Causes
Usually chronic or recurrent exposure to:
- Biological agent e.g. HPV – cervical cancer
- Radiation e.g. UV radiation – skin cancer
- Chemical agent e.g. smoking – lung cancer
Strong genetic component. FHx malignancy important
Types
- Solid tumours – managed mainly by oncologists +/- surgeons
- Haematological malignancy – managed mainly by haematologists
Pathogenesis
- Initially asymptomatic and indolent
- Some are slow growing/developing (e.g SCC, chronic leukaemia)
- Benign neoplasia may not need treatment unless causing symptoms
- Depending on tumour may enter a rapid growth phase or metastasise early
- Malignant tumours display locally invasive features (cancer= ‘crab’) i.e. margins not well demarcated and can erode surrounding vessels, capsules, lumens, imaging studies show local destruction e.g. periosteal reaction of bone cancer or ill-defined margins on imaging studies
- Effects of metastases may be the first symptom to manifest
Clinical manifestations
Unexplained weight loss is a red flag
Neoplastic
- Vascular involvement – ulceration and bleeding from mucosal/serosal surfaces, bleeding from orifices
- Luminal obstruction – e.g. bronchial collapse > dyspnoea, renal tract obstruction > prostatism, obstructive renal failure, bowel obstruction > vomiting, distension, obstipation
- Organ dysfunction – e.g. marrow infiltration > anaemia, thrombocytopenia > pallor, spontaneous bleeding
Paraneoplastic
- Due to endocrine or humoral effects at a distant site e.g. ACh antibodies > Lambert-Eaton syndrome, SIADH/lung cancer
Haematological malignancies
- Usually affects marrow components or lymph nodes
- Diagnosis from FBC, marrow biopsy or node biopsy
Investigations
- Imaging studies e.g. XR, Ultrasound, CT
- Endoscopic e.g. bronchoscopy, gastro-dueodenal endoscopy, cystoscopy, laryngoscopy
- Biopsy
- Staging investigations are needed at some point to determine treatment
Treatment
Choice of treatment depends on histology (grading including benign/malignant), local spread and presence of metastases and presence of symptoms
Surgery
- Most useful if no distant metastases
- De-bulking palliative treatment for severe symptoms
- Occasionally may be possible to resect solitary mets
- Stent insertion for luminal obstruction e.g. oesophageal, biliary, ureteric
Chemotherapy
- Most commonly employed adjuvant therapy
- Works better for faster dividing tumours
- Sometimes given pre-operatively to de-bulk tumour
- Administered by treating physician or oncologist
- Can be administered systemically to direct organ or injected directly to organ
- Occasionally may need placement of long-term vascular access e.g. Infusaport
- Acute complications affects rapidly dividing cells – marrow depression (immunosuppression (beware of febrile neutropenia: PMN count < 0.5), anaemia, thrombocytopenia, N&V&D, oral-pharyngeal mucositis, also organ-specific effects by different agents
- Late complications – other neoplasia
Radiotherapy
- Local therapy post-surgery as adjuvant therapy
- Most often used for palliation to treat symptomatic metastases e.g. bone pain
- Specifically used to primary tumour if radiosensitive e.g. ENT tumours
Can be administered as
- External beam (various modalities) – treatments divided into ‘fractions’ to minimise normal tissue damage but maximise tumour regression
- Brachytherapy – radioactive pellets directly implanted in tumour e.g. prostate cancer
- Radio-isotopes – labelled isotopes ingested and taken up directly by organ e.g. radioactive iodine/thyroid cancer
- Acute complications – cutaneous/mucosal damage or irritation, acute inflammation/bleeding, marrow depression (if large areas of body irradiated) > pancytopenia
- Chronic complications – chronic inflammation/bleeding e.g. radiation proctitis, cystitis, fibrosis/scarring, radiation osteonecrosis, other neoplasia
- Aside: Rare non-cancer uses e.g. pterygium, Dupuytren’s contracture
Other interventions
Angioembolisation
- Performed by interventional radiologist
- Feeding vessels to tumour embolised to induce tumour infarction
- Maybe performed
Other management issues
- DVT /PE risk
- Symptom control
- Failure to respond to therapy
- Late recurrence (beware of ‘cancer survivors’ with recurrent symptoms)
- Palliative care
- Reconstructive surgery e.g. breast surgery
- Other cosmesis e.g. wigs
- Psychosocial (see below)
Psychosocial issues
- Side effects of treatment e.g. loss of taste, difficulty eating, hair loss
- Disfiguring surgery or treatments e.g. mastectomy, radiation skin changes
- Travelling distances for treatment
- Loss of fertility / Family planning
- Depression / Anxiety
Prognosis
Largely dictated by
- Staging (nodal involvement, metastases) – ‘TNM’ system for solid tumours
- Grading (histological and biochemical characteristics)
Screening
Most effective in high risk groups
- Behaviour e.g. sexually active females – Pap smear
- Age e.g. breast cancer – mammography
- Strong FHx e.g. multiple endocrine neoplasia
- Pre-malignant conditions e.g. ulcerative colitis, cervical intra-epithelial neoplasia
Acute oncological emergencies
- Fever: Febrile neutropenia – urgent WCC/diff for confirmation, septic screen and rapid administration of broad spectrum antibiotics to include Pseudomonas
- Altered mental state / Seizures: Hypercalcaemia – IV hydration, biphosphonate therapy, Cerebral metastases
- Luminal obstruction: massive lung collapse, bowel obstruction, urinary obstruction/retention
- Massive bleeding from tumour erosion: haematemesis or malaena, haemoptysis, PR bleeding
- Dyspnoea: pulmonary embolus
- Tumour lysis syndrome: sever hyperkalemia/uricaemia post chemotherapy > need IVT hydration and maintain high urine output
Evaluating the possible malignancy
- Consider the presence or severity of symptoms
- Clinically evaluate for the likely source and the likelihood of abnormality
- Monitor asymptomatic or indeterminate imaging studies regularly
- Commence more extensive investigations and refer if symptoms, signs or tests change significantly
- Biopsy unexplained, persistent or changing skin lesions or nodes
- Discuss concerns with a specialist
- Urgent referral if an acute oncological emergency
The ‘cancer survivor’
- Beware of recurrent symptoms even if no longer under specialist follow-up. Consider re-instituting investigations
- Be aware of late complications of treatment
Summarising/Documenting oncological history
- Duration of symptoms
- Date of diagnosis
- Histological diagnosis and stage (if known)
- Treatments to date and response
- Any major complications of disease or treatment
- Active disease or in remission
- Any followup ongoing
- Treating clinician(s)
While unintentional weight loss warants investigation. It is grossly over-rated as a sign of malignancy. Only ~25% of people with weight loss will have malignancy. And psychiatric pathology is a more likely explanation. In one study <2% of patients developed cancer after routine history examination and basic bloods were done.
Reference UpToDate