Patients with pulmonary nodules that are highly suspected to be lung cancer often need to make important treatment decisions before a definite pathological diagnosis is available. These decisions may include whether to undergo surgery, whether to continue follow-up, whether to have further diagnostic tests, and how to understand the potential benefits and risks of different management options.

This prospective observational study aims to describe the preoperative decision-making status of adult patients with pulmonary nodules suspected of lung cancer. The study will assess patients' decision self-efficacy, decisional conflict, shared decision-making experience, and decision regret using standardized questionnaires. It will also explore factors associated with better or worse decision quality, such as demographic characteristics, clinical information, health literacy, doctor-patient communication, family involvement, and emotional status.

No treatment or intervention will be assigned by the study. Participants will receive routine clinical care, and study data will be collected mainly through questionnaires before surgery or during the preoperative period. The findings may help clinicians identify patients who need additional decision support and improve communication during preoperative decision-making for suspected lung cancer.

Pulmonary nodules that are highly suspected of malignancy represent a common and clinically challenging scenario in thoracic surgery. Before a definite pathological diagnosis is available, patients may need to make complex decisions regarding surgery, additional diagnostic procedures, active surveillance, or other management strategies. These decisions are often made under uncertainty and may be influenced by patients' understanding of medical information, perceived cancer risk, fear of treatment delay, concerns about unnecessary surgery, family involvement, and communication with clinicians.

This is a single-center, prospective observational study conducted at Sichuan Cancer Hospital. The study plans to enroll approximately 200 adult patients with pulmonary nodules highly suspected of lung cancer who are facing preoperative clinical decision-making. The study will not assign any treatment, diagnostic procedure, or behavioral intervention. All clinical management decisions will be made according to routine clinical practice and shared discussion between patients and their treating clinicians.

The primary aim of the study is to characterize preoperative decision-making among patients with pulmonary nodules suspected of lung cancer. Specifically, the study will assess decision self-efficacy, decisional conflict, and decision quality. Decision self-efficacy will be evaluated using the Decision Self-Efficacy Scale. Decisional conflict will be assessed using the Decisional Conflict Scale. Decision quality and shared decision-making experience will be evaluated using instruments such as the SDM-Q-9 and decision regret-related measures, as applicable.

The study will also explore the relationships among decision self-efficacy, decisional conflict, and decision quality. Potential associated factors may include demographic characteristics, clinical characteristics, health literacy, quality of doctor-patient communication, family involvement, emotional status, and patient preferences. Data will be collected using structured questionnaires during the preoperative outpatient or inpatient period.

Descriptive statistics will be used to summarize participant characteristics and questionnaire scores. Correlation analyses, multivariable regression models, and, if appropriate, structural equation modeling will be used to examine the associations and potential pathways linking decision self-efficacy, decisional conflict, and decision quality. The study is expected to provide evidence for identifying patients at risk of poor decision quality and for developing future decision support strategies in thoracic surgical practice.

Inclusion Criteria:

1. Age 18 years or older.
2. Adult patients with pulmonary nodules that are highly suspected of malignancy based on clinical and radiological assessment.
3. No definite pathological diagnosis of lung cancer before enrollment.
4. Patients who are facing preoperative clinical decision-making with more than one reasonable management option, such as surgery, additional diagnostic evaluation, or follow-up.
5. Able to understand the study procedures and complete the study questionnaires.
6. Able and willing to provide written informed consent.

Exclusion Criteria:

1. Patients without a real clinical decision-making choice regarding the management of the pulmonary nodule.
2. Patients with severe cognitive impairment or a history of severe psychiatric disease that would interfere with valid questionnaire completion.
3. Patients who are unable to communicate effectively with the study staff.
4. Patients who decline to participate or are unable to provide written informed consent.

The study population will include adult patients treated at Sichuan Cancer Hospital who have pulmonary nodules highly suspected of lung cancer before pathological confirmation and who are facing preoperative clinical decision-making. Eligible participants will be identified from thoracic surgery outpatient clinics and inpatient wards. Participants will receive routine clinical care, and study data will be collected using structured questionnaires during the preoperative period.

Individual participant data will not be publicly shared because the study collects sensitive clinical and decision-making information from patients before pathological confirmation. De-identified aggregate results may be reported in publications or conference presentations. Requests for de-identified data may be considered by the principal investigator and the ethics committee, subject to applicable institutional policies and participant consent.