My dad (aged 72) was diagnosed with stage 2 lung cancer last February. The cancer hadn't spread, so surgery was a good option. He is very fit and healthy and has never smoked. He had a successful lobectomy in March and they took some nearby lymph nodes which came back clear. He was advised to have four rounds of adjuvant chemotherapy as a double insurance, just to try to sweep up any stray cells that didn't show up on a scan. He finished his chemo on August 9th and had a CT scan two weeks later. The oncologist said that everything was clear and to go away and enjoy his life. He had another scan scheduled for 6 weeks later.
This was last Friday and on Sunday he experienced some short spells of confusion and was finding it hard to co-ordinate his movements. He decided to go to hospital as he thought he may be having a stroke. They scanned his head and found a 2.5cm tumour on his brain. What I'm feeling confused about is would this be likely to be a metastasis of the lung cancer, given that there was no lymphatic involvement and all his blood test came back clear? How would it have spread? Is this more likely to be a separate brain cancer or benign tumour and could it be a side effect of the chemo?
Has anyone else been through anything like this? He is due for a PET scan on Tuesday.