementation with high-dose antioxidant vitamins, especially vitamin E (alpha-tocopherol), may increase all-cause mortality. We conducted a randomized controlled trial with alpha-tocopherol (400 IU/day) and beta-carotene (30 mg/day) supplements among 540 head and neck cancer patients treated by radiation therapy. Supplementation with beta-carotene was discontinued during the trial. The supplements were given during radiation therapy and for 3 additional years. During the follow-up (median 6.5 years), 179 deaths were recorded. All death certificates were obtained. All-cause and cause-specific mortality rates were compared between the 2 arms of the trial by Cox regression. All-cause mortality was significantly increased in the supplement arm: hazard ratio: 1.38, 95% confidence interval 1.03-1.85. Cause-specific mortality rates tended to be higher in the supplement arm than in the placebo arm. Our results concur with previous reports to suggest that high-dose vitamin E could be harmful.


Asunto(s)
Antioxidantes/uso terapéutico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Vitaminas/uso terapéutico , Suplementos Dietéticos , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Placebos , Análisis de Supervivencia , Vitaminas/administración & dosificación , alfa-Tocoferol/uso terapéutico , beta Caroteno/uso terapéutico
13.
Cancer Epidemiol Biomarkers Prev ; 14(9): 2269-72, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16172243

RESUMEN

Several epidemiologic studies have examined with diverging results the relationships between circulating levels of insulin-like growth factors (IGF) and of IGF-binding proteins (IGFBP) and prostate cancer risk. We assessed the association of prediagnostic plasma levels of IGF-I, IGF-II, IGFBP-2, and IGFBP-3 and subsequent occurrence of prostate cancer in a case-control study nested in the SU.VI.MAX trial. The SU.VI.MAX study was a primary prevention trial testing a daily supplementation with low-dose antioxidant vitamins and minerals in male and female middle-aged volunteers in France. One hundred prostate cancer cases were diagnosed among 4,855 SU.VI.MAX participants over a 9-year follow-up period. For each case, four age-matched controls were selected randomly. Frozen baseline plasma samples were used to measure IGF-I, IGF-II, IGFBP-2, and IGFBP-3. Conditional logistic regression was used to assess the association between these four biochemical markers and prostate cancer risk. After controlling for the intervention group in the trial and the other IGF axis variables, the odds ratios and 95% confidence interval (95% CI) comparing the upper quartile to the baseline quartile were 1.83 (95% CI, 0.85-3.95), 1.05 (95% CI, 0.35-3.18), 0.79 (95% CI, 0.39-1.58), and 0.42 (95% CI, 0.12-1.52) for IGF-I, IGF-II, IGFBP-2, and IGFBP-3, respectively. More suggestive associations for IGF-I and IGFBP-3 were observed with advanced and aggressive cancers. Our results are consistent with those of some previous prospective studies and suggest that IGF axis variables are not long-term predictors of the occurrence of prostate cancer.


Asunto(s)
Neoplasias de la Próstata/fisiopatología , Somatomedinas/análisis , Antioxidantes/uso terapéutico , Estudios de Casos y Controles , Quimioprevención , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias de la Próstata/prevención & control , Factores de Riesgo
14.
J Clin Oncol ; 23(24): 5805-13, 2005 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-16027437

RESUMEN

PURPOSE: Many cancer patients take antioxidant vitamin supplements with the hope of improving the outcome of conventional therapies and of reducing the adverse effects of these treatments. A randomized trial was conducted to determine whether supplementation with antioxidant vitamins could reduce the occurrence and severity of acute adverse effects of radiation therapy and improve quality of life without compromising treatment efficacy. PATIENTS AND METHODS: We conducted a randomized, double-blind, placebo-controlled trial among 540 head and neck cancer patients treated with radiation therapy. Patients were randomly assigned into two arms. The supplementation with alpha-tocopherol (400 IU/d) and beta-carotene (30 mg/d) or placebos was administered during radiation therapy and for 3 years thereafter. During the course of the trial, supplementation with beta-carotene was discontinued because of ethical concerns. RESULTS: Patients randomly assigned in the supplement arm tended to have less severe acute adverse effects during radiation therapy (odds ratio [OR], 0.72; 95% CI, 0.52 to 1.02). The reduction was statistically significant when the supplementation combined alpha-tocopherol and beta-carotene for adverse effects to the larynx (OR, 0.38; 95% CI, 0.21 to 0.71) and overall at any site (OR, 0.38; 95% CI, 0.20 to 0.74). Quality of life was not improved by the supplementation. The rate of local recurrence of the head and neck tumor tended to be higher in the supplement arm of the trial (hazard ratio, 1.37; 95% CI, 0.93 to 2.02). CONCLUSION: Supplementation with high doses of alpha-tocopherol and beta-carotene during radiation therapy could reduce the severity of treatment adverse effects. However, this trial suggests that use of high doses of antioxidants as adjuvant therapy might compromise radiation treatment efficacy.


