Faculty Bibliography

BACKGROUND: Obesity is associated with increased breast cancer risk among postmenopausal women. We examined whether this association could be explained by the relationship of body mass index (BMI) with serum sex hormone concentrations. METHODS: We analyzed individual data from eight prospective studies of postmenopausal women. Data on BMI and prediagnostic estradiol levels were available for 624 case subjects and 1669 control subjects; data on the other sex hormones were available for fewer subjects. The relative risks (RRs) with 95% confidence intervals (CIs) of breast cancer associated with increasing BMI were estimated by conditional logistic regression on case-control sets, matched within each study for age and recruitment date, and adjusted for parity. All statistical tests were two-sided. RESULTS: Breast cancer risk increased with increasing BMI (P(trend) =.002), and this increase in RR was substantially reduced by adjustment for serum estrogen concentrations. Adjusting for free estradiol reduced the RR for breast cancer associated with a 5 kg/m2 increase in BMI from 1.19 (95% CI = 1.05 to 1.34) to 1.02 (95% CI = 0.89 to 1.17). The increased risk was also substantially reduced after adjusting for other estrogens (total estradiol, non-sex hormone-binding globulin-bound estradiol, estrone, and estrone sulfate), and moderately reduced after adjusting for sex hormone-binding globulin, whereas adjustment for the androgens (androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, and testosterone) had little effect on the excess risk. CONCLUSION: The results are compatible with the hypothesis that the increase in breast cancer risk with increasing BMI among postmenopausal women is largely the result of the associated increase in estrogens, particularly bioavailable estradiol

Mathematical methods exist to determine the fractions of sex hormones bound to albumin, bound to sex hormone binding globulin (SHBG), or unbound, using total hormone concentration and SHBG concentration. We used data from eight prospective studies of postmenopausal women to assess the validity of these estimates for fractions of estradiol (E2) and to investigate the impact of using calculated values in breast cancer relative risk (RR) models. Comparisons were made between measured and calculated concentrations of free and non-SHBG-bound E2 in four studies. Relationships between the hormone fractions were investigated and a sensitivity analysis of the calculation performed. Breast cancer RRs were estimated using conditional logistic regression by quintiles of free E2. There is a high correlation (r > 0.91) between calculated and measured values of both free and non-SHBG-bound E2. The calculation is highly sensitive to total hormone concentration but is relatively insensitive to SHBG concentration. In studies with both measured and calculated values, the RRs of breast cancer by quintile of free E2 were almost identical for both estimates; using calculated values in all possible studies the RR in the highest compared with the lowest quintile of free E2 was 2.29 (95% confidence interval, 1.65-3.19). The mathematical method used to calculate fractions of E2 is valid, and RR analyses using calculated values produce similar results to those using measured values. This suggests that for epidemiological studies, it is only necessary to measure total E2 concentration and SHBG concentration, with hormone fractions being obtained by calculation, producing savings in cost, time, and serum

PURPOSE: To determine the activity of biweekly oxaliplatin, combined with weekly bolus fluorouracil (FU) and low-dose leucovorin (LV) chemotherapy (bFOL), as first-line therapy for patients with metastatic colorectal cancer. PATIENTS AND METHODS: Patients with measurable metastatic colorectal cancer; no previous therapy for advanced disease (adjuvant therapy allowed if >6 months since completion); and performance status 0, 1, or 2 were eligible and were treated with oxaliplatin 85 mg/m2 days 1 and 15 plus LV 20 mg/m2 over 10 to 20 minutes, followed by a 500 mg/m2 bolus dose of FU on days 1, 8, and 15 every 28 days. Patients underwent response evaluation by computed tomographic scan every 2 months. RESULTS: Forty-two patients were entered, and 41 patients were treated, including 20 men and 22 women, nine with previous adjuvant chemotherapy and four with radiation therapy. Three patients achieved complete response, and 23 patients achieved partial response, for a response rate of 63% (95% CI, 49% to 78%). Major toxicities included cumulative neuropathy grade 2 (24%) and grade 3 (12%; requiring discontinuation of oxaliplatin), diarrhea grade 3 to 4 (29%) and grade 3 to 4 hematologic toxicity (10%). Median time to progression was 9.0 months (95% confidence interval, 7.1 to 10.8 months) with median survival of 15.9 months (95% confidence interval, 11.4 to 19.7 months). CONCLUSION: The bFOL regimen seems to have activity comparable to be infusional programs of FU combined with oxaliplatin. Prospective trials are warranted to determine the relative merits of this schedule compared with the currently indicated schedules

The 'gonadotropin hypothesis' postulates that gonadotropin overstimulation of ovarian epithelium results in its increased proliferation and subsequent malignant transformation. To address this hypothesis, we assessed the association between prediagnostic serum levels of follicle-stimulating hormone (FSH) and the risk of epithelial ovarian cancer in postmenopausal women who were part of a case-control study nested within three prospective cohorts in New York City, Umea, Sweden, and Milan, Italy. Case subjects were 88 women with primary invasive epithelial ovarian cancer diagnosed between 3 months and 13.1 years after the blood donation. Controls were 168 women who were free of cancer and matched the case on cohort, age, and enrollment date. Serum FSH was determined using a quantitative immunoradiometric assay. FSH concentrations were similar in women who subsequently received a diagnosis of epithelial ovarian cancer (median, 44.0 mIU/ml; range, 13.8-101.2) and in controls (median, 43.4 mIU/ml; range, 13.5-109.5; P = 0.17). Compared with women in the lowest third, women in the highest third of serum FSH were not at increased risk of epithelial ovarian cancer after an adjustment for potential confounders (odds ratio, 0.85; 95% confidence interval, 0.36-1.99). These observations provide no evidence for an association between circulating FSH and risk of epithelial ovarian cancer in postmenopausal women and do not appear to support the gonadotropin hypothesis of epithelial ovarian carcinogenesis

BACKGROUND: Dysregulation of apoptosis, specifically overexpression of soluble Fas (sFas), has been proposed to play a role in the development of ovarian cancer. The main objective of the present study was to evaluate serum sFas as a potential biomarker of ovarian cancer risk. METHODS: The association between serum sFas levels and the risk of ovarian cancer was examined in a case-control study nested within three prospective cohorts in New York (USA), Umea (Sweden), and Milan (Italy). Case subjects were 138 women with primary invasive epithelial ovarian cancer diagnosed between 2 months and 13.2 years after the initial blood donation. Control subjects were 263 women who were free of cancer, and matched the case on cohort, menopausal status, age, and enrollment date. Serum sFas levels were determined using a quantitative sandwich enzyme immunoassay. RESULTS: Serum sFas levels were similar in women subsequently diagnosed with ovarian cancer (median, 6.5 ng/mL; range, 4.4-10.2) and in controls (median, 6.8 ng/mL; range, 4.5-10.1). Statistically significant trends of increasing serum sFas with age were observed among cases (r = 0.39, p < 0.0001) and controls (r = 0.42, p < 0.0001). Compared to women in the lowest third, women in the highest third of serum sFas were not at increased risk of ovarian cancer after adjustment for potential confounders (odd ratio (OR), 0.87; 95% confidence interval (CI), 0.42-1.82). CONCLUSION: The results suggest that serum sFas may not be a suitable marker for identification of women at increased risk of ovarian cancer

OBJECTIVE: To investigate the association of prediagnostic circulating levels of C-peptide, as a marker of pancreatic insulin secretion, and IGF binding proteins -1 and -2, as indicators of the biologically active IGF-I concentration, with risk of developing ovarian cancer. METHODS: The study was nested within three prospective cohorts in New York (USA), Umea (Sweden) and Milan (Italy). Case subjects were 132 women with primary invasive epithelial ovarian cancer diagnosed at least one year after blood donation. For each case, two control subjects were selected, matching the case subject on cohort, menopausal status, age and date of recruitment (n = 263). Only women who did not use exogenous hormones at blood donation were included in the study. RESULTS: Odds ratios and their 95% confidence intervals for risk of developing ovarian cancer over quartiles of peptides concentrations after adjustment for BMI and fasting were: 1.00, 0.66 (0.35-1.23), 0.96 (0.51-1.82) and 0.89 (0.44-1.81) for C-peptide; 1.00, 1.10 (0.58-2.09), 1.07 (0.55-2.04) and 0.79 (0.38-1.62) for IGFBP-1; and 1.00, 1.01 (0.54-1.89), 0.98 (0.51-1.88) and 0.87 (0.45-1.68) for IGFBP-2. In women who had ovarian cancer diagnosis before age 55 the ORs for the top tertiles of IGFBP-1 and IGFBP-2 were 0.51 (0.18-1.49) and 0.53 (0.18-1.54), respectively. CONCLUSIONS: This study does not support an independent direct etiological role of C-peptide in ovarian cancer pathogenesis, but suggests a possible protective effect of circulating IGFBP-1 and -2 in women who develop ovarian cancer before age 55

Background. More than 20 studies have investigated the relation between meat and dairy consumption and breast cancer risk with conflicting results. Our objective was evaluate the risk of assess whether non-dietary risk factors modify the relation. studies from North America and Western Europe with at least 200 intakes, and a validation study of dietary assessment instrument. diagnosed with invasive breast cancer during to 15 year of intakes of total meat, red me white meat, total dairy fluids, or total dairy solids and breast cancer risk. Categor analyses suggested a J-shaped association for egg consumption where, comp to women who did not eat eggs, breast cancer risk was slightly decreased am women who consumed <2 eggs per week but slightly increased among women who consumed >=1 egg per day. Conclusions. We produ and risk of breast cancer. An inconsistent relation between egg consumption risk of breast cancer merits further investigation

Background: Reproductive and hormonal factors are involved in the etiology of breast cancer, but there are only a few prospective studies on endogenous sex hormone levels and breast cancer risk. We reanalyzed the worldwide data from prospective studies to examine the relationship between the levels of endogenous sex hormones and breast cancer risk in postmenopausal women. Methods: We analyzed the individual data from nine prospective studies on 663 women who developed breast cancer and 1765 women who did not. None of the women was taking exogenous sex hormones when their blood was collected to determine hormone levels. The relative risks (RRs) for breast cancer associated with increasing hormone concentrations were estimated by conditional logistic regression on case-control sets matched within each study. Linear trends and heterogeneity of RRs were assessed by two-sided tests or chi-square tests, as appropriate. Results: The risk for breast cancer increased statistically significantly with increasing concentrations of all sex hormones examined: total estradiol, free estradiol, non-sex hormone-binding globulin (SHBG)-bound estradiol (which comprises free and albumin-bound estradiol), estrone, estrone sulfate, androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, and testosterone. The RRs for women with increasing quintiles of estradiol concentrations, relative to the lowest quintile, were 1.42 (95% confidence interval [CI] = 1.04 to 1.95), 1.21 (95% CI = 0.89 to 1.66), 1.80 (95% CI = 1.33 to 2.43), and 2.00 (95% CI = 1.47 to 2.71; Ptrend<.001); the RRs for women with increasing quintiles of free estradiol were 1.38 (95% CI = 0.94 to 2.03), 1.84 (95% CI = 1.24 to 2.74), 2.24 (95% CI = 1.53 to 3.27), and 2.58 (95% CI = 1.76 to 3.78; Ptrend<.001). The magnitudes of risk associated with the other estrogens and with the androgens were similar. SHBG was associated with a decrease in breast cancer risk (Ptrend = .041). The increases in risk associated with increased levels of all sex hormones remained after subjects who were diagnosed with breast cancer within 2 years of blood collection were excluded from the analysis. Conclusion: Levels of endogenous sex hormones are strongly associated with breast cancer risk in postmenopausal women

Insulin-like growth factor (IGF)-I, a mitogenic and anti-apoptotic peptide, has been implicated in the development of several cancers. We hypothesized that high circulating IGF-I concentrations may be associated with an increased risk of ovarian cancer. A case-control study was nested within 3 prospective cohorts in New York (USA), Umea (Sweden) and Milan (Italy). One hundred thirty-two women with primary invasive epithelial ovarian cancer diagnosed at least 1 year after blood donation were case subjects. For each case, 2 control subjects were selected, matching the case subject on cohort, menopausal status, age and date of recruitment (n = 263). Only women who did not use exogenous hormones at blood donation were included in the study. There was no association between IGF-I concentrations and ovarian cancer risk in the study group as a whole. In analyses restricted to subjects who had developed ovarian cancer at a young age (<55), circulating IGF-I was directly and strongly associated with ovarian cancer risk (OR = 4.97; 95% CI = 1.22-20.2 for the top vs. the bottom IGF-I tertile after adjustment for parity, BMI categories and smoking). There was no significant association of IGF binding protein-3 with ovarian cancer risk. We found a strong direct relationship between circulating IGF-I levels and risk of developing ovarian cancer before age 55. Additional, larger studies of this association are needed to provide more precise estimates of effect