Oesophageal Cancer
Oesophageal cancer separates into squamous cell carcinoma and adenocarcinoma, which differ in risk factors, anatomical distribution and molecular profile — a distinction that shapes the whole discussion.
Disease categories
Major disease categories
- Oesophageal squamous cell carcinoma
- Oesophageal adenocarcinoma
- Gastro-oesophageal junction tumours
Molecular
Molecular considerations
HER2 amplification is relevant in adenocarcinoma. PD-L1 expression and mismatch repair status are commonly assessed across histologies.
Markers commonly discussed in oesophageal cancer
- HER2
- PD-L1
- MMR / MSI
- TP53
Not exhaustive, and not every marker is assessed in every patient. Which of these is relevant depends on the individual case and should be discussed with the treating team.
Testing
Genomic testing considerations
Histology-appropriate marker testing, with broader panels in advanced disease.
Germline
Germline considerations
Germline assessment is considered where family history or an unusual presentation suggests it.
Molecular monitoring
ctDNA and liquid biopsy considerations
ctDNA is under study for monitoring and residual disease assessment.
Single-cell & computation
Single-cell and algorithmic approaches
In gastrointestinal and hepatobiliary disease, single-cell sequencing is used chiefly to characterise the tumour microenvironment and to resolve clonal structure in tumours that are heterogeneous between regions. Single-cell DNA analysis helps establish whether a RAS or driver alteration is clonal or subclonal, which bears directly on how much weight it should carry. Algorithm work here includes molecular residual disease detection from serial samples, mismatch repair classification from sequencing data, and pipelines that reconcile findings across multiple biopsy sites.
Decisions
Treatment decision questions
Questions worth raising with a treating team when a decision is being made:
- Is the histological subtype unambiguous across reports?
- Have HER2 and PD-L1 been assessed where relevant?
Resistance
Resistance and recurrence questions
- Has the molecular profile been reassessed after progression?
Trials
Clinical trial considerations
Histology and biomarker status both affect plausible eligibility.
When a precision oncology review may help
A review is most useful where the standard pathway has been exhausted or where the picture is more complicated than a protocol accounts for — rare presentations, treatment resistance, complex or apparently contradictory molecular findings, or a decision between several defensible options.
The output is a structured analysis and a set of questions for the treating team. It is not treatment, and it does not replace the treating oncologist.