Role of microscopic spread beyond gross disease as an adverse prognostic factor in oral squamous cell carcinoma

Mitosis - predicting primary tumour and metastatic lymph node behaviour and beyond in OSCC - A pilot study

Background and Objectives

In the evaluation of oral cancer, mitotic index/mitotic figures are of paramount importance in histopathology. The number of mitoses in tumour cells is directly proportional to the activity of the tumour cells. In this novel study, we evaluated the status of the mitotic figures found in the metastatic deposit of the lymph nodes in addition to the primary tumour. A great deal of significance is given to this parameter in the evaluation of progress of the primary tumours in a state of distant metastasis. Therefore, we propose to analyse the lymph node mitotic index (LMI) in metastatic deposits and its relation to the primary tumour by assessing the relation between primary: LN mitosis ratio (PLMR). This also can provide an insight into the concept of understanding the dynamic state of lymph node deposits in oral squamous cell carcinoma (OSCC).

Materials and Methods

A total of 510 lymph nodes from 17 cases of surgically treated OSCC were analysed, of which 40 lymph nodes were found to be positive. These 40 lymph nodes were examined histopathologically for the presence of mitotic figures in ten randomly selected fields (x400) and compared to the mitotic activity of the primary tumour by two observers independently, along with other histopathological features. LMI and PLMR were further determined for these cases.

Observations and Results

The mitotic index was significantly higher in the metastatic deposits than in the primary tumour (P = 0.004). A higher percentage of abnormal mitoses was observed in metastatic lymph nodes, but no statistical significance (P = 0.27) was found when compared with primary tumour. Statistically significant correlation (P = 0.001) was observed between abnormal mitoses (%) and presence of ECS as well as size of the metastatic deposits. The LMI ratio showed a high mitotic rate in close to 80% of the cases. PLMR showed 58-60% cases with mitotically more active lymph nodes.

Interpretation and Conclusion

This study is the first of its kind, which examines a level further than the nature of the primary tumour. Mitotic index/numbers in lymph nodes (LMI) might be considered an important parameter to evaluate the disease spread, revealing the nature of transiently indolent and mitotically active metastatic lymph nodes. The PLMR adds a further dimension on the lymph node's dynamic status in the progression of the disease.

Assessment of the bony resection margin distance in bone-invasive oral cancer using laser-induced breakdown spectroscopy

OBJECTIVES

Inadequate resection margins of less than 5 mm impair local tumor control. This weak point in oncological safety is exacerbated in bone-infiltrating tumors because rapid bone analysis procedures do not exist. This study aims to assess the bony resection margin status of bone-invasive oral cancer using laser-induced breakdown spectroscopy (LIBS).

MATERIALS AND METHODS

LIBS experiments were performed on natively lasered, tumor-infiltrated mandibular cross-sections from 10 patients. In total, 5,336 spectra were recorded at defined distances from the tumor border. Resection margins < 1 mm were defined as very close, from 1-5 mm as close, and > 5 mm as clear. The spectra were histologically validated. Based on the LIBS spectra, the discriminatory power of potassium (K) and soluble calcium (Ca) between bone-infiltrating tumor tissue and very close, close, and clear resection margins was determined.

RESULTS

LIBS-derived electrolyte emission values of K and soluble Ca as well as histological parameters for bone neogenesis/fibrosis and lymphocyte/macrophage infiltrates differ significantly between bone-infiltrating tumor tissue spectra and healthy bone spectra from very close, close, and clear resection margins (p < 0.0001). Using LIBS, the transition from very close resection margins to bone-infiltrating tumor tissue can be determined with a sensitivity of 95.0%, and the transition from clear to close resection margins can be determined with a sensitivity of 85.3%.

CONCLUSIONS

LIBS can reliably determine the boundary of bone-infiltrating tumors and might provide an orientation for determining a clear resection margin.

CLINICAL RELEVANCE

LIBS could facilitate intraoperative decision-making and avoid inadequate resection margins in bone-invasive oral cancer.

Association between lymph node ratio and survival outcomes in patients with oral squamous cell carcinoma

BACKGROUND

Recent reports have shown that the Lymph node ratio (LNR) is useful for predicting the prognosis in some cancers, however there are few reports on the usefulness of LNR in predicting the prognosis of oral squamous cell carcinoma (OSCC). The predictive value of LNR for prognosis of OSCC was investigated.

