California Cancer Reporting System Standards Volume I: Abstracting and Coding Procedures for Hospitals
At times a cancer spreads to surrounding organs or tissue with no involvement of regional lymph nodes. Before assigning code 2 to such a case, make sure that tissue adjacent to the original organ is actually involved. The terms "penetrating" and "extension" are sometimes used to describe spreading within an organ, such as the large intestine or bladder, in which case the stage might still be localized (code 1). The Summary Staging Guide lists organs and structures considered to be regional for each site. Also see Section V.5.3 for interpretation of ambiguous terms.