Emily+Paton

**An Unforseen Trial: Andy Hinton's Battle with Head and Neck Squamous Cell Carcinoma**

 * Part I: The Cancer**

On July 2, 2015, Lucy Hinton paced back and forth in the waiting room at the University of California San Francisco (UCSF) Cancer Center. Her phone buzzed as her friends sent their words of encouragement. She watched the clock tick; it seemed painfully slow. Meanwhile, her husband, Andrew, or “Andy” as his friends called him, was down the hall, undergoing a biopsy for a potentially cancerous mass in his neck. About two months before, Andy developed what he thought was a mild case of tonsillitis. Ignoring the pain and going about his day-to-day routine as normal, he was oblivious to the tumor growing inside of him. However, when his discomfort persisted, Andy finally sought the advice of his internist, who was concerned by the isolation of pain to one side of his throat. She recommended a computerized tomography (CT) scan, which revealed two masses: one in his tonsil and one in a nearby lymph node. The results of the CT scan were indicative of cancer. Andy’s internist referred him to UCSF Cancer Center, where the masses would be biopsied. Before the procedure, the surgeon flipped through Andy’s chart: white, 53 years old, college education, father of two children, happy household, regular exercise, no pre-existing conditions, moderate alcohol consumption and a non-smoker. Apart from being a white male, Andy did not fit the profile of a typical throat cancer sufferer (1). A few days later, Andy and Lucy received the biopsy results from the pathologist: Human Papilloma Virus (HPV)-positive oropharyngeal squamous cell carcinoma (SCC). Although Andy was unaware that had been infected with HPV, his doctors informed him his positive HPV status was the main contributing risk factor for his cancer. While smoking and drinking are the top two causes of oropharyngeal SCC, HPV is an additional major risk factor for head and neck cancers, and is implicated in up to 60 percent of oropharyngeal squamous cell carcinomas (2). Andy was one of the approximately 53,805 males in the United States to be diagnosed with oropharyngeal cancer that year, and part of the even smaller fraction (approximately 10 per 100,000 population) of individuals with HPV-positive disease (3). In addition to receiving the weighty diagnosis of //cancer//, Andy also learned that tumor cells had spread to a local lymph node, which was what his doctors had seen on the CT scan. Andy’s tumor had grown to a large enough size that it pushed on local nerve endings, causing the pain he mistook for tonsillitis. However, he was relieved to learn that HPV-positive carcinomas have a “cure” rate between 70 and 90 percent, even at later stages, putting him in the “low risk” category for tumor recurrence and death (4). Andy’s seemingly favorable prognosis was not to last. To confirm that his cancer was confined to his tonsil and lymph node, Andy received a positron emission tomography (PET) scan, which revealed an additional active cancer site in his abdomen. On July 8, 2015, Andy was diagnosed with metastatic disease: Stage IVC HPV-positive oropharyngeal squamous cell carcinoma. His doctors explained that “IVC” means that his cancer has spread to distant sites in his body, a feature of aggressive cancers (5). Until recently, the association between HPV and head and neck cancers was unknown, apart from the virus being a major risk factor. HPV is now viewed as an important prognostic factor in head and neck squamous cell carcinomas (HNSCCs). If Andy were a smoker, and if his cancer were HPV-negative, his chance of surviving longer than one year would have been less than 50 percent (6). HNSCCs that are associated with HPV infection have been shown to have much more favorable prognoses than those caused by heavy smoking or drinking. In patients with this type of HNSCC, the three-year overall survival rate is 82.4 percent for stage III and IV disease (7). Nevertheless, given the current treatment options, any case of metastatic disease is, essentially, “incurable.” For this reason, Andy’s oncologist decided not to give him a definitive “cure rate” for his disease. Furthermore, Andy’s cancer displayed unusually aggressive behavior for HPV-positive carcinomas, indicating that unique pathological features might have been missed on the biopsy. For example, one study showed that HNSCCs can contain small cell components, leading to significantly more aggressive behavior and poorer prognosis (8). This study indicates that other pathological features, in addition to HPV, must be thoroughly examined. The night of July 8, Andy lay awake, unable to sleep or think of anything other than what lay ahead. As Lucy tossed and turned, he thought of his children, and the grandchildren he may never live to meet. That night, he vowed to himself to never surrender to his cancer. If one therapy stopped working, he would move on to the next. While the future seemed bleak, he felt blessed to be surrounded by an incredibly supportive group of friends and, of course, his family.
 * Part II: Molecular Basis**

