Carcinoembryonic antigen (CEA) has been shown to be associated with tumor burden in patients with colorectal cancer. However, it is also elevated to a significant degree in a number of other malignant and non-malignant conditions. We report a case of reversible CEA elevation in a patient using lithium for bipolar disorder.
A 58-year-old female with a longstanding smoking history and a past medical history of chronic obstructive pulmonary disease (COPD), bipolar illness, hypothyroidism, and obesity was found to have an elevated CEA level of 11.2 ng/ml (normal level<5 ng/ml) in the workup for postmenopausal bleeding.
Her history was not positive for malignancy of colorectum, ovaries, thyroid, or breast. She underwent a large number of imaging and endoscopic studies to evaluate for colorectal, breast, ovarian, and lung cancer; however, it did not reveal any evidence of malignancy. Upon review of her medications, she reported that she had recently started lithium for her bipolar illness. We followed up on her CEA level while her dose of lithium was reduced from 450 to 300 mg per day. Her CEA level decreased from 25 mg/dl to 6.1 mg/dl and remained stable over the course of the next eight months. Our case is the first case report that identifies lithium as a potential cause of reversible CEA elevation. The underlying mechanism is yet to be elucidated, but it underscores the importance of investigating the medications as part of the workup.
Doctors don’t always see obvious signs of cancer growth after a diagnosis. They need to hunt for clues. One way they can do that is with a carcinoembryonic antigen test. It measures a protein called CEA in the blood.
People with some types of cancers have higher than normal levels of this substance. This test helps your doctor find out if yours has grown and whether your treatment has worked.
CEA is a type of protein in the body. Babies in the womb have high levels of it. After birth, levels drop way down. Healthy adults have a very low level, but some types of cancer can cause it to rise.
Your doctor can use CEA as a “marker” to learn more about your cancer.
The test can often help predict whether the cancer is growing or spreading to other parts of your body. It can also help tell how well your treatment has worked and predict your outlook.