Clinicopathologic features of the 57 patients with advanced laryngeal cancer
The clinicopathologic features of the 57 patients with advanced laryngeal cancer are summarized in Table 1. Fifty-four patients (94.7%) were male and the remaining three patients (5.3%) were female. The mean age at the time of surgery was 68.4 years. The most frequent primary tumor site was the glottis (n=35), followed by the supraglottis (n=16) and subglottis (n=6). Regarding the T stage, four cases (7.0%) were categorized as T2, 22 cases (38.6%) were categorized as T3, and 31 cases (54.4%) were categorized as T4. Thirty-seven cases (64.9%) had no lymph-node metastasis at the time of surgery. Only one patient had distant metastasis. Twenty cases (35.1%) were categorized as Stage III, and the remaining 37 cases (64.9%) are categorized as Stage Ⅳ. The histology of all 57 cases was squamous cell carcinoma (SCC), and its histological differentiation was distributed as follows: well-differentiated SCC (n=30), moderately differentiated SCC (n=25), and poorly differentiated SCC (n=2). Thirty-eight patients (66.6%) received adjuvant therapy; the details are as follows: 32 patients received chemotherapy (uracil/tegafur [n=29], tegafur [n=2], cisplatin+5-FU [n=1]), two patients received radiotherapy, and four patients received chemoradiotherapy; the chemotherapy regimens were: uracil/tegafur (n=1), TS-1 (n=1), cisplatin (n=1), nedaplatin (n=1).
Assessment of CD1a+ DCs and theircorrelations with clinicopathologic factors
An infiltration of CD1a+ DCs was observed in all 57 cases with various densities in areas adhering to or adjacent to the tumor cells. The average number of tumor-infiltrating CD1a+ DCs was 46.92 (range 1.3–351). Using the median value (28.7) of the number of infiltrating CD1a+ DCs as a cut-off, we divided the cases into the CD1a-low group (n=29) and the CD1a-high group (n=28). Representative histological images from each group are presented in Figure 2.
The relationships between CD1a+ DC infiltration and clinicopathologic factors are summarized in Table 2. The CD1a-high group had significantly more advanced (T4 and Stage Ⅳ) cases (p=0.0448 and p=0.0377, respectively) than the CD1a-low group. No significant difference was observed between the CD1a-low and -high groups in other factors, i.e., age, gender, smoking, alcohol consumption, primary site, histological differentiation, T stage, N stage, M stage, or adjuvant therapy.
Assessment of S100+ DCs and their correlations with clinicopathologic factors
Infiltration of S100+ DCs was also observed in all 57 cases with various densities. The average number of tumor-infiltrating S100+ DCs was 68.9 (range 0.5–390.3). Using the median value (49.3) of S100+ DCs as a cut-off, we divided the cases into the S100-low group (n=29) and the S100-high group (n=28). Representative histological images from each group are provided in Figure 3. The relationships between S100+ DC infiltration and clinicopathologic factors are summarized in Table 3. Compared to the S100-low group, the S100-high group had significantly more cases of well-differentiated SCC (p=0.0120). No significant difference was observed in other factors (age, gender, smoking, alcohol drinking, primary site, T stage, N stage, M stage, or adjuvant therapy) between the S100-low and S100-high groups.
Assessment of CD8+ CTLs and their association with CD1a+ and S100+ DCs
The average number of tumor-infiltrating CD8+ CTLs was 562.8 (range 0–2,580). The results of the linear regression analysis between CD1a+ DCs or S100+ DCs and CD8+ CTLs are illustrated in Figure 4. The cases with a higher number of tumor-infiltrating CD1a+ DCs tended to have a higher number of CD8+ CTLs, although no significance was observed (p=0.4278). Similarly, the cases with a higher number of tumor-infiltrating S100+ DCs tended to have a higher number of CD8+ CTLs; no significance was observed (p=0.5409). We divided the cases into the CD8-low group (n=28) and CD8-high group (n=29) using the median value of CD8+ CTLs (435) as a cut-off value. No significant difference in clinicopathologic factors was observed between these groups.
Kaplan-Meier survival curves according to the infiltration of DCs and CD8+ CTLs
The Kaplan-Meier survival curves based on the status of CD1a+ DCs, S100+ DCs, and CD8+ CTLs are shown in Figure 5. The CD1a-low group showed significantly better DSS and OS than the CD1a-high group (p=0.0082 and 0.0324, respectively). No significant difference was observed between the S100-low group and S100-high group (p=0.3098 and p=0.5106) or between the CD8-low group and CD8-high group (p=0.2575 and p=0.5045) in both DSS and OS.
Univariate and multivariate analyses for OS and DSS
The results of the univariate analyses for OS and DSS are summarized in Table 4. The factors significantly correlated with OS were tumor subsite, T stage, N stage, and infiltration of CD1a+ DCs (p=0.0457, p=0.0083, p=0.0027, p=0.0351, respectively). The factors significantly correlated with DSS were T stage, N stage, and infiltration of CD1a+ DCs (p=0.0002, p=0.0240, p=0.0089, respectively).
The factors that were shown to be significant in the univariate analyses were further subjected to the multivariate analyses (Table 5). The multivariate analysis for OS indicated that T stage, N stage, and infiltration of CD1a+ DCs were each significantly associated with the patients' OS (p=0.0256, p=0.0069, p=0.0132 respectively). The multivariate analysis for DSS indicated that T stage, N stage, and infiltration of CD1a+ DCs were significantly associated with the patients' DSS (p=0.0005, p=0.0209, and p=0.0093 respectively).