Tumor volume, nodal status, and metastasis in breast cancer in women

The relationship between primary tumor volume at detection, number of positive nodes, and probability of and time until first distant metastasis was examined for a group of 2,663 women with breast cancer. Time until metastasis was shown to decrease and probability of metastasis to increase as tumor volume and number of nodes increased. Either factor remained significant after correction for the other. Simple proportional hazards models were shown to be inadequate to describe the data. Graphic techniques were used to obtain nonparametric estimates of the forms of the relationships between tumor volume, nodal status, and the time course of the occurrence of metastasis. A simple calculation demonstrated that the average contribution per cell to the probability of metastasis decreased with increasing volume.