Ovarian Cancer: Navigating the Challenges of Late Diagnosis, Biomarker Limitations, and Tumor Heterogeneity
Ovarian Cancer: Navigating the Challenges of Late Diagnosis, Biomarker Limitations, and Tumor Heterogeneity Ovarian cancer remains one of the most lethal gynaecologic malignancies, with a five-year survival rate of only ~50% for advanced-stage cases. Despite advances in treatment, significant challenges persist late diagnosis, inefficient biomarkers, and extreme tumour heterogeneity, each contributing to poor outcomes. Among these, late diagnosis is arguably the most formidable challenge, as it drastically limits treatment efficacy and survival. However, emerging research is paving the way for improved detection, personalized therapies, and novel treatment strategies. Late Diagnosis: The Biggest Hurdle in Ovarian Cancer Management Why Late Diagnosis is So Devastating ~70% of ovarian cancer cases are diagnosed at Stage III or IV, when the disease has already metastasized. No reliable screening test exists (unlike mammograms for breast cancer or Pap smears for cervical cancer). Symptoms (bloating, pelvic pain, urinary urgency) are non-specific, often leading to misdiagnosis (e.g., IBS, urinary infections). Consequences of Late Detection Limited surgical options: Optimal cytoreduction (tumour debulking) is harder in advanced disease. Higher chemoresistance risk: Late-stage tumours often develop resistance to platinum-based therapies. Poor survival rates: Early-stage (I/II) survival exceeds 90%, but late-stage survival drops to ~30%. Efforts to Improve Early Detection Liquid biopsies (circulating tumor DNA, exosome profiling) are under investigation. Multi-cancer early detection (MCED) tests are being explored, though none are yet FDA-approved for ovarian cancer. Awareness campaigns aim to educate on symptoms. Biomarker Limitations: The Challenge of Precision Medicine Current Biomarkers and Their Shortcomings CA-125: The most widely used biomarker, but non-specific (elevated in endometriosis, pregnancy, other cancers). HE4: Better specificity but still not definitive for early detection. HRD Testing: Helps identify PARP inhibitor responders, but 22% of high-grade serous ovarian cancers (HGSC) show spatial heterogeneity in HRD scores, leading to inconsistent results. Folate Receptor Alpha (FRα): Used for mirvetuximab soravtansine eligibility, but only ~35-40% of patients have sufficient FRα expression. Emerging Biomarkers Multi-omics profiling (genomics, proteomics, metabolomics) is identifying new signatures (e.g., FXYD6, linked to ferroptosis and immunotherapy resistance). Tumor microenvironment (TME) biomarkers (e.g., CD8+ T-cell infiltration) may predict immunotherapy response. Tumor Heterogeneity: A Major Barrier to Effective Treatment Types of Heterogeneity in Ovarian Cancer Spatial heterogeneity: Different tumour regions (e.g., ovary vs. omentum) show varying biomarker expression (e.g., PR, Ki67). Temporal heterogeneity: Recurrent tumours often evolve, acquiring new mutations (e.g., **BRCA reversion mutations** causing PARPi resistance). Molecular subtypes: High-grade serous (HGSC): Most common (~70%), highly aggressive, TP53 mutations. Low-grade serous (LGSC): Rare (~10%), younger patients, often KRAS/BRAF-mutated. Clear cell & endometrioid: Differ in chemosensitivity and molecular drivers. Impact on Treatment Chemotherapy resistance: Clonal evolution leads to subpopulations that evade treatment. Immunotherapy limitations: “Cold” tumours (low T-cell infiltration) respond poorly to checkpoint inhibitors. Current and Emerging Treatments to Overcome These Challenges Targeted Therapies PARP inhibitors (olaparib, niraparib): Effective in BRCA-mutated and HRD-positive tumours, but resistance remains a hurdle. Antibody-drug conjugates (mirvetuximab soravtansine): For FRα-positive platinum-resistant cases. MEK inhibitors (trametinib, binimetinib): Show promise in low-grade serous ovarian cancer (LGSC). Immunotherapy & Novel Approaches Combination therapies: PARPi + immunotherapy (e.g., pembrolizumab) are being tested to convert cold tumours to hot. Ferroptosis inducers: Targeting FXYD6 to trigger iron-dependent cell death. Adoptive cell therapy (CAR-T, TILs): Early-phase trials show potential in recurrent disease. Preventive Strategies Risk-reducing surgery: Salpingectomy (fallopian tube removal) and Oophorectomy (removal of ovaries) for BRCA carriers may prevent HGSOC. Genetic testing expansion: Only ~50% of ovarian cancer patients receive germline testing, missing hereditary risks (e.g., Lynch syndrome). Which Challenge is the Greatest? While biomarker limitations and tumour heterogeneity complicate treatment, late diagnosis remains the most critical challenge — without early detection, even the best therapies are less effective. However, advances in multi-omics profiling, liquid biopsies, and novel targeted agents are offering hope. The future of ovarian cancer management lies in: Better early detection tools (e.g., AI-driven imaging, blood-based assays). Comprehensive biomarker testing at diagnosis (HRD, FRα, BRCA). Personalized combination therapies to overcome resistance. With sustained research and advocacy (e.g., OCRA’s $6M funding in 2025), we may finally shift ovarian cancer from a silent killer to a manageable disease. Book an Appointment