Survival Rate of Lung Cancer Patients after Diagnosis at the National Cancer Institute: An Update from the National Cancer Institute Hospital Based Cancer Registry between 2020 and 2024

Abstract

Background: Lung cancer is a leading cause of cancer-related mortality in Thailand and globally, particularly among patients diagnosed at an advanced stage. This study aimed to evaluate mortality rates, survival rates, and compare these among groups of lung cancer patients receiving treatment at the National Cancer Institute. The specific objectives were: (1) to evaluate the overall survival rate, survival time, and survival trends of lung cancer patients diagnosed and treated at the National Cancer Institute between 2020 and 2024; (2) to analyze and compare survival stratified by key variables including sex, age, cancer cell type, and disease stage; and (3) to determine survival trends for patients in each stage of the disease. Methods: This was a retrospective cohort study using data from the cancer registry database of the National Cancer Institute between January 1, 2020, and December 31, 2024. A total of 1,325 patients diagnosed with lung cancer (ICD-O-3: C33.9, C34.0–C34.9) were included. Vital status was followed up by linking with the mortality database of the National Health Security Office. Survival analysis was performed using the Kaplan-Meier method on 1,312 patients with complete data, with death as the event of interest. Differences in survival between groups were compared using the log-rank test. Median survival times were reported alongside 95% confidence intervals (CI). Results: Among the 1,325 patients, 56.53% were male with a mean age of 63.3 ± 11.1 years, and 43.47% were female with a mean age of 62.8 ± 11.8 years. The majority had non-small cell lung cancer (96.23%) and were diagnosed at stage IV (61.96%). There were 338 deaths observed, corresponding to a mortality rate of 25.51 per 100 person-years. The overall median survival time was 0.93 years (95% CI: 0.81–1.03), indicating that half of the patients died within approximately 11 months after diagnosis. The survival rates at 1, 2, 3, 4, and 5 years were 48.2%, 30.9%, 24.2%, 17.4%, and 12.9%, respectively. When stratified by sex, females had a significantly higher median survival of 1.38 years (95% CI: 1.15–1.58) compared to males, who had a median survival of 0.68 years (95% CI: 0.59–0.80). The 1-, 3-, and 5-year survival rates for females were 57.4%, 28.8%, and 19.7%, whereas for males, they were 41.1%, 20.6%, and 6.2%, respectively. When stratified by disease stage, prominent differences in survival were observed. stage II had a median survival of 4.60 years (95% CI: 3.08–upper limit not estimable), stage III was 1.25 years (95% CI: 0.99–1.69), and stage IV was 0.63 years (95% CI: 0.56–0.74). Kaplan-Meier trends demonstrated that patients in stage I-II experienced consistently higher survival, whereas stage IV showed a rapid decline in survival beginning in the first year. Conclusion: The majority of lung cancer patients were diagnosed at an advanced stage and exhibited a median survival of less than 1 year. Sex and disease stage were significantly associated with survival, with males and advanced-stage patients having a poor prognosis. The findings of this study reflect the critical need to improve early detection and increase access to effective treatments to reduce the mortality rate.