Analysis of prognostic factors for Tis-2N0M0 early glottic cancer with different treatment methods

Guanyu Wang Guodong Li Jianjun Wu Penghui Song About the authors

Abstract

Introduction

In many regions, laryngeal carcinoma is a common upper respiratory tract cancer, most commonly involving the glottic region. The treatment of early glottic cancer includes radiotherapy, open surgery and laryngeal laser microsurgery. However, the preferred treatment for early glottic cancer is still controversial.

Objectives

To study the factors affecting the 5-year survival rate of Tis-2N0M0 early glottis cancer and to demonstrate the oncological safety of different treatments.

Methods

144 patients with early glottic cancer were analyzed retrospectively. All patients were clinically node negative. 53 patients underwent open surgery, transoral CO2 laser microsurgery in 46 cases and radiotherapy in 45 cases. The patients were followed up for 26 − 84 months, with an average follow-up period of 62.9 months.

Results

The 5-year overall survival was 82.6%. The 5 year survival rates of open surgery, laser microsurgery and radiotherapy were 83.0%, 82.6% and 82.2%, respectively. There was no significant difference in 5-year survival rate among the three treatments (p= 0.987). In multivariate analysis, age, T-stage, pathological grading, and anterior commissure involvement were important prognostic factors for early glottic cancer.

Conclusion

There was no significant difference in 5 year survival rate among patients treated by either radiotherapy, laser microsurgery or open surgery for early glottic cancer. We urge more attention to the age, T-stage, pathological grade, and anterior commissure involvement of the patients.

Keywords
Glottic cancer; 5-year survival rate; Laser microsurgery; Radiotherapy; Prognostic factors

Resumo

Introdução

Em muitas regiões, o carcinoma de laringe é um câncer comum do trato respiratório superior e geralmente envolve a região glótica. O tratamento do câncer glótico inicial inclui radioterapia, cirurgia aberta e microcirurgia a laser de laringe. Entretanto, a forma preferencial de tratamento do câncer glótico inicial ainda é controverso.

Objetivos

Estudar os fatores que afetam a taxa de sobrevida em 5 anos do câncer glótico inicial Tis-2N0M0 e demonstrar a segurança oncológica de diferentes tratamentos.

Método

Um total de 144 pacientes com câncer glótico inicial foram analisados retrospectivamente. Todos os pacientes eram clinicamente negativos para linfonodos. Cinquenta e três pacientes foram submetidos à cirurgia aberta, 46 à microcirurgia transoral a laser de CO2, e radioterapia em 45 casos. Os pacientes foram acompanhados por 26 a 84 meses, com um período médio de seguimento de 62,9 meses.

Resultados

A sobrevida global em 5 anos foi de 82,6%. As taxas de sobrevida em cinco anos da cirurgia aberta, microcirurgia a laser e radioterapia foram de 83,0%, 82,6% e 82,2%, respectivamente. Não houve diferença significante na taxa de sobrevida em cinco anos entre os três tratamentos (p = 0,987). Na análise multivariada, idade, estágio T, classificação histopatológica e envolvimento da comissura anterior foram fatores prognósticos importantes para o câncer glótico inicial.

Conclusão

Não houve diferença significante na taxa de sobrevida em 5 anos entre radioterapia, microcirurgia a laser e cirurgia aberta para câncer glótico inicial. Deve-se estar atento à idade, estágio T, histopatológico e envolvimento da comissura anterior dos pacientes.

Palavras-chave
Câncer glótico; Taxa de sobrevida em 5 anos; Microcirurgia a laser; Radioterapia; Fatores prognósticos

Introduction

In many regions, laryngeal carcinoma is a common upper respiratory tract cancer and most commonly involves the glottic region. Early glottic cancer is a highly curable disease. The 5-year local control rate in early glottic cancer patients is in the range of 85%-95% for T1N0M0 and in the range of 60%-80% for T2N0M0.11 Ferri E, Armato E. Diode laser microsurgery for treatment of Tis and T1 glottic carcinomas. Am J Otolaryngol. 2008;29:101-5.

