What is the next best test to order for a female patient with a history of triple negative breast cancer, who is receiving chemotherapy, and presents with swelling of the right arm, given normal lab results and a recently placed peripherally inserted central catheter (PICC) line?

From the Guidelines

The most appropriate test to order now for this patient is a venous ultrasound of the right arm, which should be performed immediately rather than waiting four weeks, as suggested by the NCCN clinical practice guidelines in oncology 1. Given the patient's history of triple negative breast cancer and current chemotherapy treatment, along with the presence of a PICC line placed four weeks ago, there is a high risk of developing venous thromboembolic disease. The patient's symptoms of right arm swelling for three days are concerning for a possible deep vein thrombosis (DVT) or superficial vein thrombosis (SVT), both of which are common complications in cancer patients with central venous catheters. The NCCN guidelines recommend the use of comprehensive medical history and physical examination, CBC with platelet count, PT, aPTT, liver and kidney function tests, and consideration of venous ultrasound based on clinical judgment for the diagnosis of SVT 1. Key points to consider in the management of this patient include:

• The patient's cancer history and chemotherapy treatment increase the risk of thrombosis due to hypercoagulability associated with malignancy.
• The presence of a PICC line further increases the risk of thrombosis by causing endothelial damage and disrupting blood flow.
• A venous ultrasound is the standard first-line diagnostic test for suspected DVT or SVT as it is non-invasive, highly sensitive, and can quickly confirm the diagnosis.
• Delaying diagnosis and treatment of DVT or SVT could lead to serious complications including pulmonary embolism, so immediate imaging is warranted given the patient's presentation and risk factors.
• If the ultrasound confirms the presence of a clot, anticoagulation therapy should be initiated promptly, with options including rivaroxaban or fondaparinux at prophylactic doses, as recommended by the NCCN guidelines 1.

From the Research

Patient History and Presentation

• The patient is a female with a history of triple negative breast cancer, admitted with swelling of the right arm for the past three days.
• She has been receiving chemotherapy and had a PICC line placed four weeks ago.
• Exams have shown no redness on the backside, and all labs are normal, including excellent negative venous doctor and negative D-dimer.

Relevant Studies and Findings

• A study published in 2020 2 found that PICC-related thrombosis is a serious complication that can lead to interruptions in chemotherapy and other supportive care.
• The study also found that age >60 years and chemotherapy regimens containing fluorouracil were independent risk factors for PICC-related thrombosis.
• Another study published in 2015 3 found that ultrasonography had excellent sensitivity and specificity for diagnosing PICC-DVT and is recommended as the initial diagnostic test.
• A study published in 2014 4 found that recent diagnosis of cancer and PICC gauge were associated with PICC-DVT.
• A study published in 2019 5 found that anticoagulants such as rivaroxaban and low molecular weight heparin can prevent PICC-related upper extremity venous thrombosis in cancer patients.

Recommended Tests and Next Steps

• Given the patient's history and presentation, it is recommended to order an ultrasound to rule out deep vein thrombosis (DVT) or upper extremity venous thrombosis (UEVT) 3, 4.
• The patient's PICC line should be evaluated, and consideration should be given to removing it if necessary 2, 4.
• Anticoagulation therapy may be considered to prevent further thrombotic events 5.