Chemotherapy of advanced renal adenocarcinoma

Antitumor effect of irinotecan hydrochloride (CPT-11) on human renal tumors heterotransplanted in nude mice

BACKGROUND

There has been a paucity of antitumor drugs that are active against renal tumors. Irinotecan hydrochloride (CPT-11), a DNA topoisomerase type 1 inhibitor, has demonstrated antitumor activity against human tumors, however, no antitumor effect of CPT-11 on renal tumors has been reported. The antitumor effect of CPT-11 was investigated on 2 human renal tumors (OUR-10 and OUR-20) heterotransplanted into nude mice.

METHODS

Tumor-bearing nude mice were given daily intraperitoneal injections of multiple anticancer drugs suspended in 0.2 mL of phosphate-buffered saline (PBS) 3 times at 3-day intervals. Control mice were injected with 0.2 mL of PBS. The antitumor effects were evaluated by calculating the T/C ratio (treated tumors/controls) of the tumor volume.

RESULTS

Among the 10 anticancer drugs tested, 50 mg/kg of CPT-11 showed an active antitumor effect on OUR-20 (T/C ratio 34). However, all drugs tested on OUR-10 failed to show antitumor activity.

CONCLUSION

Since CPT-11 was effective in 1 of 2 renal tumors examined without severe toxicity, this drug could be a candidate for chemotherapy of renal cell carcinoma.

Rationale for immunotherapy of renal cell carcinoma

Metastasis to distant organs is the principal cause of death from renal cell carcinoma (RCC). No commonly accepted therapy is available for disseminated RCC at present. Immunotherapy is a mode of therapy that either interferes with the immune system or makes use of drugs that have been derived from soluble mediators of the immune system. Several lines of evidence suggest that combinations of genetically engineered cytokines (e.g. interleukin-2 and interferon alpha) may be particularly active in the treatment of advanced RCC. There are two major rationales for considering immunotherapy for RCC: (1) there is currently no other therapy available, and (2) there is hardly any innovative approach besides immunotherapy. Still, immunotherapy is far from being a standard therapy for disseminated RCC.

Deoxyribonucleic acid content and medroxyprogesterone acetate treatment in metastatic renal cell carcinoma

High dose medroxyprogesterone treatment was given to 20 patients with metastatic renal cell carcinoma. Distant metastases occurred before the perifascial nephrectomy in 11 patients and following nephrectomy in 9. Tumor deoxyribonucleic acid content was analyzed by flow cytometry in 8 fresh samples from each primary tumor. Four patients had homogeneously diploid primary tumors, 5 had tumors with diploid and aneuploid samples, and all 8 tumor samples were aneuploid in 10 patients. Deoxyribonucleic acid analysis was unsuccessful in 1 patient. One patient with a diploid primary tumor died of an intercurrent disease. Three patients (16 per cent) had objective remissions and 1 had a long-lasting stable disease. Of the 4 patients with any response to medroxyprogesterone acetate treatment 3 had diploid primary tumors, and 1 had 8 diploid and 2 aneuploid samples in the primary tumor. The remaining 14 patients showed no response to treatment and had progressive disease (11 of these patients died within 14 months). All 14 patients had aneuploid primary tumors. The results indicate that tumor ploidy might be related to response to medroxyprogesterone acetate treatment. Deoxyribonucleic acid content seems to be an important parameter to consider in planning treatment of metastatic renal cell carcinoma.

Anti-tumor reactivity of human lymphokine activated killer (LAK) cells against fresh and cultured preparations of renal cell cancer

Immunotherapy utilizing the adoptive transfer of lymphokine activated killer (LAK) cells in conjunction with recombinant interleukin-2 (IL-2) is capable of mediating the regression of established cancer in a variety of animal tumor models as well as advanced metastatic cancers in humans. We have thus examined the variability of the anti-tumor lytic reactivity of LAK cells obtained from patients with metastatic renal cell cancer (RCC). Tumor cell suspensions were prepared by enzymatic digestion from 37 consecutive renal cell tumors. The mean (+/- SEM) total number of cells recovered was 1.5 +/- 2.2 X 10(9) cells per tumor. The percentage of tumor cells in the suspension was 39.1 +/- 3.3% (range: 6 to 75%). Thirteen of 13 different fresh renal tumor cell preparations tested in 57 experiments and tow of two renal tumor lines tested in 10 experiments were all lysed by LAK cells. RCC patients, like normal donors, generated good LAK effectors with broad antitumor activity against autologous as well as allogenic tumors. Both renal and nonrenal tumors were equally lysed by LAK cells. LAK killing of the erythroleukemic tumor lines K562 and Daudi was significantly better than the lysis of fresh autologous and allogeneic tumor targets or cultured RCC tumor lines. Short term tumor cultures derived from renal cancer preparations proved to be sensitive and reliable tumor targets for studying the in vitro killing by LAK cells. Clinical trials testing the therapeutic role of LAK cells and IL-2 in patients with advanced renal cell cancer are currently in progress.