MATERIALS AND METHODS

The study included 152 patients with OSCC and histologically confirmed cervical lymph node metastasis who underwent neck dissection. We analyzed the relationship between LNR and overall survival (OS) and recurrence-free survival (RFS) retrospectively in these cases, with the relationship between prognosis and clinicopathological findings also examined.

RESULTS

Using a receiver operating characteristics curve, the LNR cutoff value was set at 0.095, categorizing 64 and 88 cases into high LNR (≥ 0.095) and low LNR (< 0.095) groups, respectively. Regarding OS and RFS, the prognosis was significantly worse in the high LNR group compared with the low LNR group. In multivariate analysis, sex, postoperative nodal stage, and LNR merged as independent prognostic factors.

CONCLUSION

This study's findings suggest that LNR may represent a prognostic indicator in OSCC with cervical lymph node metastasis.

Prognostic Significance of Lymph Node Ratio in Predicting the Outcome of Oral Squamous Cell Carcinoma - A Retrospective Study

Introduction

The lymph node status is a very important prognostic factor in head-and-neck cancer. The presence of metastatic lymph nodes will reduce the overall survival by 50%. Lymph node ratio (LNR) is defined as the ratio of the number of positive lymph nodes to the total number of lymph nodes dissected. The aim of the study was to investigate the prognostic value of LNR in oral squamous cell carcinoma (OSCC).

Materials and Methods

Medical records of pathologically confirmed OSCC patients who reported with loco-regional recurrence from January 2017 to January 2022 were analysed. LNR and disease-free survival (DFS) were calculated for each patient. The endpoint of the study was disease-free survival. Spearman's correlation was used to establish a correlation between DFS and LNR.

Results

A total of 33 patients were included in the study. DFS was calculated for all the patients. LNR was calculated in patients with pathological N+ neck. There was a negative significant moderate correlation between LNR and DFS (Spearman's rho = -0.593, P < 0.001). A higher LNR value of more than 0.01 was associated with a shorter DFS period. T4 tumour stage had significantly higher LNR. A positive significant moderate correlation was found between LNR and tumour stage (Spearman's rho = 0.703, P = 0.01). As the T stage increased, the LNR ratio also increased. In the present study, tumour subsite tongue was associated with significantly higher LNR (P = 0.001).

Discussion

LNR can be considered an independent prognostic parameter for DFS in OSCC patients with cervical lymph node metastasis.

Intraoperative Assessment of Margin Accuracy in Early Oral Squamous Cell Carcinoma (cT1, T2, N0): Clinical Versus Frozen Section Analysis

Background The incidence of oral cavity cancer is increasing. During oral carcinoma surgery, to achieve a tumor-free margin, intraoperative margin assessment includes two primary methods, namely, clinical examination and frozen section analysis. With extensive preoperative imaging investigations and intraoperative clinical margin assessment, the need for further cost and resource-intensive frozen section analysis has recently come under question. This study aimed to assess whether frozen section analysis can be safely omitted in most cases of early oral squamous cell carcinoma surgeries for cost-effectiveness. Methodology A hospital-based, observational study including 30 admitted cases of early oral squamous cell carcinoma was conducted at the Department of General Surgery, Pradyumna Bal Memorial Hospital, Bhubaneswar. All consecutive confirmed cases of early oral squamous cell carcinoma of all age groups and both genders after considering the inclusion and exclusion criteria were involved in the study. A comparative assessment of the free margins after tumor excision was done by the surgeon followed by frozen section analysis. Results The mean age was 53.03 ± 13.72 years, with a male-to-female ratio of 6.5:1. Carcinoma of the lower alveolus with gingivobuccal sulcus was the most common presentation of the study (33.33%). In our study, clinically assessed margins had a sensitivity of 75.39%, a specificity of 94.43%, and an accuracy of 92.77%. Frozen section assessed margins had a sensitivity of 66.5%, a specificity of 96.94%, and an accuracy of 92.77%. Conclusions Based on the accuracy of clinically assessed and frozen section assessed margins, this study concluded that surgically resected/excised specimen by the surgeon plays a vital role in assessing the adequacy of resected/excised margins in early oral squamous cell carcinoma (cT1, T2, N0) cases, which can possibly replace the costly frozen section analysis.

