My father has 5 metastasis in lung lymph nodes in the hilar region. He also had two tumor removed by VATS procedure in march which confirmed it as melanoma. In july he started receiving the Opdivo therapy. So far he completed four cycles. Three days ago he started coughing and it is getting worse every day. Could this be the side effect of the therapy or have the metastasis progressed? He is scheduled for a CT next week but I would like to hear your opinions because I am very concerned. Thank you all in advance.