Proton pencil beam scanning radiotherapy in the postoperative treatment of p16 positive squamous cell tonsillar cancer - evaluation of toxicity and effectivity.

PURPOSE: Patients with p16 positive tonsillar cancer (p16 + TC) have an excellent prognosis and long-life expectancy. Deintensification of therapy is a prevalent topic of discussion. Proton radiotherapy is one way to reduce radiation exposure and thus reduce acute and late toxicity. The aim is to evaluate treatment outcomes and toxicity of postoperative treatment with intensity-modulated proton therapy (IMPT). METHODS: Between September 2013 and November 2021, 47 patients with p16 + TC were treated postoperatively with IMPT. Median age was 54.9 (38.2-74.9) years, 31 were males and 16 were females. All patients had squamous cell carcinoma and underwent surgery as a primary treatment. Median dose of radiotherapy was 66 GyE in 33 fractions. Bilateral neck irradiation was used in 39 patients and unilateral in 8. Concomitant chemotherapy was applied in 24 patients. RESULTS: Median follow-up time was 4.2 (0.15-9.64) years. Five-year overall survival, relapse free survival and local control were 95.7%, 97.8% and 100%. The most common acute toxicities were dermatitis and mucositis, with grade 2 + in 61.7% and 70.2% of patients. No acute percutaneous gastrostomy insertion was necessary and intravenous rehydration was used in 12.8% of patients. The most common late toxicity was grade 1 xerostomia in 70.2% of patients and grade 2 in 10.6% of patients. Subcutaneous fibrosis of grades 2 and 3 occurred in 17.0% and 2.1% of patients, respectively. One patient developed late severe dysphagia and became PEG-dependent. CONCLUSION: IMPT for the postoperative treatment of p16 + TC is feasible with excellent efficiency and acceptable acute and late toxicity.

Pencil-beam scanning proton therapy for the treatment of glomus jugulare tumours.

INTRODUCTION: Glomus jugulare tumours (GJT) are benign tumours that arise locally and destructively in the base of the skull and can be successfully treated with radiotherapy. Patients have a long-life expectancy and the late effects of radiotherapy can be serious. Proton radiotherapy reduces doses to critical organs and can reduce late side effects of radiotherapy. The aim of this study was to report feasibility and early clinical results of 12 patients treated using proton therapy. METHODS: Between December 2013 and June 2019, 12 patients (pts) with GJT (median volume 20.4 cm3 ; range 8.5-41 cm3 ) were treated with intensity modulated proton therapy (IMPT). Median dose was 54 GyE (Gray Equivalents) (50-60 GyE) with daily fractions of 2 GyE. Twelve patients were analysed with a median follow-up time of 42.2 months (11.3-86.7). Feasibility, dosimetric parameters, acute and late toxicity and local effect on tumour were evaluated in this retrospective study. RESULTS: All patients finished treatment without interruption, with excellent dosimetric parameters and mild acute toxicity. Stabilisation of tumour size was detected on MRI in all patients. No changes in symptoms were observed in comparison with pre-treatment conditions. No late effects of radiotherapy were observed. CONCLUSION: Pencil-beam scanning proton radiotherapy is highly feasible in the treatment of large GJT with mild acute toxicity and promising short-term results. Longer follow-up and larger patient cohorts are required to further identify the role of pencil-beam scanning (PBS) for this indication.

Markers of HPV infection and survival in patients with head and neck tumors.

The purpose of this study was to determine whether changes in human papillomavirus (HPV) DNA prevalence in oral rinses and/or HPV-specific antibody levels in the sera of patients with oral/oropharyngeal cancer have prognostic significance. One hundred and forty-two patients with oral/oropharyngeal tumors were enrolled. The presence of HPV DNA was assayed in tumor tissue and oral rinses and HPV-specific antibodies were assessed in the sera. Oral rinses were collected before treatment and one year after the treatment. Sera were drawn before treatment, one month, and one year after the end of the treatment. Altogether, 59.2% of tumors were HPV positive. The presence of HPV DNA in the tumors correlated with HPV DNA positivity in oral rinses and with HPV-specific antibodies in the sera. Out of 66 patients with HPV-positive oral rinses at enrolment, 84.8% became negative at one-year follow-up, while most patients remained seropositive for HPV-specific antigens. However, the mean titers of HPV16 E6 and/or E7 antibodies at follow-up were significantly lower. Of 16 patients with recurrences at follow-up (alive on second sampling), six were positive at enrolment for HPV16 E6 and/or E7 antibodies. In five of these, no decrease in antibody levels was observed. Titers of antibodies specific for HPV16 capsid antigens did not change during the follow-up. Our data suggest that the detection of antibodies specific for the HPV 16 E6 and E7 oncoproteins may serve not only as a marker of HPV etiology, but also as a marker of recurrence and a prognostic indicator in patients with HPV-positive tumors.

