LEP and cancer: On the other hand, higher serum leptin was inversely associated with cancer death in women with or without general obesity, for example, HR among women with BMI <30 kg/m2 was 0.76 (95% 0.44–1.32) and 0.30 (0.14–0.65) for moderate and high levels compared to low leptin, respectively (Ptrend = 0.003).