Does total parenteral nutrition (TPN) really promote tumor growth? A morphometric study

An experimental study was undertaken to evaluate the effects of total parenteral nutrition (TPN) on tumor growth in rats. Sato lung cancer was transplanted subcutaneously in male Donryu rats. Two weeks after inoculation, experimental animals were divided into three groups: Group I (5% G); Group II (21% G, 4% A.A; TPN) received intravenous infusion through cervical vein; Group III rats were maintained on a regular diet. All of the animals were killed on the eighth day. There was a significant increase in tumor volume and tumor weight in both G-II (7.3 +/- 3.9 cm3, 8.7 +/- 6.3 g) and G-III (7.4 +/- 4.6 cm3, 9.7 +/- 5.4 g), as compared with G-I (3.3 +/- 1.4 cm3, 3.7 +/- 1.9 g). In morphometric studies, an average area of tumor cell in G-II was 267 +/- 172 microns2, being significantly larger than in G-I (195 +/- 95 microns2) or G-III (185 +/- 93 microns2). The nuclear diameter of tumor cell was 9.9 +/- 2.2 microns in G-II, 9.2 +/- 1.9 micron in G-III, and 8.5 +/- 1.5 micron in G-I, respectively. Total water balance throughout the experimental period was +84.0 +/- 14.5 ml/100 g BW in G-II, +86.3 +/- 8.2 ml/100 g BW in G-III, and +44.8 +/- 22.5 ml/100 g body weight in G-I, respectively. Increased tumor volume and tumor weight found in G-II may not be due to hyperplasia of each tumor cell, but rather due possibly to water retention in tumor tissue.