NHRMC Annual Oncology Report 2016
Disease Site: Squamous Cell Carcinoma of the Head & Neck (SCCHN)
Patrick D. Maguire, MD
In the U.S. in 2015, an estimated 46,000 people were diagnosed with cancers of the oral cavity and pharynx (throat). Another approximately 14,000 people were diagnosed with cancer of the larynx (voicebox). These disease sites represent 3.6% of all cancer diagnoses in the U.S. These cancers are predominantly squamous cell carcinomas of the head and neck (SCCHN). We analyzed SCCHN cases diagnosed and/or treated at NHRMC from 2011 to 2015 for this report.
As can be seen in Table 1, the majority (87%) of patients diagnosed with SCCHN at NHRMC during this time period were white, while 12% were black. These numbers indicate that SCCHN affects whites relatively more frequently, since our local population is ~22-24% black. Between 2007 and 2011 in the U.S. overall, SCCHN diagnoses among white men increased by 1.3% per year, while diagnoses among blacks decreased by 3% annually for men and 1.4% annually for women. Most of the increase among white men was due to the growing subset of SCCHN that is associated with the human papillomavirus (HPV; discussed in detail below).
Table 2 shows age at diagnosis of SCCHN at NHRMC between 2011 and 2015. As expected, most patients are diagnosed between 50 and 70 years of age. However, 15% of patients were diagnosed between ages 41 and 50. Again, this statistic correlates with the national trend of increased diagnosis of oropharynx SCC among men, associated with HPV.
About 50% of NHRMC patients had HPV-associated cancer documented, as shown in Table 3. At the time of biopsy, the pathologist checks tumor cells for a protein called p16. This biomarker, known as a cyclin dependent kinase (CDK) inhibitor, is overexpressed on tumor cells as a result of HPV infection and is highly indicative of HPV as the source of the patient’s cancer. Nationally, anywhere from 50-70% of oropharynx cancers are found to be HPV-associated. Patients with HPV+ cancers tend to respond better to standard treatment and have higher cure rates than those with HPV- SCCHN.
In Table 3, 29% of patients are labelled as “HPV unknown,” which is unacceptable. For the past few years, NHRMC pathologists now routinely test all patients with oropharynx cancer for p16 to evaluate potential HPV-association, which helps to guide patient prognosis and treatment. In fact, our radiation oncologists are now actively enrolling eligible patients onto a national clinical trial testing de-intensified treatment for non-smoking patients with HPV+ oropharynx cancers, hoping to decrease treatment-related side effects while maintaining high cure rates. (https://www.nrgoncology.org/Clinical-Trials/NRG-HN002).
Patients with early stage SCCHN are often treated with surgery alone, or radiation therapy alone, depending upon the disease site of origin. Cure rates are generally >90%. On the other hand, those with advanced stage disease are most frequently treated with concurrent intensity modulated radiation therapy (IMRT) and chemotherapy (CRT). The survival curves shown in Figure 1 are mixed. Due to the relatively small number of patients recorded with stages 1-3 cancer, these survival data are less reliable. However, among the 63 patients from NHRMC documented as stage IV between 2011 and 2015, survival rates at 2 years of ~80% and 3 years of ~70% correlate well with those nationally, including major academic cancer centers.
|Observed Survival Analysis
|| Stage 1 Cases
||Stage 2 Cases
||Stage 3 Cases
||Stage 4 Cases
||2011 to 2015 Head Neck
| Beginning %
| Year 1
| Year 2
| Year 3
The multi-disciplinary team of radiation oncologists, medical oncologists, and otolaryngologists at NHRMC have been at the forefront of designing CRT regimens for patients diagnosed with SCCHN. Fifteen years ago, CRT for advanced was fairly effective but very toxic (https://www.ncbi.nlm.nih.gov/pubmed/14967423). Radiation therapy was not well refined, requiring treatment of the entire throat and neck to full doses. Chemotherapy consisted of two drugs delivered in high doses while patients were hospitalized for two weeks of their seven week course. Major side effects included permanent dry mouth and frequent long-term swallowing dysfunction. Over the past decade, the NHRMC multi-disciplinary oncology team has combined tailored IMRT with single drug outpatient weekly chemotherapy to maintain high cure rates while limiting treatment-related toxicity (https://www.ncbi.nlm.nih.gov/pubmed/20378262). They expect to publish the results of their latest efforts in 2017.