In an article published September 22, 2016 in Frontiers in Immunology, researchers at the Medical University of South Carolina (MUSC) and the Ralph H. Johnson VA Medical Center report that inhibiting prostaglandin production slows the progression of premalignant lesions to head and neck squamous cell carcinoma (HNSCC). Preclinical studies showed that treatment of premalignant lesions with indomethacin, a nonsteroidal anti-inflammatory drug (NSAID) similar to aspirin, increased the presence of immune cells and lessened tumor burden.
Cancers of the head and neck begin with lesions in the oral cavity, including the larynx, pharynx, throat, lips, mouth, salivary glands, and nasal passages. Although the incidence of HNSCC has been on the decline over the past several decades, the National Cancer Institute reports that approximately 3% of all cancers in the U.S. result from HNSCC, with men being diagnosed twice as often as women. Treatment for HNSCC includes surgical removal and chemo-radiation treatment; however, these interventions often fail, and patients have a five-year survival rate of only 50%. It is critical to determine better treatment options for HNSCC patients.
One way researchers at MUSC are trying to improve the treatment of HNSCC is by enhancing the body's own immune system to attack the tumor.
"There's a lot of effort to stimulate immune reactivity using immunotherapy. The problem with that is cancer can protect itself against the immune defenses. Head and neck cancer is notorious for that," said immunologist M. Rita Young, Ph.D., senior author for this study, who holds a dual appointment at MUSC and the Ralph H. Johnson VA Medical Center.
As an immunologist, Young has been working on addressing this problem by studying how the immune system affects tumor progression. Previous work from her laboratory has shown that the composition of immune cells within premalignant lesions differs from that within HNSCC. Significantly, as premalignant cells develop into HNSCC, the immune environment switches from stimulatory/inflammatory to immunosuppressive. This change in the tumor microenvironment prevents the immune system from combating the cancer. Prostaglandin may be an important mediator of this switch.
The current study used a novel mouse model of HNSCC to determine how inhibition of prostaglandin affects tumor progression. Mice with premalignant lesions were given indomethacin, an NSAID that inhibits the production of prostaglandin. Indomethacin treatment increased the presence of immune cells at the lesion site and led to a systemic activation of the immune system. Specifically, there was an increase in both Th1-associated cytokines (IL-2 and IFN-γ) as well as Th2-associated cytokines (IL-10). This activation of the immune system reduced the progression of premalignant lesions to HNSCC.
Future studies in this area will be focused on maintaining a strong immune presence in pre-malignant lesions for patients. If studies in humans bear out these preclinical findings, further research using more specific prostaglandin inhibitors in combination with other immunomodulatory compounds could provide a better treatment regimen to prevent the formation of HNSCC.
"Immunotherapy should be considered as a treatment strategy for premalignant lesions before they progress to cancer. We can detect them. Why not treat them?" said Young. Furthermore, these intervention strategies may be able to help prevent smaller, as yet undetectable lesions from progressing to HNSCC.
This work provides strong evidence that treatment of premalignant lesions with indomethacin reduces the tumorigenicity of HNSCC. A better understanding of the mechanisms by which the immune system combats early-stage cancer could lead to improved clinical outcomes in HNSCC, and potentially, other types of cancer as well.
"If we can be more persistent and focused on finding premalignant lesions before they become malignant, simple therapies might be beneficial," said Sara Johnson, Ph.D., a postdoctoral fellow at MUSC and a co-author on the article.
Founded in 1824 in Charleston, The Medical University of South Carolina is the oldest medical school in the South. Today, MUSC continues the tradition of excellence in education, research, and patient care. MUSC educates and trains more than 3,000 students and residents, and has nearly 13,000 employees, including approximately 1,500 faculty members. As the largest non-federal employer in Charleston, the university and its affiliates have collective annual budgets in excess of $2.2 billion. MUSC operates a 750-bed medical center, which includes a nationally recognized Children's Hospital, the Ashley River Tower (cardiovascular, digestive disease, and surgical oncology), Hollings Cancer Center (a National Cancer Institute designated center) Level I Trauma Center, and Institute of Psychiatry. For more information on academic information or clinical services, visit musc.edu. For more information on hospital patient services, visit muschealth.org.
About the Ralph H. Johnson VA Medical Center
Located in historic downtown Charleston, South Carolina, the Ralph H. Johnson VA Medical Center is a tertiary care teaching hospital providing the highest level quality care from cardiology to neurology to primary and mental health care for 70,000 Veterans along the South Carolina and Georgia coast. The Ralph H. Johnson VA achieved a 5-Star rating according to VA's Strategic Analytics for Improvement and Learning Value (SAIL) model. The SAIL rating ranks the Charleston VA in the top 10 percent of VA medical centers nationwide for quality of care and efficiency. The Charleston VA is also ranked in the top 10th percentile according to the Healthcare Effectiveness Data and Information Set (HEDIS). HEDIS is an independent review that measures performance of 90 percent of America's health plans and facilities in both the public and private sector on dimensions of care and service. The Ralph H. Johnson VA Medical Center is a center of excellence for robotic surgery and orthopedics, and is the first VA National Tele-Mental Health Hub providing care for Veterans across the U.S. The 149-bed hospital includes six community based outpatient clinics, a 20-bed nursing home, women's health, and the full range of inpatient and outpatient care, including medical and surgical intensive care. The VAMC provides more than 875,000 outpatient visits and approximately 4,400 in-patient stays annually. With more than 2,500 employees, Charleston VA has an annual budget of $458 million, research funding of more than $21 million, and more than 100 principle investigators participating in approximately 300 research studies. For more information, visit http://www.charleston.va.gov.
Frontiers in Immunology