My father, 72 is experiencing a fever in range of 102F for past six to seven days.  His CBC test is normal. ESR is highly elevated and stands at 102. Doctor has given him antibiotic Cefixime on 6th day.  Urine test showed a very mild infection (WBC are 4-6).  Chest x-ray suggested an ill defined opacity in upper and mid zone.  He has recommended a CT scan which is due tomorrow.  Doctor was saying that such high ESR is only associated with cancer.  Is it not possible that this high ESR is due to Typhoid or  Pneumonia? He does not have any cough, diarrhea or vomiting - just constact 102F temperature.
ESR is a nonspecific test which is associated with a variety of conditions, including infections, inflammation, cancers, collagen vascular diseases (e.g., lupus, vasculitis, rheumatoid arthritis). It can be very high particularly with a condition called temporal arthritis or polymyalgia rheumatic, or with severe infections, so you really can't say its just cancer. Fevers and high used rate could be seen with any of the conditions I mentioned. Certainly infections could include pneumonia and typhoid. Since he has an abnormal chest x-ray, I think it is wise to proceed with the CT scan. I would also be considering the possibility of tuberculosis. Hope this helps.