What percentage of extensive calcified lymph nodes in pulmonary hila, combined with bright red blood in sputum are cancerous in nature?

Very low: Cancerous nodes very seldom calcify much. In my old home in Kansas City, many (maybe most) folks had some calcium flecks from old histoplasmosis. I'm very concerned though if you're coughing up blood. That's cancer until proved otherwise, and you're entitled to have calcified nodes from some other cause. Please get it properly worked up. Best wishes.