BMI . However , when used in isolation , the numbers needed to treat , in order to prevent one clot , are too high to justify applying it to routine practice . There are some data that suggest it can be used to target those at greatest risk .
Where does this leave us practically ? This leaves us with cancer patients who are at high risk of developing clots during chemotherapy , but with no robust system for identifying those at greatest risk and who should have primary prophylaxis .
If we are unable to prevent clots , we must increase patient awareness of clots . This means that when a cancer patient develops red flag symptoms of a clot , they are empowered to seek help immediately .
Increasing patient awareness of clots It makes sense to increase patient awareness of clots ; the problem is , currently , we are not .
In my clinical practice , 60 % of patients will have had their clot precipitated by chemotherapy or other SACT . When I speak to them , they can tell me what to do if they were to suffer any of the symptoms of sepsis because we have raised awareness of the signs to look out for . But we are not doing that for clots , patients are not aware of the risk of clots in the same way .
This means that cancer patients are diagnosed with a deep vein thrombosis ( DVT ) or PE in a rushed and distressing way . Patients are either so ill they get administered to hospital , or they mention their swollen leg , for example , in passing and are hurried to a scan . Saddeningly , patients often say that their experience of being diagnosed with a clot was more distressing than their experience of being diagnosed with cancer in the first place .
Thrombosis is a normal part of the cancer journey , and it should be treated that way . One in five cancer patients will develop a clot . 7 We need to relay this message to our patients ; instead of talking about cancer associated thrombosis being a complication of cancer , we need to say to patients that developing a clot is quite normal .
The sooner a patient seeks help , the sooner they can get diagnosed , and faster diagnosis reduces the long-term impact of thrombosis . For me , the ultimate reason we should all be supporting earlier detection is patient quality of life .
Up to 40 % of patients will develop postthrombotic syndrome . 8 Symptoms of this include chronic swelling of the legs , pain , and ulceration . Essentially , we are left with a patient whose life we have saved by treating their cancer , but they are not the person they used to be physically because of the subsequent impact of CAT .
Ensuring safe prescribing of anticoagulants The next step is ensuring safe prescribing of
10 | Issue 101 | hospitalpharmacyeurope . com anticoagulants to avoid further patient distress .
There are two main choices of anticoagulants that we use for CAT : lowmolecular-weight heparin ( LMWH ) and direct acting oral anticoagulants ( DOACs ). For the last 15 years , we have been using LMWH , which is an injectable given subcutaneously . We encourage patients to inject themselves or have a carer do it for them . However , we can help improve their injection technique .
The patient information leaflet suggests that the drug should be injected an inch below the belly button . However , with prolonged use , this area will get bruised and painful . The truth is , patients can inject wherever there is fat , right round to the ‘ love handles ’, and can rotate sites .
We also need to warn patients that a bruise might heal with scar tissue under the skin , and that they may develop fibrosis and feel a lump . Unless we do so , cancer patients may fear they have developed secondary tumours under the skin . We should then be warning patients not to inject into that lump because it will hurt .
These pieces of education given when the drugs are administered will improve technique and compliance , but they will also prevent avoidable distress for patients .
More commonly now , DOACs are the first choice in the treatment of CAT . The pharmacy community has a real role here in protecting overzealous prescribers from giving DOACs indiscriminately . They are effective and they are safe in cancer patients , but they come with caveats .
If a DOAC is given to someone with primary oesophageal cancer , and the tumour is still there , there is a 13 % major haemorrhage risk . 9 Similarly , 8 % of patients with urothelial cancer or bladder cancer will develop haematuria . 10 We should also avoid giving DOACs to patients with a high bleeding risk . We also need to be aware of significant drug – drug interactions . Although we are still finding our feet with this , we know that many chemotherapies and many of the new SACT will have interactions with P-glycoprotein and CYP3A4 . If you have strong inhibitors or strong inducers of those drugs , there will be an interaction .
Finally , remember that a patient ’ s disease changes . You might need to change the drug or the anticoagulant over the course of the patient ’ s cancer journey .
Final thoughts The pharmacy community has an integral role in the management of the patient with CAT . This starts with managing the cancer patient who is receiving systemic treatments .
It is vital that we raise awareness of the condition among cancer patients and ensure that we are prescribing anticoagulants safely , reviewing their drug options frequently .
References 1 Fernandes Caio J et al . Cancer- Associated Thrombosis : The When , How And Why . Eur Respir Rev 2019 ; 28 ( 151 ): 180119 . 2 Dallos MC , Eisenberger AB , Bates SE . Prevention of Venous Thromboembolism in Pancreatic Cancer : Breaking Down a Complex Clinical Dilemma . Oncologist 2020 ; 25 ( 2 ): 132 – 9 . 3 Noble S , Pasi J . Epidemiology and pathophysiology of cancer-associated thrombosis . Br J Cancer 2010 ; 102 : S2 – S9 . 4 Kirwan CC et al . Incidence of venous thromboembolism during chemotherapy for breast cancer : impact on cancer outcome . Anticancer Res 2011 ; 31 ( 6 ): 2383 – 8 . 5 Breast Cancer Now . Breast cancer statistics and facts . https :// breastcancernow . org / about-us / media / facts-statistics #:~: text = Around % 20 55 % 2C000 % 20women % 20and % 20 370 , are % 20diagnosed % 20with % 20 breast % 20cancer ( accessed July 2022 ). 6 Chakraborty R et al . Venous Thromboembolism Risk With Contemporary Lenalidomide Based Regimens Despite Thromboprophylaxis In Multiple Myeloma : A Systematic Review And Meta Analysis . Cancer 2020 ; 126 ( 8 ): 1640 – 50 . 7 Hull University Teaching Hospitals NHS Trust . Cancer-Associated Thrombosis . www . hey . nhs . uk / patient-leaflet / cancerassociated-thrombosis / ( accessed July 2022 ). 8 Cosmi B et al . The Post-thrombotic Syndrome-Prevention and Treatment : VAS-European Independent Foundation in Angiology / Vascular Medicine Position Paper . Front Cardiovasc Med 2022 ; 9:762443 . 9 Al-Samkari H , Connors JM . The Role of Direct Oral Anticoagulants in Treatment of Cancer-Associated Thrombosis . Cancers ( Basel ) 2018 ; 10 ( 8 ): 271 . 10 Ording AG et al . Hematuria in anticoagulated patients with atrial fibrillation and urologic cancer . Res Pract Thromb Haemost 2022 ; 6 ( 1 ): e12629 .