Diagnosis of Oncological Diseases. Modern Diagnostic Methods and Their Importance in Oncology. TNM Classification. Performance Status of the Cancer Patient – ECOG Scale
Diagnosis of oncological diseases is a systematic process used to detect, confirm, classify and stage cancer. Accurate diagnosis is essential because treatment, prognosis and follow-up depend on the correct identification of the tumour type and stage.
Steps in the Diagnosis of Cancer
1. Medical History (Anamnesis)
A detailed history should include:
- Presenting symptoms
- Duration and progression
- Weight loss
- Fatigue
- Fever
- Night sweats
- Pain
- Bleeding
- Persistent cough
- Change in bowel or bladder habits
- Family history of cancer
- Smoking history
- Alcohol consumption
- Occupational exposure
- Previous malignancies
- Previous radiotherapy or chemotherapy
- Comorbidities
2. Physical Examination
A complete examination should include:
- General appearance
- Weight and nutritional status
- ECOG performance status
- Examination of the primary lesion
- Regional lymph node examination
- Examination for distant metastases
- Assessment of organomegaly
- Neurological examination when indicated
Laboratory Investigations
Laboratory tests support diagnosis but cannot confirm cancer alone.
Common investigations include:
- Complete blood count (CBC)
- Liver function tests
- Renal function tests
- Electrolytes
- Serum calcium
- Coagulation profile
- Urinalysis
Tumour Markers
Tumour markers are substances produced by tumour cells or by the body in response to cancer.
They are mainly used for:
- Monitoring treatment response
- Detecting recurrence
- Assessing prognosis
- Supporting diagnosis in selected cancers
Common Tumour Markers
Modern Diagnostic Methods
1. Imaging
Ultrasound (US)
Advantages:
- No radiation
- Inexpensive
- Real- time imaging
Uses:
- Liver
- Thyroid
- Breast
- Pelvis
- Guiding biopsies
Computed Tomography (CT)
Uses:
- Detecting primary tumours
- TNM staging
- Detecting lymph node involvement
- Detecting distant metastases
- Treatment planning
Advantages:
- Excellent anatomical detail
- Rapid examination
Magnetic Resonance Imaging (MRI)
Provides excellent soft tissue contrast.
Uses:
- Brain tumours
- Spine
- Liver
- Pelvis
- Breast
- Prostate
Positron Emission Tomography–CT (PET- CT)
PET- CT combines metabolic and anatomical imaging.
Most commonly uses 18F-FDG.
Indications:
- Detection of occult primary tumour
- Staging
- Restaging
- Detection of recurrence
- Assessment of treatment response
Bone Scan
Uses:
- Detection of skeletal metastases
- Evaluation of bone pain
- Prostate cancer
- Breast cancer
Endoscopy
Allows direct visualization and biopsy.
Examples:
- Gastroscopy
- Colonoscopy
- Bronchoscopy
- Cystoscopy
- Hysteroscopy
- Laryngoscopy