Definitive radiotherapy for carcinoma in situ of the true vocal cords

[Radiotherapy for patients with early-stage glottic squamous cell carcinoma of the larynx: Interest of hypofractionation?]

Hypofractionated radiotherapy of early-stage squamous cell carcinoma of the glottic larynx is a promising treatment option. This can be divided into radiotherapy with moderate hypofractionation (up to 2.5Gy per fraction), more intense hypofractionation (between 2.5 and 4.5Gy per fraction) and stereotactic radiotherapy (above 4.5Gy per fraction). Most studies evaluating moderate hypofractionation show a local control rate between 85 and 95%. Acute laryngeal toxicity is superior to conventional treatment, but only for grades 1 and 2, with no significant difference reported for severe toxicity. Stereotactic radiotherapy in this pathology is also an emerging entity, but some authors have reported significant toxicity. There are currently no standardized guidelines for treatment and management regimen. We conducted a systemic review of published prospective and retrospective trials to evaluate efficacy, toxicity, and discuss future directions.

Radiotherapy in the management of glottic squamous cell carcinoma

INTRODUCTION

Our purpose is to review the role radiotherapy (RT) in the treatment of glottic squamous cell carcinoma (SCC).

METHODS

A concise review of the pertinent literature.

RESULTS

RT cure rates are Tis- T1N0, 90% to 95%; T2N0, 70% to 80%; low-volume T3-T4a, 65% to 70%. Concomitant cisplatin is given for T3-T4a SCCs. Severe complications occur in 1% to 2% for Tis-T2N0 and 10% for T3-T4a SCCs. Patients with high-volume T3-T4 SCCs undergo total laryngectomy, neck dissection, and postoperative RT. Those with positive margins and/or extranodal extension receive concomitant cisplatin. The likelihood of local-regional control at 5 years is 85% to 90%. Severe complications occur in 5% to 10%.

CONCLUSIONS

RT is a good treatment option for patients with Tis-T2N0 and low-volume T3-T4a glottic SCCs. Patients with higher volume T3-T4 cancers are best treated with surgery and postoperative RT.

Outcome of Early-Stage Glottic Laryngeal Carcinoma Patients Treated with Radical Radiotherapy Using Different Techniques

Purpose

The aim was to evaluate the treatment outcomes and prognostic characteristics of patients with early-stage glottic laryngeal carcinoma who underwent radical radiotherapy (RT) with different techniques.

Patients and Methods

Radiotherapy was applied using the 2D conventional technique between 1991 and 2004 (130 patients), 3DCRT until 2014 (125 patients), and by VMAT until January 2017 (44 patients). Clinical T stages were 38 (12.7%) for Tis, 209 (69.9%) for T1, and 52 (17.4%) for T2. Radiotherapy technique and energy, anterior commissure involvement, and stage were analyzed as prognostic factors.

Results

The median total dose was 66 (50–70) Gy, and median follow-up time was 72 (3–288) months; 5-year disease-specific survival (DSS) rates were 95.8%, 95.5%, and 88.6%, respectively, in Tis, T1, and T2 stages. In multivariate analyses, anterior commissure involvement was found significant for all survival and local control rates. The patients treated with VMAT technique had better local control and DSS rates. However, these results were not statistically significant.

Conclusion

In early-stage laryngeal carcinomas, radical RT is a function sparing and effective treatment modality, regardless of treatment techniques.

Patterns of Care for Patients With Early-Stage Glottic Cancer Undergoing Definitive Radiation Therapy: A National Cancer Database Analysis

PURPOSE

To characterize practice patterns, including temporal trends, in fractionation schedules among patients in the United States undergoing definitive radiation therapy for early-stage glottic cancer and to compare overall survival outcomes between fractionation schedules.

METHODS AND MATERIALS

We queried the National Cancer Database for patients with TisN0M0, T1N0M0, or T2N0M0 squamous cell carcinoma of the glottic larynx diagnosed between 2004 and 2012 and undergoing definitive radiation therapy. Dose per fraction was calculated to define cohorts undergoing conventional fractionation (CFxn) and hypofractionation (HFxn). Logistic regression was performed to identify predictors of receiving HFxn, and Cox regression was used to determine predictors of death. One-to-one propensity score matching was then used to compare survival between fractionation schedules.

RESULTS

The study included 10,539 patients, with 6576 undergoing CFxn and 3963 undergoing HFxn. Patients with T1 disease comprised a majority of each cohort. Use of HFxn increased significantly over the period studied (P<.001), but even in the final year, nearly one-half of patients continued to receive CFxn. Receipt of HFxn was also independently associated with higher income and facility types other than community cancer programs on logistic regression. On multivariate Cox regression, HFxn was associated with improved survival (hazard ratio [HR] for death, 0.90; 95% confidence interval [CI], 0.83-0.97; P=.008), a finding redemonstrated on univariate Cox regression among a well-matched cohort after propensity score matching (HR, 0.88; 95% CI, 0.80-0.96; P=.003). Subgroup Cox multivariate analysis demonstrated a significant survival advantage with HFxn among patients with T1 disease (HR, 0.90; 95% CI, 0.81-0.99; P=.042) but a nonsignificant benefit among those with Tis (HR, 0.86; 95% CI, 0.57-1.30; P=.472) or T2 (HR, 0.88; 95% CI, 0.76-1.02; P=.099) disease.

