Immunohistochemical Expression of EGFR in the Patients Having Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the top 10 most common malignancies worldwide. Oral squamous cell carcinoma forms a major health problem in many countries. The reason for the high incidence of oral cavity cancers in Pakistan, and South Asia in general, is the frequent, persistent, and prevalent use of substances classified as oral cancer risk factors. These include betel quid, areca nut, smoking, smokeless tobacco, viral infections such as EBV, HPV, poor oral hygiene (including sharp teeth and decay), ultraviolet (UV) exposure, nutrition, and genetic predisposition.

For several decades the management of OSCC consisted of surgery with or without radiotherapy or chemoradiotherapy. Associated with worse prognosis, overexpression of EGFR may lead to invasion, cellular migration, enhanced angiogenesis, decreased cell apoptosis, and increased metastatic potential. However, advances in immunotherapy have had a major impact on cancer treatment.

This study was exclusively designed to highlight the immunohistochemical detection of expression pattern of EGFR in already diagnosed cases of lip and OSCC in histopathology dept of AFIP and its correlation with the grade of the tumor. In this study, contact details of all diagnosed cases of SCC of lips and oral cavity from June to November 2023 were taken from the archives of Histopathology department. The patients were contacted for consent approval for participation. The data was collected (as per proforma attached), including demographic details, location of tumor. Blocks were retrieved, grade of tumor was identified followed by the application of EGFR marker. Patterns of expression of EGFR were evaluated and compared with grade of tumor to strengthen the correlation of this association.

Oral SCC is a type of cancer that develops from the oral epithelium and accounts for more than 90% of all oral malignancies, with a death rate of more than 140,000 cases globally. It is an invading neoplasm of epithelial origin with various stages of differentiation of squamous cells having a tendency for early and widespread metastatic spread to lymph nodes. It primarily affects individuals in their fifth to sixth decades of life who drink or smoke.

The diagnosis of OSCC requires a combined approach of clinical evaluation, radiological imaging, along with histopathological evaluation. The gold standard for diagnosing OSCC is an incisional/excisional biopsy. Histopathologically, OSCC is characterized by the existence of neoplastic epithelial cells that are invading the underlying connective tissue. The differentiation degree of neoplastic cells determines the histological grade of OSCC, which is an important prognostic factor.

Treatment of OSCC, depending on the current stage of the condition, can be surgery, chemotherapy, radiotherapy, or even a combined approach comprising all these options. Early-stage OSCC can often be cured with surgery or radiotherapy, whereas advanced-stage OSCC has been associated with a worse prognosis.

In conclusion, OSCC is a significant global health issue with an elevated mortality and morbidity in patients with head and neck cancer. Early detection and prompt treatment are crucial in improving the prognosis of OSCC. Oral pathologists and clinicians ought to be mindful of the risk factors, clinical characteristics, and screening requirements for OSCC to ensure timely and accurate diagnosis and treatment for the patients. Targeted therapy has evolved recently as an important treatment modality for cancer, and the most extensively studied pathways for targeted therapy are those related to EGFR.

In the era of personalized medicine, it has been largely accepted that cancer therapy protocols should be devised in light of tumor characteristics of loco-regional population. Previous studies has revealed that the immunohistochemical overexpression of EGFR correlates with poor prognosis. EGFR overexpression is considered an attractive target for anti-EGFR therapy in various tumors. In targeted therapy, entire focus will be on EGFR. This protein has been discovered in 90% of head and neck squamous cell carcinomas. Overexpression of EGFR has unfavorable clinical outcome, poor prognosis and low survival rates in OSCC. To make the diagnosis, clinical correlation with histopathological investigations should be prioritized. There is a strong rationale supporting EGFR-targeting in OSCC. HNSCC is often treated with anti-EGFR antibodies.

Eligibility Criteria:
Inclusion Criteria:

* Cases of surgically treated lip/oral cavity squamous cell carcinoma
* Patients of all age groups, irrespective of their gender
* Patients with a tumor located in the tongue, inferior and superior gingivae, buccal mucosa, floor of the mouth, palate, alveolus and vestibule(buccal/labial and mandible/maxilla)

Exclusion Criteria:

* All specimens with inadequate or poor fixation.
* All specimen of patients having received chemotherapy/radiotherapy prior to surgery
* Very scanty tissue biopsies or those with extensive tissue necrosis
* Patients not consenting to be the part of the study