Clinical outcome of surgical treatment of T1-2 N0 squamous cell carcinoma of oral tongue with observation for the neck: Analysis of 176 cases

Comparative study on Classifications of AJCC 8th and 7th in the patients with tongue squamous cell carcinoma

OBJECTIVES

Depth of invasion (DOI) is the most important predictor for lymph node metastasis in early-stage oral cancer. This study aims to investigate the effects of the different classifications of AJCC 7th and 8th on predicting lymph node metastasis and the optimal cutoff point for DOI predicting the lymph node metastasis in patients with tongue squamous cell carcinoma (TSCC).

MATERIALS AND METHODS

We performed a retrospective study in 208 TSCC patients in early T-stage without clinical or radiological signs of lymph node metastasis. Those patients were treated with elective neck dissection (END) between April 2019 and December 2020. And the relation between DOI and lymph node metastasis was analyzed.

RESULTS

Metastases were found in 58 of 208 patients (27.88%). Of those 58 patients, the mean DOI was 8.311 mm compared to 5.425 mm in patients without metastases (P < 0.0001). The receiver operating characteristic curve (ROC-curve) showed an area under the curve of 0.7066 with the most optimal cutoff point on a DOI of 4.050 mm (sensitivity 86.21%, specificity 52%). Linear regression analysis (1 mm≤DOI≤6 mm) revealed that a DOI ≥ 3.211 mm predicated an incidence of occult lymph node metastasis greater than 20%. Regional metastases were found in 12.82% of patients with DOI ≤ 4.0 mm. Within the entire cohort, 60 cases (28.85%) got upgraded with respect to T-stage. No tumor underwent downstaging.

CONCLUSION

The 8th edition provides better lymph node metastasis prediction for TSCC than the 7th. And DOI is a poor predictor for regional metastasis in patients with early T-stage clinically node-negative TSCC. END in patients with early-stage TSCC should be performed in patients with DOI ≥ 3.211 mm.

Lymphovascular invasion as a prognostic tool for oral squamous cell carcinoma: a comprehensive review

Oral cancer is the most common malignancy of the head and neck region, characterized by a poor prognosis. Novel prognostic markers are needed to better stratify these patients. Lymphovascular invasion (LVI) has been included in the eighth edition of the AJCC Cancer Staging Manual as an additional prognostic factor, but its influence on the recurrence risk and lymph node metastasis is relatively understudied. This is a comprehensive review of the literature on the clinical and prognostic role of LVI in oral cancer. A relevant search of the PubMed, Scopus, and Web of Science databases yielded 29 articles that satisfied the inclusion criteria. Findings indicated that LVI is an independent negative prognostic factor in oral cancer patients and appears to be associated with cervical lymph node metastasis and loco-regional recurrence. Notably, in oral tongue cancer, survival outcomes progressively worsen when LVI is associated with other adverse pathological features, especially in the early stages. Therefore, these patients could benefit from elective neck dissection and/or adjuvant therapy. The high variability of LVI prevalence hinders the comparison of literature results. Several methodological limitations were found to be present in the collected articles, including the lack of a rigorous definition for LVI, the difficult detection in routine histological section, the presence of potential confounders, the retrospective nature, and an inadequate sample size in most studies. Therefore, it is necessary to conduct prognostic studies using standardized methods to define and quantify LVI.

