Lung cancer

^AThe proposed National Lung Cancer Screening Program recommends low-dose CT (LDCT) scanning every two years for people aged 50–70 years with a 30 pack-year history of cigarette smoking and for former smokers who quit within the past 10 years.⁶ This differs to the current Cancer Council Australia clinical practice guideline, which gives Grade C evidence to considering a CT scan in those aged 55–74 years with a 30 pack-year history and former smokers who have quit within the past 15 years.⁵
Tracking pack-year calculations in Aboriginal and Torres Strait Islander peoples may be a challenge and healthcare professionals are encouraged to use clinical judgement to consider daily smoking habits.

• Support and do not stigmatise people who smoke, being especially mindful of harmful colonial legacies of tobacco.
• Ensure training and systems to support the AAH (Ask, Advise, Help) approach to smoking cessation.
• Ensure smoking status is recorded and updated in the patient’s medical record.
• Use clinical judgement to consider daily smoking habits when calculating pack-years is challenging. This may include considering factors such as the age at which an individual first began smoking and their level of nicotine dependence.
• Keep up to date with recommendations and advice regarding the roll out of the National Lung Cancer Screening Program.

Clinical guidelines

• Cancer Council Australia: Clinical practice guidelines for the prevention and diagnosis of lung cancer 
• The Royal Australian College of General Practitioners (RACGP). Supporting smoking cessation: a guide for health professionals 
• Cancer Australia: Investigating symptoms of lung cancer: A guide for all health professionals – a guide and flowchart to help health professionals identify and arrange appropriate investigations of symptoms and signs of lung cancer, and to support the timely referral of patients into the multidisciplinary diagnostic pathway 

Patient resources

• Quitline: telephone 13 7848 or 13QUIT or go online to arrange a free call back and follow-up telephone calls
• Tackling Indigenous Smoking Resource and Information Centre 

Background

Lung cancer remains the most commonly diagnosed cancer among Aboriginal and Torres Strait Islander people and is the leading cause of cancer-related deaths.^2,7 Among Aboriginal and Torres Strait Islander people, the five-year survival rate for lung cancer is just 12%.⁸ Lung cancer is diagnosed at a younger age in Aboriginal and Torres Strait Islander people and, after adjusting for age at diagnosis, Aboriginal and Torres Strait Islander people are approximately twice as likely as non-Indigenous Australians to be diagnosed with lung cancer.² Data from 2015–19 showed that age-standardised mortality rates from lung cancer for Aboriginal and Torres Strait islander people were also twice that of non-Indigenous Australian.⁸

The greatest risk factor for developing lung cancer is current or former tobacco smoking, and the risk is greater for those who begin smoking in early life, smoke for a long time and smoke more often.¹ However, tobacco smoking is not the only risk factor, and in 16.1% of men and 28.9% of women diagnosed with lung cancer in Australia, there is no history of smoking.⁹ Environmental risk factors include exposure to second-hand smoke, occupational exposures (eg radon, diesel engine exhaust, welding fumes, asbestos and silica) and general air pollution. A family history of lung cancer, a personal history of chronic lung disease or radiation therapy to the chest and increasing age are some other personal risk factors to consider.¹ There are major concerns about the known and potential harms of vaping, including the potential to cause lung cancer, but evidence at this stage is equivocal and further research is needed.¹⁰ 

Tobacco smoking was introduced into Australia by European colonisers, who used it as a tool to gain favour, as a form of payment and to establish relationships with Aboriginal and Torres Strait Islander people. Tobacco smoking is innately associated with colonisation and dispossession, and racist legacies such as being used to manipulate people for services and cheap labour.¹¹ Tobacco remained a staple of both private employers and government-issued rations in lieu of wages until the 1960s.¹² More recently, harmful social control policies, racial prejudice and socioeconomic disadvantage have continued to contribute to high rates of tobacco smoking in Aboriginal and Torres Strait Islander populations.¹³ 

Smoking among Aboriginal and Torres Strait Islander people has decreased significantly in recent years, although the overall percentage of regular tobacco smokers remains higher than for non-Indigenous Australian people¹⁴ (see Chapter 2: Healthy living and health risks, Smoking for details, including how to address tobacco smoking in clinical practice⁴).

The single most effective way to reduce the risk of lung cancer is to prevent exposure to tobacco smoke by preventing smoking uptake, supporting smoking cessation and preventing exposure to second-hand smoke. The relative risk of lung cancer falls steadily after quitting and, compared with people who continue to smoke, the risk is approximately halved 10–15 years after smoking cessation.¹⁵ Furthermore, the lifetime risk of lung cancer is reduced by a greater factor if the individual can quit smoking and remain smoke free from a younger age.¹⁶ 

The Federal Government announced in May 2023 that a new National Lung Cancer Screening Program would be introduced by July 2025.³ This program will target individuals aged 50–70 years with a history of heavy smoking, aiming to detect lung cancer in its early stages to improve lung cancer outcomes and increase the chance of successful treatment. This comes after years of feasibility reports and considerations related to the introduction of a new nationwide equitable lung cancer screening program.¹⁷ Significant funding has been allocated to building capacity within the Aboriginal Community Controlled Health Organisation sector and to ensure that mainstream cancer care services are culturally safe and accessible to Aboriginal and Torres Strait Islander people.³ The commitment to codesigning the details of this program with Aboriginal and Torres Strait Islander people is important in supporting equitable outcomes. 

Modelling suggests, with a high degree of certainty, that LDCT screening for early detection of lung cancer in asymptomatic individuals aged 50–70 years with a history of heavy smoking would be cost-effective and would prevent an estimated 4080 deaths in Australia over the first six years (based on a 65% participation rate).^6,17 Consultation with community stakeholders has demonstrated that there is overall support from Aboriginal and Torres Strait Islander people for a targeted lung cancer screening program in Australia. ¹⁸ 

Harms of a screening CT include the possibility of false positives leading to unnecessary tests and invasive procedures, overdiagnosis of non-cancerous lesions and indeterminate results leading to patient distress. An evidence review for the U.S. Preventive Services Task Force reports 17 invasive procedures with less than one major complication following false-positive screening CT findings for every 1000 people screened.¹⁹ Other potentially significant non-cancer findings may also be detected. A better balance of harm and benefit is achieved by careful recruitment of high-risk individuals for LDCT screening, and by using validated evaluative techniques and protocols for any lung nodules detected.^19,20