Improved outcomes in buccal squamous cell carcinoma

The modified vermilion border-marionette line approach: A management for buccal cancer with wider indications and higher satisfaction

OBJECTIVE

The purpose of this study is to explore the effects of modified vermilion border-marionette line (MVBML) approach on postoperative facial scar, nerves injury, and prognosis of patients with buccal squamous cell carcinoma (BSCC).

PATIENTS AND METHODS

This is a single-center, prospective cohort study that enrolled 80 patients with BSCC from June 2015 to December 2020. According to the different surgical approaches, the patients were divided into two groups: the lower lip median (LLM) approach group and the MVBML approach group.

RESULTS

The results showed that the appearance (p = 0.003), scar consciousness (p < 0.001) and satisfaction with appearance (p = 0.001) of patients in the MVBML group were significantly better than those in the LLM group, and the difference was more obvious in elderly group. Statistical analysis of postoperative nerves injury showed that the MVBML group had a lower risk of facial and mental nerves injury than the LLM group, and there was a significant statistical difference in mental nerve injury between the two groups (p < 0.001). Through Kaplan-Meier survival analysis, we found no significant difference in disease-specific survival (p = 0.47) or disease-free survival (p = 0.70) between the LLM approach group and the MVBML approach group.

CONCLUSIONS

The MVBML surgical approach is worthy of advancement for the surgical treatment of BSCC.

Application of anatomy unit resection surgery for lateral basicranial surgical approach in oral squamous carcinoma

BACKGROUND

The basicranial region lacks definite boundaries and includes various anatomical units. We developed a novel concept of the posterior oral anatomical complex (POAC) to identify these anatomical units in the basicranial region. OSCC with POAC involvement is termed posterior oral squamous cell carcinoma (POSCC) with poor prognosis. The principal aim of this study was to evaluate the effect of anatomy unit resection surgery (AUSR) on patients with POSCC.

METHODS

A total of 120 POSCC patients who underwent radical surgical treatment were recruited for this study. These POSCC patients were treated with conventional surgery or AUSR. According to the extent of primary tumor resection in the AUSR group, the lateral basicranial surgical approach can be subdivided into four types: face-lateral approach I, face-lateral approach II, face-median approach or face-median and face-lateral combined approach. Facial nerve function was evaluated according to the House-Brackmann Facial Nerve Grading System.

RESULTS

The overall survival rate was 62.5% and 37.5% in the AURS group and conventional group (hazard ratio: 0.59; p < 0.0001), respectively. The disease-free survival rate was 62.5% and 34.3% in the AURS group and conventional group (hazard ratio: 0.43; p = 0.0008), respectively. The local disease control rate in the AURS group (71.4%) was significantly better than that in the conventional group (34.4%) in present study (p < 0.0001). Compared to the conventional group, all the patients undergoing AURS were classified as T4 stage and presented with more lymph node metastasis (71.4%). A total of 20 patients (face-lateral approach I and face-lateral combined approach) were temporarily disconnected from the temporofacial branch of the facial nerve. Fifteen patients exhibited slight paresis, and five patients presented with moderate or severe paresis. The survival rate of zygomatic arch disconnection was 94.6% (54 of 56 patients).

CONCLUSION

This lateral basicranial surgical approach based on AUSR improves the survival rate and enhances the local control rate while also preserving a good prognosis without damaging the nerve and zygomatic bone. This surgical approach based on AUSR provides a novel and effective surgical treatment to address POSCC with better prognosis, especially for patients without metastatic lymph nodes.

Lateral skull base surgery for posterior oral cavity cancer

The aim of this study was to better understand posterior oral cavity cancer (POCC) and its surgical treatment. This was a retrospective study of 76 patients who were diagnosed with POCC and underwent surgical treatment. Twenty-eight patients were treated with anatomical unit resection surgery (AURS) and 48 patients with conventional surgery. After initial treatment with curative intent, the patients were followed-up regularly with clinical examinations and imaging; the median duration of follow-up was 30.9 months (range 2-67 months). The 3-year overall survival was 64.3% in the experimental AURS group and 39.6% in the conventional surgery control group (hazard ratio 0.49, 95% confidence interval 0.26-0.93; P=0.031). The 3-year disease-free survival was 64.3% in the experimental group and 37.5% in the control group (hazard ratio 0.53, 95% confidence interval 0.27-1.02; P=0.114). In conclusion, AURS is an effective surgical treatment for POCC that can considerably improve patient survival rates.

