Tonsillectomy as Prevention of Tonsil and Base of Tongue Cancer: Systematic Review and Meta-analysis on the Immuno-Oncological Effect of One Among the Most Common Surgeries in the World

Otorhinolaryngology tradition is that tonsillectomy (TE) is conducted among children and adolescents for obstructive sleep apnea secondary to adenotonsillar hypertrophy and in adults for chronic disease of the tonsils and adenoids (recurrent tonsillitis). Nevertheless, over the last 50 years, we have observed a decline in TE worldwide. As a result, there is an emerging concern of a correlated possible increased risk of tonsil cancer (TC) and other subtypes of oropharyngeal squamous cell carcinoma. Since the available data on such topics are limited and controversial, our aim was to elucidate the impact of TE on the incidence mainly of TC through a systematic review of the literature and a meta-analysis of the studies. After a thorough search, 7 retrospective studies were considered eligible for review and meta-analysis (MA). At MA, patients with a history of TE seem to show a reduced risk of TC but a higher predisposition for base of tongue (BOT) cancer (p<0.001): however, the elevated heterogeneity of the studies hampers drawing firm and convincing conclusions (statistical inconsistency >95%). In future, randomized control trials will be welcome to elucidate the prophylactic role of TE against TC and its real impact on BOT cancer.

Surgical Treatment for Advanced Oropharyngeal Cancer: A Narrative Review

Background and Objectives: to describe current scientific knowledge regarding the treatment options in advanced oropharyngeal cancer. The standard care for advanced oropharyngeal cancer (OPSCC) has been chemoradiotherapy, although surgical approaches followed by adjuvant treatment have been proposed. The best therapy for each patient should be decided by an interdisciplinary tumour-board. Different strategies should be considered for the specific patient's treatment: surgery, chemotherapy and radiation therapy or combinations of them. The treatment choice is influenced by tumour variability and prognostic factors, but it also depends on cancer extension, extranodal extension, nervous invasion, human papilloma virus (HPV) presence, making the decisional algorithm not always clear. HPV-related OPSCC is strongly associated with a favourable overall survival (OS) and disease-free survival rate (DSS); by contrast, HPV-negative OPSCC often flags a worse prognosis. Consequently, the American Joint Committee on Cancer (AJCC) differentiates OPSCC treatment and prognosis based on HPV status. Methods: we carried out a review of current scientific literature to analyze the different indications and limitations of surgical treatment options in OPSCC stage III and IV. Conclusion: robotic surgery or open approaches with reconstructive flaps can be considered in advanced stages, resulting in the de-intensification of subsequent systemic therapy and fewer related side effects. Furthermore, in the event of the primary failure of systemic therapy or disease recurrence, the surgical approach constitutes an additional therapeutic option which lengthens patient survival functions.

Brachytherapy and osteoradionecrosis in patients with base of tongue cancer

BACKGROUND

Base of tongue cancer incidence and patient survival is increasing why treatment sequelae becomes exceedingly important. Osteoradionecrosis (ORN) is a late adverse effect of radiotherapy and brachytherapy (BT) could be a risk factor. Brachytherapy is used in three out of six health care regions in Sweden.

AIMS

Investigate if patients treated in regions using BT show an increased risk for ORN and whether brachytherapy has any impact on overall survival.

MATERIAL AND METHODS

We used data from the Swedish Head and Neck Cancer Register between 2008-2014. Due to the nonrandomized nature of the study and possible selection bias we compared the risk for ORN in brachy vs non-brachy regions.

RESULTS

Fifty out of 505 patients (9.9%) developed ORN; eight of these were treated in nonbrachy regions (16%), while 42 (84%) were treated in brachy regions. Neither age, sex, TNM-classification/stage, p16, smoking, neck dissection, or chemotherapy differed between ORN and no-ORN patients. The risk for ORN was significantly higher for patients treated in brachy regions compared to non-brachy regions (HR = 2,63, p = .012), whereas overall survival did not differ (HR = 0.95, p = .782).

CONCLUSIONS AND SIGNIFICANCE

Brachytherapy ought to be used cautiously for selected patients or within prospective randomized studies.

