By A/Prof Kaushalendra Rathore, Cardiothoracic Surgeon, Nedlands
Primary lung cancer accounts for 18-20% of cancer-related deaths annually.
Early diagnosis of small tumours, followed by multidisciplinary management, has been shown to improve five-year survival rates.
Tumour size and volume, particularly in solid or sub-solid pulmonary nodules (SSPN) and ground glass opacities (GGO), are key predictors of overall and cancer-free survival at any pathological stage.
The National Lung Cancer Screening Program (NLCSP), which launched in July, was established based on findings from the National Lung Screening Trial (NLST) in the United States. The NLST demonstrated a 20% improvement in cancer related mortality and these findings were further reinforced by other trials.
However, thoracic surgery training in Australia remains integrated with cardiac surgery fellowship programs, leading to a relative shortage of dedicated minimally invasive thoracic surgeons.
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The introduction of the NLCSP is expected to increase the volume of surgical and surveillance cases, exacerbating this deficit further.
Specialist deficit
Firstly, there will be a rise in younger, asymptomatic patients with early-stage (IA, IB) lung cancer. Secondly, there will be an initial increase in newly diagnosed locally advanced (IIB-IIIA) tumours during the initial years of screening.
Both scenarios require highly skilled thoracic surgeons capable of performing lung-sparing surgeries for early-stage cases like complex wedge resections and segmentectomies for SSPN or GGO, and handling intricate locally advanced tumours following neoadjuvant chemo-immunotherapy in a multimodal approach.
Recent studies advocate for lung-sparing surgeries in early-stage screening positive tumours (T1aN0, <2 cm diameter, node-negative) due to comparable five-year disease-free survival rates between sublobar and lobar resections.
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Surgical margin and tumour characteristics significantly impact recurrence rates. Studies indicate that a surgical margin of under 10mm and tumour margin distance to solid-component-size ratio below one correlate with higher loco-regional recurrence rates, reinforcing the necessity of specialised thoracic surgeons for precise surgical decision-making.
A uneven system
Australia’s healthcare distribution is highly uneven, with 29% of the population residing in rural and remote areas where lung cancer outcomes are notably poorer.
Lung adenocarcinoma is more prevalent than squamous cell carcinoma, and 75% of cases are operated on in stages I and II, with most surgeries occurring within a fortnight of referral.
A major barrier to equitable care is the unequal distribution of dedicated thoracic surgeons and specialised units. Additionally, essential services like radiotherapy, stereotactic ablative body radiotherapy (SABR), and chemotherapy centres must be accessible to all regions.
Delayed lung cancer diagnosis is a significant contributor to poor survival rates, particularly in cases involving larger nodules with high VDT.
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Other prognostic factors include histological patterns, molecular features, SSPN type (pure GGO vs heterogeneous nodules), smoking status, previous lung cancer history, and nodule size (>10 mm).
Maintaining engagement among high-risk individuals remains challenging due to variable tumour growth rates, which are influenced by age, gender, smoking history, tumour type, stage, histology, remoteness of living and genetic mutations.
The incidence of GGOs in the general population is 1-1.7%, with 29% of pure GGOs progressing to part-solid cancerous nodules.
Room for improvement
Long-term lung cancer screening presents challenges such as physical and psychological consequences, cumulative radiation exposure, overdiagnosis, overtreatment, cost-effectiveness issues, and incidental findings, such as coronary artery calcification and other malignancies.
Current NLCSP eligibility criteria focus primarily on age and smoking history, potentially overlooking high-risk individuals with occupational exposure such as asbestos, family history, prior cancers, or underlying lung diseases including emphysema and pulmonary fibrosis.
Despite the challenges associated in implementing the NLCSP, ongoing research will refine screening protocols. Incorporating additional variables to improve risk stratification, alongside improved healthcare infrastructure, will ensure optimum patient outcomes.
Author competing interests – nil
Key messages
- Primary lung cancer accounts for around one in five cancer deaths in Australia
- The new Lung Cancer Screening Program has potential to improve this by earlier detection
- There remains significant inequity between services in rural and metropolitan areas.
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