Impact of Postoperative Radiotherapy on the Prognosis of Early-Stage (pT1-2N0M0) Oral Tongue Squamous Cell Carcinoma

PURPOSE

To identify subgroups of patients with early-stage (pT1-2N0M0) oral tongue squamous cell carcinoma (OTSCC) who may benefit from postoperative radiotherapy (PORT).

PATIENTS AND METHODS

This retrospective cohort study included 528 patients diagnosed between October 2009 and December 2021. Clinicopathological characteristics and treatments with or without PORT were analyzed for their impact on outcomes.

RESULTS

Among 528 patients who underwent radical surgery (median age, 62 years [IQR, 52-69]), 145 (27.5%) also underwent PORT. Multivariate analyses revealed that PORT was associated with improved survival outcomes, whereas moderate-to-poor differentiation, perineural infiltration (PNI), lymphovascular invasion (LVI), and increasing depth of invasion (DOI) were associated with poorer survival outcomes. For patients with moderate-to-poor differentiation, the surgery + PORT group showed improved outcomes compared with the surgery-alone group. After propensity score matching, the results were as follows: overall survival (OS), 97% versus 69%, P = .003; disease-free survival (DFS), 88% versus 50%, P = .001. After excluding cases with PNI/LVI, the differences persisted: OS, 97% versus 82%, P = .040; DFS, 87% versus 64%, P = .012. Similar survival benefits were observed in 104 patients with PNI and/or LVI (OS, 81% v 58%; P = .022; DFS, 76% v 47%; P = .002). In subgroups with DOI >5 mm or close margins, PORT contributed to improved DFS (80% v 64%; P = .006; 92% v 66%; P = .049) but did not significantly affect OS.

CONCLUSION

Patients with moderately-to-poorly differentiated pT1-2N0M0 OTSCC benefited from PORT. Our study provided evidence that patients with PNI and/or LVI who underwent PORT had improved survival. PORT also offered DFS benefit among patients with DOI >5 mm.

Effect of Prognostic Factors of Postoperative Radiotherapy in Oral Squamous Cell Carcinoma: A SEER-Based Study

Objective: The treatment of oral squamous cell carcinoma (OSCC) is dominated by surgery and radiochemotherapy, but its prognosis is still unsatisfactory, with around five tenths of 5-year survival. This study aimed to assess the prognosis of OSCC patients treated with surgery with and without postoperative radiotherapy. Study Design: Retrospective study. Methods: The clinicopathological information and follow-up datasets on patients with OSCC (T1-4 and/or N+) registered from 2010 to 2015 were downloaded from the Surveillance, Epidemiology, and End Results database. Totally 7231 enrolled subjects were divided into a case group (surgery alone, n = 4167) and a control group (surgery combined with postoperative radiotherapy, n = 3064). One-to-one matching was performed by propensity score matching to make the baseline data comparable between the 2 subgroups. Multivariate Cox regression analysis was used to calculate hazard ratios (HR) of various clinicopathological features. The Kaplan-Meier method and log-rank test were used to plot the survival curves. Results: The majority of patients in case group were tumor stage I (n = 2569, 61.7%), whereas most patients in control group were stages III to IV (n = 2360, 77.1%). In the case group, the 1-, 3-, and 5-year overall survival (OS; 76%, 59.5%, 53.7%) were significantly lower than those of the control group (85.1%, 64.1%, 55.8%; P < .0001). Similarly, the 1-, 3-, and 5-year cancer-specific survival (CSS) of the case group (80.2%, 66.6%, 63.3%) were significantly lower than those of the control group (87.2%, 69.3%, 63.9%, respectively; P < .0001). Cox multivariate analysis indicated that age, differentiation, clinical stage, and tumor-node-metastasis stage affected the prognosis of OSCC patients, while postoperative radiotherapy was a protective factor (OS: HR = 0.649, P < .001; CSS: HR = 0.702, P < .001). Conclusions: Postoperative radiation was an independent protective factor, hence, the combination of surgery plus radiotherapy is more beneficial for the survival of patients with OSCC, particularly for advanced cases.

Peri-Neural Invasion Is an Important Prognostic Factor of T2N0 Oral Cancer

Background and objectives: Among patients with pathologically proven T2N0 oral squamous cell carcinoma (OSCC), a notable amount of patients still die from tumor recurrence although they have radical surgery for early stage cancers. In literature, the prognostic indicators of this specific disease entity were rarely reported. This study aims at analyzing the prognostic factors of T2N0 OSCC patients and discussing possible managements to improve the survival.

