Salvage surgery for patients with residual/persistent diseases after improper or insufficient treatment of oral squamous cell carcinoma: can we rectify these mistakes?

Enhancing oral squamous cell carcinoma prediction: the prognostic power of the worst pattern of invasion and the limited impact of molecular resection margins

Objective

Oral squamous cell carcinoma (OSCC) originates from the mucosal lining of the oral cavity. Almost half of newly diagnosed cases are classified as advanced stage IV disease, which makes resection difficult. In this study, we investigated the pathological features and mutation profiles of tumor margins in OSCC.

Methods

We performed hierarchical clustering of principal components to identify distinct patterns of tumor growth and their association with patient prognosis. We also used next-generation sequencing to analyze somatic mutations in tumor and marginal tissue samples.

Results

Our analyses uncovered that the grade of worst pattern of invasion (WPOI) is strongly associated with depth of invasion and patient survival in multivariable analysis. Mutations were primarily detected in the DNA isolated from tumors, but several mutations were also identified in marginal tissue. In total, we uncovered 29 mutated genes, mainly tumor suppressor genes involved in DNA repair including BRCA genes; however none of these mutations significantly correlated with a higher chance of relapse in our medium-size cohort. Some resection margins that appeared histologically normal harbored tumorigenic mutations in TP53 and CDKN2A genes.

Conclusion

Even histologically normal margins may contain molecular alterations that are not detectable by conventional histopathological methods, but NCCN classification system still outperforms other methods in the prediction of the probability of disease relapse.

Preoperative prediction model to evaluate salvage surgery in patients with recurrent or second primary oral cavity squamous cell carcinoma

OBJECTIVE

In approximately 50% of patients with oral cavity squamous cell carcinoma (OCSCC), the disease progresses after curative surgery. However, the role of salvage surgery (SS) is controversial, and life expectancy after SS is unknown.

METHODS

In this study, 262 patients with OCSCC with locoregional recurrence and second primary OCSCC were retrospectively enrolled and divided into a resectable (55.0%, 144/262) and unresectable (45.0%, 118/262) groups. After excluding neck recurrence only, SS had been performed 195 times in the resectable group. The corresponding preoperative clinicopathologic factors and postsurgery survival (PSS) of each SS were pooled for analysis.

RESULTS

Median survival after disease progression was 64.2 and 10.4 months for the resectable and unresectable groups, respectively. In the resectable group, one-fifth (19.5%, 37/190) of the patients died within 1 year of SS (PSS < 1 year), and one-third (32.8%, 64/195) of the patients had undergone SS two or more times. The interval from the last surgery ≤ 12 months, depth of invasion of the last surgery > 1 cm, and clinical evidence of nodal disease at the preoperative evaluation were independent predictors of poor PSS. A scoring prediction model was established with 1 point for each factor. The results revealed 1-year postsurgery death rates of 10.3% in the low-risk group (score: 0-1) and 48.6% in the high-risk group (score: 2 or 3) (P < 0.001).

CONCLUSIONS

In conclusion, an effective scoring model predicting life expectancy after SS for patients with OCSCC was established.