Inhibition of Bruton's tyrosine kinase as a therapeutic strategy for chemoresistant oral squamous cell carcinoma and potential suppression of cancer stemness

Locally advanced oral squamous cell carcinoma (OSCC) requires multimodal therapy, including surgery and concurrent chemoradiotherapy (CCRT). CCRT-resistant and recurrent cancer has a poor prognosis. We investigated the effects of Bruton's tyrosine kinase (BTK) on CCRT-resistant OSCC tissues. The effect of ibrutinib, a first-in-class BTK inhibitor, was tested on stem cell-like OSCC tumorspheres. A tissue array was constructed using tissue samples from 70 patients with OSCC. Human OSCC cell lines, SAS, TW2.6 and HSC-3, were examined. Wound healing, Matrigel invasion, and tumorsphere formation assays, as well as immunofluorescence analysis and flow cytometry, were used to investigate the effects of BTK knockdown (shBTK), ibrutinib, cisplatin, and ibrutinib/cisplatin combination on OSCC cells. We demonstrated that BTK was aberrantly highly expressed in the clinical CCRT-resistant OSCC tissue array, which resulted in poor overall survival in our local Tri-Service General Hospital and freely accessible TCGA OSCC cohorts. shBTK significantly downregulated the stemness markers Nanog, CD133, T cell immunoglobulin-3 (TIM-3), and Krüppel-like factor 4 (KLF4) in SAS tumorspheres and attenuated OSCC cell migration and colony formation. Ibrutinib reduced the number of aldehyde dehydrogenase (ALDH)-rich OSCC cells and reduced tumorsphere formation, migration, and invasion in a dose-dependent manner. Compared with ibrutinib or cisplatin monotherapy, the ibrutinib/cisplatin combination significantly reduced the formation of ALDH + OSCC tumorspheres and enhanced apoptosis. These results demonstrate that ibrutinib effectively inhibits the CSCs-like phenotype of OSCC cells through dysregulation of BTK/CD133 signaling. The ibrutinib/cisplatin combination may be considered for future clinical use.

Clinicopathologic predictors of survival in buccal squamous cell carcinoma

BACKGROUND

Buccal squamous cell carcinoma (SCC) is a locoregionally aggressive malignancy, representing a small subset of oral cancers in North America. We investigated the prognostic value of several clinicopathologic factors in a cohort of patients diagnosed with buccal SCC.

METHODS

Between years 1992 and 2017, 52 patients were diagnosed with conventional buccal SCC. Archival surgical pathology material was retrospectively reviewed for reportable findings according to the latest reporting guidelines published by the College of American Pathologists. Clinical data were obtained through chart review.

RESULTS

The majority of patients were of older age, current or past smokers, and without specific gender predilection. Most presented at a clinically advanced stage and were treated with surgery alone, or surgery followed by adjuvant radiotherapy. The tumor recurred in about 40% of patients, and almost half of the patients died from the disease by the end of the follow-up period. The worst pattern of invasion (WPOI) was associated with greater depth of invasion (DOI) (P = .031) and perineural invasion (P < .001). In univariate analyses, older age (P = .004), positive nodal status (P = .047), lymphovascular invasion (P = .012), perineural invasion (P = .05), and WPOI-5 (P = .015) were adverse predictors of 5-year overall survival (OS). In multivariate analysis, older age (P = .011), WPOI-5 (P < .001), and perineural invasion (P = .001) remained statistically significant independent prognosticators of worse 5-year OS.

CONCLUSIONS

Older age, WPOI-5, and perineural invasion are significant prognosticators of worse OS. WPOI is associated with DOI, a finding which may have important implications for the pathogenesis and biologic behavior of the disease.

Surgical Management of Oral Cancer

Today, most head and neck cancer subsites, such as the larynx, hypopharynx, nasopharynx, and oropharynx, are treated with radiation therapy with or without chemotherapy as a primary treatment modality. Surgery is reserved for the salvage of recurrent tumors that occur within the head and neck in the absence of distant (ie, lung, liver) metastasis. However, unlike all other head and neck subsites, oral cancer should ideally be managed with primary surgery with the possibility of adjuvant radiation therapy with or without chemotherapy depending on the presence of certain high-risk pathologic features.

