Circulating 25-hydroxyvitamin D and survival in women with ovarian cancer.

BACKGROUND: Vitamin D status might be associated with cancer survival. Survival after ovarian cancer is poor, but the association with vitamin D has rarely been examined. OBJECTIVE: We evaluated the association between serum 25-hydroxyvitamin D [25(OH)D], a marker of vitamin D status, and ovarian cancer survival. DESIGN: Participants were women with invasive ovarian cancer diagnosed between 2002 and 2005 who participated in the Australian Ovarian Cancer Study. Serum samples, collected at diagnosis (n = 670) or after completion of primary treatment and before recurrence (n = 336), were assayed for 25(OH)D. Sociodemographic, dietary, and lifestyle data came from questionnaires self-completed at recruitment, and clinical and survival data were from medical records, supplemented by linkage to the Australian National Death Index (October 2011). Cox proportional hazards regression was used to estimate HRs and 95% CIs for the association between circulating 25(OH)D and survival. RESULTS: Overall, 59% of the women died during follow-up, with 95% of deaths resulting from ovarian cancer. Circulating 25(OH)D concentrations (mean: 44 nmol/L) were significantly associated with age, state of residence, season of blood collection, and body mass index but not with tumor histology, stage or grade, or comorbidities. Higher 25(OH)D concentrations at diagnosis were significantly associated with longer survival (adjusted HR: 0.93; 95% CI: 0.88, 0.99 per 10 nmol/L), but there was no significant association with progression-free survival or for 25(OH)D measured after primary treatment. CONCLUSIONS: In our cohort, higher serum 25(OH)D concentrations at diagnosis were associated with longer survival among women with ovarian cancer. If confirmed in other studies, this suggests that vitamin D status at diagnosis may be an independent predictor of prognosis. Furthermore, if the association is found to be causal, improving vitamin D status may improve ovarian cancer survival rates.

Dietary phyto-oestrogens and the risk of ovarian and endometrial cancers: findings from two Australian case-control studies.

Phyto-oestrogens have been suggested to have a protective effect on hormone-sensitive cancers. However, few studies have investigated the association between dietary phyto-oestrogens and gynaecological cancers. In the present study, we analysed data from two population-based case-control studies of ovarian (1366 cases and 1414 controls) and endometrial (1288 cases and 1435 controls) cancers. Dietary intake information was obtained using a 135-item FFQ, and phyto-oestrogen intake was estimated using published food composition databases. Unconditional logistic regression was used to estimate adjusted OR and 95% CI. In multivariable analyses, there was a suggestive pattern of inverse associations between increasing intakes of total phyto-oestrogens, isoflavones and enterolignans and the risk of ovarian cancer. However, the results only reached statistical significance for the lignan compounds matairesinol and lariciresinol, where the OR for the highest v. the lowest intake category was 0.72 (95% CI 0.54, 0.96; P for trend = 0.02) for matairesinol and 0.72 (95% CI 0.55, 0.96; P for trend = 0.03) for lariciresinol. When the risk of ovarian cancer was assessed by subtype, there was an indication that increasing intakes of phyto-oestrogens may be associated with a decreased risk of mucinous (cases n 158) ovarian tumours (OR for the highest v. the lowest intake category: 0.47 (95% CI 0.24, 0.93); P for trend = 0.04). However, there were no significant associations with other histological subtypes. In contrast, dietary phyto-oestrogens (total or any subclass) were unrelated to the risk of endometrial cancer cases overall or by subtype.

Dietary antioxidants and risk of Barrett's esophagus and adenocarcinoma of the esophagus in an Australian population.

While dietary antioxidants are emerging as potentially modifiable risk factors for esophageal adenocarcinoma (EAC), studies on dietary antioxidants and its precursor Barrett's esophagus (BE) are limited. The present study extends previous work on BE by investigating risks of nondysplastic BE, dysplastic BE and EAC associated with intake of antioxidants such as vitamin C, vitamin E, ß-carotene, and selenium. Age and sex matched control subjects (n=577 for BE; n=1,507 for EAC) were sampled from an Australian population register. Information on demography, and well established EAC risk factors were obtained using self-administered questionnaires. Intake of antioxidants for patients newly diagnosed with nondysplastic BE (n=266), dysplastic BE (n=101), or EAC (n=299), aged 18-79 years, were obtained using a food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using multivariable adjusted logistic regression models. High intake of ß-carotene from food and supplement sources combined was inversely associated with risk of dysplastic BE (OR Q4 vs. Q1=0.45; 95%CI: 0.20-1.00). High intake of vitamin E from food sources (OR Q4 vs. Q1=0.43; 95%CI: 0.28-0.67), from food and supplements combined (OR Q4 vs. Q1=0.64; 95%CI: 0.43-0.96), and a high antioxidant index score were inversely associated with risk of EAC. We found no significant trends between intake of ß-carotene, vitamin C, vitamin E, and selenium and risk of nondysplastic or dysplastic BE. However, our data suggest that a high intake of ß-carotene may be associated with decreased risk of dysplastic BE.

Tea consumption and risk of ovarian cancer.

OBJECTIVE: Although the growth inhibitory effects of tea, particularly green tea, and tea polyphenols have been demonstrated in animal models of ovarian cancer, the results of epidemiological studies have been inconclusive. METHODS: We investigated this issue using data from an Australian population-based, case-control study (1,368 cases; 1,416 controls). We also systemically reviewed all the available evidence regarding the potential association between green tea and risk of ovarian cancer, given the abundance of bioavailable polyphenols and higher antioxidant capacity of green tea than black tea, to provide the best summary estimate of the association. RESULTS: In our case-control study, while we found uniformly inverse odds ratios (OR) for tea drinkers compared to non-tea drinkers [4 + cups/day any tea OR 0.71 (95% CI 0.52-0.97); green tea OR 0.82 (95% CI 0.38-1.79); herbal tea OR 0.77 (95% CI 0.28-2.14): black tea OR 0.88 (95% CI 0.66-1.18)], we saw no dose-response trends. Our meta-analysis provided some evidence that women who drink green tea have a lower risk of ovarian cancer, although the summary estimate did not reach statistical significance (0.58, 95% CI 0.33-1.01 for >or=1 cup/green tea day). This result is consistent with two recent meta-analyses that evaluated the association of tea (all types combined) and ovarian cancer risk. CONCLUSION: Overall, our findings provide some support for the hypothesis that tea consumption reduces the risk of ovarian cancer.