Targeted Therapy with PI3K, PARP, and WEE1 Inhibitors and Radiotherapy in HPV Positive and Negative Tonsillar Squamous Cell Carcinoma Cell Lines Reveals Synergy while Effects with APR-246 Are Limited

Human papillomavirus positive (HPV⁺) tonsillar and base of tongue cancer (TSCC/BOTSCC) is rising in incidence, but chemoradiotherapy is not curative for all. Therefore, targeted therapy with PI3K (BYL719), PARP (BMN-673), and WEE1 (MK-1775) inhibitors alone or combined was pursued with or without 10 Gy and their effects were analyzed by viability, proliferation, and cytotoxicity assays on the TSCC/BOTSCC cell lines HPV⁺ UPCI-SCC-154 and HPV^- UT-SCC-60A. Effective single drug/10 Gy combinations were validated on additional TSCC lines. Finally, APR-246 was assessed on several TSCC/BOTSCC cell lines. BYL719, BMN-673, and MK-1775 treatments induced dose dependent responses in HPV⁺ UPCI-SCC-154 and HPV^- UT-SCC-60A and when combined with 10 Gy, synergistic effects were disclosed, as was also the case upon validation. Using BYL719/BMN-673, BYL719/MK-1775, or BMN-673/MK-1775 combinations on HPV⁺ UPCI-SCC-154 and HPV^- UT-SCC-60A also induced synergy compared to single drug administrations, but adding 10 Gy to these synergistic drug combinations had no further major effects. Low APR-246 concentrations had limited usefulness. To conclude, synergistic effects were disclosed when complementing single BYL719 BMN-673 and MK-1775 administrations with 10 Gy or when combining the inhibitors, while adding 10 Gy to the latter did not further enhance their already additive/synergistic effects. APR-246 was suboptimal in the present context.

Targeted Therapy With PI3K and FGFR Inhibitors on Human Papillomavirus Positive and Negative Tonsillar and Base of Tongue Cancer Lines With and Without Corresponding Mutations

Objectives

Human papillomavirus positive (HPV⁺) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC), the major subsites of oropharyngeal squamous cell carcinoma (OPSCC) have favorable outcome, but upon relapse, outcome is poor and new therapies needed. Since, phosphatidyl-inositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) and fibroblast-growth-factor-receptor-3 (FGFR3) mutations often occur in such tumors, here, we tested targeted therapy directed to such genes in TSCC/BOTSCC cell lines. We also combined the two types of inhibitors with each other, and cisplatin or docetaxel that are used clinically.

Methods

The HPV⁺ CU-OP-2, -3, -20, UPCI-SCC-154, and HPV^- CU-OP-17 and UT-SCC-60A cell lines were first tested for common PIK3CA/FGFR3 mutations by competitive-allele-specific TaqMan-PCR. They were then treated with the food and drug administration (FDA) approved drugs, alpelisib (BYL719) and erdafitinib (JNJ-42756493) alone and in combination with cisplatin or docetaxel. Viability, proliferation, apoptosis and cytotoxicity responses were thereafter followed by WST-1 assays and the IncuCyte S3 Live^® Cell Analysis System.

Results

HPV⁺ CU-OP-2 had a pS249C-FGFR3, and like CU-OP-20, a pE545K-PIK3CA mutation, while no other lines had such mutations. Irrespectively, dose dependent responses to all PI3K/FGFR inhibitors were obtained, and upon combining the inhibitors, positive effects were observed. Cisplatin and docetaxel also induced dose dependent responses, and upon combination with the inhibitors, both positive and neutral effects were found.

Conclusions

The data suggest that FDA approved drugs alpelisib and erdafitinib efficiently inhibit TSCC/BOTSCC cell line growth, especially when combined irrespective of presence of corresponding mutations and should be further explored, for use upon recurrent disease.

