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Association between renal tubular cell dysfunction and increased urinary zinc excretion in cancer patients

Although an increase in renal zinc excretion in cancer patients is well documented, the mechanisms involved are still disputed. As recent studies have raised the question of the role of renal tubular cell dysfunction in the elevation of urinary zinc output, we have examined urinary zinc excretion and the excretion of N-acetyl-beta-D-glucosaminidase (NAG), an indicator of tubular cell dysfunction, in 30 patients with cancer, 28 healthy controls and 20 patients with benign non-inflammatory disorders. As expected, urinary zinc excretion was significantly higher in the cancer patients compared with controls and patients with benign disorders (2.64 +/- 3.05 vs. 0.86 +/- 0.36 and 0.89 +/- 0.29 mmol mol creatinine-1, p < 0.001). NAG activity was also elevated (18.9 +/- 20.1 vs. 4.32 +/- 3.33 and 9.99 +/- 9.72 mukat mol creatinine-1, p < 0.001 and p < 0.05, respectively). A significant correlation between urine zinc and NAG was observed in all three groups (rho = 0.73, p < 0.001, rho = 0.55, p < 0.01 and rho = 0.45, p < 0.05, respectively). In conclusion, our data provide additional support for the role of renal tubular cell dysfunction in hyperzincuria in cancer. Urinary zinc measurement may represent an alternative approach to detecting renal tubular dysfunction in human pathology.

HEPATIC ARTERIAL INFUSION CHEMOTHERAPY IN GASTRIC CANCER: A REPORT OF FOUR CASES AND ANALYSIS OF THE LITERATURE

Aims and background Gastric cancer is associated with high mortality. Although the liver is a common site of metastases in this tumor, the experience with liver-directed therapies is limited. Methods We report a single-center experience involving four patients with liver metastases from gastric cancer treated by hepatic arterial infusion (HAI). In addition, we performed a search for reports on HAI in gastric cancer metastatic to the liver and used the studies with data on survival of individual patients for a pooled analysis. Results Among three valuable patients, one had a complete response, one had stable disease and one had progressive disease. The patient with complete response is still alive 41 months after the diagnosis of liver metastases, while the other patients died 6, 22 and 31 months after the diagnosis. Objective responses were observed in 48% of the 25 patients in the pooled analysis. Objective response and limited hepatic involvement were independent predictors of survival in these patients. Conclusions Although isolated liver involvement in metastatic gastric cancer is rare, HAI seems to be similarly effective in these patients as in patients with liver metastases from colorectal cancer. The prognosis is significantly better in gastric cancer patients who have limited hepatic involvement and attain an objective response after HAI.

Urinary zinc excretion and acute phase response in cancer patients

We investigated urinary zinc and serum levels of C-reactive protein, alpha-1 acid glycoprotein, haptoglobin, transferrin and prealbumin in 55 patients with solid tumors and 20 controls. Urinary zinc, serum C-reactive protein, alpha-1 acid glycoprotein and haptoglobin were significantly higher, and serum prealbumin was significantly lower in cancer patients. A significant positive correlation between urinary zinc and C-reactive protein, alpha-1 acid glycoprotein and haptoglobin, as well as a negative correlation with transferrin and prealbumin were observed. Hyperzincuria in cancer patients appears to be linked to the acute phase response. Our data provide further evidence implicating systemic inflammatory response in increased urinary zinc excretion.