From the reports, kindly suggest whether my father has advanced lung cancer or not?

Hi doctor,

I took my dad to the hospital because of intense pain in his legs. After a lot of tests, the doctors suspected that he has advanced cancer. But they were unable to do a biopsy because of his heart disease and other problems. I received reports from hospitals about my father's condition. One report suggests that he has advanced cancer and it has spread to different parts of the body. They did a PET because of his health problems. After six weeks, again I took him to the hospital because of severe pain in the legs and the painkillers are given initially was not helpful. The other doctor did a biopsy of the lung and suggested possible stage 1 cancer. He had loss of weight and the pain in the legs increased. He has done open heart surgery before three years. He has heart disease, blood pressure, and diabetes. I am interested in getting a specialist look at the reports and images and say why there is such a difference of opinion by two cancer specialists. I would like to know what these reports mean:

Does he have advanced lung cancer or only stage 1 cancer? If he has advanced cancer, should we consider palliative care? If it is not advanced cancer, should we go through therapy? If so, chemotherapy or radiation? Just give a second opinion after reading these reports and suggest how to proceed. We need an urgent response.

Thank you doctor,

Does the biopsy report indicate that he has advanced cancer? I have been told that he needs treatment for six months as he has stage 1 lung cancer. Because of the significant difference between the reports that seem to suggest advanced cancer and the latest biopsy report seem to indicate stage 1 cancer, I want some clarification, particularly about the biopsy report.