A global epidemic increase of an HPV-induced tonsil and tongue base cancer - potential benefit from a pan-gender use of HPV vaccine

In 2007, human papillomavirus (HPV) type 16 was finally recognized as a risk factor, besides smoking and alcohol, for oropharyngeal squamous cell carcinoma (OPSCC), including tonsillar squamous cell carcinoma (TSCC), by the International Agency for Research against Cancer. Just before, in 2006, the Food and Drug Administration had approved Gardasil, the first vaccine against HPV16, 18, 6 and 11, for preventive vaccination women against cervical cancer. Concurrently, some Western countries, where smoking was decreasing, disclosed an epidemic increase in the incidence of OPSCC, especially of TSCC and base of tongue cancer (BOTSCC), together accounting for 80-90% of all OPSCCs, and mainly affecting men. The epidemic was later revealed to be due to a rise in HPV-positive cases, and scientists in the field suggested HPV vaccination also of boys. Globally, there are roughly 96 000 incident OPSCC cases/year of which 20-24% are caused by HPV, thereby accounting for around 22 000 OPSCC cases annually. Of these cases, 80-90% are due to HPV16 infection and would be prevented with the presently registered HPV vaccines. In Western countries, such as Sweden (with almost 400 TSCC and BOTSCC cases per year) and the United States, HPV prevalence in OPSCC is higher and around 70%. HPV vaccination of girls has been initiated in many countries, and the vaccines have been efficient and their side effects limited. HPV vaccination of boys has, however, been the exception, but should definitely not be delayed any further. It would benefit both girls and boys directly, and result in better and more robust herd immunity. Today, we have the possibility to eliminate several high-risk HPV types in the younger generations and avoid more than 600 000 cancer cases annually worldwide, and this possibility should be embraced by offering global pan-gender HPV vaccination.

In vitro antitumor effects of FGFR and PI3K inhibitors on human papillomavirus positive and negative tonsillar and base of tongue cancer cell lines

Human papillomavirus positive (HPV⁺) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) have better outcomes than corresponding HPV^- negative (HPV^-) cancer cases. Our previous study demonstrated that fibroblast growth factor receptor 3 (FGFR3) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit a (PIK3CA) are often mutated in HPV⁺ cancer. To investigate whether targeted therapy is an option for TSCC/BOTSCC, two HPV⁺ and one HPV^- TSCC/BOTSCC cell lines were tested for their sensitivity towards FGFR and PI3K inhibitors. The HPV⁺ cell lines UM-SCC-47 and UPCI-SCC-154, and the HPV^- cell line UT-SSC-60A were tested by competitive allele-specific TaqMan-PCR for presence/absence of frequently occurring FGFR3 and PIK3CA mutations. All cells were then treated with FGFR inhibitor AZD4547 and PI3K inhibitors BEZ235 and BKM120 alone, or with AZD4547 and BEZ235 in combination. Viability was analyzed using a WST-1 assay, cytotoxicity tested by a CellTox Green cytotoxicity assay, apoptosis analyzed by a Caspase Glo 3/7 assay and proliferation examined with the xCELLigence system. HPV⁺ UM-SCC-47 and UPCI-SCC-154 cells, and HPV^- UT-SSC-60A cells, did not exhibit any common FGFR3 or PIK3CA mutations, but were all sensitive to FGFR inhibitor AZD4547 and PI3K inhibitors BEZ235 and BKM120. Notably, HPV⁺ UPCI-SCC-154 cells were more sensitive than the other two cell lines. Furthermore, when AZD4547 and BEZ235 treatment was combined in HPV⁺ UPCI-SCC-154 and HPV^- UT-SSC-60A cells, potentiated combination effects were observed. HPV⁺ UM-SCC-47 and UPCI-SCC-154 cells, and HPV^- UT-SSC-60A cells had no common FGFR3 or PIK3CA mutations, but were sensitive to FGFR inhibitor AZD4547, and PI3K inhibitors BEZ235 and BKM120. Furthermore, the latter two cell lines were particularly sensitive to combinations of AZD4547 and BEZ235.

Differences in gene expression between high-grade dysplasia and invasive HPV+ and HPV- tonsillar and base of tongue cancer

BACKGROUND

Human papillomavirus (HPV) is a causative agent for tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC), as well as for cervical cancer. Premalignant stages in cervical cancer have been studied extensively, while little is known about premalignant stages in TSCC/BOTSCC and the role of HPV. Here we analyzed differences in gene and protein expression between high-grade dysplasia and invasive cancer in both HPV-positive (HPV+ ) and HPV-negative (HPV- ) TSCC/BOTSCC.

