Generally, what are the chances of surviving stage 2B lung cancer?

Stage IIB LngCa. Iib is a 5-7 cm tumor and n1 node positive, or >7 cm , or invasion into a resectable structure, or collapse of an entire lobe with no nodes positive. This is quite rare. If resected and proven to be just the features above, many would add chemotherapy or radiotherapy. Regardless, the survival is between 30 and 50% at 5 yrs, meaning 50 -70% die before then.
Good. The upfront therapy of choice for a physically fit person with stage iia lung cancer is surgery. The expectation of therapy for some one with stage i-iiia lung cancer is cure. We are all statistics, but the expectation for someone with stage iia lung cancer who is physically fit to undergo standard of care therapy is cure.