LAPAROTOMY AND LAPAROSCOPY DIFFERENTIALLY ACCELERATE EXPERIMENTAL FLANK TUMOR-GROWTH

Background Surgery depresses host tumoricidal activity and may increas e tumour growth. This study compared the effects of laparoscopy with l aparotomy on extraperitoneal tumour growth and immune function in a mu rine model. Methods C57BL/6 female mice aged 8-10 weeks had tumours in duced in the right flank (n = 45) and were randomized to undergo halot hane anaesthesia only, laparoscopy or laparotomy. Flank tumour volume was assessed over 10 days. A second group of animals (n = 540) were ra ndomized to undergo the same procedures and killed at 24, 48 and 96 h. Splenocytes were harvested far natural killer (NK) cell and lymphokin e activated killer (LAK) cell cytotoxicity studies. Results There was a significant increase in flank tumour growth in the first 48 h after laparotomy and laparoscopy compared with controls (P < 0.01). By 96 h the difference was only significant in the laparotomy group (P < 0.01) . Both NK and LAK cell cytotoxicities were suppressed significantly (P less than or equal to 0.03) from 24 h up to 96 h following laparotomy compared with control and laparoscopy groups. There was also a signif icant suppression in the laparoscopy group compared with controls in t he first 48 h after operation (P less than or equal to 0.02). Conclusi on Extraperitoneal tumour growth was significantly accelerated after l aparatomy and correlated with significantly suppressed NK and LAK cyto toxicity for at least 4 days after operation. Laparoscopy had a shorte r, less profound effect on tumour growth and immune function.