Background: Radiotherapy is one of the main treatment modalities for early-stage glottic carcinoma. Unfortunately, local failure may occur in a group of cases with T1-T2 glottic carcinoma. This meta-analysis sought to determine risk factors for radiation failure in patients with early-stage glottic carcinoma.
Methods: A systematic and comprehensive search was performed for related studies published between 1995 and 2014. The primary end-point was 5-year local control. Data extraction and analysis were performed using the software STATA/SE 13.1 for Windows.
Results: Twenty-seven studies were eligible. A higher risk of radiation failure was demonstrated in male patients [relative risk (RR): 0.927, p<0.001] and those with low hemoglobin level (RR: 0.891, p<0.001) with a high agreement between studies (I-squared=0.0%). Moreover, T2 tumors (RR: 0.795, p<0.001), tumors with anterior commissure involvement (RR: 0.904, p<0.001), tobacco use during/after therapy (RR: 0.824, p<0.001), and "bulky" tumors (RR: 1.270, p<0.001] or tumors bigger in size (RR: 1.332, p<0.001]. Poorly differentiated tumors had a questionable risk of local failure, although a moderate to high interstudy heterogeneity was determined. A statistically significant contribution was not detected for age, presence of comorbidity, alcohol use or subglottic extension.
Conclusion: This is the first meta-analysis which assessed the potential risk factors for radiation failure in patients with early-stage glottic carcinoma. Gender and pretreatment hemoglobin level are major influential factors associated with radiation failure in patients with early-stage glottic carcinoma. However, prospective, randomized clinical trials may permit better stratification of their relative contributions, and those who may benefit more from upfront surgery.
Keywords: Glottis; Head and neck neoplasms; Laryngeal neoplasms; Local; Meta-analysis; Neoplasm recurrence; Prognosis; Radiotherapy; Treatment failure.
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