The eighth TNM classification system for lung cancer: A consideration based on the degree of pleural invasion and involved neighboring structures

T2a-PL2 tumors could be categorized into a worse prognostic T2b category. For T3-PL3 tumors involving resectable neighboring organs, subcategorization of whether there is only pleura infiltration (T3a) or other deeper structure invasion (T3b) could be a practical consideration.