Comparison of Doses to Parotid, Temporomandibular Joint, and Pharyngeal Constrictor Muscles Using Different Techniques in Radiotherapy for Oropharyngeal Cancer

OBJECTIVE

The purpose of this research was to compare two treatment techniques for oropharyngeal cancers: conventional linac-based static intensity-modulated radiotherapy (sIMRT) and helical tomotherapy (HT). The study examined several parameters, including target coverage, organs at risk, integral dose, and beam on time. Additionally, the study evaluated the doses to the parotid, temporomandibular joint, and pharyngeal constrictor muscles, which are important for swallowing.

METHOD

The present study retrospectively analyzed the data of 13 patients with oropharyngeal cancer who underwent radiotherapy between 2019 and 2021. The treatment plans for each patient were regenerated using both sIMRT and HT treatment planning systems with the sequential boost method. The techniques were evaluated and compared based on dose-volume histogram, homogeneity index, and conformity index parameters. The target coverage and organs at risk were statistically compared for two techniques. Additionally, the doses received by the healthy tissue volume were obtained for integral dose evaluation. The beam on time for each technique was assessed.

RESULTS

When considering planning target volume evaluation, there was no difference in Dmeans between the two techniques and sIMRT demonstrated higher D2% values compared to the HT. The HT technique had better results for all organs at risk, such as the parotid, temporomandibular joint, and pharyngeal constrictor muscle. As for integral dose, it has been shown that the sIMRT technique provides better protection compared to HT. In addition, the beam on time was also longer with the HT technique.

CONCLUSION

Both techniques may provide optimal target coverage for patients with oropharyngeal cancer. HT conferred notable advantages, especially with regard to critical structures implicated in swallowing, such as the parotid, temporomandibular joint, and pharyngeal constrictor muscle, in comparison to sIMRT.

Lysosomal inhibition sensitizes TMEM16A-expressing cancer cells to chemotherapy

Cisplatin is the first line therapy for patients with head and neck cancer. However, resistance to cisplatin remains a major concern. High expression of the calcium-activated chloride channel TMEM16A in tumors portends poor survival in these patients, possibly because of drug resistance. Here, we show that TMEM16A drives the sequestration of cisplatin into lysosomes. Subsequently, cisplatin is expelled via the delivery of lysosomes to the cell surface. We show that TMEM16A enhances this process, thereby promoting cisplatin resistance. We also show that lysosomal inhibition synergizes with cisplatin to induce tumor cell death. Our data uncovers a new fundamental feature of both lysosomal physiology and cancer cell biology that can potentially impact the treatment of patients with head and neck cancer.

Squamous cell carcinoma of the head and neck (SCCHN) is a devastating disease that continues to have low cure rates despite the recent advances in therapies. Cisplatin is the most used chemotherapy agent, and treatment failure is largely driven by resistance to this drug. Amplification of chromosomal band 11q13 occurs in ∼30% of SCCHN tumors. This region harbors the ANO1 gene that encodes the TMEM16A ion channel, which is responsible for calcium-activated chloride transport in epithelial tissues. TMEM16A overexpression is associated with cisplatin resistance, and high TMEM16A levels correlate with decreased survival. However, the mechanistic underpinning of this effect remains unknown. Lysosomal biogenesis and exocytosis have been implicated in cancer because of their roles in the clearance of damaged organelles and exocytosis of chemotherapeutic drugs and toxins. Here, we show that TMEM16A overexpression promotes lysosomal biogenesis and exocytosis, which is consistent with the expulsion of intracellular cisplatin. Using a combination of genetic and pharmacologic approaches, we find that TMEM16A promotes lysosomal flux in a manner that requires reactive oxygen species, TRPML1, and the activation of the β-catenin–melanocyte-inducing transcription factor pathway. The lysosomal inhibitor hydroxychloroquine (HCQ) synergizes with cisplatin in killing SCCHN cells in vitro. Using a murine model of SCCHN, we show that HCQ and cisplatin retard the growth of cisplatin-resistant patient-derived xenografts in vivo. We propose that TMEM16A enables cell survival by the up-regulation of lysosomal sequestration and exocytosis of the cytotoxic drugs. These results uncover a model of treatment for resistance in cancer, its reversal, and a role for TMEM16A.

