Key references and resources discussed in the episode:

• Bailey SE et al. Br J Gen Pract. 2017;67(659):e405-e413.
• Mathur A et al. BMJ. 2019;366:l4183.
• Suspected cancer: recognition and referral. NICE guideline NG12. 2015.
• NHS Scotland. Scottish referral guidelines for suspected cancer.
• Fernando K. GPnotebook Shortcut. Managing unexplained thrombocytosis in primary care.

Key take-home points from the episode:

1. Thrombocytosis is generally defined as a raised platelet count >400–450 x 10⁹/L.
2. Thrombocytosis is a common incidental finding, occurring in approximately 2% of those >40 years old attending primary care.

• • 80–90% of episodes are reactive and 80% resolve within 12 weeks.

3. Thrombocytosis should not be used as a standalone diagnostic or screening test for cancer or to rule out cancer.

• • However, unexplained thrombocytosis should prompt us to “think cancer”.

4. NICE NG12 and Scottish Referral Guidelines for Suspected Cancer inform us that thrombocytosis is a risk marker for some solid tumour malignancies.

• • The Scottish referral guidelines include thrombocytosis in the investigation criteria for LEGO-C cancers: Lung, Endometrial, Gastric, Oesophageal and C

5. Suggested quality improvement activities:

• • Consider how you would respond to an incidental thrombocytosis on a full blood count?
  • Consider your safety-netting options for those found to have raised platelet counts but no other symptoms or risk factors for underlying malignancy.