CONCLUSIONS

Use of HFxn is increasing and is associated with improved survival over CFxn. Our findings support the broadened use of HFxn for patients with early-stage glottic cancer undergoing definitive radiation therapy.

Definitive Radiotherapy for Squamous Cell Carcinoma of the Glottic Larynx

Background

Depending on the extent of disease, squamous cell carcinoma (SCC) of the glottis is managed with surgery, radiotherapy (RT), or a combination of these modalities. Patients with advanced disease may receive concomitant chemotherapy in conjunction with definitive or postoperative RT.

Methods

The treatment policies of the University of Florida and patient outcomes are reviewed.

Results

The likelihood of cure after RT for carcinoma in situ (Tis) to T2 glottic SCC varies from 70% to 94% depending on tumor stage. Consideration should be given to adding weekly cisplatin for patients with T2b SCC because of the high local recurrence rate after RT alone. The probability of cure is about 65% to 80% for select low-volume (≤ 3.5 cc) T3 to T4 glottic SCC after RT. These patients should be considered for concomitant weekly cisplatin. Higher-volume tumors, particularly those with airway compromise, should be treated with laryngectomy and postoperative RT.

Conclusion

Definitive RT is an excellent treatment for select patients with laryngeal cancer.

Treatment and Survival Trends in Glottic Carcinoma in Situ and Stage I Cancer From 1988 to 2012

OBJECTIVE

To identify trends in treatment and survival for patients with stage I glottic cancer and glottic carcinoma in situ (CIS).

METHODS

The 18-registry SEER data were analyzed for CIS and stage I glottic cancer. Treatment variables and observed and relative survival were assessed separately for stage I and glottic CIS.

RESULTS

Among 14 025 cases of stage I glottic cancer identified from 1988 to 2012, radiation was the most common treatment for all eras. An increase in surgical treatment occurred with a decline in combination therapy. There were 3169 cases of glottic CIS, with surgery the most common initial treatment but with radiotherapy increasing across the years. Relative survival was similar for treatment type and era of diagnosis. Among the 3738 patients with glottic CIS, 5.4% went on to develop invasive glottic carcinoma of any stage, with invasive cancer more common in patients treated by surgery alone compared to radiation or surgery with radiation.

CONCLUSIONS

Despite changes in treatment modalities for CIS and stage I glottic cancer, there have not been significant changes in survival for CIS, with slightly improved survival for treatment with surgery alone. Patients treated with surgery alone had an increased rate of subsequent invasive cancer.

Extensive HPV-related carcinoma in situ of the upper aerodigestive tract with 'nonkeratinizing' histologic features

Over the past several decades, it has become clear that human papillomavirus (HPV) is important for the development and progression of many head and neck squamous cell carcinomas, particularly those arising in the oropharyngeal tonsillar crypts. Yet, our understanding of HPV's role in premalignant squamous lesions remains relatively poor. This is in part because premalignant lesions of the oropharyngeal tonsillar crypt tissue, where most HPV-related carcinomas arise, are difficult if not impossible to identify. Recent evidence does suggest a role for HPV in a subset of premalignant lesions of the surface epithelium, especially the oral cavity, despite the rarity of HPV-related invasive squamous cell carcinomas at this site. Furthermore, these HPV-related oral cavity dysplasias appear to have unique, bowenoid histologic features described as 'basaloid' with full-thickness loss of squamous maturation, mitotic figures and apoptosis throughout. Here, we present a unique case of an HPV-related premalignant lesion (squamous cell carcinoma in situ) extensively involving the surface epithelium of the oral cavity, oropharynx and larynx that had 'nonkeratinizing' histologic features typical of HPV-related invasive squamous cell carcinoma. This case was strongly p16 positive by immunohistochemistry and harbored transcriptionally active HPV as demonstrated by E6/E7 RNA in situ hybridization. Furthermore, the patient had an excellent response to radiation treatment.

Evidence-based practice: management of glottic cancer

The main issue in the management of glottic squamous cell carcinoma, as for all cancers, is adequate disease control while optimizing functional outcomes and minimizing morbidity. This is true for early-stage disease as for advanced tumors. This article evaluates the current evidence for the diagnostic and pretherapeutic workup for glottic squamous cell carcinoma and the evidence concerning different treatment options for glottic carcinoma, from early-stage to advanced-stage disease.