What is the clinical significance of eosinophilia with mildly elevated Carcinoembryonic Antigen (CEA)?

From the Guidelines

The combination of eosinophilia with mildly elevated Carcinoembryonic Antigen (CEA) is a significant finding that warrants thorough clinical evaluation, as it may indicate underlying conditions such as gastrointestinal or pulmonary malignancies, particularly colorectal cancer, which can present with both elevated CEA and paraneoplastic eosinophilia. This finding could also suggest non-malignant conditions such as inflammatory bowel disease, parasitic infections, allergic disorders, or certain medications. A comprehensive diagnostic approach should include a complete history and physical examination, followed by targeted investigations including complete blood count with differential, stool examination for parasites, chest imaging, and age-appropriate cancer screening including colonoscopy 1.

Some key points to consider in the evaluation of eosinophilia with mildly elevated CEA include:

• The degree of CEA elevation, with mild elevations (5-10 ng/mL) being less specific for malignancy than higher values
• Serial CEA measurements over time providing more valuable information than a single reading
• The importance of considering the patient's risk factors for colorectal cancer and age when determining the priority of colonoscopy
• The potential for non-malignant conditions to cause elevated CEA, such as gastritis, peptic ulcer disease, diverticulitis, liver diseases, chronic obstructive pulmonary disease, diabetes, and any acute or chronic inflammatory state 1

In terms of specific conditions that may be associated with eosinophilia and mildly elevated CEA, hypereosinophilic syndromes (HES) are a group of rare and heterogeneous syndromes characterized by elevated eosinophils in the peripheral blood and organ/tissue damage due to eosinophilic infiltration in the absence of other etiologies 1. HES can often be distinguished from other conditions such as eosinophilic esophagitis (EoE) by the presence of peripheral eosinophilia (AEC >1500 cells/uL), which is rare in isolated EoE 1.

Overall, the evaluation and management of eosinophilia with mildly elevated CEA should be individualized based on the patient's specific clinical presentation, risk factors, and underlying conditions. A thorough clinical evaluation and targeted investigations are necessary to determine the underlying cause of this finding and to guide appropriate treatment.

From the Research

Eosinophilia and Elevated CEA

• Eosinophilia is a condition characterized by an elevated count of eosinophils in the blood, which can be caused by various factors such as allergic disorders, parasitic infections, leukemia/lymphomas, and vasculitis-immunodeficiency diseases 2.
• The clinical significance of eosinophilia with mildly elevated Carcinoembryonic Antigen (CEA) is not directly addressed in the provided studies, but it is known that eosinophilia can be associated with various conditions, including neoplastic disorders 3.
• CEA is a tumor marker that can be elevated in certain types of cancer, such as colorectal cancer, but it can also be elevated in other conditions, such as inflammation and infection 4.

Diagnostic Approach

• The diagnostic approach to a patient with eosinophilia should include a thorough history and physical examination, followed by laboratory and instrumental investigations to identify the underlying cause of the eosinophilia 2, 3.
• The level and persistence of blood eosinophilia can help guide the diagnostic workup and identify patients who require further evaluation 2.
• A rational approach to the diagnosis of hypereosinophilia includes serologic, blood, and bone marrow cell analyses, genetic testing, and radiologic imaging, as well as input from specialists such as hematologists, dermatologists, and gastroenterologists 3.

Treatment and Management

• The treatment and management of eosinophilia depend on the underlying cause and severity of the condition, as well as the presence of organ involvement 5, 6.
• Treatment options may include medications such as immunosuppressive agents and kinase inhibitors, as well as biologics that target IL-5 and eosinophils 3.
• In cases of eosinophilic colitis, treatment options may include avoidance of food allergens, parasitic infections, and drugs that can cause colonic eosinophilia, as well as medications such as corticosteroids and immunomodulators 4, 6.