2 Ambrosch P, Fazel A. Functional organ preservation in laryngeal and hypopharyngeal cancer. GMS Curr Top Otorhinolaryngol Head Neck Surg. 2011;10, c2.

3 Mendenhall WM, Amdur RJ, Morris CG, Hinerman RW. T1-T2N0 squamous cell carcinoma of the glottic larynx treated with radiation therapy. J. Clin Oncol. 2001;19:4029-36.

4 Chera BS, Amdur RJ, Morris CG, Kirwan JM, Mendenhall WM. T1N0 to T2N0 squamous cell carcinoma of the glottic larynx treated with definitive radiotherapy. Int J Radiat Oncol Biol Phys. 2010;78:461-6.
-55 Peretti G, Piazza C, Cocco D, De Benedetto L, Del BF, Redaelli DZL, et al. Transoral CO(2) laser treatment for T(is)-T(3) glottic cancer: the University of Brescia experience on 595 patients. Head Neck. 2010;32:977-83. The treatment of early glottic cancer includes radiotherapy, open surgery and laryngeal laser microsurgery. Laser microsurgery and radiotherapy have undergone significant advancement in the past few years leading to a decrease in open partial laryngectomy. However, the preferred treatment for early glottic cancer is still controversial. Laser microsurgery requires only a short hospital stay, but radiotherapy can maintain an optimal voice quality. Many studies have shown that voice preservation is better following radiotherapy than that after any surgical operation.66 Guimaraes AV, Dedivitis RA, Matos LL, Aires FT, Cernea CR. Comparison between transoral laser surgery and radiotherapy in the treatment of early glottic cancer: A systematic review and meta-analysis. Sci Rep. 2018;8:11900.

7 Lee SH, Hong KH, Kim JS, Hong YT. Perceptual and Acoustic Outcomes of Early-Stage Glottic Cancer After Laser Surgery or Radiotherapy: A Meta-Analysis. Clin Exp Otorhinolaryngol. 2019;12:241-8.

8 Arias F, Arraras JI, Asin G, Uzcanga MI, Maravi E, Chicata V, et al. Quality of life and voice assessment in patients with early-stage glottic cancer. Head Neck. 2015;37:340-6.
-99 Gandhi S, Gupta S, Rajopadhye G. A comparison of phonatory outcome between trans-oral CO2 Laser cordectomy and radiotherapy in T1 glottic cancer. Eur Arch Otorhinolaryngol. 2018;275:2783-6. But there are also studies that do not support this conclusion.1010 JRSS B, Cox DR. 34 Regression models and life-tables (with discussion); 1972. p. 187-220. Therefore, the choice of treatment for patients with early glottic cancer should take into account the patient’s occupation, treatment cost, concomitant disease, length of stay and, most importantly, the patient’s preference.

The purpose of this study was to review the factors affecting the 5-year survival rate of Tis-2N0M0 early glottis cancer and to prove the oncological safety of different treatments. In our hospital, our methods for the treatment of early glottic cancer include radiotherapy, laryngeal laser microsurgery and open surgery. In this study, we tried to assess prognostic factors, including gender, age, treatment, T-stage, pathological grade and anterior commissure involvement.

Methods

Patients

144 patients with early glottic cancer were analyzed retrospectively. These patients had complete data and follow-up records. In this study, the stage of tumor was determined on the basis of the clinical findings and classified according to the criteria of the Union for International Cancer Control (UICC). All patients were clinically node-negative. The tumor status was evaluated by routine Computerized Tomography (CT)/Magnetic Resonance Imaging (MRI) and fiberoptic laryngoscopy under local anesthesia.

