The role of hyperthermia in regional alkylating agent chemotherapy.

The role of hyperthermia during regional alkylating agent chemotherapy is controversial. The aim of this study was to determine the exact contribution of hyperthermia to tumor response during isolated limb infusion with l-phenylalanine mustard. Rats bearing rodent fibrosarcoma on the hindlimb underwent isolated limb infusion with saline, saline plus heat, l-phenylalanine mustard, l-phenylalanine mustard under conditions of normothermia, or l-phenylalanine mustard plus hyperthermia. Heat was administered locally using an in-line hot water circulation loop. Treatment with l-phenylalanine mustard at a concentration of 15 or 50 micrograms/mL was ineffective at producing tumor growth delay (P = 0.24 and 0.41, respectively). Furthermore, thermal enhancement of l-phenylalanine mustard activity was not seen at 15 micrograms/mL. However, administration of high-dose l-phenylalanine mustard, 50 micrograms/mL, with increasing amounts of heat yielded increasing tumor growth delay, increased regressions, and decreased proliferative index. Although l-phenylalanine mustard infusion under normothermia yielded a tumor growth delay of 7.1 days, combination l-phenylalanine mustard + hyperthermia treatment produced tumor growth delay of 27.0 days (P < 0.01; with two of five animals showing a complete response). Four hours after isolated limb infusion, 50.9% of cells in tumor treated with l-phenylalanine mustard + hyperthermia experienced apoptosis, whereas only 18.1, 16, and 4.4% of cells underwent apoptosis after treatment with l-phenylalanine mustard, saline + hyperthermia, or saline. The mean concentration of l-phenylalanine mustard within tumor relative to perfusate following isolated limb infusion was found to be similar among all groups at 0.023, 0.025, and 0.032 in animals undergoing isolated limb infusion with l-phenylalanine mustard, l-phenylalanine mustard + normothermia, and l-phenylalanine mustard + hyperthermia, respectively. These data indicate a synergistic cytotoxic effect of l-phenylalanine mustard + hyperthermia in isolated limb infusion, which is not attributable to enhanced tumor drug uptake.

Extensive investigation of patients with mild elevations of serum amylase and/or lipase is 'low yield'.

BACKGROUND: Serum amylase and lipase levels are widely used as markers of pancreatic inflammation. However, it would seem that mild elevations of amylase and lipase rarely predict significant pancreatic pathology. Pancreatic imaging tests are expensive. The gold standard, endoscopic retrograde cholangiopancreatography, carries risk of morbidity and mortality. OBJECTIVE: To determine whether extensive investigation of patients with mild, nonspecific abdominal symptoms and mild elevations of amylase and/or lipase results in a significant diagnostic yield. METHODS: Outpatient evaluations were retrospectively analyzed over 12 months. Inclusion criteria were nonspecific abdominal pain, and mild elevations (less than three times the upper limit of normal) of serum amylase or lipase, or both. Exclusion criteria included a history of chronic pancreatitis, elevation of liver tests and acute pain syndromes. RESULTS: Nineteen patients over the study period met the criteria. Of the nineteen patients, 58% had elevation of lipase alone, 21% amylase alone and 21% had elevations of both. In addition, 89.5% of the patients had nonspecific abdominal pain. After imaging with one or more of ultrasound, computed tomography, magnetic resonance cholangiopancreatography, endoscopic ultrasound and endoscopic retrograde cholangiopancreatography, small bowel follow through or hepatobiliary scanning, 78.9% patients were thought to have a normal pancreas. Of the remaining patients, 15.8% had mild or equivocal changes of chronic pancreatitis, and one patient was found to have a pancreatic tail pseudocyst. The average cost of investigation was US$2,255, taking only direct procedural costs into account. No patient was found to have malignancy. CONCLUSIONS: The majority of patients with nonspecific abdominal pain and isolated elevations of amylase and/or lipase (less than three times the upper limit of normal) had no identifiable pancreatic pathology. The diagnostic yield in patients with mild elevations of lipase alone was particularly poor. The cost effectiveness and risk-benefit ratio of extensive investigation of this group of patients warrants further study.