A 7-cm inflection point: nonlinear association between maximum tumor diameter and capsular invasion risk after primary liver cancer resection

This study identifies a 7-cm inflection point in the association between maximum tumor diameter and capsular invasion risk for resectable primary liver cancer. The relationship is characterized by a progressive increase in risk below this threshold, which stabilizes for tumors larger than 7 cm. These hypothesis-generating findings question the prevailing linear size-risk assumptions and underscore the need for future validation using preoperative imaging and prospective studies with long-term follow-up to evaluate its impact on patient prognosis.