Treatments

The study included 132 males (91.7%) and 12 females (8.3%), aged 39 to 83 years, with a mean age of 52.4 years. A preoperative CT or MRI was performed in all patients to rule out any infiltration of the cartilaginous framework. 53 patients underwent open surgery (including total laryngectomy in 4 cases, partial laryngectomy in 49 cases), transoral CO2 laser microsurgery in 46 cases and radiotherapy in 45 cases (Table 1). No patient underwent prophylactic neck dissection. 45 patients received radiotherapy. The total dose was 66 Gy, 2.0 Gy per day for 33 treatments. The course of treatment was 7 weeks. During the treatment, radiation oncologists and otolaryngologists evaluated tumor regression by laryngoscopic examination. Each patient was examined once a month in the first year, every 3 months from the second to the third year, and every 6 months thereafter. Fiberoptic laryngoscopy was performed at each revisit. When follow-up laryngoscopy detected a suspicious lesion, biopsy specimens were examined to rule out tumor recurrence. The patients were followed up for 26 − 84 months, with an average follow-up period of 62.9 months. The diagnosis of local recurrence includes clinical examination, pathological diagnosis and fiberoptic laryngoscopy under local anesthesia.

Table 1
Distributions of GC patients according to the UICC 2002 staging system (n).

Statement of ethics

All experiments have been approved by the ethics committee of Heping Hospital Affiliated to Changzhi Medical College (nº 2019006) and conform to the guidelines of the local ethics committee.

Statistical analysis

All statistical analyses were performed using the SPSS 25 software. Overall survival was calculated using the Kaplan-Meier curves. Predictive factors of survival were identified by univariate and multivariate analysis considering the following variables: gender, age (≥ 60 years vs. < 60 years), treatment, T-stage, pathological grading, and involvement of the anterior commissure (yes vs. no). For multivariate analysis, all variables that were statistically significant in the log-rank tests were included in the Cox proportional hazards models.1111 Fitzmaurice C, Allen C, Barber RM, Barregard L, Bhutta ZA, Brenner H, et al. Global, Regional, and National Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life-years for 32 Cancer Groups, 1990 to 2015: A Systematic Analysis for the Global Burden of Disease Study. Jama Oncol. 2017;3:524-48. A p-value of 0.05 or less was considered to be statistically significant.

Results

The three treatment protocols of the patients are summarized in Table 1. The 5-year overall survival was 82.6%. The 5-year survival rates of open surgery, laser microsurgery and radiotherapy were 83.0%, 82.6% and 82.2%, respectively. There was no significant difference in 5-year survival rate among the three treatments (χ2 = 0.026, p = 0.987) (Fig.1). A total of 25 patients died, of which 5 cases were related to laryngeal cancer, and the rest were due to secondary cancers or to intercurrent disease.

Figure 1
Comparison of 5-year survival rate of three treatments (p= 0.987).

The median duration of follow-up was 64 months (range, 26 − 84 months). Table 2 summarized the characteristics of the patients and makes a univariate analysis to identify the factors affecting the 5-year survival rate. The 5-year survival rate of patients less than 60 years old was 86.8%, while that of patients ≥ 60 years old was 71.1% (Fig. 2). There was a significant difference between the two groups (χ2 = 5.245, p = 0.022). In the study, gender has no effect on prognosis (χ2 = 0.001, p = 0.970) (Fig. 3). In univariate analysis, higher T-stage (χ2 = 10.717, p = 0.005) (Fig. 4), poor pathological grading (χ2 = 16.806, p < 0.001) (Fig. 5) and anterior commissure involvement (χ2 = 35.193, p < 0.001) (Fig. 6) were all significant factors affecting the 5-year survival. In multivariate analysis, age, T-stage, pathological grading, and anterior commissure involvement were still important prognostic factors for early glottic cancer (Table 3).

Figure 2
Comparison of 5-year survival rate by age group (p= 0.022).

Figure 3
Comparison of 5-year survival rates by gender (p= 0.970).

Figure 4
Comparison of 5-year survival rate according to T-stage (p= 0.005).

Figure 5
Comparison of 5-year survival rate according to pathological grade (p< 0.001).

Figure 6
Comparison of 5-year survival rate according to anterior commissure involvement (p< 0.001).

Table 2
Patient characteristics and potential prognostic factors for overall survival.
Table 3
Prognostic factors for overall survival on multivariate analysis (Cox model).

