Adjuvant treatment with chemotherapeutic agents and polyadenylic-polyuridylic acid in operable stomach cancers. I. Enhancement of natural killer cell activity

Nutritional pharmacology and malignant disease: a therapeutic modality in patients with cancer

It is now established that certain nutrients have a significant effect on cellular metabolism and growth, tissue repair and regeneration, and modulation of host defences. So far, however, potential clinical benefits have been difficult to demonstrate. Nevertheless, the use of nutrients in combinations seems to have promise and may be associated with a reduction in infectious complications and length of hospital stay. Nutritional pharmacology in the future may be able to improve tumour response to chemotherapy and may minimize the metabolic effect of cachexia.

Polyadenylic-polyuridylic acid enhances the natural cell-mediated cytotoxicity in patients with breast cancer undergoing mastectomy

BACKGROUND

Surgical procedures suppress host antitumor defense mechanisms, which may increase the risk of metastatic tumor dissemination. We have evaluated the effects of the biologic response modifier polyadenylic-polyuridylic acid (PAPU) on natural cytotoxicity in patients with breast cancer undergoing operation.

METHODS

PAPU (150 mg) or placebo was given intravenously during the perioperative period (preoperative, days -1 and 0; postoperative, days 1, 3, 5, 7, and 14). The function (chromium release assay) and number (flow cytometry) of natural killer (NK) cells were measured before operation (days -2 and -1), on the day of operation (day 0), and after operation (days 1, 2, 4, 6, and 18).

RESULTS

Surgical procedures suppressed NK cell cytotoxicity in the placebo group on postoperative days 1 (p < 0.001), 4, 6, and 18 (p < 0.05), whereas inhibition on postoperative day 2 failed to reach significance. PAPU abolished this immunosuppression after operation. The NK cell activity was elevated when compared with the control group; it was significant (p < 0.05) on postoperative days 1, 2, 4, 6, and 18. Surgical procedures also reduced circulating NK cell numbers during the first postoperative week in the placebo group; the decrease was statistically significant on day 4. The decrease in NK cell numbers in the PAPU group was insignificant.

CONCLUSIONS

PAPU prevented the decrease in the circulating number and cytotoxic activity of NK cells that occurred after operation and enhanced NK cell cytotoxicity. This may have important implications for patients with cancer undergoing major operation.

Nutrition and malignant disease: implications for surgical practice

Malignant disease is often associated with weight loss and malnutrition. Nutritional support is frequently provided to patients with cancer in an attempt to improve nutritional status and reverse weight loss, with the aim of reducing morbidity and mortality rates. This review evaluates the effect of supplemental nutrition on morbidity and mortality in patients with malignancy undergoing treatment with surgery, chemotherapy or radiotherapy. It also assesses the effect nutritional supplementation has on host defence mechanisms and how nutrients affect tumour cell growth. The evidence suggests that perioperative nutritional support, if given for at least 10 days, reduces morbidity and mortality in patients with biochemical evidence of severe malnutrition, manifest as a low serum albumin concentration and excessive weight loss. In contrast, there is no evidence that parenteral nutritional support benefits patients undergoing chemotherapy or radiotherapy, in terms of either an increased tumour response rate or prolongation of survival. Current research on malignant disease is highlighting the role of specific nutrients (amino acids, essential fatty acids and polyribonucleotides) as key regulators of both anticancer host defence mechanisms and the control of nitrogen metabolism and tumour growth. Arginine, essential fatty acids and ribonucleotides have all been demonstrated to stimulate antitumour host defence mechanisms and some also modulate tumour cell metabolism. Dietary manipulation offers exciting possibilities for the innovative management of malignant disease.