Oncologic outcomes of transoral robotic surgery for HPV-negative oropharyngeal carcinomas

BACKGROUND

Patients with human papillomavirus (HPV)-negative oropharyngeal squamous cell carcinoma (OPSCC) continue to experience disappointing outcomes following chemoradiotherapy (CRT) and appreciable morbidity following historical surgical approaches. We aimed to investigate the oncologic outcomes and perioperative morbidity of a transoral robotic surgery (TORS) approach to surgically resectable HPV-negative OPSCC.

METHODS

Retrospective analysis HPV-negative OPSCC patients who underwent TORS, neck dissection and pathology-guided adjuvant therapy (2005-2017).

RESULTS

Fifty-six patients (91.1% stage III/IV) were included. Three-year overall survival, locoregional control, and disease-free survival were 85.5%, 84.4%, and 73.6%, respectively (median follow-up 30.6 months, interquartile range 18.4-66.6). Eighteen (32.1%) patients underwent adjuvant radiotherapy and 20 (39.3%) underwent adjuvant CRT. Perioperative mortality occurred in one (1.8%) patient and hemorrhage occurred in two (3.6%) patients. Long-term gastrostomy and tracheostomy rates were 5.4% and 0.0%, respectively.

CONCLUSION

The TORS approach for resectable HPV-negative OPSCC can achieve encouraging oncologic outcomes with infrequent morbidity.

TGFβ1 Genetic Variants Predict Clinical Outcomes of HPV-Positive Oropharyngeal Cancer Patients after Definitive Radiotherapy

Purpose: TGFβ1 plays a critical role in inflammation and immune responses and treatment response and survival. TGFβ1 variants may affect its expression level or functional efficiency, thus modifying tumor status and survival in human papillomavirus (HPV)-positive squamous cell carcinoma of the oropharynx (SCCOP).Experimental Design: We determined tumor HPV16 status and genotyped three TGFβ1 polymorphisms in 564 incident SCCOP patients treated with radiotherapy or chemoradiation. Univariate and multivariable Cox models were used to evaluate the associations between the three polymorphisms and survival.Results: Overall, 85% of patients (482 of 564) had HPV16-positive SCCOP. We found that TGFβ1 rs1982073 had statistically significant associations with survival, whereas TGFβ1 rs1800469 and TGFβ1 rs1800471 did not. Patients with TGFβ1 rs1982073 CT/CC variant genotypes had significantly better overall, disease-specific, and disease-free survival compared with those with the corresponding common homozygous TT genotype (all log-rank: P < 0.001). Furthermore, these genotypes were significantly associated with an approximately 5 times reduced risk of overall death, death owing to disease, and recurrence after multivariable adjustment. Moreover, the stratified analyses by tumor HPV status indicated that the significant effects of TGFβ1 rs1982073 polymorphism on survival were found among HPV16-positive SCCOP patients only. Finally, the functional relevance of these variants was further characterized.Conclusions: Our findings support that the TGFβ1 rs1982073 polymorphism plays a significant role in the prognosis of SCCOP, especially in HPV16-positive SCCOP patients treated with chemoradiation. Prospective studies with larger sample sizes are needed to confirm these findings. Clin Cancer Res; 24(9); 2225-33. ©2018 AACR.

Oral and oropharyngeal cancer

Oral and oropharyngeal cancer (OPC) is a complex and often relentless malignancy prone to local invasion and dissemination. Despite advances in understanding of the disease and improved therapeutic interventions, it continues to be diagnosed at an advanced stage and the survival rate remains poor. The financial cost of treating OPC may be the highest of all cancers in the United States and survivors often experience major detriments to quality of life. Major risk factors for OPC are tobacco, alcohol, areca nut, and human papillomavirus infection. This article updates medical practitioners on the causes, presentation, diagnosis, and management of OPC.

[Outcomes following transoral resection of oropharyngeal squamous cell carcinoma]

INTRODUCTION AND OBJECTIVES

The aim of our study was to evaluate outcomes of a minimally invasive approach, using transoral surgery (TOS) as the primary treatment for oropharyngeal carcinoma.

METHODS

We reviewed 43 previously untreated patients with oropharyngeal carcinoma, who were treated with TOS. Distribution of the primary tumor site was: tonsil (52%), soft palate (23%), base of the tongue (21%) and posterior wall (4%). Eight patients had a stage I disease, 9 had a stage II disease, 7 had a stage III disease, 16 had a stage IVA, and 3 had stage IVB disease. Eighteen patients underwent postoperative radiotherapy. Records of these patients were reviewed to obtain measures such as local and regional control, overall and disease-specific survival, and speech and swallowing function.

