The "seed and soil" hypothesis and the decline of radical surgery: a surgeon's opinion.

Controlled, clinical trials have demonstrated that recurrent breast cancer following lumpectomy may pose little risk to patient survival. There is no generally accepted biologic explanation of this dilemma. One hundred years ago Paget proposed the "seed and soil" hypothesis to describe the variation among organs in their susceptibility to tumor metastasis. This paper defines his hypothesis in a manner which attempts to explain the dilemma of local recurrence. Since individuals vary widely in their levels of natural killer (NK) cytotoxicity, they may also vary widely in their susceptibility to disseminating tumor cells. Patients who survive their initial tumor without developing distant metastases can be expected to survive a recurrence arising from residual tumor cells of the primary lesion. The "seed and soil" hypothesis supports "preservation" surgery in the treatment of malignant disease. Patients who develop distant metastases early in the course of their disease are like fertile soil for circulating tumor cells. Patients who resist the development of distant metastases are like barren soil.