Table 2.

Halstedian concepts of cancer biology (1894)

Tumors spread in an orderly defined manner based on mechanical considerations.
Tumor cells traverse lymphatics to lymph nodes by direct extension, supporting en bloc dissection.
The positive lymph node is an indicator of tumor spread and is the instigator of distant disease.
Regional lymph nodes are barriers to the passage of tumor cells.
Regional lymph nodes are of anatomic importance.
The blood stream is of little significance as a route of tumor dissemination.
A tumor is autonomous of its host.
Operable breast cancer is a local-regional disease.
The extent and nuances of operation are the dominant factors influencing patient outcome.