Discussion

Head and neck cancer encompasses a broad spectrum of malignancies, and is responsible for 550,000 new cases and 380,000 deaths worldwide annually.1212 Arias F, Arraras JI, Asin G, Uzcanga MI, Maravi E, Chicata V, et al. Quality of life and voice assessment in patients with early-stage glottic cancer. Head Neck. 2015;37:340-6. Histologically, the vast majority (about 90%) are squamous cell carcinomas. The optimal treatment approach for such high-risk patients remains unclear. Glottic cancer patients with clinical manifestations such as hoarseness can be detected in time,1313 Ma Y, Green R, Pan S, McCabe D, Goldberg L, Woo P. Long-term Voice Outcome Following Radiation Versus Laser Microsurgery in Early Glottic Cancer. J Voice. 2019;33:176-82.,1414 Wang Q, Zhao W. [Analyses of recurrences and nodal metastases of glottic carcinoma after operation]. Lin Chuang Er Bi Yan Hou Ke Za Zhi. 2003;17:529-31. and the local lymph node metastasis rate is low,1515 Dequanter D, Lothaire P, Zouaoui K, Brohee D. Epidemiology and clinical characteristics of larynx and hypopharynx carcinoma: a comparative study in the Hainaut and review of the literature. Acta Chir Belg. 2012;112:423-5.,1616 Chen JJ, Stessin A, Christos P, Wernicke AG, Nori D, Parashar B. Differences in survival outcome between stage I and stage II glottic cancer: A SEER-based analysis. Laryngoscope. 2015;125:2093-8. so they have a higher survival rate,1717 Zeng H, Chen W, Zheng R, Zhang S, Ji JS, Zou X, et al. Changing cancer survival in China during 2003-15: a pooled analysis of 17 population-based cancer registries. Lancet Glob. Health. 2018;6:e555-67. but there are still some patients with intractable disease or tumor recurrence. We retrospectively analyzed the effects of different clinical features and treatments on 5-year survival rates to identify high-risk groups for treatment failure in this subgroup.

The survival rate of cancer patients decreases with the increase of age.1818 Mucha-Malecka A, Chrostowska A, Urbanek K, Malecki K. Prognostic factors in patients with T1 glottic cancer treated with radiotherapy. Strahlenther Onkol. 2019;195:792-804. Age is also an important factor in glottic cancer. In our study, patients were divided into ≥ 60 years old and < 60 years old, and it was found that there was a significant difference in 5-year survival rate between the two groups (p = 0.022). This is consistent with the conclusions of other studies.1919 Akimoto T, Nonaka T, Kitamoto Y, Ishikawa H, Ninomiya H, Chikamatsu K, et al. Radiation therapy for T2N0 laryngeal cancer: A retrospective analysis for the impact of concurrent chemotherapy on local control. Int J Radiat Oncol Biol Phys. 2006;64:995-1001.

T stage is well known as a prognostic factor in patients with glottic cancer.2020 Kitani Y, Kubota A, Furukawa M, Sato K. Prognostic factors for local control in patients receiving radiation therapy for early glottic cancer: anterior commissure involvement and effect of chemoradiotherapy. Eur Arch Otorhinolaryngol. 2016;273:1011-7. Although it could not be identified as a significant factor in multivariate analysis of some studies,2121 Benninger MS, Gillen J, Thieme P, Jacobson B, Dragovich J. Factors associated with recurrence and voice quality following radiation therapy for T1 and T2 glottic carcinomas. Laryngoscope. 1994;104:294-8. it still had a significant effect on survival in this study (HR = 4.758, 95% CI 1.287-17.589, p = 0.019). Pathological grading is also an important factor affecting the 5-year survival rate (HR = 3.883, 95% CI 1.323-11.397, p = 0.014), which is consistent with our clinical experience.

The impact of anterior commissure involvement on local control of glottic cancer has been controversial. Some studies have thought it does not affect the local control rate significantly.2222 Sombeck MD, Kalbaugh KJ, Mendenhall WM, Parsons JT, Smith SA, Million RR, et al. Radiotherapy for early vocal cord cancer: a dosimetric analysis of 60CO versus 6 MV photons. Head Neck. 1996;18:167-73.,2323 Li H, Li EY, Kejner AE. Treatment modality and outcomes in larynx cancer patients: A sex-based evaluation. Head Neck. 2019;41:3764-74. Anatomically, the thyroid cartilage lacks protective perichondrium as a potential tumor barrier, while the anterior commissure is directly attached to the thyroid cartilage. This barrier is a weak area from the point of view of tumor dissemination. According to our data, the local failure rate was 18.08 times greater if the anterior commissure was involved. Anterior commissure involvement was also an important prognostic factor in our study (HR = 18.081, 95% CI 2.983-109.596, p = 0.002). This is consistent with our previous conjecture. However, the range of 95% CI may be large due to the sample size.

