BCG therapy of pleural and peritoneal growth of transplanted rat tumours.

Growth of intrapleurally injected cells of immunogenic methylcholanthrene-induced rat sarcomas was suppressed by intrapleural injection of viable or 1 times 10-6 R radiation-sterilized BCG vaccine. As little as 10 mug moist weight of organisms was effective, and treatment could be given several days before or after tumour challenge. Pleural effusion growth of a moderately immunogenic ascitic hepatoma was also controlled by intrapleurally administered BCG. In contrast, BCG injected intravenously, subcutaneously or intraperitoneally was without influence on pleural tumour growths. Similarly, intraperitoneal growth of these tumours was suppressed only by intraperitoneal injection of BCG. With two other transplanted tumours, a chemically induced mammary carcinoma and a spontaneous sarcoma, both of which lack significant immunogenicity, BCG treatment of pleural and peritoneal growths was less successful and more variable. Nevertheless, these studies indicate the potential of this type of treatment of thoracic and peritoneal tumour deposits for possible clinical application in the treatment of malignant mesothelioma.     

Moderate exercise training slows mammary tumour growth in adolescent rats.

Adolescence and young adulthood may be critical windows in establishing risk for breast cancer development in humans. Epidemiological data suggest that exercise during this life stage is associated with decreased breast cancer risk yet few experimental studies to elucidate the mechanism have been performed. The purpose of these studies was to evaluate the effects of moderate exercise training on mammary tumour development in adolescent rats using the 1-methyl 1-nitrosourea (MNU) chemical carcinogen model. Exercise (EX) consisted of moderate-intensity treadmill running 30 min/day, 5 days a week. A total of 274 animals were used: 94 in study 1 and 180 in study 2. Animals were injected with MNU (50 and 25 mg/kg body weight in studies 1 and 2, respectively) at 21 days of age and began training at 28 days of age. Groups of animals (n=10-30 depending on the study and time point) were sacrificed every 2 weeks for 8 weeks to evaluate tumour development. No difference in median tumour-free survival time was observed in the EX versus sham-exercise (SHAM), nor were there any differences in multiplicity at either a high or moderate dose of MNU. Latency to first tumour palpated was increased in both studies by 3-4 days. Consistent across both studies, tumour weights were less and the growth rates of the tumours, defined as tumour weight divided by the number of days elapsed since the tumour was first palpated, were reduced in the EX group. The data suggest that latency is increased and tumour growth is retarded in response to moderate exercise training.     

Transforming growth factor activity in pleural and peritoneal effusions from cancer and non-cancer patients

Tests were performed to study the transforming growth factor (TGF) activity in samples of pleural fluid and ascites in patients with solid tumors and non-neoplastic diseases such as congestive heart failure and liver cirrhosis. The measurement of the activity was carried out in terms of colony formation in soft agar with NRK cells as indicator cells. When the fluid samples were directly assayed, 24% (4/17) of the cancer cases and 1 of the 4 control cases were positive. The eluate of Bio-Gel P-60 gel filtration was positive in all cases. beta-Type as well as alpha-type TGF activity was found in pleural and peritoneal effusions not only from cancer patients, but also from patients with non-malignant diseases.     

Mitomycin C and vindesine: an ineffective combination chemotherapy in the treatment of malignant pleural mesothelioma.

Twelve patients with malignant pleural mesothelioma were subjected to mitomycin C (MMC) and vindesine (VDS) chemotherapy (MMC 10 mg/m2, i.v., d 1; VDS, 3 mg/m2, i.v., d 1-8, every 4 weeks). No objective response was obtained; 3 (25%) patients had stable disease and 9 (75%) progression of disease. We conclude that MMC plus VDS is an ineffective combination chemotherapy in the treatment of malignant pleural mesothelioma.     

Spleen weight in rats during tumour growth and in homograft rejection

The spleens of rats bearing methylcholanthrene induced sarcomas are enlarged. This applies both to primary and to isotransplanted tumours. The spleen enlarges with increasing tumour size.