Correlation between Histopathological Features and Clinical Outcomes in Patients with Oral Squamous Cell Carcinoma

ABSTRACT

Introduction:

Oral squamous cell carcinoma (OSCC) is a prevalent malignancy, with histopathological features playing a crucial role in predicting clinical outcomes. Tumor budding, lymphovascular invasion, and depth of invasion are key indicators used to assess prognosis and therapeutic response. The objective of this research is to examine the correlation between these histopathological parameters and patient outcomes.

Methods:

This retrospective analysis included patients diagnosed with OSCC. The key parameters examined were tumor budding, depth of invasion, and lymphovascular invasion. Clinical outcomes, including recurrence and survival rates, were analyzed.

Results:

Tumor budding and depth of invasion were significantly associated with increased recurrence rates and poorer survival outcomes. Lymphovascular invasion also showed a strong correlation with advanced disease stages.

Conclusion:

The histopathological features, particularly tumor budding and depth of invasion, are significant predictors of clinical outcomes in OSCC patients. These features should be emphasized in the prognosis and treatment planning of OSCC.

INTRODUCTION

OSCC is the most common type of head and neck malignancy, accounting for over 90% of cases. It remains a leading cause of cancer-related morbidity and mortality worldwide. Histopathological evaluation plays a critical role in determining the aggressiveness of the tumour and guiding clinical decisions. Tumor budding, depth of invasion, and lymphovascular invasion have been highlighted as key indicators for assessing the prognosis of OSCC. Tumor budding, defined as the presence of isolated tumor cells or small clusters at the invasive front, is associated with an increased risk of recurrence and metastasis.[1] Similarly, the depth of invasion is crucial in TNM [T describes the size of the tumor and any spread of cancer into nearby tissue; N describes spread of cancer to nearby lymph nodes; and M describes metastasis] staging and is directly correlated with patient survival.[2] Lymphovascular invasion, the spread of tumor cells into lymphatic or blood vessels, indicates a more aggressive tumor phenotype.[3,4,5,6] This research aims to explore the correlation between these histopathological features and clinical outcomes in patients with OSCC.

METHODS

This retrospective study was conducted on patients diagnosed with OSCC. Patients with a confirmed histopathological diagnosis of OSCC and complete clinical follow-up data were included in the analysis. Exclusion criteria included patients with incomplete records or a history of prior cancer treatment.

Research parameters

1. Tumor Budding: Tumor budding was assessed at the invasive front of the tumor and graded into two categories: low (fewer than five budding foci) and high (five or more budding foci).

2. Depth of Invasion: The depth of invasion was measured from the basement membrane to the deepest point of tumor penetration. Patients were categorized into three groups based on their depth of invasion: ≤5 mm, 5 mm –10 mm, and >10 mm.

3. Lymphovascular Invasion: The presence of tumor cells within lymphatic or vascular spaces was evaluated through standard histopathological methods, with findings categorized as positive or negative.

Clinical outcomes, including recurrence rates and overall survival, were collected from patient records. Statistical analysis were conducted to correlate these histopathological features with the clinical outcomes. Continuous data were expressed as means and percentages, and statistical significance was determined using the Chi-square test, with P values less than 0.05 considered statistically significant. Ethical approval for this research was obtained, ensuring adherence to all ethical guidelines.

RESULTS

A total of 120 patients were included in the analysis. The median age was 60 years, with a predominance of males (65%). The most common sites of OSCC were the tongue (40%) and the floor of the mouth (25%).

In Table 1, patients with high tumor budding (≥5 foci) had a significantly higher recurrence rate (45%) compared to those with low tumor budding (<5 foci), who had a recurrence rate of only 15%. Additionally, disease-free survival (DFS) was lower in patients with high tumor budding (50%) compared to those with low budding (80%), with both parameters showing strong statistical significance (P < 0.01). This indicates that tumor budding is a critical factor in predicting tumor recurrence and patient prognosis in OSCC.

Table 1.

Tumor budding and its correlation with recurrence and DFS

Parameter	Low Tumor Budding (%)	High Tumor Budding (%)	P
Recurrence rate	15%	45%	<0.01
DFS	80%	50%	<0.01

Table 2 highlights the impact of depth of invasion on overall survival (OS). Patients with a depth of invasion ≤5 mm showed the highest OS rate (85%), while those with deeper invasions (5 mm –10 mm and >10 mm) had progressively lower survival rates of 65% and 35%, respectively. This correlation was statistically significant (P = 0.02), suggesting that deeper tumor invasion is associated with poorer survival outcomes in OSCC patients.

Table 2.

Depth of invasion and OS correlation

Parameter	≤5 mm Invasion (%)	5 mm–10 mm Invasion (%)	>10 mm Invasion (%)	P
OS	85%	65%	35%	0.02

DISCUSSION

The findings of this research underscore the importance of tumor budding and depth of invasion as key histopathological predictors of prognosis in OSCC. Tumor budding has been extensively studied as a marker of tumor aggressiveness. Previous research has demonstrated its association with higher recurrence rates and poor survival outcomes.[4] In the current cohort, patients with high tumor budding foci had a significantly increased risk of recurrence and lower DFS, confirming these findings.

Depth of invasion, a cornerstone of the TNM staging system, also emerged as a critical determinant of survival in this research.[5] The current results showed that patients with deeper tumor invasion (>10 mm) had significantly worse OS compared to those with shallower invasion. This aligns with studies such as that of Noda et al., which have highlighted the prognostic value of this parameter in OSCC.[2]

Lymphovascular invasion, though less frequently reported, was present in a significant portion of the current cohort and was associated with more advanced disease.[6] This feature indicates a more aggressive tumor phenotype and correlates with poorer outcomes in OSCC patients.

These results support the integration of these histopathological features into routine clinical practice to guide treatment planning and improve patient outcomes. Further studies should aim to refine these prognostic markers and explore their potential for inclusion in future revisions of the TNM staging system.[7,8,9,10]

CONCLUSION

This research demonstrates the significant prognostic value of histopathological features such as tumor budding, depth of invasion, and lymphovascular invasion in patients with OSCC. High tumor budding and deeper invasion are associated with higher recurrence rates and poorer OS. Incorporating these parameters into routine clinical evaluation can improve risk stratification and guide personalized treatment strategies. Further research is needed to refine these markers and assess their potential in enhancing current staging systems for OSCC. Early identification of these features may ultimately lead to better patient outcomes and improved survival rates.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.