A new study from NYU College of Dentistry researchers provides insight as to why patients with metastatic oral cancer experience greater pain than patients with oral cancer that has not spread to other parts of the body. The study is published in the journal Scientific Reports.
Study author Brian L. Schmidt, DDS, MD, PhD, is director of the NYU Oral Cancer Center. He has dedicated his career to understanding oral cancer. "I have been investigating the underlying cause of oral cancer pain for two decades. This is the first time that we have demonstrated a correlation between a patient's pain and the clinical behavior of the cancer," says Schmidt.
Oral cancer can cause patients severe pain when talking and eating. Now genetic and cellular clues suggest that oral cancer is more likely to metastasize in patients experiencing high levels of pain. When oral cancer spreads to the lymph nodes, survival rates drop by half. Yet, detecting this spread through the available imaging methods is difficult. If pain levels could be used as indicators of spread, say the researchers, it may be possible to detect metastasis earlier on.
"Clinicians and researchers are keen to define a biomarker that accurately predicts metastasis," said lead author Aditi Bhattacharya, PhD, an assistant professor in the Department of Oral and Maxillofacial Surgery at NYU College of Dentistry and an investigator at NYU Bluestone Center for Clinical Research. "Given that patients with metastatic oral cancer experience more pain, we thought that a patient's level of pain might help predict metastasis. A surgeon could then use this knowledge to only remove lymph nodes in patients with cancers that are most likely to metastasize."
As of now, surgeons often preemptively remove lymph nodes in an invasive surgery called prophylactic neck dissection in order to stave off metastasis. However, estimates suggest that up to 70% are unnecessary.
In conducting their analysis, the researchers found differences in gene expression between metastatic cancers from patients with high levels of pain versus non-metastatic cancers from patients not experiencing pain. The team found 40 genes that were more highly expressed in painful metastatic cancers.
The researchers say these genes could act as biomarkers for oral cancer metastasis and could assist providers in making difficult decisions about surgery procedures. "While we need to undertake a follow-up study, our current data reveals that a patient's pain intensity score works as well as the current method--the depth of invasion, or how deeply a tumor has invaded nearby tissue--as an index to predict metastasis," said Bhattacharya.