METHODS

High-grade dysplasia and invasive carcinoma were laser microdissected from HPV+ and HPV- TSCC/BOTSCC tumor sections. Differential gene expression was studied utilizing nanoString RNA-panels and genes of interest were validated on the protein level by immunohistochemistry.

RESULTS

Forty genes in the HPV+ tumors showed significantly different expression between high-grade dysplasia and invasive cancer and 33 genes in the HPV- tumors. Five out of the nine most significant pathways showed similar increased activity in invasive cancer as compared to high-grade dysplasia in both HPV+ and HPV- tumors. Lastly, significant differences in protein expression was confirmed for SPARC, psoriasin, type I collagen and galectin-1 in both HPV+ and HPV- tumors.

CONCLUSIONS

This is to our knowledge the first study disclosing differences and similarities in gene expression between dysplastic and invasive HPV+ and HPV- TSCC/BOTSCC.

TLR5 and TLR7 are differentially expressed in human papillomavirus-positive and negative base of tongue squamous cell carcinoma, and TLR7 may have an independent prognostic influence

BACKGROUND

Human papillomavirus-positive (HPV⁺) base of tongue squamous cell carcinoma (BOTSCC) has a better outcome than corresponding HPV^- cancer. TLR5 and TLR7 expression was previously shown to differ depending on HPV - status and correlate with outcome in oropharyngeal squamous cell carcinoma.

AIMS/OBJECTIVES

For validation, TLR5 and TLR7 were analyzed in a BOTSCC-cohort for correlation with HPV, survival, CD4⁺ and CD8⁺ tumor-infiltrating lymphocyte (TIL) counts, the latter being a well-documented prognostic marker.

MATERIALS AND METHODS

BOTSCC biopsies, (49HPV⁺/28HPV^-) were analyzed by immunohistochemistry for TLR5 and TLR7, and correlated with the above parameters.

RESULTS

TLR5 expression was more frequently absent/weak than medium/strong in HPV⁺ compared to HPV^- BOTSCC (p < .001). The opposite was observed for TLR7 (p < .007). TLR5 and TLR7 expression did not correlate to survival in either the HPV^- or HPV⁺ cases, or to CD4⁺ TILs. TLR5, (but not TLR7) expression was correlated to CD8⁺ TIL counts (p = .023).

CONCLUSION AND SIGNIFICANCE

Absent/weak TLR5 and medium/strong TLR7 expression was validated as more frequent in HPV⁺ compared with HPV^- BOTSCC. A correlation between CD8⁺ TIL counts, and TLR5 expression was disclosed, but not with TLR7. Therefore, it could be useful to investigate TLR7 further as a potential independent prognostic marker.

Total Glossectomy With Free Flap Reconstruction: Twenty-Year Experience at a Tertiary Medical Center

OBJECTIVES/HYPOTHESIS

To characterize the demographics, clinicopathologic characteristics, and treatment and reconstructive outcomes of patients who underwent total glossectomy STUDY DESIGN: Retrospective chart review at an academic tertiary-care medical center.

METHODS

All patients who had undergone total glossectomy (as an individual procedure or as part of a more extensive resection) between January 1, 1995 and December 31, 2014 were included in the analysis. Patient characteristics and clinical outcomes were reviewed.

RESULTS

Forty-eight patients underwent total glossectomy for oral tongue and base of tongue cancer. The mean age of the patients was 56 (range, 29-92 years). History of tobacco and heavy alcohol use was found in 76% and 11% of patients, respectively. The majority of patients had advanced cancer (91.7% at stage IV), and 60.4% had salvage therapy for recurrent disease. T4 disease comprised 81% of patients. Sixty percent had clinical or radiographic evidence of nodal metastasis. Reconstruction of the defect was performed with free flaps from the rectus abdominus (40%), fibula (25%), anterolateral thigh (23%), and other donor tissues. One- and 5-year survival rates were 42% and 26%, with locoregional and distant recurrence reported at 36% and 25%, respectively.