Asunto(s)
Antioxidantes/uso terapéutico , Neoplasias de Cabeza y Cuello/radioterapia , Traumatismos por Radiación/prevención & control , alfa-Tocoferol/uso terapéutico , beta Caroteno/uso terapéutico , Enfermedad Aguda , Análisis de Varianza , Distribución de Chi-Cuadrado , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Calidad de Vida , Análisis de Supervivencia
15.
Int J Cancer ; 116(2): 182-6, 2005 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-15800922

RESUMEN

Randomized trials have shown, unexpectedly, that supplementation with selenium or vitamin E is associated with a reduction of prostate cancer risk. We assess whether a supplementation with low doses of antioxidant vitamins and minerals could reduce the occurrence of prostate cancer and influence biochemical markers. The SU.VI.MAX trial comprised 5,141 men randomized to take either a placebo or a supplementation with nutritional doses of vitamin C, vitamin E, beta-carotene, selenium and zinc daily for 8 years. Biochemical markers of prostate cancer risk such as prostate-specific antigen (PSA) and insulin-like growth factors (IGFs) were measured on plasma samples collected at enrollment and at the end of follow-up from 3,616 men. Cox regression models were used to estimate the hazard ratio and related 95% confidence interval of prostate cancer associated with the supplementation and to examine whether the effect differed among predetermined susceptible subgroups. During the follow-up, 103 cases of prostate cancer were diagnosed. Overall, there was a moderate nonsignificant reduction in prostate cancer rate associated with the supplementation (hazard ratio = 0.88; 95% CI = 0.60-1.29). However, the effect differed significantly between men with normal baseline PSA (< 3 microg/L) and those with elevated PSA (p = 0.009). Among men with normal PSA, there was a marked statistically significant reduction in the rate of prostate cancer for men receiving the supplements (hazard ratio = 0.52; 95% CI = 0.29-0.92). In men with elevated PSA at baseline, the supplementation was associated with an increased incidence of prostate cancer of borderline statistical significance (hazard ratio = 1.54; 95% CI = 0.87-2.72). The supplementation had no effect on PSA or IGF levels. Our findings support the hypothesis that chemoprevention of prostate cancer can be achieved with nutritional doses of antioxidant vitamins and minerals.


Asunto(s)
Antioxidantes/farmacología , Neoplasias de la Próstata/prevención & control , Selenio/farmacología , Zinc/farmacología , Adulto , Anciano , Suplementos Dietéticos , Esquema de Medicación , Humanos , Masculino , Persona de Mediana Edad , Placebos , Antígeno Prostático Específico/sangre , Somatomedinas/análisis
16.
J Natl Cancer Inst ; 97(7): 481-8, 2005 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-15812073

RESUMEN

BACKGROUND: Although low dietary intakes of antioxidant vitamins and minerals have been associated with higher risks of cancer, results of trials testing antioxidant supplementation for cancer chemoprevention have been equivocal. We assessed whether supplementation with antioxidant vitamins could reduce the incidence of second primary cancers among patients with head and neck cancer. METHODS: We conducted a multicenter, double-blind, placebo-controlled, randomized chemoprevention trial among 540 patients with stage I or II head and neck cancer treated by radiation therapy between October 1, 1994, and June 6, 2000. Supplementation with alpha-tocopherol (400 IU/day) and beta-carotene (30 mg/day) or placebo began on the first day of radiation therapy and continued for 3 years after the end of radiation therapy. In the course of the trial, beta-carotene supplementation was discontinued after 156 patients had enrolled because of ethical concerns. The remaining patients received alpha-tocopherol or placebo only. Survival was evaluated by Kaplan-Meier analysis. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: After a median follow-up of 52 months, second primary cancers and recurrences of the first tumor were diagnosed in 113 and 119 participants, respectively. The effect of supplementation on the incidence of second primary cancers varied over time. Compared with patients receiving placebo, patients receiving alpha-tocopherol supplements had a higher rate of second primary cancers during the supplementation period (HR = 2.88, 95% CI = 1.56 to 5.31) but a lower rate after supplementation was discontinued (HR = 0.41, 95% CI = 0.16 to 1.03). Similarly, the rate of having a recurrence or second primary cancer was higher during (HR = 1.86, 95% CI = 1.27 to 2.72) but lower after (HR = 0.71, 95% CI = 0.33 to 1.53) supplementation with alpha-tocopherol. The proportion of participants free of second primary cancer overall after 8 years of follow-up was similar in both arms. CONCLUSIONS: alpha-Tocopherol supplementation produced unexpected adverse effects on the occurrence of second primary cancers and on cancer-free survival.


Asunto(s)
Antioxidantes/administración & dosificación , Antioxidantes/efectos adversos , Neoplasias de Cabeza y Cuello/radioterapia , Neoplasias Inducidas por Radiación/prevención & control , Neoplasias Primarias Secundarias/prevención & control , alfa-Tocoferol/administración & dosificación , alfa-Tocoferol/efectos adversos , beta Caroteno/administración & dosificación , beta Caroteno/efectos adversos , Adulto , Anciano , Anticarcinógenos/administración & dosificación , Anticarcinógenos/efectos adversos , Factores de Confusión Epidemiológicos , Método Doble Ciego , Esquema de Medicación , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Neoplasias Inducidas por Radiación/epidemiología , Neoplasias Primarias Secundarias/epidemiología , Neoplasias Primarias Secundarias/etiología , Oportunidad Relativa , Modelos de Riesgos Proporcionales , Radioterapia/efectos adversos , Análisis de Supervivencia , Insuficiencia del Tratamiento
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