Baseline urinary phytoestrogen levels and the natural history of untreated, localised prostate cancer in a British population.

AIM: To determine whether urinary concentrations of phytoestrogens are associated with the rate of disease progression in men with untreated, localised prostate cancer. PATIENTS AND METHODS: Patients with untreated, localised prostatic adenocarcinoma on a prospective clinical study of active surveillance had urine samples collected at baseline. Patients underwent monitoring with serial PSA levels and repeat octant prostate biopsies. Disease progression was defined as either adverse histology on repeat biopsy (primary Gleason grade >or= 4, or >50% positive cores) or radical treatment for PSA velocity >1 ng/mL/year. Time to disease progression was analysed with respect to baseline urinary levels of genistein, enterolactone, daidzein and equol, assayed using liquid chromatography/tandem mass spectrometry. RESULTS: 191 patients were evaluable, with a median follow-up of 2.5 years. 71 patients experienced disease progression. No significant association was seen between time to disease progression and baseline urinary levels of daidzein (p=0.85), genistein (p=0.81), enterolactone (p=0.085) or equol (p=0.33). No significant association was seen between adverse histology on repeat biopsy and urinary levels of either daidzein (p=0.85), genistein (p=0.58), enterolactone (p=0.88) or equol (p=0.71). There was no significant correlation between PSA velocity and urinary levels of daidzein (p=0.90), genistein (p=0.98), enterolactone (p=0.10) or equol (p=0.60). CONCLUSION: These data do not support the hypothesis that phytoestrogens prevent disease progression in men with localised prostate cancer.

Diagnostic radiation procedures and risk of prostate cancer.

Exposure to ionising radiation is an established risk factor for many cancers. We conducted a case-control study to investigate whether exposure to low dose ionisation radiation from diagnostic x-ray procedures could be established as a risk factor for prostate cancer. In all 431 young-onset prostate cancer cases and 409 controls frequency matched by age were included. Exposures to barium meal, barium enema, hip x-rays, leg x-rays and intravenous pyelogram (IVP) were considered. Exposures to barium enema (adjusted odds ratio (OR) 2.06, 95% confidence interval (CI) 1.01-4.20) and hip x-rays (adjusted OR 2.23, 95% CI 1.42-3.49) at least 5 years before diagnosis were significantly associated with increased prostate cancer. For those with a family history of cancer, exposures to hip x-rays dating 10 or 20 years before diagnosis were associated with a significantly increased risk of prostate cancer: adjusted OR 5.01, 95% CI 1.64-15.31 and adjusted OR 14.23, 95% CI 1.83-110.74, respectively. Our findings show that exposure of the prostate gland to diagnostic radiological procedures may be associated with increased cancer risk. This effect seems to be modified by a positive family history of cancer suggesting that genetic factors may play a role in this risk association.

How patients manage gastrointestinal symptoms after pelvic radiotherapy.

BACKGROUND: Approximately 13,000 patients undergo pelvic radiotherapy annually in the UK. It is not clear how frequently patients develop a permanent change in bowel habit after pelvic radiotherapy that affects their quality of life because the measures of gastrointestinal toxicity used in trials in the past have generally been inadequate. It has been suggested that patients who are symptomatic are only rarely referred to a gastroenterologist and it is not known how patients manage their symptoms. METHODS: Patients who had completed radiotherapy for pelvic cancer at least 1 year previously were invited to answer 30 structured questions in a face-to-face interview to determine the frequency of gastrointestinal symptoms and what orthodox, dietary and complementary therapies they used to deal with them. They were also asked to score the effectiveness of the measures they had taken. RESULTS: One hundred and seven patients were recruited [35 males; median age, 65 years (range, 35-80 years); 72 females; median age, 67.5 years (range, 31-87 years)]. Eight had been treated for a gastrointestinal primary tumour, 34 for a urological tumour and 65 for gynaecological tumours. Eighty-seven patients (81%) described new-onset gastrointestinal problems starting after radiotherapy. These symptoms affected the quality of life in 56 patients (52%). Significant effects on the quality of life were caused by diarrhoea or constipation (n = 53), faecal leakage (n = 19), abdominal, rectal or perineal pain (n = 14) and rectal bleeding (n = 6). Fifty-nine patients had seen a doctor for their symptoms (86% found this helpful), 12 had seen a dietician or nurse (50% found this helpful) and 14 had seen alternative practitioners (88% found this helpful). Dietary manipulation generally did not improve symptoms, except in a small group of patients (14/15) who avoided raw vegetables to great benefit. CONCLUSIONS: At least 1 year after pelvic radiotherapy, gastrointestinal symptoms which have an adverse effect on the quality of life may be more common than generally reported. Patients found that advice from doctors and alternative practitioners was equally valuable. Dietary manipulation was generally unhelpful for gastrointestinal symptoms after pelvic radiotherapy, although the role of eliminating raw vegetables may benefit from further evaluation.

Association between the GCG polymorphism of the selenium dependent GPX1 gene and the risk of young onset prostate cancer.

Epidemiological studies have suggested an association between low selenium levels and the development of prostate cancer. Human cellular glutathione peroxidase I (hGPX1) is a selenium-dependent enzyme that protects against oxidative damage and its peroxidase activity is a plausible mechanism for cancer prevention by selenium. The GPX1 gene has a GCG repeat polymorphism in exon 1, coding for a polyalanine tract of five to seven alanine residues. To test if the GPX1 GCG repeat polymorphism associates with the risk of young-onset prostate cancer we conducted a case-control study. The GPX1Ala genotypes were determined for 267 prostate cancer cases and 260 control individuals using polymerase chain reaction (PCR) amplification with fluorescently labelled primers and an ABI 377 automated genotyper. Associations between specific genotypes and the risk of prostate cancer were examined by logistic regression. We found no significant association between the GPX1 genotypes and prostate cancer. There was however an increased frequency of the GPX1Ala6/Ala6 genotype in the prostate cancer cases compared to controls (OR: 1.67; 95% CI: 0.97-2.87). The result of this study suggests that the GPX1 genotype is unlikely to be associated with the risk of developing prostate cancer.