A type of blood test known as Platelet count has been discovered to be associated with cancer.
Platelets are tiny blood cells that circulates the body, they are responsible for the clotting of blood thereby helping in wound healing. Researchers have said that, when too many of these platelets are produced in an individual due to a condition known as “thrombocytosis” it can be a good predictor of getting any cancer, even lump in the breast which could lead to breast cancer.
This is a clue which can be used in practice by GPs to help them select patients for further investigation… most excitingly in some patients who may not already have other symptoms of cancer to achieve earlier diagnosis
Before now, studies had indicated that there was a connection between thrombocytosis and various cancers, especially in those who had thrombocytosis for long. There were even recent guidelines from the National Institute for Health and Care Excellence advicing high platelet counts could be a sign of cancer of the oesophagus, stomach, lung or uterus. It was just unclear whether the condition could signal an increased risk of ALL cancers, and how it relates with factors like age and sex.
Bailey and her colleagues reported in the British Journal of General practice of how they had examined data from about 50,000 people aged 40 and above, who had been given a blood test by their GP. They were selected at random from a national data base. Over 31,000 were found to have a raised platelet count, 8000 did not in the total analysis.
The team discovered later within a year that cancer was more common among those who had thrombocytosis- raised platelet count. 11.6% of men and 6.2% of women were found to have cancer compared to 4.1% of men and 2.2% of women without raised platelet counts. In the general population, 1% of individual over the age of 40 develop cancer each year. Among women aged 50-59 who had discovered breast lump, 8.5% were found to have breast cancer.
We found cancer was more commonly diagnosed in men with raised platelet count than it was in women with raised platelet counts and we believe that is because there are more causes of raised platelet counts in women that are not cancer. Bailey added
Although many different types of cancer were common in both sexes, the team found out that breast cancer and prostate cancers were less common among those with thrombocytosis than in the general population, while lung and colorectal cancers were more common.
A professor who was not involved in the research also welcomed the study.
This is an excellent study that demonstrates the potential of commonly used blood test to identify some patients with cancer earlier. This work should begin to change practice, so that GPs should be testing patients with raised platelet counts for cancer, especially those without other potential cancer symptoms.
Cancer Research UK’s health information officer, Dr Jasmine Just, said that more research needed to be done to confirm whether further test following a high platelet count would save lives. She said “There are lots of possible reasons a person’s platelet count might be high, and in most cases it won’t be down to cancer. Measuring platelet count in patients who don’t otherwise warrant a blood test is not necessarily a good idea. But if a patient has a blood test for another reason and a high platelet count is found, then one of the possible diagnoses doctors should consider is cancer.”
Platelets, also called thrombocytes are a component of blood whose function (along with the coagulation factors) is to stop bleeding by clumping and clotting blood vessel injuries. Platelets have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation. A normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Having more than 450,000 platelets is a condition called thrombocytosis; having less than 150,000 is known as thrombocytopenia. You get your platelet number from a routine blood test called a complete blood count (CBC).