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Squamous cell carcinoma (SCC) of the oropharynx affects nearly 50,000 individuals in the United States each year, and, with the rising incidence of the human papillomavirus (HPV), the number of patients diagnosed with SCC is expected to continue to grow (American Cancer Society 2018; Coughlan and Frick 2012). Oropharyngeal squamous cell carcinoma (OPSCC) has traditionally been treated with wide surgical extirpation often involving removal of portions of the oral cavity, pharynx, and jaw; this kind of surgery can be disfiguring and has been associated with significant post-operative complications (Brickman and Gross 2014). In the late 20th century, clinicians began favoring the use of chemoradiation therapy instead of surgery in an effort to spare patients the morbidity associated with surgical techniques at the time (Mercante et al. 2015). While chemoradiation offers excellent survival for patients with SCC, this therapeutic strategy has been observed to have its own debilitating post-treatment side effects (Hamilton and Paleri 2017). An important advancement in the management of OPSCC occurred about 20 years ago with the advent of transoral robotic surgery (TORS), a surgical technique that uses a robotic system to operate through the natural opening of the mouth. Proponents of TORS suggest that the technology improves on conventional surgery and may provide patients with functional outcomes superior to those seen with chemoradiation with no sacrifice in survival (Yeh et al. 2015; Hay et al. 2017). This review investigates the validity of the concept that TORS has significant advantages in the modern-day treatment of OPSCC. This report includes three components. First, the TORS technology, its advantages, and its drawbacks are explained. Second, relevant medical literature is reviewed to provide an understanding of the rationale for utilizing TORS in the treatment of OPSCC. Review and analysis of published reports show that TORS can provide patients with excellent post-operative function, good quality of life, and acceptable survival rates. Notable exceptions include patients with advanced disease. Third, this review discusses future studies that will better inform caregivers about the utility of TORS in the treatment of OPSCC. TORS is a relatively new technology that seems to offer the possibility of helping to improve the lives of patients with OPSCC.

The p63 transcription factor, a member of the p53 family, plays an oncogenic role in squamous cancers, while its expression is often repressed in breast cancers. In the canonical conserved Hippo pathway, known to play a complex role in regulating the growth of cancer cells, the protein kinases Mammalian Ste20 like kinases 1/2 (MST) and Large tumor suppressor kinases 1/2 (LATS) act sequentially to phosphorylate and inhibit the Yes-associated Protein/Transcriptional coactivator PDZ binding transcription factors (YAP/TAZ). We found that in the MCF10A mammary epithelial cell line and insquamous and breast cancer cell lines, expression of deltaNp63 RNA and protein is strongly repressed by inhibition of specific components of the Hippo pathway in a manner that is independent of p53. While the Hippo pathway protein kinases MST1/2 and LATS1 are required for p63 expression, the next step of the pathway namely phosphorylation and degradation of the YAP/TAZ transcriptional activators, is not required for repression of p63. This suggests that regulation of p63 expression occurs by a non-canonical version of the Hippo pathway. Interestingly, we observed that experimentally lowering p63 expression leads to increased Yes Associated Protein protein levels, thereby constituting a feedback loop. In addition, p63 loss reduces the growth of MCF10A and squamous cancer cell lines. These results, which reveal the intersection of the Hippo and p63 pathways, may prove useful for the control of their activities in cancer cells.

It is has been observed in several cell systems that cisplatin can radiosensitize and that the response of cells to combination cisplatin and radiation depends on several factors. These include the radiation dose and drug concentration used, the order in which the two treatments are administered, and the time between their administration. The response of a head and neck squamous carcinoma cell line to combination cisplatin-radiation treatment was examined. The response was found to be additive when cisplatin was given first, regardless of the timing and magnitude of the treatments administered. When cells were treated with radiation first, antagonism was observed for low radiation doses and drug concentrations. The response may be explained by a low radiation dose induction of processes that protect the cell from a second damaging agent, similar to the adaptive response. There is some indication in the literature that cisplatin can preferentially radiosensitize cells that are proficient in certain types of DNA repair. Therefore, the response of a cisplatin-resistant strain of the SCC-25 cell line was also investigated. The cisplatin-resistant cell line was found to be substantially radiosensitized by cisplatin for moderate amounts of radiation and cisplatin. The results are discussed with reference to the current proposed mechanisms for cisplatin-radiation interaction. / Thesis / Master of Science (MS)

Thesis (Ph. D.)--Ohio State University, 2007. / Full text release at OhioLINK's ETD Center delayed at author's request

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2008. / Härtill 4 uppsatser.