To determine the best possible treatment regimen for Andy’s cancer, doctors analyzed samples from his tumors to uncover specific targets for therapy. Most notably, his doctors confirmed that his tumor was HPV positive via genotypic analysis through PCR amplification of certain HPV genes that integrate into human chromosomes (9). Andy’s tumor expressed HPV-16, a “high risk” subtype of HPV that is associated with chronic inflammation and cancers of the oropharynx (10). A high level of immune cell infiltration was confirmed in Andy’s tumor by scoring the leukocytes and neutrophils (10). In addition to increasing inflammation, high-risk HPV genes in Andy’s tumor also activated cancer growth and prevented the early cancer cells from undergoing apoptosis, or programmed cell death (11). Interestingly, the overall mutation rate in high-risk HPV-positive tumors is about half of that in HPV-negative tumors, indicating that certain molecular hallmarks of HPV-positive oropharyngeal cancers are due to viral oncogene expression (11). Namely, HPV-16 protein E6 inactivates the tumor suppressor p53, a protein that regulates the cell cycle (Figure 1) (11). This malignant transformation occurs when E6 binds to and activates the cellular ubiquitin-protein ligase E6-AP, an enzyme that targets p53 for degradation (11). Because HPV E6 greatly alters p53 activity, mutations in p53 are less common in HPV-16 positive oropharyngeal cancers than HPV-16 negative, where the mutation rate is nearly 50 percent (12). Indeed, Andy’s tumor samples did not show mutations in the p53 locus and did not express the functional protein. Both a loss-of-function mutation in p53, as in the case of HPV-16 negative tumors, and degradation of the protein, due to HPV-16 protein E6, can lead to decreased cell cycle regulation. However, studies have revealed that these distinct mechanisms of p53 inactivation are functionally inequivalent (13). Chiefly, tumors expressing HPV-16 gene products display a higher level of chemo and radiosensitivity; this observation suggests that these cancer cells retain their apoptotic response more than p53 mutant tumors (13). A study on HPV-positive tumors found that radiation induced p53 phosphorylation at Ser15 and Ser20, which weakens its interaction with a negative regulator (15). This phosphorylation increases p53 activity in response to DNA damage, as in the case of radiation, leading to apoptosis (15). Based on this hallmark of HPV-positive oropharangeal cancers, Andy’s tumor is a candidate for combined chemotherapy and radiation. In addition to p53 downregulation, Andy’s tumor also lacked a functional retinoblastoma tumor suppressor protein (Rb) (11). Several studies have shown that HPV viral protein E7 disrupts the Rb signaling pathway, which is important in cell cycle regulation (Figure 1) (14). Specifically, E7 binds to and inactivates the hypophosphorylated state of Rb, which, in normal conditions, prevents cell division. This inhibition leads to the release of E2F, a transcription factor that promotes DNA synthesis and cell division (15). Andy’s tumor did not show a mutation in the Rb gene, indicating that the HPV virus is an important factor in the downregulation of Rb, similar to p53. In a study of HPV-positive and HPV-negative tumors, the majority of Rb defective tumors expressing HPV did not have genetic defects in the RB1 gene. Interestingly, Rb defective tumors in the study were all metastatic but the patients with these tumors had more favorable prognoses than tumors not expressing HPV. These patients responded well to radiation following tumor resection surgery, an observation that partially explains their longer survival (16). With this data in mind, Andy’s doctors presented him with two options for treatment, both of which would account for the HPV-16 expression in his tumor. In accordance with the standard of care, Andy was given the option of undergoing chemotherapy and radiation following debulking surgery of his primary tumor. Alternatively, he could enroll in a clinical trial of INO-3112, an immunotherapy drug designed to target viral oncoproteins E6 and E7 in cervical and oropharyngeal cancers (17). Given the aggressive nature of his cancer and early metastasis, his decision would be met with great difficulty. **Part III: Treatments** Cetuximab, radiation, INO-3112 immunotherapy: Andy was bombarded with foreign vocabulary and scientific jargon as he sat alongside Lucy, across from his medical and