Assoc. Prof.Cengiz Dibekoğlu, MD

General Surgeon

Laparoscopic · Robotic · Oncologic Surgery

Conditions/Oncologic surgery

Biomarkers

Molecular Testing in Cancer

Biomarkers that guide therapy — not good/bad labels

More tests are not always better — the question comes first.

Molecular and biomarker tests describe tumor or hereditary features that guide targeted drugs, immunotherapy, surgical sequencing, and family screening. Examples include MMR/MSI, RAS/BRAF, HER2, PD-L1, NTRK fusions, and CLDN18.2 protein expression — not all are “mutations.” Somatic tumor testing answers treatment questions; germline testing answers family-risk questions — mixing them confuses patients. A positive targetable result does not erase stage, fitness, or surgical judgment. Ordering panels without a clinical question wastes time and can delay necessary care.

Molecular Testing in Cancer · educational illustration

Educational figures

Tap a figure to enlarge. These English illustrations mirror the Turkish hub gallery for this condition.

  • Overview
  • Colorectal
  • Gastric
  • Breast

  • Pathway selectors

    Results choose roads; they are not moral labels.

  • NTRK fusions

    Rare; may open TRK inhibitor options.

  • CLDN18.2

    Protein expression — especially relevant in gastric cancer.

  • Germline vs somatic

    Family-risk testing is a different conversation.

Key points for patients

  • MMR / MSI
    Tap for details

    Can open immunotherapy discussions and Lynch evaluation. Often considered early in colorectal diagnosis.

  • Targetable changes are different classes
    Tap for details

    Mutations, amplifications, fusions, and protein expression are not interchangeable words.

    • RAS/BRAF → often mutations
    • HER2 → amplification/expression
    • NTRK → usually fusion
    • CLDN18.2 → protein expression
  • Limits of testing
    Tap for details · key note inside

    A test does not equal cure; stage, performance status, and resectability still matter.

  • Do not delay emergencies
    Tap for details · key note inside

    Necessary emergency surgery is not postponed waiting for every molecular result; systemic steps can follow when results return.

  • How we use reports together
    Tap for details

    Pathology, imaging, and biomarkers are read as one story in tumor board — not as competing scores.

Patient journey

In this hub — follow the pathway step by step. Full Turkish illustrated pages remain linked from each chapter.

Oncologic surgery5 chapters

Appointment / info

Bring pathology reports — we can map which tests matter for your tumor type and stage.

+90 542 725 50 70WhatsAppTumor boardFull Turkish hub →

Educational information only; not a substitute for clinical evaluation.

Medical editor: Assoc. Prof. Cengiz Dibekoğlu, MD · English patient-education hub.

AppointmentWhatsAppMessageTumor boardRequest