AJCC 8th Edition oral cavity squamous cell carcinoma staging - Is it an improvement on the AJCC 7th Edition?

The AJCC Cancer Staging Manual 8th Edition includes both the depth of primary tumour invasion and extracapsular extension of lymph node metastases. The AJCC 8th Edition OSCC staging system showed improved disease-free survival discrimination between overall stages and between T categories, while AJCC 7th Edition did not.