The Khorana Score is a widely used clinical prediction tool designed to estimate the risk of venous thromboembolism (VTE) in patients who have cancer and are about to begin chemotherapy. VTE includes serious and potentially life-threatening conditions such as deep vein thrombosis (DVT) and pulmonary embolism (PE), which occur when blood clots form in the veins, most commonly in the legs, and can travel to the lungs.
Developed by Dr. Alok Khorana and colleagues, the score is based on a combination of risk factors that are commonly available in clinical practice. These include the type of cancer a person has, specific laboratory test results such as platelet count, hemoglobin levels, and white blood cell count, as well as the patient’s body mass index (BMI). Each factor contributes a certain number of points to the total score, which helps stratify patients into different risk categories.
The scoring system is simple and non-invasive. Patients are assigned a score ranging from 0 to 6 or more. A higher total score indicates a higher risk of developing blood clots. For example, cancers like stomach or pancreatic cancer carry a higher point value due to their stronger association with clotting events. Lab abnormalities and a high BMI also increase the overall score.
The Khorana Score is especially important because patients with cancer are already at an increased risk for VTE compared to the general population. Identifying high-risk patients early allows healthcare providers to consider preventive treatments, such as anticoagulant medications, which can reduce the likelihood of a clot forming. However, because anticoagulants also carry a risk of bleeding, it's essential to balance the benefits and risks before starting any preventive therapy.
This tool has become a standard part of cancer care planning in many healthcare settings. It supports personalized treatment decisions and enhances patient safety by helping medical professionals proactively manage clotting risks in a targeted way.
This calculator is intended for use by healthcare professionals, patients undergoing cancer treatment, and caregivers who want to better understand the risk of blood clots during chemotherapy. It is especially useful for patients who have recently been diagnosed with cancer and are about to start or have already started chemotherapy, as this is a period when the risk of venous thromboembolism (VTE) is often elevated.
Oncologists, hematologists, and general practitioners may use the Khorana Score Calculator as part of their clinical assessment to identify patients who could benefit from preventive measures against blood clots. By inputting simple clinical and laboratory information, they can quickly estimate a patient's risk level and consider whether anticoagulation therapy or increased monitoring is appropriate.
Patients and caregivers can also use this calculator to have more informed discussions with their medical team. Understanding the potential risk of VTE can help patients ask the right questions, prepare for treatment, and recognize warning signs early. However, the calculator should never be used to make medical decisions without consulting a qualified healthcare provider.
In short, this tool is best suited for:
Using the Khorana Score Calculator is simple and takes only a few minutes. It involves selecting specific risk factors that are known to contribute to the likelihood of developing blood clots (venous thromboembolism) during cancer treatment. Follow the steps below to calculate your score:
The final score gives an estimate of the patient's risk level for developing blood clots. This score should be discussed with a healthcare professional to determine if any preventive measures, such as blood thinners, might be recommended.
Note: You can change any selection at any time and click "Calculate" again to update the score.
Different types of cancer are associated with varying levels of risk for developing venous thromboembolism (VTE), such as deep vein thrombosis or pulmonary embolism. The Khorana Score assigns a specific number of points based on the cancer site to reflect this risk. These points contribute to the total score and help determine the overall likelihood of clotting complications during chemotherapy.
These cancers are considered high-risk for VTE because they are strongly associated with increased clotting activity in the body. Patients with these cancers automatically receive 2 points toward their Khorana Score.
These cancer types carry a moderate risk of VTE. If the patient has any of these cancers, 1 point is added to the total score.
If the patient has a type of cancer not mentioned in the categories above (such as breast, prostate, or skin cancer), they receive 0 points for cancer site in the Khorana Score. These cancers are associated with a lower risk of clot formation during chemotherapy.
In addition to the cancer type, the Khorana Score considers several other clinical and laboratory factors that can increase the risk of developing venous thromboembolism (VTE). Each of these risk factors adds 1 point to the total score. These values are typically known before starting chemotherapy and can help provide a more accurate risk assessment.
A high number of platelets in the blood may indicate an increased tendency for clotting. If the patient's platelet count is equal to or greater than 350,000 per cubic millimeter before chemotherapy, 1 point is added to the score.
Hemoglobin is the protein in red blood cells that carries oxygen. A low hemoglobin level can be a sign of anemia, which is common in cancer patients. The use of erythropoietin-stimulating agents to treat anemia can also increase the risk of blood clots. If either condition applies, 1 point is added.
Elevated white blood cell (WBC) counts before chemotherapy may reflect an inflammatory or immune response, which can also contribute to a higher clotting risk. If the WBC count is greater than 11,000 per cubic millimeter, the patient receives 1 additional point.
A BMI of 35 or higher is considered severe obesity. Obesity is a known risk factor for blood clots, especially during periods of reduced physical activity, such as during chemotherapy. Patients with a BMI at or above this threshold receive 1 point in the scoring system.
Each of these factors is scored independently. When combined with the cancer site risk level, they help provide a clearer picture of a patient's risk for VTE and can guide clinical decisions about whether preventive measures are needed.
The Khorana Score is calculated by assigning point values to several known risk factors that are associated with a higher chance of developing venous thromboembolism (VTE) in cancer patients. These risk factors include the type of cancer, certain blood test results, and body mass index (BMI). Each factor contributes a fixed number of points, which are added together to determine the patient’s total score.