CONCLUSIONS

Total glossectomy for oncologic control is most commonly performed in patients who have stage IV cancers. Despite high reconstructive success rates, the likelihood of locoregional and distance recurrence was high. Most patients can communicate intelligibly and achieve decannulation, but swallowing outcomes remain guarded, especially considering previous irradiation and resection of the base of tongue.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:1087-1092, 2019.

Changes in incidence and prevalence of human papillomavirus in tonsillar and base of tongue cancer during 2000-2016 in the Stockholm region and Sweden

BACKGROUND

Tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) has increased. In Stockholm, the proportion of human papillomavirus (HPV)-positive cases and the incidence of TSCC rose between 1970 and 2006 then stabilized. Here, HPV-prevalence, and TSCC/BOTSCC incidence 2000-2016, in Stockholm and Sweden were followed.

METHODS

Incidence data for 2000-2016 were obtained from the Swedish Cancer Registry. TSCC/BOTSCC biopsies, 2013-2016 from Stockholm, were examined for HPV DNA and p16^INK4a , or data obtained from medical reports. For cases 2000-2012, data were available from previous studies.

RESULTS

The incidence of TSCC/BOTSCC has continued to rise in Stockholm and Sweden 2000-2016, especially after 2008. HPV DNA and p16^INK4a analysis was determined for 795 Stockholm cases from 2000 to 2016, with 72% being HPV DNA and p16^INK4a positive 2013-2016, and 70% positive 2000-2016.

CONCLUSION

During 2000-2016, especially after 2008, the incidence of TSCC/BOTSCC has continued to increase in Stockholm and Sweden, with an HPV-prevalence of approximately 70% in Stockholm.

Human papillomavirus (HPV) is absent in branchial cleft cysts of the neck distinguishing them from HPV positive cystic metastasis

BACKGROUND

Distinguishing branchial cleft cysts (BCCs) from cystic metastases of a human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma (OPSCC) is challenging. Fine needle aspirates (FNAs) from cystic metastasis may be non-representative, while reactive squamous cells from BCC can be atypic. Based on cytology and with the support of HPV DNA positivity many centers treat cystic metastasis oncological and thus patients are spared neck dissection. To do so safely, one must investigate whether HPV DNA and p16^INK4a overexpression is found exclusively in cystic metastases and not in BCC.

PATIENTS AND METHODS

DNA was extracted from formalin fixed paraffin embedded (FFPE) surgically resected BCCs from 112 patients diagnosed 2007-2015 at Karolinska University Hospital and amplified by PCR. A multiplex bead-based assay used to detect 27 HPV-types and p16^INK4a expression was analyzed by immunohistochemistry (IHC).

RESULTS

All 112 BCCs were HPV DNA negative, and of 105 BCCs possible to evaluate for p16^INK4a, none overexpressed p16^INK4a.

CONCLUSIONS

HPV DNA and p16^INK4a overexpression were absent in BCCs. Lack of HPV DNA and p16 protein overexpression in BCCs is helpful to discriminate benign BCCs from HPV⁺ OPSCC metastasis. HPV testing definitely has a role in the diagnostics of cystic masses of the neck.

Overexpression of FGFR3 in HPV-positive Tonsillar and Base of Tongue Cancer Is Correlated to Outcome

BACKGROUND/AIM

Human papillomavirus-positive (HPV⁺) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) have better outcome than corresponding HPV^- cancers. To better individualize treatment, additional predictive markers are needed. Previously, we have shown that mutated fibroblast growth factor receptor 3 protein (FGFR3) was correlated to poorer prognosis and here FGFR3 expression was further analyzed.

PATIENTS AND METHODS

One-hundred-fifteen HPV⁺TSCC/ BOTSCC biopsies were analyzed for FGFR3 by immunohistochemistry (IHC), and 109/115 were analyzed for FGFR3 mutations by Ion Proton sequencing, or by Competitive Allele-Specific Taqman PCR (CAST-PCR). Disease-free survival (DFS) was then calculated according to FGFR3 IHC expression.

