performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. it is important to know the stage of the disease in order to plan the best treatment.
出典:Wiktionary
staging (countable かつ uncountable, 複数形 stagings)
the stage
作りつけること
the batter's box
the morning market
「staging」は動詞「stage」の現在分詞です