No abstract

Cancer of the ovary is a major clinical problem and the most common cause of death from gynaecological malignancy in the United Kingdom. A particular feature is late presentation and the majority of patients present with advanced disease. Selection of effective first-line chemotherapy is therefore central to effective management.The development of in vitro assays for the growth of clonogenic tumour cells in soft agar (Hamburger & Salmon, 1977;Hamburger et al., 1978) suggested a system which might be of benefit, not only in selecting chemotherapeutic regimes following surgical ablation of tumour, but also in identifying those drugs to which a patient might be sensitive after extensive pretreatment. Success in using such a system has been claimed by Alberts et al. (1980a) who predicted clinical response based on in vitro tests in 62% of patients with ovarian cancer and had an accuracy of 99% in the prediction of resistance.Following a pilot study with a small number of ovarian tumours (Simmonds et al., 1981) this investigation was undertaken with the aims of (i) culturing ovarian tumour material using the stem cell or clonogenic assay, (ii)

The use of verapamil, a calcium channel antagonist, to circumvent established resistance in human cancer cell lines has been reported for lung (Fetherston et al., 1985) and ovary (Rogan et al., 1984) using adriamycin and the vinca alkaloids. We were interested in its potential use for the enhancement of cytotoxicity of vindesine and cisplatinum in non-small cell cancer of lung (NSCCL). An earlier study (Simmonds et al., 1986) using primary patient material in clonogenic assay has confirmed the overall poor clinical response rates to these drugs reported by Elliott et al. (1984).In this study, 18 lung tumour samples, 17 squamous and 1 adenocarcinoma, were removed at thoracotomy of previously untreated patients and grown in the bilayered agar clonogenic assay system. In brief, samples were mechanically disaggregated with crossed scalpels in Hanks balanced salt solution (HBSS) with penicillin and streptomycin and resulting cell suspensions passed through needles of decreasing gauge to obtain single cells. Tumour cells obtained were suspended in RPM1-1640+10% FBS and aliquots of 106 viable cells were exposed for 1 h at 37°C to concentrations representing 10% of the peak plasma concentration for cis-platinum (0.25 pg ml -1) and vindesine (0.02 pgml-1) (Alberts et al., 1980) Figure 1 shows the response to cis-platinum. All specimens except no. 13 were resistant in vitro when tested alone, the degree of resistance varying from moderate to very marked. Fourteen of the 18 patients demonstrated greater than 70% survival following treatment with this drug. In the presence of verapamil, only one patient, number 8, showed a change to sensitivity from 60% to 36% survival. Patient 13 had sensitivity changed to resistance while samples number 7, 11, 12, 17 and 18 demonstrated increased resistance. A change in the degree of resistance was observed for patients 2, 4, 5, 6, 9, 10, 14, and 15; this was lessened while specimens from patients 1, 3 and 16 were unaffected. Plating efficiencies in every case were sufficiently high for these drug results to be significant (11/18PE>0.03%) and the treatment of cells with verapamil alone produced no cytotoxic effects (figures not shown). Figure 2 shows the response to vindesine. In the absence of verapamil all samples were resistant and 10/18 patients exhibited greater than 70% survival following treatment with this drug. Pronounced changes, however, were observed in vindesine response in the presence of verapamil for 7 samples; patient numbers, 2, 5, 6, 7, 8 and 13 became

Summary Lung tumours of non small cell pathology were cultured by clonogenic assay in several media. Culture was successful in spleen conditioned medium, but only 57% grew and low plating efficiencies (PE) meant that only 23% of the original number produced significant drug results. Comparison of rat erythrocyte lysate (REL) medium with serum free defined medium (HITES) and HITES +10% FBS demonstrated clear enhancement of PE in REL although growth was 100% successful in all these media. Ninety-three percent of samples tested against drugs in REL produced significant results. A later comparison of REL with McCoy's SA+rbc+hydrocortisone produced relatively poor culture success for these 3 media and equivocal growth patterns. Low PE was attributed to age of rats used for rbc. Vindesine and cis-platinum cytotoxicity in spleen conditioned medium were 61% and 15% sensitivity respectively. These do not concur with clinical experience but the figures for overt resistance, at 39% and 69%, correspond with expected non-responders to these regimes. Drug testing in REL produced figures correlating more closely with clinical performance at 45% sensitivity to platinum and 36% of patients sensitive to both drugs, but the vindesine sensitivity at 55% is again discrepant with performance of this drug as a single agent.

A total of 45 patients with advanced non-small-cell lung cancer were treated with a combination of 1.5 g/m2 ifosfamide given on days 1-5 every 3 weeks for four courses with 3 million IU a2b-interferon (Intron A) given s.c. three times a week for 12 weeks. Nine objective responses were seen, including two complete responses (CRs) and seven partial responses (PRs). Haematological and non-haematological toxicities were generally mild and did not necessitate discontinuation of therapy.