Once all applicable risk factors are selected, their point values are added together to produce the final Khorana Score. The calculator does this automatically when you click the “Calculate” button.
For example, a patient with lung cancer (1 point), a high platelet count (1 point), and a high BMI (1 point) would have a total score of 3.
The higher the score, the greater the risk of developing blood clots during chemotherapy, which can help guide decisions about preventive care and monitoring.
Once you’ve calculated your Khorana Score, it’s important to understand what the result indicates about your risk of developing venous thromboembolism (VTE) during cancer treatment. The score helps categorize patients into three risk groups: low, intermediate, and high risk. Each group provides guidance on how closely the patient should be monitored and whether preventive steps may be needed.
A score of 0 suggests a low risk of developing blood clots. Most patients in this category are unlikely to experience VTE during chemotherapy. In general, routine preventive anticoagulation (blood-thinning medication) is not recommended for low-risk individuals unless there are other strong reasons to consider it. However, it is still important to stay alert for symptoms such as leg pain, swelling, or sudden shortness of breath.
A score of 1 or 2 places the patient in the intermediate-risk category. This means the risk of VTE is higher than in the general cancer population, but not as high as in those with scores of 3 or more. For patients in this group, healthcare providers may consider preventive anticoagulation based on individual factors such as personal or family history of blood clots, other medical conditions, or specific cancer types. Regular monitoring and awareness of symptoms are especially important in this group.
A score of 3 or more indicates a high risk of developing blood clots. Patients in this group have the greatest chance of experiencing VTE during chemotherapy. In many cases, doctors may recommend preventive anticoagulant therapy unless there is a medical reason not to. These patients may also receive closer follow-up and education on how to spot early warning signs of blood clots.
The calculator helps estimate the risk of blood clots (venous thromboembolism) in cancer patients undergoing chemotherapy. It provides a score based on certain risk factors, allowing patients and healthcare providers to better understand potential clotting risks and decide if preventive treatment is needed.
Yes, the calculator is simple to use and can be completed by patients, caregivers, or healthcare providers. However, the result should always be discussed with a medical professional before taking any action, especially regarding medication or treatment changes.
If your cancer type is not included among the options provided, you should leave the cancer site section unchecked. This means you receive 0 points for that category, indicating a lower associated risk based on current medical research.
No. A high Khorana Score means you are at increased risk, but it does not guarantee that a blood clot will occur. It simply helps guide decisions about prevention and monitoring. Many high-risk patients never develop clots, especially if preventive measures are taken.
If your score is 3 or higher, you should speak with your doctor about whether preventive blood thinners or closer monitoring is appropriate for your situation. Never start or stop any treatment based on your score alone.
No. This tool is designed to support—not replace—the advice of a healthcare professional. It provides useful information, but only your doctor can consider your full medical history and make personalized recommendations.
The Khorana Score is a validated clinical tool and widely used in cancer care. However, like all risk assessment tools, it has limitations. It should be used as part of a broader clinical evaluation.
Venous Thromboembolism (VTE):
A condition where blood clots form in the veins, most commonly in the legs (deep vein thrombosis) or lungs (pulmonary embolism). It can be life-threatening if not treated promptly.
Deep Vein Thrombosis (DVT):
A type of blood clot that typically forms in the deep veins of the legs. Symptoms may include swelling, pain, and redness in the affected area.
Pulmonary Embolism (PE):
A serious condition that occurs when a blood clot travels to the lungs and blocks blood flow. Symptoms include shortness of breath, chest pain, and coughing.
Platelet Count:
A measure of the number of platelets in the blood. Platelets help with blood clotting. A high count (≥ 350,000/mm³) can increase the risk of forming unwanted clots.
Hemoglobin:
A protein in red blood cells that carries oxygen throughout the body. Low levels (less than 10 g/dl) may indicate anemia, which can influence clotting risk.
Erythropoietin:
A hormone or medication that stimulates the production of red blood cells. It is sometimes used to treat anemia in cancer patients, but it may also increase clotting risk.
White Blood Cell Count (WBC):
A measure of the body’s immune cells. A high WBC count (more than 11,000/mm³) can be a sign of inflammation or infection and may raise clotting risk.
Body Mass Index (BMI):
A number calculated from a person’s weight and height to determine body fat. A BMI of 35 or higher is classified as obesity, which can increase the risk of blood clots.
Chemotherapy:
A type of cancer treatment that uses drugs to destroy cancer cells. It can affect blood components and increase the risk of clotting in some patients.
Khorana Score:
A scoring system used to estimate the risk of VTE in cancer patients receiving chemotherapy. It is based on cancer type, blood counts, and BMI.
The Khorana Score Calculator is intended for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. While the calculator uses established clinical guidelines to estimate the risk of venous thromboembolism (VTE) in cancer patients, it cannot account for all individual factors or provide a complete risk assessment.
Always consult your doctor or a qualified healthcare provider with any questions you may have about your health or medical condition. Never ignore or delay seeking professional medical advice because of something you read or calculate using this tool.
This calculator does not provide medical or therapeutic recommendations and should not be used to make treatment decisions, including starting or stopping any medication. Only a licensed healthcare provider can determine whether preventive treatment for blood clots is appropriate for your specific situation.
Use of this tool does not establish a doctor-patient relationship. The creators of this calculator are not responsible for any health outcomes resulting from the use or misuse of the information provided.