Pressure effects on the EXAFS Debye-Waller factor of iron.

The pressure effects on atomic mean-square relative displacement characterizing the extended X-ray absorption fine structure (EXAFS) Debye-Waller factor of iron metal have been investigated based on the Debye model. The analytical expressions of the Debye frequency and EXAFS Debye-Waller factor have been derived as functions of crystal volume compressibility. Based on the well established equation-of-state including the contributions of the anharmonic and electronic thermal pressures, numerical calculations have been performed for iron up to a pressure of 220 GPa and compared with experimental data when possible. These results show that the Debye frequency increases rapidly with compression, and beyond 150 GPa it behaves as a linear function of pressure. Meanwhile the mean-square relative displacement curve drops robustly with pressure, especially at pressures smaller than 100 GPa. This phenomenon causes the enhancement of EXAFS signals at high pressure. Reversely, the increasing of temperature will reduce the amplitude of EXAFS spectra.

Dependence on temperature and pressure of second cumulant and correlation effects during EXAFS in intermetallic alloys.

The present article is aimed to investigate the second cumulants, and the thermodynamic quantities are dependent on temperature and pressure in the X-ray absorption fine structure spectrum. The expressions have been build by using the model of the non-harmonic correlation of Einstein and Debye. A simple calculation was used to instead complex problems caused by the interaction of many particles in the system. The significant results of this work are the Morse potential parameters have been theoretically calculated method, determined the temperature dependence of the second cumulant, mean square displacement and correlation function for copper, tungsten, and copper-tungsten alloy of ratio 93-07 percent (W93Cu07) under pressure up to 14GPa. Calculated the second cumulant dependence on the pressure in a range from 0GPa to 14GPa and clearly analysed the difference between the second cumulant at different pressure for atoms of tungsten, copper and tungsten-copper alloy. Numerical results according to the present theory agree well with experimental data and previous views.

Quinacrine sterilization and gynecologic cancers: a case-control study in northern Vietnam.

BACKGROUND: Over 100,000 women worldwide have been sterilized by insertion of quinacrine into the uterus to induce tubal scarring. Concern has been expressed about possible carcinogenicity, and specifically the risk of uterine cancer. METHODS: From 2001 through 2006, we conducted a population-based, case-control study of gynecologic cancers in 12 provinces in northern Vietnam, where relatively large numbers of women had received quinacrine. Cases of incident cervical, ovarian, and uterine cancer were identified at provincial hospitals or at referral hospitals in Hanoi. For each case, 3 age- and residence-matched controls were randomly selected from the population registries of the case's home community. RESULTS: The prevalence of quinacrine exposure was 1.2% among cases and 1.1% among controls. For cervical cancer, analysis of 606 cases (9 exposed) and their 1774 matched controls (18 exposed) produced an odds ratio of 1.44 (95% confidence interval = 0.59-3.48) (adjusted for several covariates including human papillomavirus risk score). For ovarian cancer, based on 262 cases (3 exposed) and 755 controls (8 exposed) and adjusted for age and number of years of ovulation, the odds ratio was 1.26 (0.21-5.45). For uterine cancer, none of the cases-including 23 cases of leiomyosarcoma-was exposed to quinacrine. The 95% confidence interval, based on 161 cases (none exposed) and 470 controls (7 exposed) and adjusted only for age, was 0-1.85. CONCLUSION: We found no evidence of a relationship between quinacrine sterilization and gynecologic cancer.

A regional cooperative clinical study of radiotherapy for cervical cancer in east and south-east Asian countries.

