It is probably just a cold or bronchitis. But, please mention it to your doctor, perhaps when he has the biopsy. Or, call sooner. The reason I say this is they will very likely want to do a pelvic CT scan and a bone scan. They could easily scan his lungs while he is having the pelvic scan done. I got called back after my surgery for a lung CT scan because they saw a suspicious nodule in the pre-surgery chest X-ray. It turned out to be nothing of concern. But, by all means, air your concern with the doctor.
As far as spread goes, I was relatively fortunate, given my high PSA. No lymph node involvement and negative margins. But, it had spread into my seminal vesicles. So it was good news/bad news.