Myeloproliferative neoplasms (MPN’s) are a group of blood cancers.  MPN’s are bone marrow disorders which results in an excess of blood cells.  As a result, these blood cancers are associated with risks of clots and low-dose aspirin is often used in many patients along with other treatments.  There are three major types of MPN blood cancers that are often treated with low-dose aspirin, namely polycythaemia vera, essential thrombocythaemia and primary myelofibrosis.  There are many cancer charities that provide information and support to those patients with MPN’s.  This includes Cancer Research UK with the link below:

https://www.cancerresearchuk.org/about-cancer/myeloproliferative-neoplasms

Aspirin also has a therapeutic role in a subgroup of gynaecological cancers.   Lynch syndrome is a genetic condition associated with an increased risk of several cancers, particularly bowel.  Aspirin has been shown to reduce the risk of developing bowel cancer in patients with Lynch syndrome as per link below.

https://www.nice.org.uk/guidance/ng151/resources/lynch-syndrome-should-i-take-aspirin-to-reduce-my-chance-of-getting-bowel-cancer-pdf-8834927869

Lynch syndrome also confers an increased risk of gynaecological cancers, such as endometrial.  The National Institute for Health and Care Excellence (NICE) have noted that ‘endometrial cancer is often the first cancer that people with Lynch syndrome will have’, thus testing for the condition is important in women diagnosed with the disease.  In such cases, low-dose aspirin would also be beneficial to help reduce the risk of bowel cancer from developing. 

https://www.nice.org.uk/guidance/dg42/chapter/1-Recommendations

Of course, aspirin could also be used therapeutically in patients with cancer who also have a history of vascular disease.  Aspirin has been shown to reduce the risk of subsequent vascular events, such as heart attacks.  There is evidence that stopping aspirin increases the risk of vascular events so compliance is crucial.

Rodríguez LA, Cea-Soriano L, Martín-Merino E, Johansson S. Discontinuation of low dose aspirin and risk of myocardial infarction: case-control study in UK primary care. BMJ. 2011 Jul 19;343:d4094. doi: 10.1136/bmj.d4094. PMID: 21771831; PMCID: PMC3139911.

The effect of stopping aspirin on cancer progression is unclear.  An unconfirmed trial, ASPREE, unexpectedly found that patients randomised to aspirin had a higher risk of cancer death (doi: 10.1056/NEJMoa1803955).  Explanations for this include chance yet there was a high non-compliance rate so possibly stopping aspirin after a diagnosis of cancer may confer harmful risks to patients.

With particular emphasis on the importance of compliance