@ginny100
Regarding a lung biopsy:

Did they tell you how your biopsy would be performed? With a needle from the outside or how? There are many methods to do lung biopsies depending on the size and location of the tumor.

I had a lung biopsy due to my rare neuroendocrine lung cancer (not related to my breast cancer). Mine is very slow growing cancer (Ki-67 2%). They first discovered over 50 tumors in both my lungs back in 2008 with a CT for chronic bronchitis. They wanted to do a biopsy, but the largest tumor was buried deep and only about 1 cm then and they couldn't reach it with any certainty any way except to filet my chest and lung and I felt that was too much to go through and recover from so I declined. They were guessing it was either metastatic cancer with an unknown primary cancer or it could be something benign. They were baffled. I was not going through a major surgery just to hear it was benign.

Fast forward to 2020 when my breast cancer came back. The largest lung tumor was now 2.6 cm and they said they could now successfully do a needle biopsy from the outside. They insisted on the biopsy to see if it was related to the BC. I anxiously and reluctantly agreed. I was as concerned as you are. The biopsy took about 45 minutes, 8 tissue samples, while I was awake. They went through my back into my lung. It hurt some, but not unbearable. Note that pain meds and sedatives don't work on me. It was not a pleasant procedure, but doable.

There was a 15% chance of getting a collapsed lung and I did get a partially collapsed lung afterwards. That caused chest pain, severe fatigue and breathlessness, but healed up in about a week. Again, doable. I was borderline of having to go in the hospital so I chose to stay home to heal. I just had to go for a chest xray every day to monitor. I did not need a tube inserted. I later had microwave ablation to successfully destroy the largest tumor and that also resulted in a partially collapsed lung, same story. They believe the reason I likely got the collapsed lung both times was because I had a chronic cough and they think the coughing didn't allow the opening in my lung to heal.

There is an 85% chance you will not get a collapsed lung. Ask about that. Maybe procedures have even improved in the past four years.

A biopsy will tell you if the tumor is related to the breast cancer or not. It may not be and, if not, the treatment may be different. It turned out not only was mine not connected to my breast cancer, and not only was it a rare neuroendocrine lung cancer, but I also have an even rarer condition called DIPNECH (only 300 documented cases) that is what causes me to have so many tumors and all the respiratory issues of chronic coughing for 30 years and shortness of breath misdiagnosed as asthma. The DIPNECH is why 20 doctors over 12 years couldn't figure out what was in my lungs until the biopsy. Most doctors still have never heard of it. I can't have my lung tumors resected because there are so many tumors scattered across my lungs so we'll just destroy any that become 2 cm or take off from the pack as those are more likely to metastasize. Most are 1+ cm now. I have advanced DIPNECH, but after all these years, my neuroendocrine lung cancer is still considered stage 1 since it's confined to my lungs.

Please share your decision and outcome. Prayers for a good outcome all the way around.