A multi-center case-control study on osteoporosis risk in cancer patients receiving chemotherapy.

12033 Background: Chemotherapy and cancer can worsen osteoporosis, a growing concern with improved cancer survival rates. This study aimed to assess osteoporosis risk in chemotherapy patients versus healthy individuals and identify predictive factors. Methods: This multi-center case-control study included 257 chemotherapy-treated cancer patients and 257 age- and gender-matched controls (1:1) using propensity score matching. Exclusions included recent alcohol use, severe organ impairments, endocrine disorders, specific treatments (estrogen, progesterone, glucocorticoids, bisphosphonates, calcium supplements), and cancer-related bone conditions. Bone mineral density (BMD) at the femur and lumbar spine (L1-L4) was measured via dual-energy X-ray absorptiometry (DXA), with T-scores categorized as normal (T ≥ −1.0), osteopenia (−2.5 < T < −1.0), or osteoporosis (T ≤ −2.5).Statistical analyses were performed using SPSS 24.0, with t-tests, Mann-Whitney U tests, and regression analysis (p<0.05). Results: The study included 174 females and 83 males (median age 59) in both groups. Of cancer patients, 112 had breast, 54 had colorectal, 39 had upper gastrointestinal, 32 had lung, and 20 had gynecological cancer. Among cancer patients, 35.8% had osteopenia, and 21.0% had osteoporosis in lumbar vertebrae, compared to 15.2% and 2.3% in controls (p<0.001). For total femur, 28.0% had osteopenia, and 5.8% had osteoporosis in cancer patients, versus 16.3% and 1.2% in controls (p<0.001). Median lumbar BMD was 0.90 g/cm² in cancer patients and 1.22 g/cm² in controls (p<0.001); median femur BMD was 0.89 g/cm² and 0.98 g/cm², respectively (p<0.001). No correlation was found between osteoporosis and cancer stage. Breast cancer had the highest normal BMD (51.2%) but shared the highest osteoporosis rate (31.5%) with colorectal cancer. Gastric cancer showed the highest osteoporosis rate for femur BMD (33.3%, p=0.024). Vitamin D deficiency (<12 ng/mL) was more common in cancer patients (50.6% vs. 18.1%) and linked to reduced bone density (p=0.009). BMI was a significant predictor of osteoporosis (<0.001), with higher BMI protective; obesity (BMI >30) was more frequent in controls (50.2%) than cancer patients (26.9%).Serum creatinine, alkaline phosphatase, calcium, and phosphate levels were similar in groups, with no link to osteoporosis. Logistic regression showed cancer increased osteoporosis risk 6.8-fold (p<0.001, 95% CI: 4.024–11.494). BMI was protective, reducing odds by 4.5% per unit increase (p=0.036, 95% CI: 0.915–0.997). Conclusions: Lumbar osteoporosis and osteopenia were 9.1 and 2.3 times more common in cancer patients, with lumbar and femur BMD reduced by 26.2%and 9.2%, compared to controls. Cancer type and Vitamin D levels are key predictors of osteoporosis. Addressing bone health in cancer patients is crucial for improving quality of life and reducing osteoporosis burdens. Future research on survival, fracture risks, and outcomes will inform proactive bone health management.