Although some studies have shown that gender is an independent factor affecting the overall survival rate of laryngeal cancer,2424 Majszyk D, Bruzgielewicz A, Osuch-Wojcikiewicz E, Rzepakowska A, Niemczyk K. Gender-related incidence, risk factors exposure and survival rates of laryngeal cancers - the 10-years analysis of trends from one institution. Otolaryngol Pol. 2019;73:6-10.,2525 Piazza C, Peretti G, Cattaneo A, Garrubba F, De Zinis LO, Nicolai P. Salvage surgery after radiotherapy for laryngeal cancer: from endoscopic resections to open-neck partial and total laryngectomies. Arch Otolaryngol Head Neck Surg. 2007;133: 1037-43. we have not come to such a conclusion in our study.

In most patients with early glottic cancer, organ preservation is gradually considered to be the best initial treatment. Transoral laser microsurgery and radiotherapy have become important treatments for early glottic tumors. In our study, there was no significant difference in the 5-year survival rate between the two treatments and open surgery. Laser microsurgery requires good exposure of the surgical area to ensure an adequate margin of safety. But for recurrent tumors, this is not a good treatment.2626 Agra IM, Ferlito A, Takes RP, Silver CE, Olsen KD, Stoeckli SJ, et al. Diagnosis and treatment of recurrent laryngeal cancer following initial nonsurgical therapy. Head Neck. 2012;34:727-35.,2727 Rydell R, Schalen L, Fex S, Elner A. Voice evaluation before and after laser excision vs. radiotherapy of T1A glottic carcinoma. Acta Otolaryngol. 1995;115:560-5. It is likely that the direct view of the tumor together with a more extended excision of involved seems to guarantee a better local control after radiotherapy relapse than these achieved by microsurgery. Voice quality is reported to be better after radiotherapy.2222 Sombeck MD, Kalbaugh KJ, Mendenhall WM, Parsons JT, Smith SA, Million RR, et al. Radiotherapy for early vocal cord cancer: a dosimetric analysis of 60CO versus 6 MV photons. Head Neck. 1996;18:167-73.,2828 Tripathi N, Verma RK, Panda NK, Ghosal S, Sharma A. Early evaluation of voice quality in glottic cancer (T1, T2) following curative radiotherapy. Rev Laryngol Otol Rhinol (Bord). 2014;135:91-6.,2929 Aref A, Dworkin J, Devi S, Denton L, Fontanesi J. Objective evaluation of the quality of voice following radiation therapy for T1 glottic cancer. Radiother Oncol. 1997;45:149-53. However, when assessed by acoustic analysis and speech aerodynamic studies, the quality of the voice does not return to normal following irradiation.3030 Zouhair A, Azria D, Coucke P, Matzinger O, Bron L, Moeckli R, et al. Decreased local control following radiation therapy alone in early-stage glottic carcinoma with anterior commissure extension. Strahlenther Onkol. 2004;180:84-90. This is probably due to the tumor itself, or because radiotherapy produces a geometric asymmetry and, henceforth, a loss of elasticity of the vocal folds.77 Lee SH, Hong KH, Kim JS, Hong YT. Perceptual and Acoustic Outcomes of Early-Stage Glottic Cancer After Laser Surgery or Radiotherapy: A Meta-Analysis. Clin Exp Otorhinolaryngol. 2019;12:241-8. When choosing a treatment plan, we should explain to the patients the advantages and disadvantages of various treatment methods, which are ultimately decided by the patients themselves.

Conclusion

There was no significant difference in the 5-year survival rate of early glottic cancer treated with radiotherapy, laser microsurgery or open surgery. Multivariate analysis showed that age, T-stage, pathological grading, and anterior commissure involvement were important factors affecting prognosis.

