Skip to content

Lung Cancer

  1. Home
  2. >>
  3. Summary Notes
  4. >>
  5. Diseases
  6. >>
  7. Lung Cancer

Topics Covered

Introduction

Lung cancer is a very important topic, as it is the second most common new cancer diagnosis in the world. As everyone knows by now, the continued prevalence of smoking has a massive part to play in this.

There are many different types of lung cancer, with unique symptoms attached to them depending on cell type and where they arise in the lung. There are however a variety of universal symptoms that patients can present with for all types.

Universal Symptoms

  • Persistent New Cough (3+ weeks)
    • Due to new mass stimulating receptors that initiate the cough reflex (attempting to clear the mass)
  • Haemoptysis (coughing blood)
    • Due to neovascularisation in cancer tissue, this tissue frequently ulcerates due to fragile, leaky vessels that have formed.
  • Chest pain
    • Due to invasion into the chest cavity, compression on healthy tissue (like the pleura) can produce pain
  • Shortness of breath
    • Mass in lung means less surface area for healthy alveoli, so less oxygen transfer
    • Pleural effusion can contribute – since lung cancer cells can produce pleural fluid
      • Can in turn cause finger clubbing
  • Stridor, Wheeze and Recurrent Infection
    • Invasion and consequent obstruction of the larger airway can produce these abnormal sounds.
    • Additionally recurrent infection can occur due to mucociliary escalator dysfunction as anything caught in mucous can no longer be cleared efficiently.
  • Weight loss + Fatigue
    • Due to growth of cancer- uses energy, so increased metabolic turnover – leading to energy storage depletion

Local Invasion/Compression Symptoms

  • Hoarse voice
    • Due to compression on the recurrent laryngeal nerve (close to lungs)
  • Dysphagia (difficulty swallowing)
    • Due to compression on oesophagus
  • Swelling and redness of head + headache
    • Superior Vena Cava Obstruction means increased backpressure superiorly
  • Fluttering Feeling in chest
    • Atrial Fibrillation (fast and irregular heart beat) can occur due to invasion into the pericardium
    • Pericardial effusion (fluid within the space between tissue surrounding heart and heart itself) can contribute
      • Both increasing breathlessness

Categorisation

The broad classification of Lung cancer can be split into:

  • Small Cell (most aggressive) -[12% of cancers] and Non-Small Cell (everything else) [88%]
    • This is a helpful classification to remember as it dictates treatment options.

The following is a list of the most common to least common forms:

Adenocarcinoma

  • MOST COMMON
  • If not smoker- most likely to develop adeno.
  • Immunotherapy response good
  • Glandular tissue
  • Slow growing – BEST PROGNOSIS

Squamous Cell Carcinoma (SCC)

  • SMOKERS
  • Keratin Core
  • Can secrete PTH – which causes increase in Calcium in blood (hypercalcaemia)
    • Can lead to abnormal bony growths throughout the body.

Small-cell Carcinoma

  • VERY AGGRESSIVE- WOST PROGNOSIS
  • Endocrine type cell – CAN DEVELOP TO PRODUCE HORMONES- causes systemic effects
    • Secretion of hormones from a tumour = “Neuroendocrine tumour”
    • Can produce ACTH – causes cortisol release from adrenal glands -> leads to Cushing’s Syndrome
    • Can also produce ADH – Acts on kidneys to keep water in – leading to urinary retention-> a high blood pressure and electrolyte imbalance (due to dilution with water retained) [Syndrome of Inappropriate ADH Secretion (SIADH)]

Large-cell Carcinoma

  • RAREST – Diagnosis of exclusion from samples – if not anything else it must be this
  • SECOND WORST PROGNOSIS

Pancoast Tumours

  • NOT a type of cell
  • But a type of cancer – defined as ANY cell type of cancer in apex of lung
    • MOST commonly a Squamous Cell Carcinoma, followed by Adenocarcinoma
  • Important due to unique set of symptoms it causes due to compression of the BRACHIAL PLEXUS
    • Horner’s syndrome (in affected side) – group of symptoms in face due to lack of SYMPATHETIC INNERVATION
      • Constricted pupil
      • Drooping pupil
      • Lack of sweating on affected side of face
      • Redness of affected side of face
    • Swelling of arm of affected side
    • Pain in shoulder of affected side

Mesothelioma

Cancer of the pleura

Result of Asbestosis 

Covered further on: Restrictive Lung Diseases page

Investigation

  • Anyone presenting with red flag symptoms of lung cancer should be PROMPTLY investigated:
  • First line = Chest X-Ray + Blood Tests
  • If mass found/doubt of CXR findings- Confirm with a CT scan – gives better visualisation of mass.
  • Once CT-Scan confirms mass – take a biopsy via:
    • Bronchoscopy (camera down trachea via mouth or nose)
      • Can be ultrasound guided (also visualises lymph nodes)
        • Biopsy determines cancer type and stages it to see how far it has spread.
        • Informs management options
  • IF radical treatment (total cure of cancer) possible -PET scan performed – highlights areas with large energy consumption (IE Cancer).
    • Makes sure there is no metastatic spread.

Management

  • As small cell is very aggressive- surgery is unlikely to be an option due to large spread
    • HOWEVER it is chemo-sensitive
    • Radiotherapy performed after
  • Ever other lung cancer (adenocarcinoma, SCC and large cell) are all relatively slow growing tumours, with little metastasis – so surgery remains the mainstay of treatment
    • If little spread – can just remove mass
    • If more local spread can remove lobe
    • If compromise of lung, can remove whole lung (pneumonectomy)
    • Can have chemotherapy post-surgery
  • Immunotherapy a growing treatment
    • Adenocarcinoma particularly sensitive – Tyrosine Kinase Inhibitors
  • If cure is impossible- palliative care to maximise quality of life is commenced in accordance with patient and family wishes.