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**Overview**: Triple-Negative Breast Cancer TNBC IHC Panel**Introduction**: The Triple-Negative Breast Cancer TNBC IHC Panel is a diagnostic tool designed for breast cancer typing using FFPE tissue samples. In India, breast cancer is the most common cancer in women (~178,000 new cases/year), with triple-negative breast cancer (TNBC) comprising ~15-25 percent (higher in younger age, premenopausal, and rural/low-SES groups), characterized by lack of ER/PR/HER2 expression, aggressive behavior, poor prognosis, and limited targeted therapies. High morbidity from under-testing in rural/low-SES patients with breast lumps, limited IHC labs, delayed chemotherapy or clinical trial referral leading to advanced presentation and high mortality. Per oncology practices aligned with ICMR, National Cancer Control Programme, and Indian Society of Medical & Pediatric Oncology guidelines, the test employs immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR), and HER2/neu over 3â€"5 days with high accuracy, valuable for confirming TNBC (negative ER/PR/HER2) and guiding chemotherapy (anthracyclines/taxanes) or PARP inhibitors in BRCA-associated cases. This diagnostic falls under cancer screening and targets women with breast malignancy or suspicious biopsy, addressing accurate subtyping to inform prognosis and therapy. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling precise TNBC identification and reducing late-stage burden. Its FFPE-based approach ensures reliable receptor expression assessment.**Other Names**: TNBC IHC Pnl.**FDA Status**: FDA approved, CLIA certified for histopathology/immunology, compliant with 2025 standards.**Historical Milestone**: ER/PR/HER2 IHC standard in breast cancer classification; in India, mandatory per NCCN-adapted guidelines.**Purpose**: The test assesses 3 parameters including Estrogen Receptor (ER) to guide breast cancer typing, confirm TNBC subtype, inform chemotherapy/targeted therapy.**Test Parameters**: 1. Estrogen Receptor (ER), 2. Progesterone Receptor (PR), 3. HER2/neu.**Pretest Condition**: No fasting required; patients should have breast biopsy/tissue.**Specimen**: FFPE tissue block (0.5â€"2 cm³), transported within specified times to maintain sample integrity.**Sample Stability at Room Temperature**: 8 hours with proper handling to preserve antigenicity, ensuring reliable test performance.**Sample Stability at Refrigeration**: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.**Sample Stability at Frozen**: 6 months at -20 degrees Celsius, allowing long-term storage for retesting, though freezing may affect some antigens.**Medical History**: Patients should provide details on lump, family history, prior reports.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of undetected TNBC including poor prognosis, benefits of subtyping, and minimal discomfort from biopsy (already performed).**Procedural Considerations**: The test involves sample processing using immunohistochemistry by trained personnel to ensure sterile technique, proper antigen retrieval, and interpret results within 3â€"5 days using provided controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.**Factors Affecting Result Accuracy**: Delays beyond stability periods, improper fixation/storage, or low tumor content can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: Negative ER/PR/HER2 confirms TNBC (aggressive subtype, chemotherapy mainstay), necessitating specialist input.**Specialist Consultation**: Medical oncologists should be consulted for management.**Additional Supporting Tests**: Ki-67, BRCA testing, PD-L1 for confirmation.**Test Limitations**: Requires adequate tumor tissue; comprehensive approach required.**References**: Indian Journal of Medical Oncology 2024, Breast Cancer Studies India 2023. |
