Skin involvement and ipsilateral nodal metastasis as a predictor of contralateral nodal metastasis in buccal mucosa cancers

Contralateral Nodal Relapse in Well-lateralised Oral Cavity Cancers Treated Uniformly with Ipsilateral Surgery and Adjuvant Radiotherapy With or Without Concurrent Chemotherapy: a Retrospective Study

AIMS

To evaluate the incidence and pattern of contralateral nodal relapse (CLNR), contralateral nodal relapse-free survival (CLNRFS) and risk factors predicting CLNR in well-lateralised oral cavity cancers (OCC) treated with unilateral surgery and adjuvant ipsilateral radiotherapy with or without concurrent chemotherapy.

MATERIALS AND METHODS

Consecutive patients of well-lateralised OCC treated between 2012 and 2017 were included. The primary endpoint was incidence of CLNR and CLNRFS. Univariable and multivariable analyses were carried out to identify potential factors predicting CLNR.

RESULTS

Of the 208 eligible patients, 21 (10%) developed isolated CLNR at a median follow-up of 45 months. The incidence of CLNR was 21.3% in node-positive patients. CLNR was most common at level IB (61.9%) followed by level II. The 5-year CLNRFS and overall survival were 82.5% and 57.7%, respectively. Any positive ipsilateral lymph node (P = 0.001), two or more positive lymph nodes (P < 0.001), involvement of ipsilateral level IB (P = 0.002) or level II lymph node (P < 0.001), presence of extranodal extension (P < 0.001), lymphatic invasion (P = 0.015) and perineural invasion (P = 0.021) were significant factors for CLNR on univariable analysis. The presence of two or more positive lymph nodes (P < 0.001) was an independent prognostic factor for CLNR on multivariable analysis. CLNR increased significantly with each increasing lymph node number beyond two compared with node-negative patients.

CONCLUSION

The overall incidence of isolated CLNR is low in well-lateralised OCC. Patients with two or more positive lymph nodes have a higher risk of CLNR and may be considered for elective treatment of contralateral neck.

Prognostic Implications of Skin Invasion in Locally Advanced Oral Cavity Squamous Cell Carcinoma

OBJECTIVE

To evaluate the effect of histopathologic skin invasion on 2- and 5-year disease-free survival (DFS) and overall survival (OS) in patients treated with primary surgery for locally advanced oral cavity squamous cell carcinoma (OCSCC).

STUDY DESIGN

A retrospective case-control study was performed comparing previously untreated patients with pT4a OCSCC with and without skin invasion.

SETTING

Academic medical center.

METHODS

Propensity score-matched cohorts were derived by age, sex, surgical margins, pathologic N classification, adjuvant treatment, and primary tumor site. The Kaplan-Meier method was used to evaluate 2- and 5-year OS and DFS, which were compared between cohorts via the log rank (Mantel-Cox) test statistic.

RESULTS

Overall 25 patients were identified to have pathologic skin invasion, and 50 were selected for the matched control group. OS was significantly lower for patients with skin invasion as compared with controls at 2 years (30.8% vs 53.3%, P = .018) and 5 years (16.6% vs 42.2%, P = .01). DFS was significantly lower for patients with skin invasion vs controls at 2 years (23.7% vs 47.7, P = .037) and 5 years (15.8% vs 41.4%, P = .024).

CONCLUSION

Histopathologic skin invasion in OCSCC is associated with dismal prognosis in patients who underwent primary surgical treatment. OS outcomes for patients with skin invasion are comparable to survival of patients with recurrent/metastatic disease and T4N2 disease.

Pattern of locoregional failure in postoperative cases of locally advanced carcinoma of buccal mucosa treated with unilateral versus bilateral neck radiation: lesson learned from a basic practice setup

Background

Carcinoma of buccal mucosa forms a sizeable percentage of the diagnosed oral cavity cancers in India. There is limited data on elective treatment of the contralateral neck for well-lateralized carcinoma with no involved nodes in the contralateral neck. We conducted this study to compare locoregional control in patients treated with unilateral vs. bilateral neck irradiation.

Materials and methods

48 patients with carcinoma of buccal mucosa were selected. Patients were divided into unilateral and bilateral arms based on radiation treatment of the ipsilateral or bilateral neck. All patients received adjuvant radiation with Cobalt 60 unit. Patient-specific and follow-up data were collected from records and dosimetric data from treatment planning system (TPS). Chi-square and unpaired t-test was used to compare data between arms and Kaplan Meier plot; Cox regression was used for survival analysis.

Results

After a median follow-up of 23 months, 15 (31.3%) patients had developed disease recurrence, 8 and 7 in the unilateral and bilateral arms, respectively (p = 0.591). There was no contralateral neck failure during the follow-up period. The 2-year disease-free survival was 68.2% and 72.2% in the unilateral and bilateral arms, respectively. Among risk factors for disease recurrence, depth of invasion (DOI), delay in starting radiation and planning target volume (PTV) coverage were significant contributing factors. Cox multivariate regression suggested DOI and delay in starting radiation to be significant prognostic factors for disease-free survival (DFS).

Conclusion

Bilateral neck radiation does not provide any advantage over ipsilateral neck radiation for properly selected well lateralized buccal mucosal squamous cell carcinoma. Ipsilateral neck radiation facilitates better sparing of organs at risk.