Results
Forty-four patients with early-stage laryngeal cancer and treated with RT were retrospectively evaluated. Their mean age was 59.8±9.0 (43–81) and 41 were men. Before treatment, all patients were confirmed as having early-stage disease according to the findings of indirect laryngoscopic and radiologic evaluation and were reported as SCC according to pre-treatment biopsy. Thirty-four patients had T1 glottic tumor and 11 had T2 glottic tumors. There were not anterior commissure involvement seen at all patients. All of the patients were diagnosed as early-stage glottic carcinoma according to the classification system of AJCC 2017 (23).
There were 20 patients (all men) in the non-recurrent group and 24 patients (22 men and 3 women) in the recurrent group. Median follow-up time was 48 months (22–88 months). Treatment failure was observed in 24 cases. Table 1 shows the demographic and clinical features of the patients.
Table 2 shows demographic and clinical features of the patients according to treatment response. While positive ALDH1 staining (p=0.0001) was found to be significant risk factor for treatment failure, positive CD44 staining (p=0.114) and age group (p=0.287) were not significant factors.
Means and medians for disease-free survival (DFS) time are shown in Table 3. The mean OS was 60.7 months (median: 62.0 months). Cumulative proportion of surviving patients was 81% at 12 months (1 year), 56% at 24 months (2 years), and 42% at 36 months (3 years). Figure 1 shows total DFS times. DFS was shorter in cases with positive ALDH1 staining and CD44 staining (p=0.0001); Figure 2A shows DFS times according to ALDH1 positivity and Figure 2B shows DFS times according to CD44 positivity.
Table 4 shows results of the Cox regression analyses. Two Cox regression models were created using significant parameters detected in univariate survival analysis: age, ALDH1 positivity, CD44 positivity. According to Cox regression model, only the ALDH1 positivity was found to be a significant independent factor for DFS, with positivity associated significantly increasing the poor prognosis HR:16.4 (95% CI: 3.6-73.5, p=0.0001).