01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Possible cancer often presents through common symptoms: bleeding, change in bowel habit, cough, dysphagia, weight loss, fatigue, lymphadenopathy, persistent pain or a new mass. The task is not to diagnose malignancy in primary care but to recognise when probability and potential harm justify urgent investigation. NICE NG12 supplies symptom-, sign- and test-based routes, including direct-access investigation and urgent suspected-cancer referral. Local services determine operational booking without changing the clinical need.
Referral urgency differs from physiological emergency. A patient with a stable suspicious lesion can use an urgent diagnostic pathway; a patient with stridor, cord compression, major haemorrhage or obstruction requires acute care immediately. Baseline tests can identify anaemia, organ dysfunction and competing diagnoses, but extensive low-yield testing should not delay the recommended definitive route. Tumour markers are rarely suitable general screening tests for undifferentiated symptoms.
Safety-netting is part of diagnosis. Record the working differential, why cancer is possible, what was requested, when results or appointments should occur and who will act. If a test is normal but the symptom continues, reassess the original probability rather than treating the result as absolute. People should know how and when to return, including earlier triggers.
Key points
- Cancer recognition combines symptom, examination, age, duration, risk factors and trajectory; no single red flag is sufficiently sensitive to exclude disease when absent.
- Use the current NICE NG12 site-based or symptom-based recommendations and local referral form rather than memorised historical thresholds.
- An urgent suspected-cancer referral means cancer must be excluded promptly; it does not mean that cancer is the most likely diagnosis.
- Some pathways begin with a primary-care test such as chest radiography, full blood count, FIT, CA125 or ultrasound, but the correct sequence is symptom-specific.
- A normal initial test does not close the case when symptoms persist, progress or remain discordant with the result.
- Explain the reason for referral, expected contact time and how to chase a missing appointment; unclear language increases non-attendance and distress.
- Safety-net every unresolved presentation with a named review interval, trigger symptoms and ownership of outstanding results.
- Consider cancer in people with multimorbidity and in younger adults when the pattern is unusual; diagnostic overshadowing causes delayed diagnosis.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Local primary cancer
A developing tumour can cause bleeding, obstruction, ulceration, mass effect or organ dysfunction before producing systemic symptoms.
Metastatic presentation
Cancer may first appear through bone pain, neurological deficit, lymphadenopathy, thrombosis, hypercalcaemia or failure of an organ distant from the primary.
Benign and inflammatory mimics
Common infection, medication effects, inflammatory disease and benign structural lesions produce similar symptoms, so referral expresses risk rather than a diagnosis.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Clonal growth disrupts tissue
Expanding malignant cells replace or compress normal structures, invade basement membranes and alter local blood vessels, producing mass, pain, bleeding or obstruction.
- 2Systemic signalling develops
Inflammatory cytokines, catabolism, marrow infiltration and ectopic hormone production can cause weight loss, fatigue, cytopenias or paraneoplastic biochemical change.
- 3Dissemination creates emergencies
Lymphatic, haematogenous or direct spread can compromise spinal cord, airway, major vessels, bowel, bone or brain before the primary tumour is recognised.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Haemoptysis, postmenopausal bleeding, visible haematuria, rectal bleeding or persistent intermenstrual bleeding requires site- and age-specific assessment.
Increasing dysphagia, jaundice, bowel obstruction, stridor or urinary obstruction suggests structural disease and may need acute rather than outpatient care.
A breast, testicular, neck, abdominal, pelvic or soft-tissue mass is characterised by duration, fixation, growth, nodes and systemic features.
Unintentional weight loss, drenching sweats, persistent fatigue, thrombosis or unexplained laboratory change gains significance when progressive or combined.
New focal weakness, sphincter disturbance, severe bone pain, confusion or hypercalcaemic dehydration may be the first cancer presentation.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Focused history and examinationFirst step - Why
- Localise the likely organ system and identify emergency complications.
- Interpretation and limitations
- Document duration, progression, relevant exposure, family history and negative findings that affect the specific NG12 route.
- 02
Symptom-directed primary-care test - Why
- Use the recommended initial investigation where guidance places testing before referral.
- Interpretation and limitations
- Examples differ by presentation; interpret the result within the referral algorithm and do not substitute unrelated tumour markers.
- 03
Baseline full blood count and biochemistry - Why
- Detect anaemia, cytopenia, cholestasis, kidney injury or hypercalcaemia that changes urgency.
- Interpretation and limitations
- Normal results do not exclude localised cancer, while severe abnormalities may require same-day treatment and specialist discussion.
