Serum 25-hydroxyvitamin D and nasopharyngeal carcinoma risk and survival: a hospital-based matched prospective case-control study in Malaysia

Abstract Serum 25(OH) D deficiency may be one of the underlying molecular mechanisms through which chronic inflammation is associated with risk and survival of nasopharyngeal carcinoma (NPC). This study was conducted to determine the association between serum 25(OH) D and NPC risk and survival. A multi-centric case-control study was conducted from two local hospitals. A total of 300 histologically confirmed NPC cases were matched with controls for age, gender and ethnicity and assessed for vitamin D status and other factors. Mean serum 25(OH) D was significantly lower in NPC patients compared with controls (25.3 ± 7.7 ng/mL vs. 27.0 ± 9.2 ng/mL, p = 0.016). Multiple logistic regression analysis indicated that higher levels of serum 25(OH) D was associated with reduced odds of NPC (AOR = 0.73, 95% CI = 0.57–0.94) controlling for confounders including BMI, physical activity, smoking status, alcohol consumption, consumption of food high in vitamin D, salted fish consumption and family history of NPC. There was a significant association between insufficient serum 25 (OH) D status with accumulation of four risk factors and increased odds of getting NPC using fractional polynomial analysis. Increased NPC odds was observed after accumulation of second risk factors with presence insufficient serum 25 (OH) D status (OR = 0.54, 95% CI = 0.27, 4.77, OR = 1.04, 95% CI = 0.64, 1.72, OR = 1.15, 95% CI = 0.73, 1.80, OR = 1.93, 95% CI = 1.13, 3.31, and OR = 5.55, 95% CI = 1.67, 10.3 respectively). The 5-year survival rates were 51.0%, 57.0% and 43.0% for serum 25(OH) D deficiency, insufficiency and sufficient respectively. These findings highlight the potential preventive benefits of maintaining higher levels of serum 25(OH) D in mitigating NPC risk, though further research is needed to explore its impact on survival outcomes.