A recent study published in JAMA Oncology presents promising new data on a treatment regimen beneficial to patients with a subset of head and neck cancer known as oropharyngeal cancer. A rare malignancy that forms in the middle of the throat, oropharyngeal cancer can develop in the roof of the mouth, tonsils, the back of the throat, or the back of the tongue.
A history of human papillomavirus (HPV) presents a significant risk factor for developing oropharyngeal cancer, as about two-thirds of patients carry HPV DNA. Oncologists classify these cases as human papillomavirus−positive oropharyngeal cancer (HPV+ OPC). Compared to oropharyngeal cancers not associated with HPV, treatment regimens involving chemotherapy and radiation significantly prolong survival in HPV+ OPC. Despite the treatment efficacy associated with chemoradiotherapy, long-lasting toxicities associated with these treatments remain a clinical challenge.
In search of a treatment regimen that retains tumor control with limited side effects, a team of researchers from the University of Chicago designed a clinical trial to evaluate the response and toxicity associated with a treatment regimen involving chemotherapy and an immune checkpoint inhibitor (ICI), nivolumab. ICIs, the class of immunotherapies that block the interaction between proteins on immune cells that would dampen the immune response if engaged, have efficacy in treating several types of cancer, often with limited toxicity. In the current clinical trial, ICI and chemotherapy serve as a neoadjuvant, drugs given in hopes of shrinking a tumor prior to an additional treatment. Not all patients received the same treatment following the neoadjuvant administration of chemotherapy and ICI. The research team first evaluated the clinical characteristics and response to the neoadjuvant regimen and assigned an appropriate “response-adapted locoregional therapy” involving standard treatments, including surgery, chemotherapy, and radiation.
The phase 2 clinical trial (NCT03107182) included 73 eligible patients with advanced HPV+ OPC. Researchers evaluated how well neoadjuvant nivolumab plus chemotherapy shrunk tumors. By comparing measurements before and after treatment, the doctors classified responders as patients whose tumors shrunk by at least 50%.
Notably, 51 of 73 patients (70.8%) responded to the neoadjuvant chemotherapy and ICI. Two years following treatment, progression-free survival (PFS) and overall survival (OS) each reached at least 90%. Patients also demonstrated improved swallowing, an important characteristic influencing quality of life in oropharyngeal cancer survivors.
The authors conclude that neoadjuvant ICI and chemotherapy are tolerated and feasible for HPV+ OPC. The study provides novel information on how oncologists can personalize therapeutic regimens to best suit patients based on initial responses to neoadjuvant therapy.
Sources: JAMA Oncol, NEJM
