Stephen Paget

Stephen Paget proposed the seed and soil hypothesis in 1889, the foundational theory of cancer metastasis stating that metastatic cancer cells (seeds) only grow in organs (soil) that provide a compatible microenvironment, based on his analysis of over 900 breast cancer autopsy cases showing non-random patterns of metastatic organ involvement. His observation that certain cancers preferentially metastasize to specific organs challenged the prevailing mechanical hypothesis that metastasis was simply determined by blood flow patterns. His theory has been validated by modern molecular biology identifying specific gene signatures mediating organ-tropic metastasis. His seed and soil concept remains the central organizing framework for all metastasis research over 135 years later.