Thesis (M.S.)--University of Southern California, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Southern California, 1998. / Includes bibliographical references.

AIM & OBJECTIVES: Human papilloma virus (HPV) has been related to cervical infection, however, its part in Head and Neck Squamous Cell Carcinoma (HNSCC) is still debatable and is easy to refute. Suspicion of HPV causation is heightened when carcinomas arise in patients that are young and have never smoked. The present UK based study undertaken at Northampton NHS Trust endeavoured to determine the extent to which HPV is an entity in HNSCC in the UK. Furthermore, the study investigated whether sexual behaviour (as measured by sexual health clinic (SHC) attendance) is linked the acquisition of HPV associated HNSCC in young age groups. HNSCC incidences and sexual trends in the UK were collected from publicly available databases to identify if there were any changes at a national level in sexual behaviours and their influence on HNSCC in young age groups. MATERIALS & METHODS: PCR was used to evaluate the presence of HPV in biopsy samples from of 99 patients diagnosed with HNSCC at Northampton Hospital from 2006 to 2014. Patient demographics on age, sex, smoking, alcohol use and SHC attendance were also collected. All HPV PCR positive biopsies were further genotyped using an ABI 3130xl genetic analyser. Databases in the UK; including GLOBOCAN, NATSAL and PHE were searched for data on HNSCC prevalence, sexual behaviour trends and vaccine uptake. Multinomial regression explored the relationship between HPV positivity and sex, age, smoking, drinking, race and SHC attendance. RESULTS: PCR showed that 25.2% (25/99) of biopsies tested were positive for HPV and were all obtained from white participants. Most specimens (23, 92%) were high-risk (HR) HPV 16 positive with a mean age of 56 for HPV positivity and 72% of the cases 50-60 years old. Smokers were 11% in total (11/99) with most 88.9% participants (88/99) being non-smokers. HPV positivity was strongly linked with non-smoking history (p < 0.001); no alcohol abuse (p < 0.001); male gender (p < 0.001); young age less than 60 years (p < 0.001) and SHC attendance (p < 0.001). A Kruskal-Wallis post hoc test affirmed the impact of age on HPV positivity (p= < 0.05). GLOBOCAN and Cancer Research demonstrated a rising UK HNSCC pattern of over 200% for both sexes from 1975 to 2011. The three NATSAL surveys undertaken in 1990-1991, 1999-2001 and 2010-2012 demonstrated an overall increase in opposite and same sex partners. The UK average of individuals engaging in oral sex was in the younger age groups of between 16 and 54 with at least 70% of males and 63% females of that age engaging in oral sex. Finally, NASTAL 1, 2 and 3 surveys reported 20 vs 15; 25 vs 55; 55 vs 65 of males and females respectively with more than 10 sexual partners to have attended the SHC. The UK immunization take-up was over 90% countrywide. CONCLUSION: Few research studies have been conducted to date on HPV as a cause of HNSCC in the UK. The present research showed 25.2% of HNSCC to be caused by HPV, with the high risk (HR) genotype 16 (the leading cause of cervical cancer) accounting for 92% (23/25) of the cases. These outcomes affirmed the high prevalence of HR-HPV in HNSCC, with a rate of 25.2% similar to those reported previously. Routine HPV testing in those aged below 60 is therefore warranted. Smoking and drinking showed negative correlation; the young age of below 60 and attendance of the SHC for both sexes showed a positive correlation with HPV positive HNSCC. NATSAL data showed increased sexually risky behaviour coupled with attending the SHC in younger ages for both sexes. Increased sexually risky behaviour as shown in NASTAL surveys may be the reason why young age and SHC attendance is positively correlated with HPV HNSCC. The study highlights a conceivable relationship between HPV positive HNSCC in those under 60 years with no smoking history who attended the SHC. Smoking and drinking are known risks for HNSCC in those past 65 years of age; the negative association with HPV HNSCC in the young in the present research revealed smoking and drinking to have reduced association with HPV HNSCC. The reported HR-HPV positive HNSCC in young age groups inform future vaccination strategies and consequently decrease the quantity of HPV HNSCC's.

