Screening for malignancy in patients with unprovoked VTE

Dr Mark Crowther is a professor and chair of the Department of Medicine and the Leo Pharma Chair in Thromboembolism Research at McMaster University.

Is it rational to perform screening tests for malignancy in patients with unprovoked VTE?

Mark Crowther, MD, MSc: A very important question. There is no doubt that venous thromboembolism (VTE) is increased in patients with cancer and it varies across different types of cancer. Dr Marc Carrier, who is an expert and works at the Ottawa Hospital at the University of Ottawa, has recently published a lot of information on how to optimally evaluate patients with VTE and determine if they have cancer.

There are 2 strategies that you can follow. The first strategy: if a 58-year-old man shows up with a new deep vein thrombosis (DVT), you aggressively evaluate him to see whether or not he has a cancer, because in somewhere between 5% and 10% of cases you will probably find one. That strategy relies on the fact that finding the cancer and treating it actually improves the patient’s outcome, and we do not have evidence for that yet.

The other strategy: here is a 58-year-old gentleman who has an episode of DVT, let us do age-appropriate screening—so screening as recommended by the national societies—do simple clinical evaluations and laboratory testing looking for evidence of a cancer and if you do not find one, then do not proceed any further unless the person develops symptoms.

That latter strategy is the preferred one because there is no evidence yet that aggressive screening actually improves the outcome of patients.