  • Peer Review under the responsibility of Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial.

References

  • 1
    Ferri E, Armato E. Diode laser microsurgery for treatment of Tis and T1 glottic carcinomas. Am J Otolaryngol. 2008;29:101-5.
  • 2
    Ambrosch P, Fazel A. Functional organ preservation in laryngeal and hypopharyngeal cancer. GMS Curr Top Otorhinolaryngol Head Neck Surg. 2011;10, c2.
  • 3
    Mendenhall WM, Amdur RJ, Morris CG, Hinerman RW. T1-T2N0 squamous cell carcinoma of the glottic larynx treated with radiation therapy. J. Clin Oncol. 2001;19:4029-36.
  • 4
    Chera BS, Amdur RJ, Morris CG, Kirwan JM, Mendenhall WM. T1N0 to T2N0 squamous cell carcinoma of the glottic larynx treated with definitive radiotherapy. Int J Radiat Oncol Biol Phys. 2010;78:461-6.
  • 5
    Peretti G, Piazza C, Cocco D, De Benedetto L, Del BF, Redaelli DZL, et al. Transoral CO(2) laser treatment for T(is)-T(3) glottic cancer: the University of Brescia experience on 595 patients. Head Neck. 2010;32:977-83.
  • 6
    Guimaraes AV, Dedivitis RA, Matos LL, Aires FT, Cernea CR. Comparison between transoral laser surgery and radiotherapy in the treatment of early glottic cancer: A systematic review and meta-analysis. Sci Rep. 2018;8:11900.
  • 7
    Lee SH, Hong KH, Kim JS, Hong YT. Perceptual and Acoustic Outcomes of Early-Stage Glottic Cancer After Laser Surgery or Radiotherapy: A Meta-Analysis. Clin Exp Otorhinolaryngol. 2019;12:241-8.
  • 8
    Arias F, Arraras JI, Asin G, Uzcanga MI, Maravi E, Chicata V, et al. Quality of life and voice assessment in patients with early-stage glottic cancer. Head Neck. 2015;37:340-6.
  • 9
    Gandhi S, Gupta S, Rajopadhye G. A comparison of phonatory outcome between trans-oral CO2 Laser cordectomy and radiotherapy in T1 glottic cancer. Eur Arch Otorhinolaryngol. 2018;275:2783-6.
  • 10
    JRSS B, Cox DR. 34 Regression models and life-tables (with discussion); 1972. p. 187-220.
  • 11
    Fitzmaurice C, Allen C, Barber RM, Barregard L, Bhutta ZA, Brenner H, et al. Global, Regional, and National Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life-years for 32 Cancer Groups, 1990 to 2015: A Systematic Analysis for the Global Burden of Disease Study. Jama Oncol. 2017;3:524-48.
  • 12
    Arias F, Arraras JI, Asin G, Uzcanga MI, Maravi E, Chicata V, et al. Quality of life and voice assessment in patients with early-stage glottic cancer. Head Neck. 2015;37:340-6.
  • 13
    Ma Y, Green R, Pan S, McCabe D, Goldberg L, Woo P. Long-term Voice Outcome Following Radiation Versus Laser Microsurgery in Early Glottic Cancer. J Voice. 2019;33:176-82.
  • 14
    Wang Q, Zhao W. [Analyses of recurrences and nodal metastases of glottic carcinoma after operation]. Lin Chuang Er Bi Yan Hou Ke Za Zhi. 2003;17:529-31.
  • 15
    Dequanter D, Lothaire P, Zouaoui K, Brohee D. Epidemiology and clinical characteristics of larynx and hypopharynx carcinoma: a comparative study in the Hainaut and review of the literature. Acta Chir Belg. 2012;112:423-5.
  • 16
    Chen JJ, Stessin A, Christos P, Wernicke AG, Nori D, Parashar B. Differences in survival outcome between stage I and stage II glottic cancer: A SEER-based analysis. Laryngoscope. 2015;125:2093-8.
  • 17
    Zeng H, Chen W, Zheng R, Zhang S, Ji JS, Zou X, et al. Changing cancer survival in China during 2003-15: a pooled analysis of 17 population-based cancer registries. Lancet Glob. Health. 2018;6:e555-67.
