Objective: To examine the casual association between age at first sexual intercourse and gynecologic malignant tumors using Mendelian randomization (MR) approach. Methods: The single nucleotide polymorphisms (SNPs) associated with age at first sexual intercourse were obtained from a meta-analysis of genome-wide association study (GWAS), and the SNPs related to gynecologic malignant tumors (ovarian cancer, endometrial cancer, cervical cancer), and their subtypes were sourced from the IEU OpenGWAS database. Using age at first sexual intercourse as the exposure and gynecologic malignant tumors as the outcome, a MR analysis was performed with the inverse-variance weighted (IVW) method. Heterogeneity was assessed using Cochran's Q test, horizontal pleiotropy was evaluated using MR-Egger regression and MR-PRESSO test, and bias was examined using funnel plots. Results: The Mendelian randomization analysis demonstrated that younger age at first sexual intercourse was significantly associated with an increased risk of low-grade serous ovarian carcinoma (OR=0.553, 95%CI: 0.335-0.911), cervical cancer (OR=0.674, 95%CI: 0.466-0.974), endometrial cancer (OR=0.854, 95%CI: 0.730-0.999), and endometrioid carcinoma (OR=0.830, 95%CI: 0.690-0.998). No statistical association was found between the age at first sexual intercourse and ovarian cancer, high-grade serous ovarian cancer, mucinous ovarian cancer, endometrioid ovarian cancer, or non-endometrioid ovarian cancer (all P>0.05). Sensitivity analysis showed no evidence of undetected instrumental variable heterogeneity or horizontal pleiotropy (all P>0.05), and the funnel plot indicated no presence of bias. Conclusion Younger age at first sexual intercourse may be associated with an increased risk of certain gynecologic malignant tumors, highlighting the need to strengthen adolescent sex education.

Objective To investigate the predictive value of the C-reactive protein to albumin ratio (CAR) combined with grip strength and serum prealbumin for survival and malnutritionin patients with esophageal cancer. Methods A total of 212 patients with esophageal cancer were selected as study objects, and baseline characteristics, pretreatment CAR, grip strength, and serum prealbumin results were collected. Nutritional status was assessed, and overall survival was followed up. Receiver operating characteristic (ROC) curves were used to evaluate the predictive value of pretreatment CAR, grip strength, and serum prealbumin for malnutrition. Kaplan-Meier survival curves and Cox regression models were employed to analyze their predictive value for survival outcomes. Results ROC curve analysis revealed that grip strength had the largest area under the curve (0.625) for predicting malnutritionin esophageal cancer patients, followed by serum prealbumin and CAR (0.604, 0.594). Based on the Youden index, the optimal cut-off values for CAR, grip strength, and serum prealbumin were 0.732, 23.1 kg, and 0.190 g/L, respectively. The sensitivity of the combined detection of three indicators was 80.7%. Kaplan-Meier survival curve analysis showed that patients with elevated CAR (≥0.732), reduced grip strength (< 23.1 kg), and decreased serum prealbumin levels (< 0.190 g/L) had shorter overall survival compared to those with CAR < 0.732, grip strength ≥23.1 kg, and serum prealbumin levels ≥0.190 g/L, respectively (P < 0.01). Multivariate Cox regression analysis identified elevated pretreatment CAR (≥0.732), reduced grip strength (< 23.1 kg), and decreased serum prealbumin levels (< 0.190 g/L) as independent risk factors for poor survival prognosis in esophageal cancer patients (P < 0.05). Conclusion Pretreatment CAR, grip strength, and serum prealbumin are important indicators for assessing nutritional status and survival prognosis in esophageal cancer patients. Combined detection of these biomarkers may facilitate early diagnosis and timely intervene malnutrition, potentially improving survival outcomes in esophageal cancer patients.