RESULTS

CAST-PCR was useful for detecting the three most common FGFR3 mutations. Focusing especially on the 98/115 patients with HPV⁺TSCC/BOTSCC and wild-type FGFR3, high FGFR3 expression correlated to significantly better 3-year DFS, p=0.043.

CONCLUSION

In patients with HPV⁺TSCC/BOTSCC and wild-type FGFR3, overexpression of FGFR3 was correlated with better DFS.

Protein Expression in Tonsillar and Base of Tongue Cancer and in Relation to Human Papillomavirus (HPV) and Clinical Outcome

Human papillomavirus (HPV) is a major etiological factor for tonsillar and the base of tongue cancer (TSCC/BOTSCC). HPV-positive and HPV-negative TSCC/BOTSCC present major differences in mutations, mRNA expression and clinical outcome. Earlier protein studies on TSCC/BOTSCC have mainly analyzed individual proteins. Here, the aim was to compare a larger set of cancer and immune related proteins in HPV-positive and HPV-negative TSCC/BOTSCC in relation to normal tissue, presence of HPV, and clinical outcome. Fresh frozen tissue from 42 HPV-positive and 17 HPV-negative TSCC/BOTSCC, and corresponding normal samples, were analyzed for expression of 167 proteins using two Olink multiplex immunoassays. Major differences in protein expression between TSCC/BOTSCC and normal tissue were identified, especially in chemo- and cytokines. Moreover, 34 proteins, mainly immunoregulatory proteins and chemokines, were differently expressed in HPV-positive vs HPV-negative TSCC/BOTSCC. Several proteins were potentially related to clinical outcome for HPV-positive or HPV-negative tumors. For HPV-positive tumors, these were mostly related to angiogenesis and hypoxia. Correlation with clinical outcome of one of these, VEGFA, was validated by immunohistochemistry. Differences in immune related proteins between HPV-positive and HPV-negative TSCC/BOTSCC reflect the stronger activity of the immune defense in the former. Angiogenesis related proteins might serve as potential targets for therapy in HPV-positive TSCC/BOTSCC.

Targeted sequencing of tonsillar and base of tongue cancer and human papillomavirus positive unknown primary of the head and neck reveals prognostic effects of mutated FGFR3

BACKGROUND

Human papillomavirus positive (HPV+) tonsillar cancer (TSCC), base of tongue cancer (BOTSCC) and unknown primary cancer of the head and neck (HNCUP) have better outcome than corresponding HPV- cancers. To find predictive markers for response to treatment, and correlations and differences in mutated oncogenes and suppressor genes between HPV+ TSCC/BOTSSCC and HPV+ HNCUP and HPV- TSCC/BOTSCC targeted next-generation sequencing was performed of frequently mutated regions in 50 cancer related genes.

PATIENTS AND METHODS

DNA from 348 TSCC/BOTSCC and 20 HNCUP from patients diagnosed 2000-2011, was sequenced by the Ion Proton sequencing platform using the Ion AmpliSeq Cancer Hotspot Panel v2 to identify frequently mutated regions in 50 cancer related genes. Ion Torrent Variant Caller software was used to call variants.

RESULTS

279 HPV+ TSCC/BOTSCC, 46 HPV- TSCC/BOTSCC and 19 HPV+ HNCUP samples qualified for further analysis. Mutations/tumor were fewer in HPV+ TSCC/BOTSCC and HNCUP, compared to HPV- tumors (0.92 vs. 1.32 vs. 1.68). Differences in mutation frequency of TP53 and PIK3CA were found between HPV+ TSCC/BOTSCC and HNCUP and HPV- TSCC/BOTSCC. In HPV+ TSCC/BOTSCC presence of FGFR3 mutations correlated to worse prognosis. Other correlations to survival within the groups were not disclosed.

CONCLUSIONS

In HPV+ TSCC/BOTSCC mutation of PIK3CA was most frequently observed, while TP53 mutations dominated in HPV- TSCC/BOTSCC. In HPV+ TSCC/BOTSCC and HNCUP, mutations/tumor were similar in frequency and fewer compared to that in HPV- TSCC/BOTSCC. Notably, FGFR3 mutations in HPV+ TSCC/BOTSCC indicated worse prognosis.

