Maria-Jose Sánchez

Metabolically Defined Body Size Phenotypes and Risk of Endometrial Cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Abstract Background: Obesity is a risk factor for endometrial cancer but whether metabolic dysfunction is associated with endometrial cancer independent of body size is not known. Methods: The association of metabolically defined body size phenotypes with endometrial cancer risk was investigated in a nested case–control study (817 cases/ 817 controls) within the European Prospective Investigation into Cancer and Nutrition (EPIC). Concentrations of C-peptide were used to define metabolically healthy (MH; <1st tertile) and metabolically unhealthy (MU; ≥1st tertile) status among the control participants. These metabolic health definitions were combined with normal weight (NW); body mass index (BMI)<25 kg/m2 or waist circumference (WC)<80 cm or waist-to-hip ratio (WHR)<0.8) and overweight (OW; BMI≥25 kg/m2 or WC≥80 cm or WHR≥0.8) status, generating four phenotype groups for each anthropometric measure: (i) MH/NW, (ii) MH/OW, (iii) MU/NW, and (iv) MU/OW. Results: In a multivariable-adjusted conditional logistic regression model, compared with MH/NW individuals, endometrial cancer risk was higher among those classified as MU/NW [ORWC, 1.48; 95% confidence interval (CI), 1.05–2.10 and ORWHR, 1.68; 95% CI, 1.21–2.35] and MU/OW (ORBMI, 2.38; 95% CI, 1.73–3.27; ORWC, 2.69; 95% CI, 1.92–3.77 and ORWHR, 1.83; 95% CI, 1.32–2.54). MH/OW individuals were also at increased endometrial cancer risk compared with MH/NW individuals (ORWC, 1.94; 95% CI, 1.24–3.04). Conclusions: Women with metabolic dysfunction appear to have higher risk of endometrial cancer regardless of their body size. However, OW status raises endometrial cancer risk even among women with lower insulin levels, suggesting that obesity-related pathways are relevant for the development of this cancer beyond insulin. Impact: Classifying women by metabolic health may be of greater utility in identifying those at higher risk for endometrial cancer than anthropometry per se.

Thyroid hormones and epithelial ovarian cancer risk and survival: results from the European Prospective Investigation into Cancer and Nutrition study

Abstract Background Thyroid-stimulating hormone (TSH) and thyroid hormones (free triiodothyronine [fT3] and free thyroxine [fT4]) may influence cancer outcomes, but evidence for ovarian cancer is limited. Methods We conducted a nested case–control study comparing 578 epithelial ovarian cancer (EOC) cases with matched controls within the European Prospective Investigation into Cancer and Nutrition (EPIC). To examine associations between circulating TSH, fT3, and fT4 levels and EOC risk, we estimated risk ratios (RRs) and 95% confidence intervals (CIs) per SD using conditional logistic regression. Among cases, we evaluated all-cause and EOC-specific survival by prediagnostic hormone levels. Hazard ratios (HRs) and 95% confidence intervals were calculated using multivariable Cox regression. We also estimated covariate-adjusted restricted mean survival time (RMST) and survival probabilities at 5 and 10 years. Results Thyroid hormones were not associated with EOC risk (RR [95% CI] per SD increase: TSH = 0.99 [0.87 to 1.12], fT3 = 1.12 [0.70 to 1.79], and fT4 = 1.08 [0.56 to 2.07]) levels. However, higher TSH levels were associated with better survival (HR [95% CI] per SD: all-cause death = 0.90 [0.82 to 0.99], EOC-specific = 0.88 [0.79 to 0.97]), whereas higher fT4 levels were associated with worse survival (all-cause = 1.10 [1.00 to 1.22], EOC-specific = 1.17 [1.05 to 1.30]), but no association for fT3. RMST and survival probabilities showed similar patterns: for TSH, 10-year RMST and survival increased from 5.3 years and 42.2% in Quartile 1 (Q1) to 6.4 years and 50.7% in Q4. Conversely, for fT4, 10-year RMST declined from 5.6 years (Q1) to 5.1 years Q4, and survival from 46.3% to 37.8%. Conclusion TSH and thyroid hormones might not affect ovarian cancer risk. However, high fT4 and low TSH concentrations may be associated with poorer survival. Further evaluation is suggested in other populations.