Intermittent blood flow in tumour microvasculature is believed to contribute to heterogeneity in tumour oxygen delivery; transient vessel nonperfusion is thought to result in acutely hypoxic cells resistant to conventional radiotherapy. This thesis describes three main areas of work: (1) the development of a histologic method capable of detecting intermittent blood flow in experimental tumours at the single vessel level; (2) the quantification and characterization of tumour blood flow fluctuations in the murine SCCVII carcinoma; and (3) the modification of tumour blood flow and the reduction of flow heterogeneity using vasoactive drugs. A double staining technique involving the sequential intravenous injection of two fluorescent vascular markers was used to detect transient episodes of tumour vessel nonperfusion. The stains employed were Hoechst 33342 and the carbocyanine dye, DiOC₇(3), both of which have short (< 3 minutes) circulation half-lives and preferentially stain cells adjacent to perfused blood vessels. When injections of the vascular markers are separated by some interval, each stain defines only those tumour vessels which were perfused during the few minutes immediately post-injection; thus, two "pictures" of tumour microvascular flow are obtained and tumour vessels subject to periods of nonperfusion can be easily visualized in frozen sections since they are outlined by one stain but not the other. Using the double staining technique, in which Hoechst 33342 and then DiOC₇(3) are administered intravenously 20 minutes apart to unrestrained C3H/He mice, staining mismatch (indicative of transient vessel nonperfusion) is regularly observed in subcutaneous SCCVII carcinoma. Vessels stained with DiOC₇(3) only (reperfusion of previously nonperfused vessels) or with H33342 only (nonperfusion of previously perfused vessels) are observed in approximately equal numbers. The percentage of tumour vessels subject to intermittent flow is a function of SCCVII tumour size: tumours ≤100 mg do not exhibit statistically significant amounts of mismatch. At sizes > 100 mg, overall staining mismatch is significantly increased over background levels and maximum mismatch is observed at tumour sizes >400 mg (8.6 ±2.9%). In most tumours, transient vessel nonperfusion is more pronounced in central tumour regions. In addition to mismatch observed in individual vessels, large "patches" of unequal staining are also seen. Anaesthesia or restraint do not significantly influence intermittent blood flow. The above information suggests that transient episodes of tumour vessel nonperfusion occur as a consequence of flow reduction in a feeding vessel; vessels in central regions of large tumours may be susceptible to collapse as a result of elevated tumour interstitial pressure. In the SCCVII tumour, a small number of peripheral vessels possess vascular smooth muscle and thus may be capable of vasomotor activity. The importance of perfusion pressure in the control of tumour microcirculatory flow was examined using vasoactive drugs. Hydralazine, a vasodilator which lowers blood pressure, causes a profound reduction in tumour RBC flow to 8.7 + 6.4% of pretreatment values in unanaesthetized mice. The drug causes collapse of central tumour vessels: following a dose of 10mg/kg intravenously, 36±16% of vessels are completely nonperfused, as detected using the double staining technique. Conversely, elevation of blood pressure using the vasoconstrictor angiotensin II results in a 2-3x increase in tumour blood flow. In addition, angiotensin II infusion significantly reduces the number of tumour vessels subject to transient nonperfusion from 8.1 % to 2.0%. However, intermittent blood flow in the SCCVII carcinoma can also be influenced by nonvasoactive drugs: nicotinamide, the amide form of vitamin B3, reduces episodes of transient nonperfusion. In summary, intermittent blood flow has been characterized in a transplanted murine squamous cell carcinoma using a novel fluorescent double staining method which allows the detection of flow fluctuations in solid tumours at the microvascular level. If transient episodes of nonperfusion occur in human tumours and result in impaired oxygen or drug delivery, then such flow fluctuations may be an important factor limiting tumour cure or local control by radiotherapy or chemotherapy. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate