C-peptide, IGF-I, sex-steroid hormones and adiposity: a cross-sectional study in healthy women within the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVES

The risk of some cancers is positively associated with body weight, which may influence circulating levels of sex-steroid hormones, insulin and IGF-I. Interrelationships between these hormones and the associations with adiposity were evaluated in healthy women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

A cross-sectional analysis was performed on anthropometric and hormonal data from 743 pre- and 1217 postmenopausal women. Body mass index (BMI) and waist circumference were used as indicators of adiposity. C-peptide, Insulin Growth Factor (IGF)-I, Insulin Growth Factor binding protein (IGFBP)-3, androgens, estrogens and sex hormone binding globulin (SHBG) were measured by immunoassays; free sex steroid concentrations were calculated.

RESULTS

BMI and waist circumference were positively correlated with estrogens in postmenopausal women and with C-peptide, free testosterone and inversely with SHBG in all women. C-peptide and IGF-I were inversely correlated with SHBG, and positively with free sex steroids in postmenopausal women. IGF-I was positively associated with postmenopausal estrogens and androgen concentrations in all women.

CONCLUSIONS

Sex-steroid concentrations appear to be regulated along several axes. Adiposity correlated directly with estrogens in postmenopausal women and with insulin, resulting in lower SHBG and increased levels of free sex steroids. Independent of adiposity and insulin, IGF-I was associated with decreased SHBG levels, and increased concentrations of androgens and postmenopausal estrogens.

Circulating soluble E-cadherin levels are of prognostic significance in patients with multiple myeloma

BACKGROUND

The epithelial transmembrane molecule E-cadherin (E-Cad) is the prime mediator of epithelial cell-cell adhesion, through homotypic interactions. It also participates in the maintenance of cytoskeletal structure and cell-cell signalling, while there are no published reports of expression of E-Cad in non-epithelial tissues. We examined whether the circulating levels of soluble E-Cad in newly diagnosed patients with multiple myeloma (MM) are of prognostic significance.

PATIENTS AND METHODS

We used an ELISA method to determine the levels of circulating soluble E-cadherin (sE-Cad) in 21 newly diagnosed patients with MM and in 29 healthy volunteers, as a control group.

RESULTS

MM patients demonstrated increased circulating levels of sE-Cad, compared with controls (p<0.0001). Increased circulating sE-Cad levels correlated with LDH levels at diagnosis (p<0.001) and poor prognosis. Multivariate analysis demonstrated that sE-Cad levels are an independent prognostic factor of survival (p<0.0207).

CONCLUSION

Our data suggest that adhesion molecules play a role in the pathogenesis of MM, establish sE-Cad as an independent marker of survival and, finally, provide evidence of non-epithelial production of E-Cad in MM patients.

Dietary and lifestyle factors in relation to plasma insulin-like growth factor I in a general population sample

There is evidence that the insulin-like growth factor system (IGF), particularly IGF-I, is important in human carcinogenesis. We studied in a general, though not strictly random population sample of 620 adults, the relationship of IGF-I to demographic, lifestyle and dietary factors, the latter ascertained through an extensive validated questionnaire. Plasma IGF-I levels declined significantly with age and the decline was more evident among women than among men. Tobacco smoking, body mass index and regular physical activity were unrelated to this hormone and a positive association with height was not statistically significant. Neither protein nor carbohydrate intake was related to plasma IGF-I levels but there was inconsistent evidence that ethanol intake may be inversely associated with plasma IGF-I and saturated and polyunsaturated lipids may be positively associated with it. The findings are evaluated in conjunction with evidence indicating that the incidence of cancer is lower among women than among men, height is a risk factor for several forms of cancer, and saturated and polyunsaturated lipids have been more closely linked to human and animal carcinogenesis than monounsaturated lipids.

Clinical significance of serum and urinary c-erbB-2 levels in colorectal cancer

In this study we measured serum and urinary c-erbB-2 levels in 63 patients with colorectal cancer and 29 healthy controls, assessing their role in cancer-specific survival and the effects of resectional surgery. Serum and urinary c-erbB-2 levels were measured by an enzyme-linked immunosorbent assay, preoperatively and 7 days following tumor resection. Preoperative serum c-erbB-2 concentrations were significantly higher in the cancer patients and correlated with disease stage and the presence of liver metastases. Urinary c-erbB-2 was detected more often in cancer patients, although levels did not differ from controls and there was no association with any clinicopathological variable. Serum c-erbB-2 levels decreased significantly in those patients resected for cure and were an independent prognostic factor for cancer-specific survival with higher preoperative concentrations correlating with worse overall survival. These findings suggest that serum assessment of c-erbB-2 concentration may be valuable in defining colorectal cancer prognosis.

Clinical significance of preoperative serum vascular endothelial growth factor levels in patients with colorectal cancer and the effect of tumor surgery

BACKGROUND

Vascular endothelial growth factor (VEGF) is an angiogenic cytokine involved in the progression of solid tumors. In this study we evaluated the clinical usefulness of preoperative serum VEGF concentrations in patients with colorectal cancer. The changes in serum VEGF levels after tumor surgery were also evaluated.

METHODS

Serum VEGF levels were determined by an enzyme-linked immunosorbent assay in the sera of 61 healthy control subjects and 67 patients with colorectal cancer preoperatively and 7 and 30 days after surgery.

RESULTS

Serum VEGF levels in patients with colorectal cancer (median, 492 pg/mL; interquartile range, 281 to 737 pg/mL) were higher (P <.0001) than in control subjects (median, 186 pg/mL; interquartile range, 100 to 273 pg/mL). There was a significant association between serum VEGF levels and disease stage, invasion depth of the tumor, the presence of lymph node and distant metastases, and the degree of differentiation. Curative but not palliative resection of the primary tumor resulted in a significant decrease of preoperative serum VEGF levels but normalized in only 72% of patients. Failure of a return of VEGF to normal after resection for cure was associated with an increased although not statistically significant risk of metastasis during follow-up. Univariate analysis showed a lower survival rate for patients with increased preoperative serum VEGF levels (P <.002). Multivariate regression analysis showed that the prognostic value of serum VEGF level was not independent of tumor stage.

CONCLUSIONS

These findings suggest that VEGF plays an important role in tumor progression and the formation of distant metastases in colorectal cancer. It is at present unclear whether serial estimation of serum VEGF is clinically useful in the prediction of tumor relapse.