Molecular and Genetic studies in Gynaecological Malignancies

Speaker: Dr. Rajiv Dhall

Alumni- PGIMER

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Description

Molecular and genetic studies in gynecological malignancies have revolutionized diagnostics, prognostics, and targeted therapies. Advances in genomic sequencing have identified key mutations in ovarian (BRCA1/2, TP53), endometrial (PTEN, MSI), and cervical cancers (HPV integration, PIK3CA). These findings aid in precision medicine, guiding individualized treatments like PARP inhibitors for BRCA-mutated ovarian cancer. Epigenetic modifications, including DNA methylation and miRNA regulation, further influence tumor progression and therapeutic response. Emerging technologies like liquid biopsies and multi-omics approaches enhance early detection and monitoring. Understanding these molecular pathways is crucial for developing novel therapies and improving survival outcomes in gynecological malignancies.

Summary Listen

  • Gynecological cancer management has shifted from surgery, chemotherapy, and radiotherapy to a molecular and genetic approach due to advances in molecular biology and genetics, leading to better treatment guidelines and vaccine development. The rising incidence of gynecological cancers parallels overall cancer increases, attributed to unhealthy lifestyles, obesity, smoking, environmental pollution, radiation exposure, and infections like HPV, which is communicable and linked to cervical and vaginal cancers.
  • Molecular level approaches involve investigating tumor markers in blood, tissue samples, and genetic mutations, which may be inherited or sporadic. The body's genome is structured to repair mismatches in DNA and combat infections, but HPV can disrupt this process. Genetic approaches, combined with clinical findings, symptoms, and operative techniques, are crucial for managing cancer effectively.
  • Gynecological cancers can arise in various organs, including the ovary, cervix, vagina, vulva, or placental tissue. Ovarian cancer includes epithelial, germ cell, and stroma tumors, while endometrial cancer has two types: endometrialoid (estrogen-dependent) and serous (estrogen-independent). Cervical cancer is often linked to HPV infections and can be squamous cell carcinoma or adenocarcinoma. Vulvar cancer is typically squamous cell carcinoma, and fallopian tube cancer is related to serous adenocarcinoma.
  • Gestational trophoblastic neoplasia, arising from placental tissue, includes invasive mole, choriocarcinoma, and placental-site trophoblastic tumor. The challenges in gynecological cancer management include a rising clinical load, proper clinical and investigational assessment, accurate pathology and immunohistochemistry, appropriate management planning, and prevention of recurrence.
  • Molecular genetics and epigenetics are crucial for understanding and managing cancer. Epigenetics, which causes alterations in the genome without altering DNA sequence, provides insights into etiology and targeted therapy. Root cause analysis requires going to the genetic and molecular levels.
  • Basic knowledge of DNA, RNA, genes, and chromosomes is essential. DNA's double helix facilitates duplication, and genetic variations can be inherited or somatic, leading to mutations. Genetic studies, such as BRCA gene testing, assess risk and help develop targeted therapies, utilizing techniques like PCR and MLPA for gene sequencing and mutational analysis.
  • Tumor suppressor proteins like TP53, if mutated, are found in high-grade serous ovarian carcinoma and are sensitive to radiotherapy. BRCA1/2 mutations increase the risk of breast and ovarian cancers and are responsive to platinum-based chemotherapy and PARP inhibitors. MSI (microsatellite instability) and deficient MMR (mismatch repair) indicate the use of immune checkpoint inhibitors.
  • Understanding genetic pathways, like PI-3K/AKT/mTOR and Wnt/beta-catenin, is important for cancer therapies. Chemical biomarkers like CA-125 and HE4 are used for ovarian cancer, while SCC antigen is used for squamous cell carcinoma. Alpha-fetoprotein and CEA 19-9 can indicate cancers of other organs, requiring a comprehensive tumor marker assessment.
  • Biomarkers, including genetic, epigenetic, protein, and metabolic markers, aid in diagnosis, prognosis, prediction, and monitoring. P16 overexpression is a surrogate marker for HPV-driven cancers, and HRD (homologous recombination deficiency) indicates responsiveness to PARP inhibitors. CTDNA (circulating tumor DNA) helps detect recurrence at the microscopic level.
  • HRR (homologous recombination repair) deficiencies, common in high-grade serous ovarian carcinomas, lead to sensitivity to PARP inhibitors. The HPV genome, with its oncogenes E6 and E7, is studied for vaccine development. Roma assessment, combining HE4, CA-125, and menopausal status, helps assess the risk of ovarian malignancy.
  • Lynch syndrome, linked to MMR gene mutations, increases the risk of endometrial and ovarian cancers, diagnosed through MSI and MMR testing. Peutz-Jeghers syndrome, involving STK11/LKB1 gene mutations, increases the risk for ovarian sex cord tumors and uterine cancer. The Hayflick limit explains cellular division limits and the role of telomeres in apoptosis.
  • CRISPR is a gene editing technique using molecular scissors to cut, repair, and edit genes, with potential applications in gene disorders and cancer treatment. Personalized therapy targets oncogenic drivers directly, and circulating tumor DNA detects minimal residual disease. Multiobeids and artificial intelligence identify novel biomarkers for cancer.

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