Sorry about your husband situation.
Quite strange to have the Dr and Nurses at cancer centre to hv such attitude .
Would suggest your husband to visit a good chest specialist to get some opinion and chk on lung condition .
I am regulary have follow-up visit to my chest specialist Dr. beside of the Dr. in cancer centre . As I believe that the chest specialist dr. know my lung better and can have a better advise of the lung function condition than the Dr in cancer centre . As the Dr in cancer centre is specialist in treating cancer , not Lung specialist .
I wish my opinion can be helpful to you .
Be strong ; pray to LORD and seek his healing .
SK