- 04
Urgent site-specific imaging or endoscopy - Why
- Visualise the suspected primary and obtain tissue where appropriate.
- Interpretation and limitations
- The specialist pathway selects modality and biopsy route to preserve staging and resectability; primary care should avoid poorly planned biopsy.
- 05
Histopathology - Why
- Confirm malignancy and subtype before definitive treatment.
- Interpretation and limitations
- Adequacy, grade, biomarkers and tissue origin guide staging and treatment; inconclusive tissue requires MDT-directed repeat sampling.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Benign site-specific disease
Haemorrhoids, fibroids, cysts, reflux and other common disorders often explain symptoms, but persistent or progressive features still require appropriate exclusion.
Infection or inflammation
Chronic infection, autoimmune disease and granulomatous disorders can cause weight loss, nodes, imaging abnormalities and laboratory changes that resemble malignancy.
Medicine-related effect
Anticoagulants, hormones, immunosuppressants and other medicines can cause bleeding or constitutional change while also modifying underlying cancer risk.
Haematological or metabolic illness
Anaemia, endocrine disease, liver failure and other systemic disorders may reproduce cancer-associated fatigue, weight change or biochemical disturbance.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01EmergencyStabilise a cancer complicationFirst stepThe presentation includes airway, neurological, haemorrhagic, obstructive or metabolic instability.+
- 1Use ABCDE assessment, treat immediate physiology and contact the relevant acute oncology, surgical, critical-care or site team.
- 2Obtain urgent targeted imaging and blood tests without allowing the absence of a known cancer diagnosis to delay emergency treatment.
- 3After stabilisation, coordinate tissue diagnosis and staging so emergency intervention does not fragment the longer cancer pathway.
02ReferUse the current suspected-cancer routeThe symptom, sign or test meets NICE or local urgent-referral criteria without acute instability.+
- 1Select the site-specific or non-site-specific pathway, attach the relevant examination, test results and communication needs, and state diagnostic uncertainty honestly.
- 2Tell the person why cancer needs exclusion, what the pathway involves and when contact should occur; provide a route to chase delay.
- 3Track referral acceptance and attendance, responding to service redirection rather than assuming another team owns the unresolved risk.
03ReviewSafety-net residual uncertaintyInitial tests or specialist assessment do not explain a persistent concerning symptom.+
- 1Set a specific review date based on symptom risk and expected resolution, with earlier return triggers for deterioration.
- 2AlternativeCheck outstanding results and reconsider the differential, including alternative cancer site, inflammatory disease and treatment effects.
- 3EscalationEscalate or re-refer when trajectory and test result disagree; repeated reassurance without reassessment is not safety-netting.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Diagnostic delay
Missed referral, false reassurance or untracked results allow a potentially curable tumour to progress and increase the intensity of later treatment.
Acute organ compromise
Airway obstruction, spinal cord compression, severe bleeding, bowel obstruction and metabolic emergencies can cause irreversible harm before histological confirmation.
Psychological and access harm
Unclear communication creates fear or non-attendance, while inaccessible appointments can widen diagnostic delay for already underserved groups.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Maintain a results log showing requested test, expected date, result, communication and responsible clinician.
- Confirm urgent referral receipt and attendance, especially where language, learning disability, transport or deprivation creates access barriers.
- Reassess symptom trajectory rather than simply repeating the same test when an unexplained feature persists.
- Monitor anaemia, calcium, renal, hepatic or coagulation abnormalities when they create immediate treatment risk.
- Document patient understanding of the referral and the exact symptoms that should trigger emergency attendance.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Urgent is not certain
Clear explanation avoids the twin harms of telling someone they have cancer and falsely reassuring them that referral is merely routine.
Normal tests are conditional
A result is reassuring only to the sensitivity of that test, the disease stage and the correctness of the original pathway.
Tumour markers are selective
Most lack sufficient specificity for general symptom triage and can cause false reassurance or cascades when used indiscriminately.
Comorbidity can conceal
Weight loss, anaemia or pain may be attributed to chronic disease, but a new trajectory still requires independent explanation.
Safety-net has ownership
A time, trigger and responsible professional are necessary; simply advising return if worried leaves failure points invisible.
11Common pitfallsFrequent interpretation and management errors.
- 01
Using screening instead of diagnostic testing.
- 02
Waiting for multiple red flags to coexist.
- 03
Sending an unstable patient to routine clinic.
- 04
Ordering broad tumour markers before localisation.
- 05
Failing to explain the urgent referral.
- 06
Assuming a normal first test ends assessment.
- 07
Leaving referral or result ownership unclear.