Thank you for your letter, which discusses the 1-year cancer incidence of 4.1% in males aged >40 years with a normal platelet count.1 We were surprised at this too.
You raise an interesting point and one that we are currently investigating. The 4.1% risk found in the males with a normal platelet count in the present cohort probably reflects the increased likelihood of something being wrong with a patient who has a blood test, regardless of the test result. Investigation for malignancy would not be recommended based on the findings in this study:2 in effect, all men with a full blood count would be considered for cancer. Rather, we expect the GP would investigate on the symptoms or signs that prompted the blood test; this would also focus any investigation.
It is likely the higher risk for cancer is clustered at the high end of the normal platelet count and we have recently been awarded funding to investigate this possibility in a fresh cohort of patients.
- © British Journal of General Practice 2017