The CancerWeb Report, What's New In Cancer: July, 1996
Ovarian Cancer

• A new gene therapy strategy in sight? - One of the potential new strategies for cancer treatment involves the use of gene therapy, in this case, the insertion of genetic material into the tumor to make it more sensitive to chemotherapy. A brief report in the July, 1996 issue of Clinical Cancer Research describes a modification of this approach used in isolated human ovarian cancer cells. The erb-2 gene, when overexpressed, increases the resistance of tumor cells to chemotherapy by altering the cell surface. A group of researchers at the University of Alabama in Birmingham, used an anti-erb-2 gene carried by a virus that could infect the cells and neutralize the effect of the increased erb-2 activity they contained. As a result, there was a great increase in sensitivity of the cells to cisplatin, a drug that is widely used to treat ovarian cancer. While still far from practical clinical use, this experimental work does demonstrate one of the many ways in which the potentials of gene therapy may eventually be exploited. (Barnes, Clin Cancer Res 2:1089, 1996)

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• Protection against side effects of chemotherapy with amifostine - Patients with cancer frequently fear the side-effects of chemotherapy almost as much as the disease itself, and with reason, since many of these adverse effects may be serious, even life-threatening. While many measures can be taken to prevent or minimize the side-effects, in some cases there is a distinct possibility, or even a high probability, that these protective measures may reduce the efficacy of the treatment. A multi- institutional study from groups around the US, reported in the July, 1996 issue of the Journal of Clinical Oncology that pretreatment with 910 mg/m2 of an organic thiophosphate compound, amifostine, significantly reduced the hematologic, renal (kidney), and neurologic side-effects of two major drugs used to treat ovarian cancer, cyclophosphamide (Cytoxan) and cisplatin. This occurred without any diminution in antitumor effect, since the response rate was 37% in the amifostine group compared with 28% in the group not pretreated, with identical median survival of 31 months. (Kemp, J Clin Oncol 14:2101, 1996)

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• Optimal dosage of cisplatin - Trials seeking to establish an appropriate dosage level for cisplatin in ovarian cancer have not been in agreement, in part because they have not established whether the total dose given rather than the dose intensity (dose per treatment) is critical. An article appearing in the July, 1996 issue of the Journal of Clinical Oncology, from the Scottish Gynecology Cancer Trials Group, is a follow-up to an earlier report on the same trial which had showed a significant advantage of high-dose cisplatin. These patients were given six cycles of chemotherapy involving 750 mg/m2 of cyclophosphamide with 50 (LD) or 100 mg/m2 (HD) of cisplatin. Four years and 9 months later, 115 of the 159 cases with advanced ovarian cancer are dead. Overall survival is 32.4% for HD and 26.6% for LD, but toxicity, especially neurologic problems are still prevalent at 10/31 of the HD group, while only 1/24 shows these side-effects in the LD group. The authors recommend a dose of 75 mg/m2 as a reasonable compromise of efficacy and potential toxicity. (Kaye, J Clin Oncol 14:2113, 1996)