Overexpression of CD164 in oral cavity squamous cell carcinoma predicts a favourable prognosis

The aim of the present study was to investigate the association between cluster of differentiation (CD) 164 expression with clinicopathological parameters and prognosis among patients with oral cavity squamous cell carcinoma (OSCC). The present study retrospectively reviewed 70 patients with OSCC who underwent curative primary surgery. A number of patients subsequently received postoperative chemoradiotherapy although the specimens were not exposed to radiation or chemotherapy prior to anti-CD164 antibody immunohistochemical staining. CD164 overexpression was arbitrarily defined as exhibiting an H-score of ≥120. Univariate and multivariate analyses were performed for sex, age, American Joint Committee on Cancer stage, tumour location, histological grade, surgical margin and H-score. The 5-year overall survival rate was 54.4% and the median follow-up time was 46 months for surviving patients. Univariate analyses revealed that a low overall survival rate was associated with advanced-stage disease (P<0.001), buccogingival tumour location (P=0.038) and a CD164 H-score of <120 (P=0.016). Multivariate Cox's regression analyses revealed that poor overall survival rate was associated with advanced-stage disease (P=0.001) and a CD164 H-score of <120 (P=0.04). CD164 overexpression in OSCC was associated with favourable survival rate. Thus, CD164 expression may be a clinically useful predictor of prognosis in patients with OSCC.

Comparative clinical outcomes of Taiwanese patients with resected buccal and tongue squamous cell carcinomas

OBJECTIVES

Although patients with buccal squamous cell carcinoma (SCC) usually show acceptable outcomes, local control and survival rates are generally lower than those observed for tongue SCC. This study was designed to compare the clinical outcomes of Taiwanese patients with these two common oral cavity malignancies.

METHODS

Patients with first primary buccal or tongue SCC who were included in the Taiwanese Cancer Registry Database between 2004 and 2012 were eligible. The study sample consisted of 16,379 patients (7870 buccal SCC and 8509 tongue SCC) who received surgery with or without adjuvant therapy. The 5-year disease-specific survival (DSS) and overall survival (OS) rates served as the outcome measures.

RESULTS

Compared with tongue SCC, patients with buccal SCC had a higher prevalence of males (95.7% vs. 86.4%, p<0.0001), pT4 disease (21.4% vs. 12.7%, p<0.0001), and p-Stage IV (30.4% vs. 24.8%, p<0.0001) but a lower frequency of pN2 disease (15.2% vs. 18.5%, p<0.0001). The 5-year DSS and OS rates of buccal SCC patients were slightly higher than those of tongue SCC (78% vs. 77%, p=0.0297; and 71% vs. 69%, p=0.0231, respectively). Multivariate analysis identified tumor site (tongue vs. buccal SCC), sex (male vs. female), age (≥65 vs. <65years), pT classification (T4/T3/T2 vs. T1), and pN classification (N3/N2/N1vs. N0) as independent prognostic factors in the entire study cohort.

CONCLUSIONS

The survival advantage of buccal SCC over tongue SCC appears significant in large clinical samples, despite a higher prevalence of p-Stage IV disease in the former.

Unit resection of buccal squamous cell carcinoma: Description of a new surgical technique

This study characterized the infiltration of primary tumors along the muscles, fascia and spaces of the maxillofacial region in buccal squamous cell carcinoma (BSCC) and suggested a new surgical strategy that is suitable for most stages. Based on the anatomic characteristics and infiltration of the primary tumor a new surgical approach - unit resection buccal surgery (URBS) - was developed. We evaluated this new surgical strategy, across a cohort of 127 BSCCs: 60 cases treated with URBS and 67 cases treated with conventional surgery. Notably there was no statistical difference in the clinicopathological variables between the two groups. After initial treatment with curative intent, the patients were regularly followed-up with clinical examination and imaging. URBS proved suitable for almost all stages of BSCC, and was particularly advantageous for advanced stages of BSCC. At 2 years post-treatment, the rates of overall survival were 83.3% in the URBS group and 60.1% in the conventional surgery group, respectively (hazard ratio 0.38; 95% CI 0.20 to 0.75; P=0.005). Similarly, the rates of disease-free survival were 76.6% and 51.9% in the URBS group and the conventional surgery group, respectively (hazard ratio 0.42; 95% CI 0.23 to 0.75; P=0.003). The principles of URBS are suitable for almost all stages of BSCC, especially advanced stages. URBS may improve the prognosis of BSCC patients.