PURPOSE: Radiotherapy differed widely in east and south-east Asia because of technical, cultural, and socio-economic differences. With the purpose of standardizing radiotherapy for cervical cancer in the region, an international clinical study was conducted. MATERIALS AND METHODS: Eleven institutions in eight Asian countries participated in the study. Between 1996 and 1998, 210 patients with stage IIIB cervical cancer were enrolled. Patients were treated with a combination of external beam radiotherapy (total dose, 50Gy) and either high-dose-rate (HDR) or low-dose-rate (LDR) intracavitary brachytherapy (ICBT) according to the institutional practice. The planned point A dose was 20-28Gy/4 fractions for HDR-ICBT and 30-40Gy/1-2 fractions for LDR-ICBT. RESULTS: Hundred patients were treated with HDR-ICBT and 110 were treated with LDR-ICBT. The ICBT doses actually delivered to point A ranged widely: 12-32Gy in the HDR group and 26-52.7Gy in the LDR group. The 5-year follow-up rate among the countries differed greatly, from 29% to 100%. The 5-year major complication rates were 6% in the HDR group and 10% in the LDR group. The 5-year overall survival rates were 51.1% in the HDR group and 57.5% in the LDR group. CONCLUSIONS: Although there were several problems with treatment compliance and patients' follow-up, the study suggests that the protocols provided favorable outcomes with acceptable rates of late complications in the treatment of advanced cervical cancer in east and south-east Asia.

Mastectomy and oophorectomy by menstrual cycle phase in women with operable breast cancer.

BACKGROUND: It is unclear whether the phase of the menstrual cycle in which primary surgical treatment occurs influences disease-free survival (DFS) and overall survival (OS) in premenopausal women with breast cancer. We investigated this question in the context of a clinical trial comparing mastectomy alone with mastectomy plus adjuvant oophorectomy and tamoxifen in premenopausal women with operable breast cancer. METHODS: The date of the first day of the last menstrual period (LMP) was used to estimate the phase of the menstrual cycle when the surgeries were done. Follicular phase was defined as day 1-14 from LMP. Luteal phase was defined as day 15-42 from LMP. DFS and OS statistics were determined and analyzed by Cox proportional hazards ratios and Kaplan-Meier methods. All statistical tests were two-sided. RESULTS: We analyzed results for 565 women who reported an LMP within 42 days before surgery. For women in the mastectomy only arm (n = 289), there were no differences in DFS or OS by menstrual cycle phase. For women in the adjuvant treatment arm (n = 276), those whose surgery occurred during the luteal phase (n = 158) had better DFS (relative risk [RR] = 0.54; 95% confidence interval [CI] = 0.32 to 0.96; P =.02) and OS (RR = 0.53; 95% CI = 0.30 to 0.95; P =.03) than those whose surgery occurred during the follicular phase (n = 118). Moreover, women whose surgery occurred during the luteal phase and who received adjuvant therapy had better 5-year DFS than did women whose surgery occurred during the follicular phase (84%; 95% CI = 78% to 90% versus 67%; 95% CI = 58% to 78%; P =.02); they also had better OS (85%; 95% CI = 78% to 92% versus 75%; 95% CI = 66% to 84%; P =.03). CONCLUSIONS: The phase of the menstrual cycle at which surgery was done had no impact on survival for women who received mastectomy only. However, women who received a mastectomy and surgical oophorectomy and tamoxifen during the luteal phase had better outcomes than women who received surgery during the follicular phase.

Her-2/neu overexpression and response to oophorectomy plus tamoxifen adjuvant therapy in estrogen receptor-positive premenopausal women with operable breast cancer.

PURPOSE: Studies evaluating the relationship of HER-2/neu breast tumor status and response to adjuvant endocrine therapy have reached conflicting conclusions about resistance of HER-2/neu-positive tumors to this treatment. We studied 282 patients participating in a randomized controlled trial of adjuvant oophorectomy and tamoxifen or observation who had estrogen receptor-positive tumors and whose tumors were evaluated for HER-2/neu overexpression by immunohistochemistry. PATIENTS AND METHODS: Univariate and multivariate Cox proportional hazards regression models and Kaplan-Meier disease-free and overall survival estimate methods were used. RESULTS: HER-2/neu overexpression was a negative prognostic factor for overall survival. In univariate analyses, in HER-2/neu-positive patients, the hazard ratio (HR) for disease-free survival (DFS) with adjuvant endocrine therapy was 0.37 (95% confidence interval [CI], 0.26 to 0.89); for HER-2/neu-negative patients, the corresponding HR for DFS was 0.48 (95% CI, 0.31 to 0.71). The overall survival (OS) data were HR=0.26 (95% CI, 0.07 to 0.92) and HR=0.68 (95% CI, 0.32 to 1.42) for HER-2/neu-positive and HER-2/neu-negative patients, respectively. In multivariate models, the P values for tests of interaction of HER-2/neu status and response to adjuvant endocrine therapy were 0.18 and 0.07 for DFS and OS, respectively. Kaplan-Meier DFS and OS curves and 3-year DFS estimates were consistent in showing greater benefit to the HER-2/neu-positive subgroup given adjuvant treatment. CONCLUSION: HER-2/neu overexpression does not adversely and may favorably influence response to adjuvant oophorectomy and tamoxifen treatment in patients with estrogen receptor-positive tumors.

