Radiation Therapy versus Surgery in Patients With T1N0 Squamous Cell Carcinoma of the Glottic Larynx–A Population Based Study on Outcomes and the Risks of Secondary Malignancies

Article Outline

• Purpose/Objective(s)
• Materials/Methods
• Results
• Conclusions
• Copyright

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Purpose/Objective(s) 

In the treatment of T1N0M0 SCC of the Glottic Larynx, radiotherapy and surgery are common choices of comparable efficacy. Thus comparisons of the long term potential sequela, such as functional outcome and the risk of second malignancy (SM) are critical factors when determining optimal treatment of choice.

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Materials/Methods 

Between 1988 and 2003 a total of 3898 patients were identified from the SEER Database with a histologically proven T1N0M0 Squamous Cell Carcinoma of the Glottic Larynx who underwent Primary Surgery or Primary Radiotherapy (EBRT). Patients were excluded if they had a history of prior malignancy, nonsquamous histology, positive nodes, metastatic disease, follow up less than 3 months, autopsy diagnosis, or adjuvant radiotherapy. Patients prior to 1988 were excluded due to lack of information regarding surgical procedure. Secondary malignancies that were diagnosed <3 months were excluded from this analysis.

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Results 

Of the cohort of 3898 patients, 2667 underwent primary EBRT and 1231 underwent primary surgery. Median age at diagnosis was 65 with an attained median range of 69. Median survival was 61 months (range 4 to 191 months). Demographics include 87% of patients were male, 87% were white, 11% Black, 78% of patients hade Grade 1/2 Tumors, 72% had T1a lesions and 13% had T1b lesions. Groups were well matched for age, attained age, race, tumor grade, time from first primary. The overall risk of SM (all solid and hematologic except larynx) among the EBRT group vs the Surgical cohort was 13.3% (355 cases) vs. 15.0% (185 cases) (p = .149). The overall risk of developing a solid SM (non-laryngeal) was 12.6% and 14.2% respectively (p = .083). The likelihood of developing a second H&N primary were 0.9% and 0.7% respectively (p = .583). There were no differences in the risk of developing a secondary lung, esophageal, thyroid cancer or sarcoma. Primary surgical management was associated with a higher risk of developing a second laryngeal primary, 1.5% in the Surgical arm vs. 0.2% in the EBRT arm (p < .001). In patients who survived >5 y this trend was still evident (2.1% with surgery vs 0.2% with EBRT, p < .001) as well as in patients surviving >10 years (2% vs. 0%, p = .014). The adjusted relative risk at 3 years for development of a secondary laryngeal primary was 10.4, for the Surgery group compared with the EBRT group (p < .001, 95% CI: 3.03–36.1). Overall Survival at 5 years was identical between patients that received EBRT and Surgery, 75% vs 76% (p = .995) as was DFS at 5 years 93% vs 93% (p = .742).

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Conclusions 

Primary radiotherapy for patients with T1N0M0 Squamous Cell Carcinoma of the Glottic Larynx is not associated with a increased risk of secondary malignancies compared to a surgical control. More importantly, surgical management of these patients results in a long term statistically significant increase in the risk of developing a second laryngeal primary which radiation appears to be protect against. Because of equivalent long term survival, when deciding on a therapeutic modality for patients with early glottic cancer this finding as well as functional outcomes deserve greater consideration.