HPV involvement in tonsillar cancer: prognostic significance and clinically relevant markers.

The association of high-risk human papillomaviruses (HR HPVs) with tonsillar cancer (TC) has been documented. Because patients with HPV-associated tumors show better survival rates, modification of their treatment regimen is being considered. It is therefore crucial to find markers for the identification of patients whose tumors are linked to viral infection. A cohort of 109 patients with primary TC was screened for HPV DNA presence in the tumor tissues and HPV-specific antibodies in sera. Data regarding risk factors and clinical parameters were collected. Forty-five specimens were analyzed for the expression of viral E6 and E2-region mRNA, and the p16 and p53 protein expression status was assessed by immunohistochemistry. The overall prevalence of HPV DNA in TC tissues was 65.1%. Ninety-three percent of HR HPV DNA-positive samples expressed E6*I mRNA. E2-region mRNA expression was detected in 36% of positive samples, which implies that the virus is integrated in 64% of HPV DNA/RNA-positive tumors. p16 overexpression and the presence of antibodies specific to HPV16 E6/E7 oncoproteins correlated well with HPV DNA and RNA presence. The disease-specific survival rate of patients with HPV DNA-positive tumors was significantly higher than that of HPV DNA-negative patients. In addition to providing further evidence of the involvement of HPV infection in the etiopathogenesis of a proportion of TC cases, our study demonstrates that p16 immunostaining and anti-E6/E7 antibodies as surrogate markers of HPV involvement represent specific, sensitive and clinically accessible assays for the identification of TC patients who have a considerably better prognosis.

Human papillomavirus in head and neck tumors: epidemiological, molecular and clinical aspects.

High-risk types of human papillomaviruses (HR HPV) play an important role in the etiology of a group of head and neck squamous cell cancers (HNSCC). This review is focused on epidemiological, molecular, and clinical aspects of HPV infection in head and neck cancer. High risk HPV DNA is being detected in a very different proportion of HNSCC with the highest prevalence in oropharynx. Patients with HPV-associated tumors are characterized by moderate tobacco and alcohol consumption. Some aspects of sexual behavior may represent a risk factor. Recently, it has been shown that HPV infection is spreading and the rising prevalence of HPV-positive tumors can probably be attributed to this epidemic. On molecular level the viral oncoproteins E6 and E7 were shown to be involved in oncogenesis. HPV-positive cancers have better prognosis and HPV status should be considered in clinical decision-making. The rising proportion of HPV-positive tumors underlines the importance of HPV vaccination also for the prevention of HNSCC.

Demographic and risk factors in patients with head and neck tumors.

The association between human papillomavirus (HPV) infection and the development of head and neck cancer has been documented recently. In this study on 86 head and neck cancer patients and 124 controls, data regarding demographics, behavioral risk factors, and risks related to HPV exposure were collected. HPV detection was carried out using polymerase chain reaction in the tumors and in oral exfoliated cells, and HPV typing by a reverse line blot assay specific for 37 HPV types. Sera were tested by an enzyme-linked immunosorbent assay specific for HPV proteins. Head and neck cancer cases report significantly more oral-anal contact (P = 0.02) and tobacco and alcohol use than controls (P = 0.001; P = 0.02, respectively). High-risk HPV DNA was detected in 43% of oral washings of cases and 4% of controls (P < 0.0001). The association between the presence of high-risk HPV DNA in oral exfoliated cells and in tumor tissues was statistically significant (adjusted P < 0.0001). The prevalence of HPV-specific antibodies was significantly higher in cases than in controls (adjusted P < 0.0001). These results provide epidemiological and immunological evidence for HR HPV as a strong risk factor (OR = 44.3, P < 0.0001) for head and neck cancer, even after controlling for age, tobacco and alcohol use. The detection of high-risk HPV DNA in oral exfoliated cells and HPV-specific antibodies in serum can be considered as clinically relevant surrogate markers for the presence of a HPV-associated head and neck cancer, with a high sensitivity (83%) and specificity (88%).