Lung cancer is the leading cause of mortality in the world, and also in Taiwan.Despite the researches and availability in new therapies, it causes the highest mortality and is one of the most preventable cancers as well. Smoking is the most common cause of lung cancer worldwide. Compared to lung cancer in smokers, lung cancer in never-smokers is associated with East Asian ethnicity, female sex, and adenocarcinoma histology. This unique risk group is likely to have distinct molecular drivers, especially EGFR, ALK, and ROS1 mutations.In National Taiwan Cancer Registry data, more than half (53%) of all newly diagnosed lung cancer patients and 93% of female patients are lifelong never-smokers. This scenario is common in East Asia. It is essential to develop a different strategy for screening lung cancer patients with other high-risk profiles. Several risk factors have been identified in never-smoking lung cancer and one of the most important factor is a lung cancer family history (LCFH) in a first-degree relative. Other high-risk occupational or environmental factors include air-pollution exposed occupations (such as traffic policeman and street cleaners) for at least 10 years, cooking index ≥ 110, defined as 2/7 * days cooking by pan frying, stir frying, or deep frying in one week * years cooking, cooking without using ventilation, passive smoke exposure, and history of pulmonary tuberculosis or chronic obstructive pulmonary disorders.

As described above, three high risk groups are interested in this study, the previous heavy smokers (group 1); those who has family history (group 2) and those who have high risk occupation or environment factors (group 3). From the published researches, we assume the detection rate to be 1.1% for group 1 based on NLST results16, 2.6% for group 2 (395 out of 12,011 subjects in TALENT), and we assume the detection Group 3 to be 1% after consulting board-certified senior specialists in this field.

This is a prospective, multi-center, single arm study in Taiwan of subjects who are eligible to receive LDCT screening based on recommendation of Health Promotion Administration of Taiwan.

The primary objective of TRIO part A is the LDCT screening acceptance rate of high lung cancer risk subjects.

The primary objective of TRIO part B is the exact lung cancer detection rates in these three groups.

Other secondary objectives are also included.

Inclusion Criteria:

Group 1: Previous heavy smokers Age 50 to 80 years, meet both criteria in the followings.

1. Cigarette smoking of at least 20 pack-years
2. With successful smoking cessation history (stopping smoking for more than 6 months), but less than 15 years

Group 2: First-degree relatives of lung cancer patients

1. aged more than 50 years
2. age less than 50 years old, but older than the age at diagnosis of the youngest lung cancer proband in the family

Group 3: With other high-risk occupational or environmental factors Age 50 to 80 years, meet one or more of the following criteria.

1. air-pollution exposed occupations (such as traffic policemen, and street cleaners….) for at least 10 years
2. cooking index ≥ 110, defined as 2/7 * days cooking by pan frying, stir-frying, or deep frying in one week * years cooking.
3. cooking without using ventilation for more than 20 years
4. history of pulmonary tuberculosis and complete anti-tuberculosis treatment with intervals more than 5 years before this study

Exclusion Criteria:

1. previous history of lung cancer
2. another malignancy except for cervical carcinoma in situ or non-melanomatous carcinoma of the skin within 5 years
3. an inability to tolerate transthoracic procedures or thoracotomy
4. chest CT examination was performed within 18 months
5. hemoptysis of unknown etiology within one month
6. body weight loss of more than 6 kg within one year without an evident cause
7. a known pregnancy
8. Not capable of understanding or responding to the written questionnaire even through the help from the study team

High risk population for lung cancer