MATERIALS AND METHODS

From January 2012 to December 2017, the data of 166 pathologically proven T2N0 oral cancer patients proved by radical surgery were retrospectively collected. The clinical and pathologic factors including age, gender, tumor differentiation grade, perineural invasion (PNI), angiolymphatic invasion (ALI), margin status, and adjuvant therapy were analyzed by univariate and multivariate analysis to determine their association with disease-specific survival (DSS), and disease-free survival (DFS), which were calculated by Kaplan-Meier method.

RESULTS

After median follow up time of 43.5 months, overall 3-year rates of DSS and DFS were 86.1% and 80.1% respectively for our 166 patients. Univariate analysis showed that the 3-year DSS of 90.8% for PNI negative patients was significantly better than DSS of 57.0% for PNI positive patients (p = 0.0006). The 3-year DFS of 84.2% for PNI negative patients was also significantly better than DFS of 54.6% for PNI positive patients (p = 0.001). Further multivariate analysis revealed PNI was the only independent prognostic factor associated with both DSS (Hazard Ratio (HR) = 5.02; 95% Confidence Interval (CI) = 1.99-12.6; p = 0.001), and DFS (HR = 3.92; 95% CI = 1.65-9.32; p = 0.002). Nearly 10% (16) of the 166 patients had adverse pathologic feature of PNI only. In the 11 patients without adjuvant therapy, 5 patients died from OSCC. No patients had recurrence or mortality after they received adjuvant therapy with chemotherapy ± radiotherapy.

CONCLUSION

PNI was an independent prognostic factor for T2N0 oral cancer patients. Adjuvant chemotherapy and radiotherapy may benefit the survival of this specific disease entity, but further investigations are needed to elucidate the optimal regimen.

Role of Adjuvant Radiotherapy in Early Stage Tongue Cancer: Need for Establishing Stringent Guidelines

The primary objective of this study was to determine, using population-based data, whether the addition of postoperative radiotherapy (RT) provides an overall survival benefit in patients with early primary squamous cell carcinoma (SCC) of tongue. The study included the data of tongue cancer patients treated between January 2016 and July 2019 retrieved from our hospital database. Tumours limited to pathologic T1 and T2 category managed with primary surgery with or without postoperative external beam RT were included. Overall survival (OS) and disease-free survival (DFS) were the main outcomes of interest. A total of 211 cases of oral cancer were evaluated and all the patients had clear surgical and pathological margins. Postoperative adjuvant therapy (PORT) was received by 16 patients. Comparison of DFS and OS at 2-year follow-up depicted a similar outcome (p = 0.582 and p = 0.312 respectively). Findings from our study suggest that in the absence of any absolute advantage on quantifiable survival and disease control, it is necessary to define stringent criteria when advocating PORT in early tongue cancer.

Clinical Outcomes of Patients With pT1-T2N0 Oral Tongue Squamous Cell Carcinoma

OBJECTIVE

The objective of this study was to evaluate the clinical outcomes in a cohort of patients with early-stage oral tongue squamous cell carcinoma (OTSCC).

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with pT1-T2N0 (American Joint Committee on Cancer [AJCC] seventh edition) OTSCC treated from 2000 to 2018. Two-year actuarial rates of local regional control, cancer-specific survival, and overall survival were calculated for the entire cohort and patients with/without adjuvant radiation.

RESULTS

Ninety-six patients met the criteria with a median follow-up of 4 years; 14 had adjuvant radiation, while 82 had surgery alone. Two-year local regional control was 82.7% (75.4% to 90.8%) for the entire cohort, 84.9% (77.8% to 93.2%) for surgery only, and 70.7% (50.2% to 99.6%) for patients with adjuvant radiation. Two-year progression-free survival was 82.7% (75.3% to 90.8%). Of the 20 patients with recurrence, 11 (55%) were successfully salvaged.

CONCLUSION

Local regional recurrence remains modest in early-stage OTSCC, but salvage is possible with high survival rates.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

A New Nomogram for Predicting Overall Survival and Assisting Postoperative Adjuvant Treatment Decision-Making in Stage II Oral Tongue Squamous Cell Carcinoma: A Surveillance, Epidemiology and End Results (SEER) Database Analysis

PURPOSE

The survival benefit of postoperative adjuvant treatment (POAT) for stage II oral tongue squamous cell carcinoma (OTSCC) remains controversial. This large SEER-based study aims to establish a prognostic nomogram to visualize the overall survival of these patients and to aid in POAT decision making.

