LEP and neoplasm: Additionally, female sex (Beta 0.619; p < 0.0001), BMI (Beta −0.472; p = 0.011), distal third tumour location (Beta 0.786; p < 0.0001), advanced T stage (Beta −0.962; p < 0.0001), early N stage (Beta 0.649; p = 0.003), perioperative therapy (−0.859; p = 0.001), low/high tumour grade (Beta 0.596; p < 0.0001), perineural invasion (Beta 0.572; p = 0.001), Lauren diffuse histological type (Beta 0.691; p < 0.0001), absence of ulceration (Beta −0.251; p = 0.027), and distal resection margin (Beta 1.362; p < 0.0001) were associated significantly with the relative serum levels of leptin on day seven.