RESULTS

The overall recurrence rate was 44%, and the local recurrence rate was 18%. The 5-year overall survival and disease-specific survival rates were 55% and 66%, respectively. Five-year disease-specific survival rates by site were as follows: 100%, 85%, 44%, and 30% for posterior wall, tonsil, soft palate and base of the tongue, respectively. Five-year estimates for local control were 100%, 90%, and 0% for palate, tonsil and for base of the tongue tumors, respectively. All of the patients preserved the larynx and live without tracheotomy and oral alimentation was successfully without feeding tube.

CONCLUSIONS

TOS as the primary treatment approach offers a surgical alternative for treatment of the primary oropharyngeal tumor, in the era of chemoradiation therapy. This approach confers a good local control and functional outcomes.

Transposition of a lingual thyroid to the submandibular space using a modified technique

OBJECTIVE

We report a modified surgical technique for transplanting an ectopic, lingual thyroid to the submandibular space, in order to maintain thyroid function while relieving obstructive symptoms.

CASE REPORT

A 52-year-old woman complained of progressive dysphagia and dyspnoea. Ectopic lingual thyroid tissue was diagnosed. The ectopic thyroid gland was transplanted into the submandibular region via a lateral pharyngeal approach. A random muscle pedicle was prepared to provide a vascular supply to the transposed gland.

RESULTS

Twelve-month follow up confirmed the survival of the transplanted thyroid gland, with preserved thyroid function.

CONCLUSION

Surgical transplantation of a lingual thyroid to the submandibular region offers an alternative treatment method for this anomaly, which avoids the need for resection and lifelong thyroxine replacement.

Human papillomavirus and oropharyngeal squamous cell carcinoma: what the clinician should know

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is rising in contrast to the decreasing incidence of carcinomas arising in other subsites of the head and neck. The human papillomavirus (HPV) infection has played an increasing role in these epidemiological changes and as the etiology for a significant fraction of head and neck squamous cell carcinomas, OPSCC in particular. Most importantly, many retrospective studies have shown that the prognosis differs significantly between patients with HPV-associated tumors and non-HPV associated tumors. Thus, questions arise on the choices of treatment for patients based on HPV status and the consequences of therapy. Given the recognized relevance of HPV status in OPSCC, many new questions concerning the biology, treatment, and prevention of HPV infection arise. This review is intended to highlight some of the major issues and frequently asked questions relevant for the clinician dealing with patients with OPSCC.

Matched survival analysis in patients with locoregionally advanced resectable oropharyngeal carcinoma: platinum-based induction and concurrent chemoradiotherapy versus primary surgical resection

PURPOSE

The outcome of a prospective case series of 47 patients with newly diagnosed resectable locoregionally advanced oropharyngeal squamous cell carcinoma treated with platinum-based induction-concurrent chemoradiotherapy (IC/CCRT) was compared with the outcome of 47 matched historical control patients treated with surgery and postoperative RT.

METHODS AND MATERIALS

A total of 47 control patients with locoregionally advanced oropharyngeal squamous cell carcinoma were identified from review of a prospectively compiled comprehensive computerized head-and-neck cancer database and were matched with a prospective case series of patients undergoing IC/CCRT by disease stage, nodal status, gender, and age (± 5 years). The IC/CCRT regimen consisted of one cycle of induction chemotherapy followed by conventionally fractionated RT to a total dose of 66-70 Gy concomitantly with two cycles of chemotherapy. Each cycle of chemotherapy consisted of cisplatinum, 100 mg/m(2), and a continuous infusion of 5-fluorouracil, 1,000 mg/m(2)/d for 5 days. The survival analysis was performed using Kaplan-Meier estimates. Matched-pair survival was compared using the Cox proportional hazards model.

RESULTS

No significant difference was found in the overall survival or progression-free survival rates between the two groups. The matched analysis of survival did not show a statistically significant greater hazard ratio for overall death (hazard ratio, 1.35; 95% confidence interval, 0.65-2.80; p = .415) or progression (hazard ratio, 1.44; 95% confidence interval, 0.72-2.87; p = .301) for patients undergoing IC/CCRT.

CONCLUSION

Although the sample size was small and not randomized, this matched-pair comparison between a prospective case series and a historical cohort treated at the same institution showed that the efficacy of IC/CCRT with salvage surgery is as good as primary surgical resection and postoperative RT.