Ch. Dittrich

Phase I and pharmacokinetic study of BIBX 1382 BS, an epidermal growth factor receptor (EGFR) inhibitor, given in a continuous daily oral administration.

The pyrimido-pyrimidine BIBX 1382 BS inhibits the intracellular tyrosine kinase domain of the epidermal growth factor receptor (EGFR), thus specifically reverting the aberrant enzymatic activity from overexpressed and constitutively activated EGFR. A phase I and pharmacokinetic study of this new specific molecule was carried out. After initially performing an accelerated titration design from the first toxicities onwards, a modified Fibonacci scheme was used to escalate the daily oral dose. The following dosages and cycles (defined as treatment during 28 days) were applied: 25 mg: 6; 50 mg: 3; 100 mg: 6; 200 mg: 7; 150 mg: 3. Over a 10 months accrual phase, 11 patients (pts) (7 females, 4 males) with a median age of 63 years (range 50-73 years), World Health Organization Performance Status (WHO PS) 0:5 pts, 1:6 pts and miscellaneous solid tumours were entered. The median number of cycles applied per pt was 2 (range 1-7). Reversible, dose-dependent increase of liver enzymes (maximal Common Toxicity Criteria (CTC) grades: gamma-glutamyl transferase (GGT): 4, aspartate aminotransferase (GOT): 3, alanine aminotransferase (GPT): 3, alkaline phosphatase (AP): 3, bilirubin: 3) occurred. Oral medication yielded plasma levels far below those expected to be efficacious. In conclusion, target plasma levels could not be reached via the oral route at a reasonable dosage. Meanwhile, a preclinically unknown metabolite was identified from the urine of one patient. Subsequently, this metabolite was found to be abundant in patient plasma. The metabolite was demonstrated to be pharmacologically inactive. Due to a dose-limiting increase of liver enzymes, low bioavailability of BIBX 1382 BS and the detection of a pharmacologically inactive metabolite, this trial was discontinued.

Separation of clonogenic and differentiated cell phenotypes of ovarian cancer cells (HOC-7) by discontinuous density gradient centrifugation

We isolated clonogenic cells from differentiated HOC-7 ovarian cancer cells. Both cell subsets were characterised in respect to morphology, growth behaviour, DNA content and expression of tumour-associated antigens and nuclear oncogenes. Ten cell fractions (Fr) were separated by centrifugation in a discontinuous density gradient (Fr 1 less than 1.037 g/ml to Fr 10 greater than 1.069 g/ml, steps 0.004 g/ml). Large adenoid cells containing vacuoles filled with neutral polysaccharides were concentrated in Fr 1-4. These cells were non-clonogenic in soft agar. The growth on solid substrate was highest in Fr 6 and 7, intermediate in Fr 2-5 and Fr 8-10 and lowest in Fr 1. The mean cloning efficiencies of the fractions in soft agar were highest in Fr 6 (8.1%) and lowest in Fr 2 and 3 (0.1%). Diploid and near tetraploid cell subsets were found with similar frequency in all fractions. Immunocytochemistry revealed 4-7% Ki-67 positive cells in Fr 1-6 and 12-20% in Fr 7-10. In Fr 3-10 greater than or equal to 79% of the cells expressed CA 125. Positivity for c-myc, c-myb and c-fos (greater than or equal to 74%) was not correlated with clonogenicity. In conclusion, differentiated cells (Fr 1-4) were separated from cells with higher growth rates (Fr 5-10). Clonogenic cells were enriched in Fr 6. These data indicate that discontinuous density gradient fractionation represents a useful method for separation of cells with different degrees of differentiation, growth potential and clonogenicity.

Analysis of factors influencing clonogenic growth in vitro of cells from ovarian carcinoma patients

Clonogenic growth (defined as the formation of greater than or equal to 5 colonies per 5 x 10(5) viable nucleated cells per plate) of ovarian cancer specimens assessed in our clonogenic assay system was significantly associated with the proportion of tumor cells in the suspensions plated (N = 87; P = 0.0006), although there was no quantitative relationship with the corresponding plating efficiencies. An inverse correlation was observed between monocytes/macrophages/mesothelial cells (M) proportion and clonogenic growth (P = 0.013). These associations were most evident when only effusions were considered. Univariate analyses identified tumor cell content, M proportion and, to a lesser degree, granulocyte content as the only factors out of 12 examined to be correlated with colony formation. Multivariate analysis using a logistic regression model identified the proportion of tumor cells as the only significant factor predicting clonogenic growth in vitro (P = 0.0006). The overall accuracy of prediction for growth or non-growth was 63.2%.

The value of second-look operation in patients with advanced epithelial ovarian carcinoma.

