Genetically engineered mouse models of head and neck cancers

The head and neck region is one of the anatomic sites commonly afflicted by cancer, with ~1.5 million new diagnoses reported worldwide in 2020 alone. Remarkable progress has been made in understanding the underlying disease mechanisms, personalizing care based on each tumor's individual molecular characteristics, and even therapeutically exploiting the inherent vulnerabilities of these neoplasms. In this regard, genetically engineered mouse models (GEMMs) have played an instrumental role. While progress in the development of GEMMs has been slower than in other major cancer types, several GEMMs are now available that recapitulate most of the heterogeneous characteristics of head and neck cancers such as the tumor microenvironment. Different approaches have been employed in GEMM development and implementation, though each can generally recapitulate only certain disease aspects. As a result, appropriate model selection is essential for addressing specific research questions. In this review, we present an overview of all currently available head and neck cancer GEMMs, encompassing models for head and neck squamous cell carcinoma, nasopharyngeal carcinoma, and salivary and thyroid gland carcinomas.

Long-term results of RTOG 91-11: a comparison of three nonsurgical treatment strategies to preserve the larynx in patients with locally advanced larynx cancer

PURPOSE

To report the long-term results of the Intergroup Radiation Therapy Oncology Group 91-11 study evaluating the contribution of chemotherapy added to radiation therapy (RT) for larynx preservation.

PATIENTS AND METHODS

Patients with stage III or IV glottic or supraglottic squamous cell cancer were randomly assigned to induction cisplatin/fluorouracil (PF) followed by RT (control arm), concomitant cisplatin/RT, or RT alone. The composite end point of laryngectomy-free survival (LFS) was the primary end point.

RESULTS

Five hundred twenty patients were analyzed. Median follow-up for surviving patients is 10.8 years. Both chemotherapy regimens significantly improved LFS compared with RT alone (induction chemotherapy v RT alone: hazard ratio [HR], 0.75; 95% CI, 0.59 to 0.95; P = .02; concomitant chemotherapy v RT alone: HR, 0.78; 95% CI, 0.78 to 0.98; P = .03). Overall survival did not differ significantly, although there was a possibility of worse outcome with concomitant relative to induction chemotherapy (HR, 1.25; 95% CI, 0.98 to 1.61; P = .08). Concomitant cisplatin/RT significantly improved the larynx preservation rate over induction PF followed by RT (HR, 0.58; 95% CI, 0.37 to 0.89; P = .0050) and over RT alone (P < .001), whereas induction PF followed by RT was not better than treatment with RT alone (HR, 1.26; 95% CI, 0.88 to 1.82; P = .35). No difference in late effects was detected, but deaths not attributed to larynx cancer or treatment were higher with concomitant chemotherapy (30.8% v 20.8% with induction chemotherapy and 16.9% with RT alone).

CONCLUSION

These 10-year results show that induction PF followed by RT and concomitant cisplatin/RT show similar efficacy for the composite end point of LFS. Locoregional control and larynx preservation were significantly improved with concomitant cisplatin/RT compared with the induction arm or RT alone. New strategies that improve organ preservation and function with less morbidity are needed.

Treatment of hypopharyngeal carcinoma with primary chemoradiotherapy: functional morbidity

PURPOSE OF REVIEW

This review aims at unravelling the medical literature which has reported on the treatment of 'larynx preserving' chemoradiotherapy strategies and separating the treatment sites, larynx and hypopharynx, from each other and reporting on the adverse effects and functional outcomes of patients with hypopharyngeal cancer.

RECENT FINDINGS

The literature reports on the treatment of advanced laryngeal and hypopharyngeal cancer with chemoradiotherapy together as a 'common cancer site'. Although the chemotherapeutic drugs affect the tumour and the normal tissues similarly in both the larynx and hypopharynx, their effects on the patient groups are different, mainly affecting swallow, airway protection mechanisms and voice/speech to a greater or lesser extent. Pretreatment symptoms and function should be documented subjectively and objectively prior to commencing nonsurgical treatment. Hypopharyngeal cancer should be reported separately, and preferably stratified into the three subsites, according to the T stage of disease rather than TNM stage. Equipment for such testing and the process for such documentation are available in most clinical areas, worldwide.

SUMMARY

Future analysis relies on the conscientious monitoring of adverse effects of all treatment modalities and an assessment of function as well as quality of life impact on the patient. Thus, the specialty can make informed decisions on the most appropriate and most suitable mode of treatment for individual patients based upon their tumour, their preoperative organ function, their likely future organ function and the likelihood of cure.

Laryngeal tumor volume as a predictor for thyroid cartilage penetration

BACKGROUND

Review of laryngectomy specimens demonstrated that preoperative CT scanning is suboptimal in predicting both thyroid cartilage penetration and extralaryngeal spread. We investigated the association between the CT-based gross tumor volume (GTV) with pathologic evidence of thyroid cartilage penetration among patients undergoing laryngectomy for squamous cell carcinoma (SCC) of the larynx.

METHODS

Ninety-four patients were identified who underwent total laryngectomy for SCC of the larynx. GTV, as defined by preoperative diagnostic CT scan, was contoured and analyzed using treatment-planning software.

RESULTS

Among the 49 nonirradiated patients, the mean GTVs of patients with (n = 15) and without (n = 34) thyroid cartilage penetration was 60.1 and 28.0 cm(3) (p = .004). When the nonirradiated patients were divided into 3 GTV groups (≤25 cm(3), 25-50 cm(3), >50 cm(3)), the rates of thyroid cartilage penetration were 23%, 17%, and 78%, respectively (p = .003).

CONCLUSIONS

Laryngeal tumor volume is associated with pathologic evidence of thyroid cartilage penetration in nonirradiated patients.

Current trends in initial management of hypopharyngeal cancer: the declining use of open surgery

Squamous cell carcinoma of the hypopharynx represents a distinct clinical entity. Most patients present with significant comorbidities and advanced-stage disease. The overall survival is relatively poor because of high rates of regional and distant metastasis at presentation or early in the course of the disease. A multidisciplinary approach is crucial in the overall management of these patients to achieve the best results and maintain or improve functional results. Traditionally, operable hypopharyngeal cancer has been treated by total (occasionally partial) laryngectomy and partial or circumferential pharyngectomy, followed by reconstruction and postoperative radiotherapy in most cases. Efforts to preserve speech and swallowing function in the surgical treatment of hypopharyngeal (and laryngeal) cancer have resulted in a declining use of total laryngopharyngectomy and improved reconstructive efforts, including microvascular free tissue transfer. There are many surgical, as well as nonsurgical, options available for organ and function preservation, which report equally effective tumor control and survival. The selection of appropriate treatment is of crucial importance in the achievement of optimal results for these patients. In this article, several aspects of surgical and nonsurgical approaches in the treatment of hypopharyngeal cancer are discussed. Future studies must be carefully designed within clearly defined populations and use uniform terminology and standardized functional assessment and declare appropriate patient or disease endpoints. These studies should focus on improvement of results, without increasing patient morbidity. In this respect, technical improvements in radiotherapy such as intensity-modulated radiotherapy, advances in supportive care, and incorporation of newer systemic agents such as targeted therapy, are relevant developments.