Lymph Node Ratio May Predict Cancer Risk

A patient’s lymph node ratio (LNR) may help predict the course of a patient’s disease, thus guiding health care professionals to choose the most appropriate postsurgical therapy for patients with oral cancer, according to University of Colorado Cancer Center researchers. Patients with squamous cell carcinoma of the oral cavity who present with high LNR ratios may require more aggressive adjuvant therapies.

If cancer cells break away from the original tumor and travel to other parts of the body, the lymph nodes are often the first area the cancer cells spread to. For this reason, distinguishing location, number, size, and burden of cancer cell-affected lymph nodes can provide valuable information. This includes how fast the cancer grows, and how likely the cancer will spread to more distant parts of the body.

In the study, “Association Between Lymph Node Ratio and Recurrence and Survival Outcomes in Patients With Oral Cavity Cancer,” published in JAMA Otolaryngology, researchers identified the extent of lymph node involvement as a factor in predicting cancer risk. The team made the determination after looking at patterns of 149 patients treated at UCHealth University of Colorado Hospital with surgery and/or postsurgical treatments for locally advanced oral cavity squamous cell carcinoma from 2000 to 2015. The subjects studied had a median of 29 lymph nodes removed during surgery.

Results show about 9% of the lymph nodes removed tested positive for cancer. Subjects with an LNR (defined as the ratio of positive lymph nodes to the total number of lymph nodes surgically removed) greater than 10% had a 2.5 times greater risk of cancer recurrence, and 2.7 greater risk of death than those below 10%. Additional risk factors that predicted shorter overall survival includes having a larger primary tumor, having margins around the tumor that tested positive for cancer after surgery, or having tumors on surrounding tissues.

Although advances in imaging and therapeutic modalities for oral cavity squamous cell carcinoma have led to improved locoregional control, there has not been a marked improvement in survival rates over past decades, says the study’s first author Ding Ding, a MD candidate working with Sana Karam, MD, PhD, an assistant professor in the Department of Radiation Oncology at the University of Colorado Denver School of Medicine.

“Because of the often-delayed clinical diagnosis, poor prognosis, and expensive therapeutic approaches for this disease, prognostic accuracy is of paramount importance in improving survival outcomes of patients with oral cavity squamous cell carcinoma,” says Ding.

The National Institute of Dental and Craniofacial Research estimates 91,200 Americans are living with oral cancer, and that approximately 37,000 new cases are diagnosed every year. It is estimated that many cases that prove fatal could have been prevented with early diagnosis and treatment.¹

Early detection of oral cavity squamous cell carcinoma can be made in a dental setting during a conventional visual and tactile examination. Prompt oral cancer detection and diagnosis allows patients to begin appropriate therapy without delay.

“We believe these findings are hypothesis generating for treatment intensification and can help clinicians in prognosis prediction, clinical decision making, and the development of novel treatment strategies for management this disease,” says Ding.

Traditional treatment of oral cavity squamous cell carcinoma consists of removing the primary tumor by surgery, followed by radiation and/or chemotherapy if cancer cells are present in the surgical margins after the tumor is removed.

REFERENCE

1. National Institute of Dental and Craniofacial Research. Oral Cancer. Available at: https://report.nih.gov/NIHfactsheets/ViewFactSheet.aspx?csid=106. Accessed January 15, 2019.