SummaryA second-look operation was performed on 151 patients with stage III and IV epithelial ovarian carcinoma who had responded to primary surgery and chemotherapy. 19% of the 79 patients who appeared clinically to be free of disease had microscopic recurrences and 23% had macroscopic residual disease at a second-look operation. The 5-year survival rate for patients with no histological and for those with microscopic secondaries at second-look operation were 55% and 35% respectively (P=0.45). Only patients with well or moderately well differentiated tumors and a small residual tumor mass at first operation had a good prognosis after a second-look operation even without further chemotherapy. Median survival after secondary debulking was 15 to 17 months and was independent in the radicality of the second-look procedure. Outside of clinical trials second-look laparotomy should therefore only be performed as a diagnostic procedured as a diagnostic procedure in patients with well or moderately well differentiated tumors who are left with a small residual tumor mass at the time of the first operation. Because this is a group of patients in whom chemotherapy can be discontinued after a negative second-look operation.

CHOP-firstline treatment in NHL with unfavorable prognosis — Evaluation of therapeutic response and factors influencing prognosis

Summary58 NHL-patients (9 large cell centrocytic, 18 centroblastic, 16 immunoblastic, 15 lymphoblastic lymphomas) were treated immediately after diagnosis with CHOP-chemotherapy regardless of the extent of disease. Because of the advanced age of the majority of patients (median age 61 years, range 22–85 years) a reduced dose in the first two cycles was administered. Statistically significant prognostic variables influencing survival were the following: histologic subtypes according to the Kiel-classification (p<0,05), B-symptoms (p<0,001), blood sedimentation rate (p<0,02) and LDH (p<0,0005). With regard to prognosis there was no difference between patients over 60 years of age and younger ones (p<0,4). Patients achieving complete remission survived significantly longer (p<0,0001). Ann Arbor stages were of limited value, since patients with CS II disease and accumulation of risk factors (B-symptoms, abdominal disease, bulky tumor masses) showed a poorer outcome than patients with CS III who did not have these risk factors. A risk factor score summarizing features influencing prognosis is described and might be a useful tool in stratifying the heterogenous group of NHL with unfavorable prognosis.

Assessment of the Human Tumor Cloning Assay for Urologic Malignancies with Special Emphasis on Bladder Cancer

Specimens of different urologic malignancies such as cancer of the bladder, renal pelvis, prostate, testis and renal cell carcinomas were sent to our laboratory for cultivation with the clonogenic assay. Of the 62 samples--biopsies, bladder barbotages and effusions--48% were considered to be evaluable; the others had to be excluded from evaluation because of negative histologic/cytologic findings, insufficient cell viability, inadequate tumor material, or contamination. All test procedures were done using a slightly modified human tumor cloning assay originally described by Hamburger and Salmon [Science 197: 461-463, 1977]. Overall growth was seen in about one third of all tumors cultivated; the mean colony count being 13 +/- 8, the mean cloning efficiency 0.0026%. About one third of bladder cancer specimens and half of the renal cell carcinomas showed colony growth. No correlation between tumor stage or grade and the overall colony growth rate in vitro was seen. Furthermore, it was impossible to correlate the growth rate in vitro and the overall survival of the patients included in the study.

MACOP-B treatment in patients with Ki-1-positive large-cell anaplastic lymphoma

SummaryNine adult patients with Ki-1-positive largecell anaplastic lymphoma were treated with MACOP-B. Two suffered from relapsed disease and had previously received chemotherapy; a third patient had received a single dose of 100mg/m2 cisplatin before initiation of MACOP-B. The stage of lymphoma was determined according to the Ann Arbor Conference criteria and was II in one, III in two and IV in six patients. All patients had constitutional symptoms. Five patients had achieved complete remission 4 weeks after termination of the protocol and there were two partial remissions. One patient died of massive pulmonary embolism during the 4th week of treatment; another patient, who had received MACOP-B as salvage therapy, died of progressive lymphoma 1 month after completion of the regimen. Maximal observed toxicities according to WHO were mucositis grade 3 (n=3) and there were three cases with thromboembolic complications, including a fatal pulmonary embolism in a young patient. However, MACOP-B appears an effective, fairly well-tolerated and feasible therapy for patients with Ki-1-positive large-cell anaplastic lymphoma.

Der Stellenwert der Second-Look-Operation beim Ovarialkarzinom

Berichtet wird uber 171 Patientinnen mit Ovarialkarzinom des Stadiums III und IV, bei welchen nach initialer Operation und Chemotherapie eine Second-Look-Operation durchgefuhrt wurde. Nach einer medianen follow-up Zeit von 44 Monaten zeigte sich in den einzelnen Gruppen folgendes Uberleben: 1) Histologisch negativer Second-Look (n = 55): mediane Uberlebenszeit 66 Monate; 2) Mikroskopisch positiver Second-Look (n = 20): medianes Uberleben 46,5 Monate. 3) Sekundare Tumorreduktion (n = 48): 15,2–17,5 Monate medianes Uberleben, unabhangig von der Radikalitat des Tumordebulkings. 4) Patienten mit ausschlieslicher Carcinosis peritonei (n = 26): 17,3 Monate und 5) Inoperabilitat wegen ausgedehnter Tumormassen (n = 22): 5,1 Monat medianes Uberleben.