Clinical significance of preoperative imaging in oral squamous cell carcinoma compared with lymph node status: a comparative retrospective study

Value of preoperative computed tomography in predicting the local staging of cancer of the tongue at primary surgery

Preoperative staging is essential for the planning of treatment of cancer. This study was designed to evaluate the accuracy of computed tomography (CT) in predicting the local stage of tongue cancer by comparing it with the gold standard of histopathology. A total of 233 patients with newly-diagnosed tongue cancer was retrospectively reviewed, and the size of the tumour and the status of the cervical lymph node were compared between CT images and histopathological results. Patients with stage II cancer were followed up to assess the influence of inaccurate preoperative staging on prognosis. The accuracy of local staging by CT was 47.6% (111/233), with 59.7% (139/233) for tumour stage, and 70.4% (164/233) for nodal stage. The greatest dimension of the tumour on the CT image was about 2mm less than that measured by histopathology. The estimated volume of tumour was a quarter smaller. The accuracy of predicting malignant lymph nodes by CT was 68.9% (n=161). Among patients with stage II disease, simultaneous neck dissection was less likely in the understaged group than in the accurately staged one. The reoperation rate was a little higher but not significantly so. We conclude that the accuracy of CT in predicting local staging for tongue cancer was only moderate, because it underestimated the size of the tumour and needed to improve the criteria for detecting malignant lymph nodes. Understaging on CT images may influence the prognosis of patients with early stage tongue cancer.

Bilateral versus ipsilateral neck dissection in oral and oropharyngeal cancer with contralateral cN0 neck

Objective

Contralateral elective neck dissection (cEND) in oral and oropharyngeal squamous cell cancer (OC/OPC) is still a matter of debate. The current study analyzed the outcome in OC/OPC patients with/without cEND.

Methods

OC/OPC patients (n = 471) were diagnosed with contralateral N0 after CT/MRI-scan combined with neck ultrasound. Clinico-pathological features were analyzed using Chi-square/Fisher exact/Student’s t test. Survival rates were calculated using Kaplan–Meier and log-rank test. Prognostic variables were evaluated by Cox regression. Primary/secondary endpoints were overall/recurrence-free survival (OS/RFS).

Results

Pre-therapeutic imaging revealed a significantly over-staged N-status (p = 0.01), while occult contra-lateral N + was diagnosed in one patient only (0.4%). OC patients did not show differences in OS/RFS between the groups (ipsi- vs. bi-lateral). There was a strong tendency towards a better OS in OPC patients who underwent ipsi-lateral ND (p = 0.07). Cox-regression demonstrated that only tumor recurrence was associated with a fivefold increased risk of recurrence-associated death (p < 0.0001) that referred to a significant higher recurrence rate at primary tumor site (rT +) and increased distant metastatic outgrowth in OPC who underwent bi-lateral neck dissection (p = 0.03). While RFS of any cause (rT + /rN + /rM +) was significantly better in OPC with ipsi-lateral ND (p < 0.05), RFS of contralateral lymph node recurrence (rN2c) was comparable in both groups.

Conclusion

END of the contralateral cN0 neck is not correlated by an increased RFS or OS. Standard imaging techniques including CT/MRI scan and neck ultrasound warrant watchful waiting for neck dissection of the contralateral cN0 neck.