Robotic lateral oropharyngectomy following diagnostic tonsillectomy is oncologically safe in patients with human papillomavirus-related squamous cell cancer: Long-term results

INTRODUCTION

To report the long-term oncological and functional outcomes of en bloc TORS lateral oropharyngectomy to address the close/involved margin following diagnostic tonsillectomy in HPV-related SCC of unknown primary.

MATERIAL AND METHODS

A single tertiary center observational cohort over a 4-year period. Primary outcome measures were disease-specific survival (DSS), overall survival (OS), and PSS NOD (Performance Status Scale-Normalcy of Diet) scores.

RESULTS

TORS specimens did not evidence residual carcinoma in 93% of patients. Of 14 patients, 50% received surgery alone (median follow-up 57 months; range 46-96), the remainder surgery and adjuvant therapy (median follow-up of 58 months; range 51-69) with 100% DSS, OS and no deterioration of PSS NOD scores.

CONCLUSIONS

Long-term oncological outcomes confirm TORS lateral oropharyngectomy alone is an oncologically safe treatment. Due consideration of this approach is warranted to mitigate against the morbidity of adjuvant radiotherapy treatment in this group of patients.

Worst pattern of invasion in oral squamous cell carcinoma is an independent prognostic factor

Introduction

Biologic aggressiveness of OSCC (Oral Cavity Squamous Cell Carcinoma), has intrigued research in various prognosticating histopathological markers over past few decades. DOI (Depth of Invasion) is one such histopathological factor which affects outcomes and was included in the AJCC 8th edition TNM staging. Pattern of Invasion (POI) has been widely reported as an adverse prognostic factor associated with higher locoregional failure and poor prognosis. However, these factors are not utilized for treatment decision making and for outcome assessment.

Materials and methods

This is a retrospective analysis of 320 patients with OSCC who underwent treatment, from October 2018-February 2020. Clinic demographic details were extracted from electronic medical records. Univariate and multivariate analysis was done for the parameters. WPOI (Worst Pattern of Invasion) was correlated with all histopathological prognostic factors. Survival analysis was done using Kaplan Meier for WPOI type's I-V. DFS (Disease free Survival) was evaluated for different grades of WPOI.

Results

We analyzed the results comparing, early and advanced T (Tumor) stages, cohesive WPOI I-III, non-cohesive WPOI IV-V. Univariate analysis showed a significant association of T-stage (p = 0.001), N (Nodal) -stage (p = 0.002), DOI (p = 0.008), PNI (Peri-neural invasion) (0.001) and Tumor differentiation Grade (p = 0.001). On multivariate analysis, non-cohesive WPOI (IV & V) showed significant association with grade, PNI, DOI (0.002, 0.033 & 0.033 respectively). Non-cohesive WPOI had significantly higher locoregional failures and short DFS.

Conclusion

Presence of invasive WPOI is associated with advanced T stage, poor differentiation, PNI, greater depth of invasion, and higher chances of nodal metastasis. WPOI is associated with poor DFS, treatment intensification in early stage disease with WPOI type IV & V may improve survival.

Frozen section is not cost beneficial for the assessment of margins in oral cancer

BACKGROUND

Routine use of frozen section (FS) is a costly procedure and sparsely available in resource poor countries. A proper cost benefit analysis may help to reduce its routine use and would empower surgeons to perform oral cancer surgeries without having FS facility. FS is performed to identify microscopic spread beyond gross disease that cannot be assessed clinically.

OBJECTIVE

Our primary aim was to determine the cost benefit analysis of FS in the assessment of margins in oral cavity squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Retrospective study of prospectively collected data of 1311 consecutive patients who were operated between January 2012 and October 2013. The gross and microscopic margin status of each patient was extracted from the patient's chart. The cost estimates were performed to calculate the financial burden of FS as well as expenses incurred on adjuvant treatment resulting from inadequate margins.

RESULT

Microscopic spread changed the gross margin status in 5.2% (65/1237) patients. Of this entire cohort of 1237 patients, FS helped 29 (2.3%) patients to achieve tumor free margin, and it changed the adjuvant treatment plan in 9 (0.7%) patients. The cost of FS for each patient was INR 11052. The cost-benefit ratio of FS was 12:1. Gross examination alone could have identified majority of the inadequate margins.

CONCLUSION

Frozen section for assessment of margin status bears poor cost-benefit ratio. Meticulous gross examination of the entire surgical specimen is sufficient to identify majority of inadequate margins.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to "surgical management of oral cancer" published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient's treatment goals.