The discovery of the lymphatic system has a long and fascinating history. The interest in anatomy and physiology of this system paralleled that of the blood cardiocirculatory system and has been maybe obscured by the latter. Paradoxically, if the closed blood system appeared open in Galen's anatomy and physiology, and took a very long time to be correctly described in terms of pulmonary and general circulation by ibn Al‐Nafis/Michael Servetus/Realdo Colombo and William Harvey, respectively, the open lymphatic system was incorrectly described as a closed circuit connected with arteries and veins. In ancient times only macroscopic components of the lymphatic system have been described, although misinterpreted, including lymph nodes and lacteals, the latter being easily identified because of their milk‐like content. For about 15 centuries the dogmatic acceptance of Galen's notions did not allow a significant progress in medicine. After Vesalius’ revolution in anatomical studies, new knowledge was accumulated, and the 17th century was the golden age for the investigation of the lymphatic system with several discoveries: gut lacteals (Gaspare Aselli), cloacal bursa (Hieronimus Fabricius of Acquapendente), reservoir of the chyle (Jean Pecquet), extra‐intestinal lymphatic vessels (Thomas Bartholin and Olaus Rudbeck dispute), hepatic lymph circulation (Francis Glisson). In the Enlightenment century Frederik Ruysch described the function of lymphatic valves, and Paolo Mascagni provided a magnificent iconography of the lymphatic network in humans. In recent times, Leonetto Comparini realized three‐dimensional reconstructions of the liver lymphatic vessels, and Kari Alitalo discovered the lymphatic growth factor/receptor system. Far from a complete understanding of its anatomy and function, the lymphatic system still needs to be profoundly examined.

To evaluate UFT and cyclophosphamide (CTX) based metronomic chemotherapy plus celecoxib (CXB) for the treatment of patients with heavily pre-treated advanced gastrointestinal malignancies. Thirty-eight patients received 500 mg/mq2 CTX i.v bolus on day 1 and, from day 2, 50 mg/day CTX p.o. plus 100 mg/twice a day UFT p.o. and 200 mg/twice a day CXB p.o. Tegafur, 5-FU, 5-FUH2, GHB and uracil pharmacokinetics were assessed. Plasma vascular endothelial growth factor (VEGF), soluble VE-cadherin (sVE-C) and thrombospondin-1 (TSP-1) levels were detected by ELISA and real-time PCR of CD133 gene expression on peripheral blood mononuclear cell was also performed. Seventeen patients (45%) obtained stable disease (SD) with a median duration of 5.8 ms (range, 4.2–7.4). Median progression free survival (PFS) and overall survival (OS) were 2.7 ms (95% CI, 1.6–3.9 ms) and 7.1 ms (95% CI, 4.3–9.9 ms), respectively. No toxicities of grade >1 were observed. Pharmacokinetics of 27 patients (13/14, SD/progressive disease, PD) after the first treatment of UFT revealed that 5-FU AUC and Cmax values greater than 1.313 h × μg/ml and 0.501 μg/ml, respectively, were statistically correlated with stabilization of disease and prolonged PFS/OS. VEGF and sVE-C plasma levels were greater in the PD group when compared to SD group. CD133 expression increased only in the PD patients. Metronomic UFT and CTX with CXB in heavily pre-treated gastrointestinal patients were well tolerated and associated with interesting activity. Potential predictive pharmacokinetic parameters and pharmacodynamic biomarkers have been found.