The goal of this interventional study is to learn about the effect of a structured educational intervention in patients undergoing surgery for lung cancer. The study will examine whether this intervention can improve patients' acceptance of the disease, quality of life, pain levels, and postoperative clinical and biometric outcomes.

The main question it aims to answer is: Does a structured educational intervention improve disease acceptance, quality of life, pain levels, and postoperative clinical and biometric outcomes in patients undergoing surgery for lung cancer? Participants are assigned to two groups. Participants in the intervention group receive a structured educational intervention in addition to usual care, while participants in the control group receive usual care only. Data are collected through questionnaires and clinical and biometric measurements after surgery, with follow-up assessments over a 5-year period.

This is a two-arm parallel-group interventional study evaluating the impact of a structured educational intervention in patients undergoing surgery for lung cancer. The study is conducted at a referral center, where all interviews, educational sessions, follow-up assessments, and data collection procedures take place.

Before enrollment, all eligible patients receive written information about the study and provide written informed consent. By signing the consent form, participants give permission for the researcher to collect study-related data through personal interviews and from their medical records.

Baseline preoperative data are collected from all participants before the delivery of the educational intervention. These data are collected using specially designed questionnaires administered through personal interviews with the patient and include demographic characteristics, hospital admission information, biometric measurements, lifestyle-related factors such as smoking, physical activity, dietary habits and alcohol consumption, as well as personal and family medical history.

Participants are allocated to either an intervention group or a control group. Allocation is performed using a predefined alternating sequence according to the order of surgery. On the first surgical day of the study, the research team determines the initial group assignment for the first eligible participant undergoing the first scheduled surgery. Subsequently, eligible participants are allocated alternately to the intervention and control groups according to the order of surgery. On the next surgical day, the allocation sequence starts with the opposite group, and this alternating pattern continues throughout enrollment.

The intervention group receives usual care plus a structured educational intervention supported by printed educational material. Participation of a caregiver is required during the educational session together with the patient. The printed material includes the date of the educational intervention, the researcher-educator's contact details, and the scheduled follow-up appointment.

The educational intervention includes detailed information about lung cancer and the patient's treatment pathway. Patients are informed about the disease, imaging-based staging, and the possible contribution of histological findings to final disease staging and further treatment planning. Information is also provided about potential adjuvant treatments, including chemotherapy, immunotherapy, and radiotherapy, when clinically indicated.

The intervention also covers the surgical procedure and the expected postoperative course. Patients receive information about postoperative drains, surgical incisions, wound care, mobilization, recovery after surgery, and orientation to the clinical setting. Education is provided on lifestyle modification, including smoking cessation, alcohol use, nutrition, physical activity, exercise after surgery, permitted weight limits, and general self-care during recovery.

In addition, patients are trained in preoperative respiratory exercises to support postoperative respiratory function. A dedicated section focuses on postoperative pain, including pain recognition, pain management strategies, relaxation techniques, and the importance of adequate sleep. Throughout the intervention, patients and their caregivers are encouraged to ask questions, express concerns, and discuss issues related to the disease, surgery, recovery, and follow-up care.

The control group consists of patients in whom the same variables are assessed without receiving the educational intervention. Participants in the control group receive usual clinical care according to the protocol of the Thoracic Surgery Department of the referral center. Interviews and data collection for the control group are also conducted at the referral center. Participants in the control group are reassessed at the same time points as participants in the intervention group.

The first interview and educational session for the intervention group are conducted during the patient's preoperative hospitalization. For both groups, baseline assessment is performed preoperatively. A second interview and educational session for the intervention group are conducted during the first three postoperative days and serve as the first postoperative reassessment. Participants in the control group are reassessed during the same postoperative period without receiving the educational intervention.

Additional follow-up assessments are conducted at the same time points for both groups: at 1 month and 6 months after surgery, after the first postoperative year, and during the planned long-term follow-up period of 5 years.

Patient-reported outcomes are assessed using validated Greek versions of standardized questionnaires. Illness perceptions and disease-related cognition are evaluated using the Illness Cognition Questionnaire for Chronic Diseases, which consists of 18 closed-ended items rated on a four-point scale. The questionnaire assesses three domains: illness acceptance, perceived benefits of the illness, and helplessness related to the illness.

Quality of life is assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and the lung cancer-specific module EORTC QLQ-LC13, both validated in the Greek language. These instruments assess physical, psychological, and social aspects of quality of life, as well as cancer-related and lung cancer-specific symptoms.

Pain intensity is assessed using the Pain Rating Scale of The British Pain Society. The scale is administered at the predefined study assessment time points in order to monitor postoperative pain and changes in pain levels during follow-up.

Clinical information and biometric measurements are also collected at the predefined assessment time points. Treating physicians and nursing staff are not informed of participants' group allocation.

Inclusion Criteria:

• Patients diagnosed with lung cancer.
• Patients admitted to the referral hospital and undergoing surgical treatment for lung cancer.
• Age older than 18 years.
• Signed written informed consent.
• Ability to speak, understand, and read the Greek language.
• Undisturbed level of consciousness allowing cooperation with the researcher and the healthcare team.
• Ability to participate in a personal interview and complete the study questionnaires.
• Availability of a supportive psychosocial network/caregiver, where required for participation in the educational intervention.

Exclusion Criteria:

• Inability to provide written informed consent.
• Inability to speak, understand, or read the Greek language.
• Impaired level of consciousness that prevents cooperation.
• Presence of a chronic condition affecting behavior or ability to cooperate with the study procedures.
• Lack of a supportive psychosocial network.
• Inability to cooperate with the medical and nursing staff.
• Inability to participate in the interview process or complete the required study assessments.

Individual participant data will not be shared due to privacy and confidentiality considerations and because the informed consent does not include permission for sharing individual-level data with external researchers.