PATIENTS AND METHODS

The cut-off points of age at diagnosis and examined lymph node number (ELN) were determined using the population-based data from the SEER database. Univariate and multivariate Cox hazards regression models were utilized to identify prognostic factors that were integrated into the establishment of the prognostic nomogram. Patients with stage II OTSCC were then stratified into 3 cohorts based on this nomogram. The survival benefit of POAT was evaluated in these cohorts.

RESULTS

Age at diagnosis (with cutoff points of 50 and 75 years) and ELN (with cutoff points of 0 and 22) was significantly associated with the survival outcomes in patients with stage II OTSCC. After the multivariate analysis, 4 factors, including age at diagnosis, sex, ELN, and differentiation grade, were identified as independent prognostic factors. Additionally, a prognostic nomogram with these factors was constructed to predict overall survival and to stratify these patients. Only patients in the high-risk cohort could significantly benefit from postoperative adjuvant treatment.

CONCLUSIONS

This prognostic nomogram could accurately predict the overall survival of stage II OTSCC patients after curative surgery. Notably, this model could also assist the decision-making of postoperative adjuvant treatment for patients with stage II OTSCC.

What has the National Cancer Database taught us about oral cavity squamous cell carcinoma?

The wealth of data in the National Cancer Database (NCDB) has allowed numerous studies investigating patient, disease, and treatment-related factors in oral cavity squamous cell carcinoma (OCSCC); however, to date, no summation of these studies has been performed. The aim of this study was to provide a concise review of the NCDB studies on OCSCC, with the hopes of providing a framework for future, novel studies aimed at enhancing our understanding of clinical parameters related to OCSCC. Two databases were searched, and 27 studies published between 2002 and 2020 were included. The average sample size was 13,776 patients (range 356-50,896 patients). Four areas of research focus were identified: demographic and socioeconomic status, diagnosis, prognosis, and treatment. This review highlights the impact of age, sex, ethnicity, and socioeconomic status on the prognosis and management of OCSCC, describes the prognostic factors, and details the modalities and indications for neck dissection and adjuvant therapy in OCSCC. In conclusion, the NCDB is a very valuable resource for clinicians and researchers involved in the management of OCSCC, offering an incomparable perspective on a large dataset of patients. Future developments regarding hospital information management, review of data accuracy and completeness, and wider accessibility will help clinicians to improve the care of patients affected by OCSCC.

Depth of invasion versus tumour thickness in early oral tongue squamous cell carcinoma: which measurement is the most practical and predictive of outcome?

AIMS

The 8th edition of the American Joint Committee on Cancer (AJCC) Staging introduced depth of invasion (DOI) into the pT category of oral cavity squamous cell carcinoma. However, we noted multiple practical obstacles in accurately measuring DOI histologically in our daily practice.

METHODS AND RESULTS

To compare the prognostic effects of DOI and tumour thickness (TT), a meticulous pathology review was conducted in a retrospective cohort of 293 patients with AJCC 7th edition pT1/T2 oral tongue squamous cell carcinoma. Overall survival (OS) and nodal metastasis rate at initial resection were the primary and secondary outcomes, respectively. We found that TT and DOI were highly correlated with a correlation coefficient of 0.984. The upstage rate was only 6% (18 of 293 patients) when using TT in the pT stage compared with using DOI. More importantly, DOI and TT, as well as pT stage using DOI and pT stage using TT, performed identically in predicting risk of nodal metastasis and OS.

CONCLUSIONS

We therefore propose to replace DOI, a complicated measurement with many challenges, with TT in the pT staging system.

Magnetic resonance imaging differentiates locoregional flaps from free flaps after reconstructive surgical treatment of tongue cancer

OBJECTIVE

The aim of this study was to compare magnetic resonance imaging (MRI) features of reconstruction with locoregional flaps (LRFs) with free flaps (FFs) after surgical treatment for tongue cancer.

STUDY DESIGN

In total, 115 cases of postoperative tongue carcinoma (67 cases of LRF surgery and 48 cases of FF surgery) were retrospectively reviewed. All patients had undergone nonenhanced and contrast-enhanced MRI at 0-4, 5-12, and 13-48 months after surgery. Signal intensity, margins, maximal size, contrast enhancement, change in the hyoglossus and mylohyoid muscles, recurrence, lymph node metastasis, and complications were evaluated.