Human Papillomavirus and Potentially Relevant Biomarkers in Tonsillar and Base of Tongue Squamous Cell Carcinoma

Human papillomavirus (HPV)-positive tonsillar- and base of tongue cancer is increasing epidemically and has much better outcome than corresponding HPV-negative cancer and most other head and neck cancers with around 80% 3-year disease free survival with conventional radiotherapy and surgery. Consequently, most HPV-positive cancer patients may not require the intensified chemoradiotherapy given to many head and neck cancer patients and would, with tapered treatment, avoid several severe side-effects. Moreover, intensified therapy has not improved survival and treatment alternatives are needed. To identify patients eligible for tapered or targeted therapy, additional biomarkers are required. Several studies have, therefore, focused on finding predictive markers, some of which are also potentially targetable. To conclude, better-tailored therapy, either as tapered or targeted, is important for increasing numbers of patients with HPV-positive tonsillar- and base of tongue cancer. This review deals with some of these issues and presents some promising markers.

Tongue-out versus tongue-in position during intensity-modulated radiotherapy for base of tongue cancer: Clinical implications for minimizing post-radiotherapy swallowing dysfunction

BACKGROUND

The purpose of this study was to assess whether different tongue positions change the radiation doses to swallowing organs at risks: the pharyngeal constrictor, oral cavity, and larynx during intensity-modulated radiotherapy (IMRT) for base of tongue (BOT) cancer.

METHODS

IMRT plans with Tongue-out (IMRT-TO) and tongue-in position (IMRT-TI) was compared in 3 cases.

RESULTS

Distance from BOT to pharyngeal constrictor was increased to 1.8 ± 0.8 cm with IMRT-TO from 0.9 ± 0.6 cm with IMRT-TI (P < .01). Compared to IMRT-TI, IMRT-TO significantly decreased the radiation dose to the anterior oral cavity, oral tongue, superior pharyngeal constrictor, middle pharyngeal constrictor, and supraglottic larynx (all P ≤ .04). IMRT-TO also had a smaller volume irradiated than IMRT-TI to the anterior oral cavity and the oral tongue receiving ≥30 Gy (V30) and V35, and superior pharyngeal constrictor and middle pharyngeal constrictor for V55 and V65 (all P ≤ .04).

CONCLUSION

Dosimetric advantage with IMRT-TO over IMRT-TI may potentially reduce post-IMRT swallowing dysfunction in selected patients with BOT cancer.

Human Papillomavirus as a Diagnostic and Prognostic Tool in Cancer of Unknown Primary in the Head and Neck Region

Human papillomavirus (HPV) is recognized as a risk factor for oropharyngeal squamous cell carcinomas (SCC), especially tonsillar and base of tongue cancer. Furthermore, HPV-positive tonsillar and base of tongue SCC have a significantly better prognosis than their HPV-negative counterparts and head and neck cancer (HNSCC) in general. HPV has recently also been implicated in cancer of unknown primary (CUP) in the head and neck region, where a primary tumour is not found despite extensive workup. Using fine-needle aspiration cytology to determine CUP HPV status in cervical lymph nodes could be of advantage, since it is minimally invasive and it is assumed that an HPV-positive lymph node metastasis likely has an HPV-positive otopharyngeal SCC origin. We review the current knowledge of HPV in HNSCC, with an emphasis on CUP of the head and neck region, its relation to oropharyngeal, tonsillar and base of tongue SCC and implications of HPV status for diagnosis, prognosis and treatment.

Human papillomavirus and oropharyngeal cancer, the epidemics, and significance of additional clinical biomarkers for prediction of response to therapy (Review)

