ABSTRACT
BACKGROUND: The transforming growth factor beta-1 gene (TGFB1) is a plausible candidate for breast cancer susceptibility. The L10P variant of TGFB1 is associated with higher circulating levels and secretion of TGF-beta, and recent large-scale studies suggest strongly that this variant is associated with breast cancer risk in the general population. METHODS: To evaluate whether TGFB1 L10P also modifies the risk of breast cancer in BRCA1 or BRCA2 mutation carriers, we undertook a multi-center study of 3,442 BRCA1 and 2,095 BRCA2 mutation carriers. RESULTS: We found no evidence of association between TGFB1 L10P and breast cancer risk in either BRCA1 or BRCA2 mutation carriers. The per-allele HR for the L10P variant was 1.01 (95%CI: 0.92-1.11) in BRCA1 carriers and 0.92 (95%CI: 0.81-1.04) in BRCA2 mutation carriers. CONCLUSIONS: These results do not support the hypothesis that TGFB1 L10P genotypes modify the risk of breast cancer in BRCA1 or BRCA2 mutation carriers.
Subject(s)
Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , Genes, BRCA1 , Genes, BRCA2 , Genotype , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/physiology , Adult , Alleles , Cohort Studies , Female , Genetic Predisposition to Disease , Heterozygote , Humans , Mutation , RiskABSTRACT
BACKGROUND: The most frequent site of metastases from prostate cancer is bone. Adjuvant bisphosphonate treatment improves outcomes of patients with bone metastasis-negative breast cancer, but the effects of bisphosphonates on bone metastases in prostate cancer are not known. METHODS: We performed a randomized double-blind placebo-controlled trial to determine whether a first-generation bisphosphonate could improve symptomatic bone metastasis-free survival (time to symptomatic bone metastases or death from prostate cancer) in men with nonmetastatic prostate cancer who were at high risk of developing bone metastases. Between June 1, 1994, and December 31, 1997, 508 men from 26 UK sites and one New Zealand site who were within 3 years of initial prostate cancer diagnosis with no evidence of metastases from current bone scanning were randomly assigned to daily oral sodium clodronate (2080 mg/day, n = 254) or placebo (n = 254) for a maximum of 5 years. Estimates of outcome risks were compared using Kaplan-Meier analyses. RESULTS: The groups allocated to each treatment were well balanced. After a median follow-up of nearly 10 years, no evidence of benefit to the clodronate group was observed in terms of bone metastases-free survival (clodronate versus placebo, 80 events versus 68 events; hazard ratio [HR] = 1.22; 95% confidence interval [CI] = 0.88 to 1.68) or overall survival (clodronate versus placebo, 130 deaths versus 127 deaths; HR = 1.02; 95% CI = 0.80 to 1.30). Adverse events, notably gastrointestinal problems and increased lactate dehydrogenase levels, were more frequent in the clodronate group than in the placebo group; otherwise, clodronate was well tolerated. Modification of trial drug dose was more frequent in the clodronate group than the placebo group (HR = 1.63, 95% CI = 1.21 to 2.19). CONCLUSION: Adjuvant sodium clodronate does not modify the natural history of nonmetastatic prostate cancer.
Subject(s)
Bone Density Conservation Agents/administration & dosage , Clodronic Acid/administration & dosage , Prostatic Neoplasms/drug therapy , Administration, Oral , Aged , Antineoplastic Agents/therapeutic use , Bone Density Conservation Agents/adverse effects , Clodronic Acid/adverse effects , Combined Modality Therapy , Disease Progression , Double-Blind Method , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Prostatic Neoplasms/mortality , RadiotherapyABSTRACT
BACKGROUND: The most frequent site of metastases from prostate cancer is bone. Bisphosphonates reduce excessive bone turnover while preserving bone structure and mineralization in patients with other tumor types. We conducted a double-blind, placebo-controlled, randomized trial to determine whether the first-generation bisphosphonate sodium clodronate could improve bone progression-free survival (BPFS) times among men with bone metastases from prostate cancer. METHODS: Between June 1994 and July 1998, 311 men who were starting or responding to first-line hormone therapy for bone metastases were randomly assigned to receive oral sodium clodronate (2080 mg/day) or placebo for a maximum of 3 years. The primary endpoint of the trial was symptomatic BPFS. Secondary endpoints included overall survival, treatment toxicity, and change in World Health Organization (WHO) performance status. Time-to-event data were analyzed using the log-rank chi-square test and Kaplan-Meier curves. All statistical tests were two-sided. RESULTS: Baseline characteristics were balanced across the two groups. After a median follow-up of 59 months, the sodium clodronate group showed statistically nonsignificant better symptomatic BPFS (hazard ratio [HR] = 0.79, 95% confidence interval [CI] = 0.61 to 1.02; P =.066) and overall survival (HR = 0.80, 95% CI = 0.62 to 1.03; P =.082) than the control group. Patients in the clodronate group were less likely to have a worsened WHO performance status (HR = 0.71, 95% CI = 0.56 to 0.92; P =.008). However, the clodronate group reported more gastrointestinal problems and increased lactate dehydrogenase levels and required more frequent modification of the trial drug dose (HR for any adverse event = 1.71, 95% CI = 1.21 to 2.41; P =.002). Results of subgroup analyses suggested that clodronate might be more effective the sooner after diagnosis of metastatic bone disease it is started. CONCLUSION: These results suggest that further studies of the effect of newer generation bisphosphonates on BPFS in men with metastatic prostate cancer are warranted.