  • 18
    Mucha-Malecka A, Chrostowska A, Urbanek K, Malecki K. Prognostic factors in patients with T1 glottic cancer treated with radiotherapy. Strahlenther Onkol. 2019;195:792-804.
  • 19
    Akimoto T, Nonaka T, Kitamoto Y, Ishikawa H, Ninomiya H, Chikamatsu K, et al. Radiation therapy for T2N0 laryngeal cancer: A retrospective analysis for the impact of concurrent chemotherapy on local control. Int J Radiat Oncol Biol Phys. 2006;64:995-1001.
  • 20
    Kitani Y, Kubota A, Furukawa M, Sato K. Prognostic factors for local control in patients receiving radiation therapy for early glottic cancer: anterior commissure involvement and effect of chemoradiotherapy. Eur Arch Otorhinolaryngol. 2016;273:1011-7.
  • 21
    Benninger MS, Gillen J, Thieme P, Jacobson B, Dragovich J. Factors associated with recurrence and voice quality following radiation therapy for T1 and T2 glottic carcinomas. Laryngoscope. 1994;104:294-8.
  • 22
    Sombeck MD, Kalbaugh KJ, Mendenhall WM, Parsons JT, Smith SA, Million RR, et al. Radiotherapy for early vocal cord cancer: a dosimetric analysis of 60CO versus 6 MV photons. Head Neck. 1996;18:167-73.
  • 23
    Li H, Li EY, Kejner AE. Treatment modality and outcomes in larynx cancer patients: A sex-based evaluation. Head Neck. 2019;41:3764-74.
  • 24
    Majszyk D, Bruzgielewicz A, Osuch-Wojcikiewicz E, Rzepakowska A, Niemczyk K. Gender-related incidence, risk factors exposure and survival rates of laryngeal cancers - the 10-years analysis of trends from one institution. Otolaryngol Pol. 2019;73:6-10.
  • 25
    Piazza C, Peretti G, Cattaneo A, Garrubba F, De Zinis LO, Nicolai P. Salvage surgery after radiotherapy for laryngeal cancer: from endoscopic resections to open-neck partial and total laryngectomies. Arch Otolaryngol Head Neck Surg. 2007;133: 1037-43.
  • 26
    Agra IM, Ferlito A, Takes RP, Silver CE, Olsen KD, Stoeckli SJ, et al. Diagnosis and treatment of recurrent laryngeal cancer following initial nonsurgical therapy. Head Neck. 2012;34:727-35.
  • 27
    Rydell R, Schalen L, Fex S, Elner A. Voice evaluation before and after laser excision vs. radiotherapy of T1A glottic carcinoma. Acta Otolaryngol. 1995;115:560-5.
  • 28
    Tripathi N, Verma RK, Panda NK, Ghosal S, Sharma A. Early evaluation of voice quality in glottic cancer (T1, T2) following curative radiotherapy. Rev Laryngol Otol Rhinol (Bord). 2014;135:91-6.
  • 29
    Aref A, Dworkin J, Devi S, Denton L, Fontanesi J. Objective evaluation of the quality of voice following radiation therapy for T1 glottic cancer. Radiother Oncol. 1997;45:149-53.
  • 30
    Zouhair A, Azria D, Coucke P, Matzinger O, Bron L, Moeckli R, et al. Decreased local control following radiation therapy alone in early-stage glottic carcinoma with anterior commissure extension. Strahlenther Onkol. 2004;180:84-90.

Publication Dates

  • Publication in this collection
    27 June 2022
  • Date of issue
    May-Jun 2022

History

  • Received
    22 May 2020
  • Accepted
    25 June 2020
Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Sede da Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico Facial, Av. Indianópolia, 1287, 04063-002 São Paulo/SP Brasil, Tel.: (0xx11) 5053-7500, Fax: (0xx11) 5053-7512 - São Paulo - SP - Brazil
E-mail: revista@aborlccf.org.br