Oophorectomy and tamoxifen adjuvant therapy in premenopausal Vietnamese and Chinese women with operable breast cancer.

PURPOSE: In 1992, the Early Breast Cancer Trialists' Collaborative Group reported that a meta-analysis of six randomized trials in European and North American women begun from 1948 to 1972 demonstrated disease-free and overall survival benefit from adjuvant ovarian ablation. Approximately 350,000 new cases of breast cancer are diagnosed annually in premenopausal Asian women who have lower levels of estrogen than western women. PATIENTS AND METHODS: From 1993 to 1999, we recruited 709 premenopausal women with operable breast cancer (652 from Vietnam, 47 from China) to a randomized clinical trial of adjuvant oophorectomy and tamoxifen (20 mg orally every day) for 5 years or observation and this combined hormonal treatment on recurrence. At later dates estrogen- and progesterone-receptor protein assays by immunohistochemistry were performed for 470 of the cases (66%). RESULTS: Treatment arms were well balanced. With a median follow-up of 3.6 years, there have been 84 events and 69 deaths in the adjuvant treatment group and 127 events and 91 deaths in the observation group, with 5-year disease-free survival rates of 75% and 58% (P =.0003 unadjusted; P =.0075 adjusted), and overall survival rates of 78% and 70% (P =.041 unadjusted) for the adjuvant and observation groups, respectively. Only patients with hormone receptor-positive tumors benefited from the adjuvant treatment. In Vietnam, for women unselected for hormone receptor status, a cost-effectiveness analysis suggests that this intervention costs $350 per year of life saved. CONCLUSION: Vietnamese and Chinese women with hormone receptor-positive operable breast cancer benefit from adjuvant treatment with surgical oophorectomy and tamoxifen.

Young age as an adverse prognostic factor in premenopausal women with operable breast cancer.

Data regarding young age as an independent prognostic factor have been conflicting. We investigated this variable in 696 premenopausal Vietnamese and Chinese women with operable breast cancer who participated in a clinical trial of adjuvant surgical oophorectomy and tamoxifen. Tumor size and axillary lymph node status did not vary with age. Women < 35 years had a greater fraction of histologic grade III tumors (P = 0.06), and in the two thirds of patients with available data, in women < 35 years, there was a lower percentage of estrogen- and progesterone receptor-positive tumors and a higher percentage of HER2/neu-positive tumors (P > 0.14 for each group). In univariate analyses, compared to women > or = 45 years, women < 35 years and 35-39 years were at greater risk for death (P = 0.002 and P = 0.023, respectively), and compared to women > or = 40, women < 40 were at greater risk of death (P = 0.002). Multivariate analyses supported a conclusion that younger age was an independent adverse prognostic factor for survival (P = 0.005, age as a continuous variable). Kaplan-Meier analyses in all patients and in oophorectomy and tamoxifen-treated patients, but not in observation-only patients, showed statistically significant poorer disease-free and overall survival in women < 40 years compared to those > or = 40 years. Thus, despite efficacy of the combined adjuvant hormonal therapy, younger age was a risk factor for poorer survival.

Radioprotective effects of vitexina for breast cancer patients undergoing radiotherapy with cobalt-60.