radiation oncologists, in an unwelcoming medical office. As if his diagnosis of metastatic cancer was not enough to swallow, his doctors continued to force-feed him convoluted information on his cancer, its possible treatments, and their potentially detrimental side effects. Dr. Jimenez, Andy’s medical oncologist, reassured Andy that although his cancer had spread, he still had two very promising treatment options. With a three-year overall survival rate of 25 percent, the prognosis for his HPV-positive oropharangeal cancer was still better than it would be if his cancer were HPV-negative, which has a 15 percent three-year survival rate (18). Despite the difference, Dr. Jimenez noted the standard of care for these two distinct subtypes was the same, with combination chemotherapy and radiation as the typical treatment regimen (19). This strategy had proven to be the most effective treatment for Stage IV HPV-positive head and neck cancer patients in the past (15). However, Dr. Jimenez and Dr. Stahl, Andy’s radiation oncologist, emphasized the severity of the side effects should he choose the standard of care. From the seven weeks of daily radiation burning the surface of his tongue, he would lose his ability to taste food (20). Eventually, he would be forced to eat through a feeding tube, his throat becoming too swollen and painful to swallow (22). After every cycle of combined cetuximab, platinum, and 5-flurouracil chemotherapy (19), he would feel unrelenting nausea and persistent fatigue. Even long after treatment, Andy would face jaw stiffness from the bone loss due to radiation (21). Unconvinced that the benefits of aggressive radiochemotherapy outweighed its side effects, Andy considered the alternative: an immunotherapy drug, INO-3112. INO-3112 was developed to target HPV proteins E6 and E7 in HPV-positive tumors of various locations (17). Until recently, however, it was only studied in clinical trials of cervical cancers (20). Researchers investigating the drug hypothesized that, because the molecular profiles of HPV-associated tumors are similar regardless of location, INO-3112 has the potential to generate immunity that could prevent disease progression (20). Indeed, evidence from the small sample (n=19) of patients enrolled in the study, as of June 2015, suggests that the drug increases HPV-specific immunogenicity (20). Strong evidence for drug efficacy in the cervical cancer clinical trials, as well as limited but significant data on its ability to produce immune responses in head and neck cancer patients, prompted Dr. Jimenez to offer the Phase I/II trial to Andy as an alternative to the standard of care. While the early clinical trial results were encouraging, the small sample size and lack of information on long-term patient outcomes left Andy skeptical. The trial was in an early phase; the side effects of doses higher than those given to earlier patients were largely unknown. Would he become the test subject, visiting the hospital every other week to have his blood sampled? Or against all odds, would the immunotherapy drug somehow cure his metastatic cancer? After several days of consideration, Andy finally decided to enroll in the clinical trial. He would receive INO-3112 via electroporation: to increase cell membrane permeability, his body would be pulsed with electrical fields (23). Every 3 weeks for 4 total doses, Andy and Lucy would return to the University of Colorado Cancer Center, hoping each time that the drug was working to shrink his tumors. If successful, his body would begin to produce antibodies against E6 and E7, destroying the viral gene products that block the p53 and Rb pathways (20). Although there was no guarantee the drug would work, Andy was relieved to avoid a treatment that would severely hinder his quality of life, and was reassured by his doctors’ support for his decision. Not all cancers are created equal. For Andy Hinton, this reality gave him hope for an effective treatment: an immunotherapy drug that targeted the HPV proteins expressed in his cancer. Others are not as fortunate. Had smoking or drinking caused Andy’s cancer, his chances of survival would have diminished significantly. Let us continue to search for different ways in which we can target all cancer types, to give hope to those patients who would have previously had no options.
 * Aperçu**

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 * References: **
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