Expression of p63 and Bcl-2 in Malignant Thyroid Tumors and their Correlation with other Diagnostic Immunocytochemical Markers
Published: July 1, 2016 | DOI: https://doi.org/10.7860/JCDR/2016/.8157
Ashumi Gupta, Shyama Jain, Nita Khurana, Arun Kumar Kakar
1. Assistant Professor, Department of Pathology, Baba Saheb Ambedkar Medical College and Hospital, New Delhi, India.
2. Professor and Head of the Department, Department of Pathology, Maulana Azad Medical College, New Delhi, India.
3. Professor, Department of Pathology, Maulana Azad Medical College, New Delhi, India.
4. Director Professor, Department of Surgery, Lok Nayak Hospital, New Delhi, India.
Correspondence
Dr. Ashumi Gupta,
Assistant Professor, Department of Pathology, Baba Saheb Ambedkar Medical College and Hospital,
Rohini, New Delhi-110085, India.
E-mail: ashumi.gupta@gmail.com
Introduction: Bcl-2 is a marker recently studied in thyroid tumours and proposed to have prognostic significance. p63 is expressed in a proportion of papillary thyroid carcinoma cases and may have a role in tumour progression.
Aim: To study expression of Bcl2 and p63 in thyroid tumours and correlation of Bcl-2 with diagnostic markers including Thyroglobulin, Calcitonin and Carcinoembryonic antigen.
Materials and Methods: Cytology smears of 35 cases of thyroid cancer were studied over a period of 18 months. In 20 cases histopathology was available. Immunocytochemistry for Bcl-2 and p63 was done, and diagnostic markers were applied as and when required.
Results: p63 showed focal nuclear expression in 46.1% of papillary thyroid carcinoma cases, and was negative in all other tumours. Bcl-2 was positive in 88.9% of follicular carcinomas, 100% of papillary carcinomas and 83.3% of medullary carcinoma cases, and showed focal weak expression in 40% of Anaplastic Carcinoma (ATC) cases, thereby signifying down regulation (p-value = 0.001). There was significant down regulation of Thyroglobulin (Tg) in ATC vs well differentiated follicular derived tumours (p-value = 0.016). Positive correlation was noted between expression of Bcl-2 and Calcitonin (0.93) and Bcl-2 and Carcinoembryonic Antigen (CEA) (0.89), and weak positive correlation (0.65) between Tg and Bcl-2.
Conclusion: Bcl-2 is downregulated in anaplastic carcinomas as compared to well differentiated thyroid tumours, and shows correlation with differentiation associated tumour antigens. Thus, loss of Bcl-2 was associated with loss of differentiation in thyroid tumours. Anaplastic carcinoma as such is associated with worse prognosis and loss of Bcl-2 may be partly responsible for the same. p63 is specific but less sensitive marker for PTC. Further studies are required to determine the role of Bcl-2 and p63 in thyroid tumours.
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