Vitexina, a product containing the flavonoid vitexin as the main component, is derived from a plant, Vigna radiata (L.), that has been traditionally used in Vietnam for detoxification. This remedy is also used to treat the symptoms of conditions classified as "hot" in traditional medicine. The present study is a randomized, placebo-controlled comparative clinical trial for investigating the radioprotective effects of Vitexina for breast cancer patients undergoing radiotherapy with cobalt-60. No relevant weight loss, (even weight gain), occurred in 70% of patients in the Vitexina group, whereas 73% of the placebo group lost 1 to 2 kg of weight after 6 weeks of radiation therapy. The administration of Vitexina produced a significantly protective effect in peripheral blood cells in amount and in lymphocyte blast-transformation function. Condition of hot was observed in almost all cancer patients in this study by tongue examination. Hot condition did not change in the Vitexina group, but the incidence of hot and extreme hot cases were significantly increased in the placebo group after 6 weeks of radiation therapy. The results suggest that application of medicinal plants of the "clearing heat and detoxification" classification as an adjuvant would be a potential solution in integrative cancer therapy.

The situation with cancer control in Vietnam.

Vietnam is one of the poor, developing countries. Malnutrition and infectious diseases are still major health problems. Cancer ranks in a relatively modest position of priority. The reason is partly explained by a shortage of treatment facilities and poor quality of health and vital statistics. The leading cancers in the country are lung, liver, stomach, colon-rectum and nasopharynx in males and breast, cervix, stomach, liver, colon-rectum and lung in females. Although the country has some common patterns of cancer such as a relatively high incidence of nasopharynx, liver and stomach and a relatively low incidence of breast and prostate cancer compared with international data, the geographical distribution of cancer is not homogenous within the country. The most remarkable difference is observed in cancer of the cervix uteri, of which the incidence in the South is, at least four times higher than that in the North. Other less extensive differences are observed in cancer of the lung, stomach, nasopharynx and breast, the incidence of which seems to be higher in the North than in the South, and the liver, which seems to be more frequent in the South than in the North. It was estimated that in 1990 the cancer incidence in Vietnam was about 133 per 100 000 in males and 91.7 per 100 000 in females and that the mortality was 105.9 and 58.5 per 100 000, respectively (standardization to the world's population). In that year, Vietnam had at least 52 700 new cancer cases and 37 700 dead from cancer. Although the National Cancer Control Program is still in preparation, some efforts by the government have already been made with tobacco control, improving the cancer treatment net, mass media education and production of vaccine against HBV. Cancer control in Vietnam still has to deal with challenges such as poor quality of cancer morbidity and mortality data, shortage of resources for establishing a comprehensive cancer control network from the center to the peripheries, lack of data for an anti-tobacco program and misunderstanding or limited knowledge of general practitioners and the public about the disease.

Duration of signs and survival in premenopausal women with breast cancer.

UNLABELLED: CONDENSED: Among 550 women reporting a lump as the first sign of breast cancer, those with this sign for 6-29 months compared to those with 1-6 months, had bigger tumors and more frequent axillary node involvement. Overall survival, however, was not significantly different in these two groups. BACKGROUND: The relationship of delay in diagnosis of breast cancer to survival is uncertain. METHODS: We evaluated the relationship of patient-reported duration of signs of breast cancer to survival in participants in a clinical trial of adjuvant hormonal therapy in Vietnam and China. RESULTS: Among 550 women reporting a lump as the first sign of breast cancer and information on when this appeared, the median duration of this sign before diagnosis was 6 months. Comparing two groups of patients with durations of lumps 1-6 months and 6-29 months, the group with longer duration of lumps had larger tumors clinically and pathologically (p = 0.0006, and p = 0.004), more frequent axillary node involvement (p = 0.008), and shorter but not statistically different disease-free and overall survival from the time of diagnosis (p = 0.09 and 0.35, respectively). CONCLUSIONS: Breast cancer evolves slowly in the detectable period of its natural history. The impact of delays in diagnosis of less than 6 months is likely to be very limited; delays more than 6 months appear to have some, but marginal impact on survival.