In 2007, the International Agency for Research against Cancer (IARC) recognized human papillomavirus (HPV), especially HPV16, besides smoking and alcohol, as a risk factor for oropharyngeal squamous cell carcinoma (OPSCC), where tonsillar and base of tongue cancer dominate. Moreover, during the past decade, in many Western countries, a sharp rise in the incidence of OPSCC, more specifically of HPV-positive OPSCC has been observed. Notably, patients with HPV-positive OPSCC, where the majority are men, particularly never-smokers have a better clinical outcome than patients with HPV-negative OPSCC and other head neck cancer (roughly 80 vs. 40% disease-free survival with conventional radiotherapy and surgery). This suggests that many patients with HPV-positive OPSCC may not require the more aggressive intensified chemo-radiotherapy given to head neck cancer patients today, and could with somewhat tapered treatment maintain excellent survival, avoiding some of the severe side effects along with intensified treatment. However, before de-intensified treatment is administered additional biomarkers are necessary in combination with HPV-positive status in order to predict and select patients that will respond favorably to therapy. In conclusion, noteworthy issues within this field with an increasing cohort of patients with HPV-positive OPSCC are better-tailored therapy and prevention. Patients with HPV-positive OPSCC, with biomarkers for good response to therapy e.g., low MHC class I, or CD44 expression or high numbers of CD8+ tumor infiltrating lymphocytes, could be included in randomized trials with less severe therapy. Furthermore, possibilities to screen for HPV-positive OPSCC and to vaccinate boys against HPV infection should be further investigated.

HLA-A*02 in relation to outcome in human papillomavirus positive tonsillar and base of tongue cancer

BACKGROUND/AIM

Patients with human papillomavirus (HPV)-positive tonsillar and base of tongue cancer have a better outcome than those with corresponding HPV-negative tumors (80% vs. 40% 5-year disease free survival with conventional radiotherapy). They should not all need chemoradiotherapy, but before tapering treatment, more markers are needed to predict treatment response. In the present study, human leukocyte antigen (HLA) - HLA-A*02 was analyzed with HPV as a prognostic factor for tonsillar and base of tongue cancer.

PATIENTS AND METHODS

Pre-treatment biopsies, previously tested for HPV DNA, from 425 patients diagnosed with tonsillar and base of tongue cancer between 2000-2009 at the Karolinska University Hospital were examined for HLA-A*02.

RESULTS

HLA-A*02 was present in 144/305 (47.2%) of the HPV-positive and 63/120 (52.8%) of the HPV-negative tumours. Among 383 patients treated with curative intent, absence of HLA-A*02 was correlated with increased disease-free survival in the HPV-positive (p=0.016), but not in the HPV-negative group.

CONCLUSION

Absence of HLA-A*02 correlated with better disease-free survival for patients with HPV-positive tonsillar and base of tongue cancer.

Long-term results from a uniform clinical series

Purpose

To evaluate long time outcome with regard to local tumour control, side effects and quality of life of combined pulsed dose rate (PDR) boost and hyperfractionated accelerated external beam radiotherapy (EBRT) for primary base of tongue (BOT) cancers.

Material and methods

Between 1994 and 2007, the number of 83 patients were treated with primary T1-T4 BOT cancers. Seven patients (8%) were T1-2N0 (AJCC stage I-II) and 76 (92%) patients were T1-2N+ or T3-4N0-2 (AJCC stage III-IV). The mean estimated primary tumour volume was 15.4 (1-75) cm³. EBRT was given with 1.7 Gy bid to 40.8 Gy to primary tumour and bilateral neck lymph nodes in 2.5 weeks. PDR boost of 35 Gy and a neck dissection in clinical node positive case was performed 2-3 weeks later. The patients were followed for a median of 54 (2-168) months.

Results

The 2-, 5- and 10-years rates of actuarial local control were 91%, 89% and 85%, overall survival 85%, 65% and 44%, disease free survival 86%, 80% and 76%, respectively. The regional control rate was 95%. Six patients (7%) developed distant metastases. A dosimetric analysis showed a mean of 100% isodose volume of 58.2 (16.7-134) cm³. In a review of late complications 11 cases of minor (13%) and 5 of major soft tissue necroses (6%), as well as 6 cases of osteoradionecroses (7%) were found. The patients median subjective SOMA/LENT scoring at last follow up was as follow: grade 0 for pain and trismus, grade 1 for dysphagia and taste alteration, and grade 2 for xerostomia. Global visual-analogue-scale (VAS) scoring of quality of life was 8.

Conclusion

Local and regional tumour control rate was excellent in this treatment protocol. The data shows the PDR boost as at least as effective as published continuous low dose rate (CLDR) results.