RESULTS

Significant differences were found between LRF and FF for signal intensity (P < .001) in all 3 periods, with LRF mostly isointense with muscle on T1-weighted images (T1WIs) and FF producing mixed hyperintensity with muscular striations in all cases in T1WIs and T2-weighted images (T2 WIs). Margin definition was similar between groups in the early period, but sharp margins were more common in FF after 4 months (P ≤ .018). LRF was significantly smaller than FF in all periods (P ≤ .017). Both mylohyoid and hyoglossus enlargements were common in the early period in both groups, but all cases became atrophic later.

CONCLUSIONS

MRI can differentiate LRFs from FFs in a variety of parameters after flap reconstructive surgery for tongue cancer.

Implications of Tumor Size, Subsite, and Adjuvant Therapy on Outcomes in pT4aN0 Oral Cavity Carcinoma

Objective

To determine if tumor size, subsite, and adjuvant radiation therapy (AXRT) are associated with overall survival (OS) in patients with pT4aN0 oral cavity squamous cell carcinoma (OSCC) who underwent mandibulectomy with negative surgical margins (NSMs).

Study Design

Retrospective cohort study.

Setting

National Cancer Database (NCDB).

Subjects and Methods

Retrospective analysis of the NCDB that included patients diagnosed with pT4aN0 OSCC who underwent mandibulectomy with NSMs between 2004 and 2015. The association of age, Charlson-Deyo score (CDS), tumor size, subsite, and AXRT with OS was analyzed. The cases were divided into 3 subgroups based on maximal tumor dimension for subgroup analysis; tumors ≤2.0 cm, tumors 2.1 to 4.0 cm, and tumors >4.0 cm.

Results

For the entire cohort; age ( P < .001; hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.02-1.03), CDS ( P = .013; HR, 0.57; 95% CI, 0.37-0.89), tongue subsite ( P = .003; HR, 2.01; 95% CI, 1.27-3.40), floor of mouth subsite ( P = .001; HR, 1.76; 95% CI, 1.28-2.42), tumor size ( P < .001; HR, 0.57; 95% CI, 0.45-0.72), and AXRT ( P < .001; HR, 1.46; 95% CI, 1.24-1.72) were associated with OS on multivariate analysis. On subgroup analysis, AXRT not significantly associated with OS in patients with gingival, hard palate, retromolar trigone, and not specified tumors ≤2.0 cm ( P = .323; HR, 1.29; 95% CI, 0.78-2.15).

Conclusions

In patients with pT4aN0 OSCC who underwent mandibulectomy with NSMs, age, CDS, tongue subsite, floor of mouth subsite, tumor size, and AXRT are associated with OS. AXRT was not significantly associated with overall survival in patients with gingival, hard palate, retromolar trigone, and not specified tumors ≤2.0 cm.

Elective Neck Dissection, but Not Adjuvant Radiation Therapy, Improves Survival in Stage I and II Oral Tongue Cancer with Depth of Invasion >4 mm

Purpose/objective(s)

In early-stage, node negative oral tongue cancer, there is limited data supporting tumor depth of invasion (DOI) as an indication for post-operative radiotherapy (PORT) to the primary site. The primary aim of this study is to examine the effect of tumor DOI and PORT on overall survival (OS).

Materials and methods

The National Cancer Database (NCDB) was used to query patients with AJCC stage I and II oral tongue cancer (2006-2013). Patients were stratified by receipt of PORT, elective neck dissection (ND), and DOI (≤4 mm or >4 mm). Kaplan-Meier analysis was performed to compare OS (using the log-rank test) between PORT versus no-PORT. Multivariable Cox proportional hazards regression model performed to evaluate the independent effect of PORT and neck dissection on OS.

Results

Among 939 patients, 69.3% were clinical stage I, 67.4% received ND, 23.4% had DOI >4 mm, and 10.4% received PORT. The addition of PORT did not improve OS with tumor DOI ≤4 mm (p = 0.634) or >4 mm (p = 0.816). The addition of elective neck dissection improved OS for DOI >4 mm (p = 0.010), but not for ≤4 mm (p = 0.128). On multivariable analysis, ND improved OS if DOI >4 mm (HR, 0.37; 95% CI, 0.17-0.81 [p = .012]), when also controlling for age, sex, PORT status, clinical stage, and pathological stage.

Conclusion

Tumor DOI should not be used as a sole indication for PORT in early stage oral tongue cancers. Elective neck dissection at the time of excision of the primary tumor results in higher OS for tumors with DOI >4 mm.