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

Area of Science:

• Oncology
• Histopathology
• Cancer Biology

Background:

• Mitotic index is crucial for assessing oral cancer cell activity.
• Evaluating mitotic figures in lymph node metastases provides insights into disease progression.

Purpose of the Study:

• To analyze lymph node mitotic index (LMI) in metastatic deposits.
• To assess the primary:LN mitosis ratio (PLMR) in oral squamous cell carcinoma (OSCC).
• To understand the dynamic state of lymph node deposits in OSCC progression.

Main Methods:

• Histopathological analysis of 40 positive lymph nodes from 17 OSCC cases.
• Examination of mitotic figures in metastatic deposits and primary tumors.
• Calculation of LMI and PLMR by two independent observers.

Main Results:

• Mitotic index was significantly higher in metastatic deposits than primary tumors (P=0.004).
• Abnormal mitoses correlated significantly with extranodal extension (ECS) and metastatic deposit size (P=0.001).
• LMI indicated a high mitotic rate in ~80% of cases; PLMR showed more mitotically active lymph nodes in 58-60% of cases.

Conclusions:

• LMI is a significant parameter for evaluating OSCC disease spread.
• LMI and PLMR reveal the dynamic nature of metastatic lymph nodes.
• This study is the first to examine mitotic activity beyond the primary tumor in OSCC.