Surgical treatment of early tongue squamous cell carcinoma and patient survival

Surgical options for treating early tongue squamous cell carcinoma and patient survival were explored. Clinical records of 128 patients with early tongue squamous cell carcinoma who were treated in Henan Province Hospital of TCM from June, 2010 to June, 2013 were retrospectively analyzed. According to adopted treatment plan, the patients were divided into 3 groups: 42 patients in surgical therapy alone group, 46 patients in preoperative radiotherapy group, and 40 patients in postoperative radiotherapy group. Statistical analysis was performed on the general data of patients and clinical records, as well as the 5-year survival rate and recurrence rate. The overall 5-year survival rate for all patients was 86.7% (111/128), and the 5-year disease-specific survival rate was 88.8% (111/125). In the individual groups, the 5-year survival rate and the 5-year disease-specific survival rate were 91.3% (84/92) and 91.3% (84/92), respectively, in the surgical therapy alone group 76.9% (10/13) and 83.3% (10/12), respectively, in the preoperative radiotherapy group, and 73.9% (17/23) and 81.0% (17/21), respectively, in the postoperative radiotherapy group. There were no statistically significant differences in 5-year survival rate (χ²=5.990, P=0.051) and 5-year disease-specific survival rate (χ²=2.223, P=0.329) among the three groups. In total, there were 25 cases of recurrence during follow-up. The recurrence rate was 19.5%; the local recurrence rate was 11.7% (15/128); and the regional recurrence rate was 7.8% (10/128). There were 6 cases of metastasis, and the metastatic rate was 4.7%. There were no statistically significant differences in recurrence rate and metastatic rate among the three groups. Compared with surgical therapy alone, radiotherapy combined with surgical therapy neither improved 5-year survival rate nor reduced recurrence rate. Therefore, surgical therapy alone is suggested to be the preferred option for treating early tongue squamous cell carcinoma.

Small oral tongue cancers (≤ 4 cm in diameter) with clinically negative neck: from the 7th to the 8th edition of the American Joint Committee on Cancer

One of the main changes in the 8th edition of the American Joint Committee on Cancer (AJCC) for staging of oral cancer is the inclusion of depth of invasion (DOI) in the T category. However, cancers in different oral subsites have variable behavior, with oral tongue squamous cell carcinoma (OTSCC) being the most aggressive one even at early stage. Thus, it is necessary to evaluate the performance of this new T category in homogenous cohort of early OTSCC. Therefore, we analyzed a large cohort of patients with a small (≤ 4 cm) OTSCC to demonstrate the differences in T stage between the AJCC 7th and 8th editions. A total of 311 early-stage cases (AJCC 7th) of OTSCC were analyzed. We used 5 mm and 10 mm DOI for upstaging from T1 to T2 and from T2 to T3 respectively, as in the AJCC 8th. We further reclassified the cases according to our own proposal suggesting 2 mm to upstage to T2 and 4 mm to upstage to T3. According to AJCC 7th, there were no significant differences in the survival analysis. When we applied the 8th edition, many cases were upstaged to T3 and thus associated with worse disease-specific survival (HR 2.37, 95% CI 1.12-4.99) and disease-free survival (HR 2.12, 95% CI 1.09-4.08). Based on our proposal, T3 cases were associated with even worse disease-specific survival (HR 4.19, 95% CI 2.27-7.74). The 8th edition provides better survival prediction for OTSCC than the 7th and can be further optimized by lowering the DOI cutoffs.

Genomic analysis to assess disease progression and recurrence in patients with oral squamous cell carcinoma: - a preliminary study

We studied the progression from dysplasia to invasive carcinoma and subsequent second primaries or locoregional recurrences in 11 patients with recurrent squamous cell carcinoma (SCC). Between one and six samples were sequenced/patient. DNA samples were prepared, and libraries multiplexed to between 40 and 80 samples/lane of an Illumina HiSeq 3000 and sequenced with 2×100bp paired end sequencing. Copy number data were generated by CNAnorm (Bioconductor package). Samples of recurrent SCC showed unique patterns of descent when compared with earlier samples from the primary tumour, and three main patterns emerged. In four patients there was convincing evidence that the later lesion was descended directly from cells from the first, and in a further four there were no detectable genomic events between the two lesions. Three patients had some shared events between the early and later lesions, but although there were enough differences to deduce that the two lesions had a shared ancestor, they were not directly descended from each other. We present the patients' characteristics in detail, including the overall survival in each group. There was a distinct genomic pattern after a second episode of SCC in all the groups. A larger study that uses similar methods and a longer duration could provide reliable conclusions with respect to survival. With the use of new techniques, genomic data can be available to clinical teams during the planning of treatment.