Written and medically reviewed by: Assoc. Prof. Cengiz Dibekoğlu, MD, General SurgeryLast updated:
Hereditary Cancers
Lynch, BRCA, FAP, CDH1, and related syndromes — in surgical patient language
Most cancers are not inherited. Some findings change family screening and treatment choices.
Most cancers are sporadic. Lynch, BRCA1/2, FAP, CDH1, Li-Fraumeni, Peutz–Jeghers, and selected other germline conditions can raise risk for the patient and relatives. This hub is not a genetics clinic: it answers common surgical-patient questions and links to molecular testing. Tumor (somatic) results are not the same as germline results — confusing them causes unnecessary fear or missed cascade testing.
Educational schematic. Some structures may be simplified or emphasized for clarity; not an exact anatomical depiction.
© Cengiz Dibekoğlu — illustrative; not for unauthorized use
Five terms before you read further
- Germline test
- DNA from blood or saliva — family-risk question
- Pathogenic variant
- High-risk gene change (preferred term over casual “mutation”)
- VUS
- Variant of uncertain significance — not enough data to act alone
- Penetrance
- How often carriers develop related cancers
- Somatic change
- In tumor only — does not automatically trigger family testing
Figure summary
- Hero figure: hereditary cancer risk education overview.
- Related figures cover syndromes, counseling steps, and risk-reducing pathways.
Educational figures
Tap a figure to enlarge. These English illustrations mirror the Turkish hub gallery for this condition.
Overview Educational schematic. Some structures may be simplified or emphasized for clarity; not an exact anatomical depiction.
© Cengiz Dibekoğlu — illustrative; not for unauthorized use
FAP Educational schematic. Some structures may be simplified or emphasized for clarity; not an exact anatomical depiction.
© Cengiz Dibekoğlu — illustrative; not for unauthorized use
BRCA Educational schematic. Some structures may be simplified or emphasized for clarity; not an exact anatomical depiction.
© Cengiz Dibekoğlu — illustrative; not for unauthorized use
Counseling Educational schematic. Some structures may be simplified or emphasized for clarity; not an exact anatomical depiction.
© Cengiz Dibekoğlu — illustrative; not for unauthorized use
Lynch / FAP
Colorectal risk via MMR/MSI or polyposis pathways.
BRCA / CDH1
Breast–ovarian or hereditary diffuse gastric risk.
Rarer syndromes
Li-Fraumeni, Peutz–Jeghers — counseling first.
Molecular link
Tumor testing ≠ automatic hereditary diagnosis.
What to know
Five terms before you read further
Hereditary pages use precise genetics language. Start here:
- Germline test: DNA from blood/saliva — family-risk question
- Pathogenic / likely pathogenic variant: high-risk gene change (preferred term over casual “mutation”)
- VUS (variant of uncertain significance): not enough data to act alone
- Penetrance: how often carriers develop related cancers
- Somatic change: in tumor only — does not automatically trigger family testing
When to think hereditary
Young-onset cancer, multiple primaries, first-degree relatives with related cancers, a known family mutation, or dMMR/MSI-H on pathology are clues to discuss genetics — not reasons to panic alone.
- Key note inside
Tumor vs germline
Note: Declining germline counseling is not the same as skipping tumor MMR testing.Somatic tumor tests guide treatment. Germline tests need separate consent and counseling; cascade testing for relatives follows pathogenic germline findings only.
What this hub is not
It does not diagnose syndromes, order panels, or sell “miracle screening packages.” It helps you ask the right questions and find the molecular-testing pages.
What happens next
When hereditary risk is considered and how sequencing works
- 1
Hereditary Cancer Overview
When hereditary risk is considered and how sequencing works
Read this chapter - 2
Lynch Syndrome
MMR/MSI, colorectal risk, and family screening
Read this chapter - 3
BRCA and Familial Breast Risk
Who is offered testing; surgery and surveillance frame
Read this chapter - 4
FAP
Polyposis, APC, and surgical timing
Read this chapter - 5
MUTYH and Serrated Polyposis
MAP, serrated pathway, and surveillance intervals
Read this chapter - 6
CDH1
Hereditary diffuse gastric cancer risk
Read this chapter - 7
Li-Fraumeni Syndrome
TP53 and multi-cancer spectrum
Read this chapter - 8
Peutz–Jeghers Syndrome
Hamartomatous polyps and surveillance
Read this chapter - 9
Genetic Counseling
Consent, results, and talking with relatives
Read this chapter - 10
Molecular Testing in Cancer
Organ-specific biomarkers that often open this conversation
Read this chapter
Appointment / info
Bring pathology, family history notes, and any prior genetic reports — we clarify which questions matter next.
This page is for education. It is not medical advice and does not replace genetic counseling or a visit with your physician.
Medical editor: Assoc. Prof. Cengiz Dibekoğlu, MD · English patient-education hub.