The natural history of metastasis of a syngeneic murine squamous carcinoma and the prognostic implications of primary tumour size and duration of growth

Abstract

Summary.-A study has been made of the natural history of metastasis of a spontaneous murine squamous carcinoma implanted into syngeneic recipients-a situation where biologically different tumours and variable " host resistance " are not complicating issues. The time distribution of deaths from metastatic disease was incompatible with a log-normal distribution but was accurately described by an exponential pattern of survival following an initial lag. While the average life of doomed mice correlated with predictions based on growth rates, there was a wide range of survival times indicating random influences on the evolution of metastatic disease.Insofar as tumours which grew to 20 mm3 or less in 5 days after tumour cell injection failed to initiate metastases, while tumours which reached a size of 120 mm3 or greater (irrespective of duration) produced metastases in 38/39 mice, tumour size was a prognostic index. However, within the size range 33-150 mm3 the correlation between metastatic risk and size was not statistically significant. No correlation between metastatic risk and duration of tumour growth from 6 to 29 days was observed. Two integral functions of tumour size and duration were tested but neither gave a better correlation with metastatic risk than did size alone.

A study of the influence of various diagnostic and therapeutic procedures applied to a murine squamous carcinoma on its metastatic behaviour

“…For this reason, and to increase the analogy with human tumours which present as a function of size rather than duration, it was decided to use tumour size as the criterion for randomizing mice into their appropriate experimental group. Subsequent analysis of the data, however, indicated that the correlation of size with metastatic risk was not statistically significant within the range employed (Peters, 1975).…”

“…The first 3 of these major objections are overcome in a system which has been developed from a murine squamous carcinoma and the model has been used to investigate some of the factors which have variously been alleged to influence metastasis. In addition, the natural history of the tumour has been studied in relation to its metastatic behaviour (Peters, 1975).…”

Value and Perspectives of Proton Radiation Therapy for Limited Stage Prostate Cancer

“…Studies with animal models [18] as well as our experience with high-dose conformal radiation of prostate cancer support the hypothesis that localized therapeutic modalities have a curative potential in tumors that are still confined to their local or local-regional site at the time of treatment. With continuing improvement in screening and early detection of common cancers such as prostate cancer one can expect that more tumors will be detected when they are still confined.…”

Inhibition of collagen peptidase in HeLa cells and human tumours by compounds including drugs used in cancer therapy

“…5-FU produced variable levels of inhibition and not all tumour extracts were inhibited. Phenanthroline, a potent inhibitor of collagen peptidase, produces a neuromuscular reaction in mice at levels above 5 ,ug/g (Peters, 1975).…”