The CancerWeb Report, What's New In Cancer: February, 1997
Cancer in General

• A more potent drug to treat high blood calcium levels in cancer patients - Cancer patients frequently develop high blood calcium levels. These are caused either by the action of a substance released by tumors that resembles the normal parathyroid hormone, or by destruction of bone by the spread of tumor metastases. Although media advertisements stress that calcium is something your body needs anyway, too much in the form of high blood levels can cause a variety of very serious problems, including heart function irregularities, and kidney and lung damage. Two phosphorus-containing drugs, pamidronate (the more active) and clodronate, have been the principle ones used to treat this condition. European researchers in Scotland, Germany, Switzerland, England, Sweden, France and Belgium reported on a new related compound ibandronate, which is 50-times more potent than pamidronate, in the February, 1997 issue of the British Journal of Cancer. A single 2-hour intravenous infusion of 4 or 6 mg of the drug normalized blood calcium in about three-quarters of 147 patients studied, beginning at 2 days, with maximum reduction at 5 days, and lasting up to 36 days in 25% of patients. There were no serious drug-related side-effects. (Ralston, Br J Cancer 75:295, 1997)

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• Improved test for sensitivity to chemotherapy - Chemotherapy is typically accompanied by serious side-effects, but does not always provide benefits sufficient to justify its use. From the beginnings of cancer chemotherapy, clinicians and researchers have looked for ways of predicting whether responses to individual drugs were likely so as both to spare patients needless side-effects of ineffective drugs, and to direct their treatment immediately to the most promising therapy. Unfortunately, the various tests that have been developed had drawbacks and problems that severely limited their usefulness. Among the earlier tests, which this editor himself has used, is the uptake of radioactive thymidine by isolated cells - it also has defects. An article by researchers at Fukui Medical School in Japan, appearing in the February, 1997 issue of Clinical Cancer Research, describes improvements to this test that increase its predictive value. They added a preculture phase in which the tumor cells grew and adhered to the surface of collagen-coated flasks. This extra step increased uptake of thymidine into cell DNA and raised the evaluability of the test from 49% to about 76%. When the sensitivity of the isolated tumor cells to chemotherapy was compared with the clinical response in 16 patients, the test showed an overall predictive correlation of 92%. (Kitaoka, Clin Cancer Res 3:295, 1997)

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• Mistletoe immunoprotective in treated cancer patients? - Treatment of cancer by radiation or chemotherapy very often leads to reduced immune system function, and this may occur after surgery also. Depressed immune function may not only reduce quality of life through increased susceptibility to infections, but also may affect any possible innate antitumor action against residual cancer cells. A body of research carried out principally in Europe, suggests that components extracted from mistletoe, principally substances known as lectins, may act as immune stimulants. One such report from the University of Cologne, Germany, appeared in the December, 1996 issue of Anticancer Research. In patients with brain cancers (Stage III/IV gliomas), treatment by the normal procedure of surgery, radiotherapy and dexamethasone, produced marked reductions in lymphocytes and their various subsets (CD-3, CD-4, CD-8, CD-25), and natural killer cells, major cell types involved in the immune response. Those treated twice weekly for 3 months with subcutaneous injections of a standardized mistletoe lectin (ML-1; Eurixor) had levels of various immune cells equal to or greater than the pretreatment values. There may be something here that needs more intensive study. (Lenartz, Anticancer Res 16:3799, 1996)