06-06-2025
Small Ear-Wax Sample, Big Diagnostic Clues
A recent BBC report suggests that cerumen, commonly known as earwax, may harbor biomarkers to aid in the diagnosis and monitoring of conditions such as cancer, Alzheimer's disease, and metabolic disorders.
Cerumen Profile
The primary function of cerumen is to keep the external auditory canal clean and lubricated, preventing invasion by bacteria, fungi, and insects. Beyond this, cerumen may reflect systemic metabolism by concentrating a broader array of compounds than blood, urine, sweat, and tears. Its relative stability allows the accumulated cerumen to provide long-term snapshots of metabolic changes.
Disease Associations
Researchers have defined genetically determined wet and dry cerumen phenotypes. In the US, Caucasian, African American, and German women with wet cerumen faced roughly four times the risk of dying from breast cancer compared with Japanese and Taiwanese women with dry cerumen. The study found that Japanese women with breast cancer were more likely to carry the wet-cerumen allele than were healthy controls. However, large-scale studies in Germany, Australia, and Italy failed to confirm these associations.
A recent analysis reported that patients with Ménière's disease had lower levels of three fatty acids in the cerumen compared with healthy controls — the first biomarker identified for that disorder.
In a 2019 study led by Nelson Roberto Antoniosi Filho, PhD (Federal University of Goiás Goiânia in Brazil), researchers analyzed cerumen samples from 52 patients with lymphoma, carcinoma, or leukemia and 50 healthy volunteers, using a method that identifies volatile organic compounds (VOCs). The researchers identified 27 VOCs that served as diagnostic fingerprints for cancer, predicting the cancer status with 100% accuracy. The assay could not distinguish among cancer types, indicating that these VOCs represent a general response to malignant cells.
Another investigation by the same group showed that cerumen analysis can detect metabolic disturbances in premalignant stages when cells exhibit dysplastic changes that may lead to cancer but remain nonmalignant, potentially enabling much earlier intervention. The team is also investigating whether metabolic alterations caused by neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease, can be detected in the cerumen.
Diagnostic Tool
Antoniosi Filho and colleagues proposed that cancer, as a mitochondrial metabolic disorder, releases VOCs that accumulate in cerumen, allowing differentiation between healthy and cancerous individuals via an assay they call the cerumenogram. The aim was to develop a cerumenogram as a diagnostic tool to accurately predict certain cancers from a small cerumen sample.
Clinical Adoption
Hospital Amaral Carvalho in Jaú, São Paulo — a national reference center for oncology and bone marrow transplantation — has recently implemented cerumenograms for cancer diagnosis and monitoring.
Future Directions
An April 2025 paper in Scientific Reports by Antoniosi Filho concluded that the cerumenogram could:
1. Identify oncologic risk by detecting premalignant cells before cancer onset, introducing a novel screening modality
2. Show that mitochondrial impairment in premalignant cells — such as hypermetabolic inflammation and dysplasia — produces the same VOC biomarkers as malignant cells, distinct from those in benign lesions, opening new paths for risk management and early intervention
3. Correlate cerumenogram findings with established imaging techniques such as 2-deoxy-2-[fluorine-18] fluoro-D-glucose PET/CT (18F-FDG PET/CT) and gallium-68 PSMA PET/CT, demonstrating alignment with clinical results while offering a noninvasive, lower-cost alternative
4. Monitor treatment response and cancer remission, supporting assessment of therapeutic efficacy and cellular return to normal
5. Confirm metabolic indicators of malignancy to guide clinical decisions alongside imaging and biopsy
6. Drive the development of targeted therapies aimed at metabolites overproduced in malignant conditions.
In conclusion, the cerumenogram may serve as a valuable assay for evaluating precancerous indicators, cancer progression, and remission, with the potential to reduce mortality, alleviate patient suffering, and lower disease-related costs.
Congratulations to Nelson Roberto Antoniosi Filho, PhD, and his team.
