Recent Trends in Demographics, Surgery, and Prognosis of Patients with Surgically Resected Lung Cancer in a Single Institution from Korea

Abstract

Background: Over the past few decades, demographics information has changed significantly in patients with surgically resected lung cancer. Herein, we evaluated the recent trends in demographics, surgery, and prognosis of lung cancer surgery in Korea.

Methods: Patients with surgically resected primary lung cancer from 2002 to 2016 were retrospectively analyzed. Multivariable Cox regression analysis was conducted to identify prognostic factors for overall survival. The annual percent change (APC) and statistical significance were calculated using the Joinpoint software.

Results: A total of 7,495 patients were enrolled. Over the study period, the number of lung cancer surgeries continued to increase (P < 0.05). The proportion of women to total subjects has also increased (P < 0.05). The proportion of elderly patients (≥ 70 years) as well as those with tumors measuring 1-2 cm and 2-3 cm significantly increased in both genders (all P < 0.05). The proportion of patients with adenocarcinoma, video-assisted thoracic surgery, sublobar resection, and pathological stage I significantly increased (P < 0.05). The 5-year overall survival rate of lung cancer surgery increased from 61.1% in 2002-2006 to 72.1% in 2012-2016 (P < 0.001). The operative period was a significant prognostic factor in multivariable Cox analysis (P < 0.001).

Conclusion: The mean age of patients with lung cancer surgery increased gradually, whereas tumor size reduced. Prognosis of lung cancer surgery improved with recent increases in the frequency of adenocarcinoma, video-assisted thoracic surgery, sublobar resection, and pathological stage I. The operation period itself was also an independent prognostic factor for overall survival.

Keywords: Demography; Non-Small Cell Lung Cancer; Republic of Korea; Surgical Outcome; Surgical Resection; Time Trend.

Fig. 1. Changes in the number of lung cancer surgeries for total, men, and women patients and the proportion of women to total patients according to the year. The numbers at the bottom of each variable in the legend indicate APC during the years shown in parentheses.

APC = annual percent change. ^*Significantly different from zero at (P < 0.05).

Fig. 2. Changes in the proportion of adenocarcinoma, pathological stage I, VATS operation, sublobar resection according to the year. The numbers at the bottom of each variable in the legend indicate APC during the years shown in parentheses.

APC = annual percent change, VATS = video-assisted thoracic surgery. ^*Significantly different from zero at (P < 0.05).

Fig. 3. Changes in age-specific distribution according to the year. The numbers at the bottom of each variable in the legend indicate APC during the years shown in parentheses.

APC = annual percent change. ^*Significantly different from zero at (P < 0.05).

Fig. 4. Changes in tumor size distribution according to the year. The numbers at the bottom of each variable in the legend indicate APC during the years shown in parentheses.

APC = annual percent change. ^*Significantly different from zero at (P < 0.05).

Fig. 5. Kaplan-Meier estimates of overall survival according to the operation period. The P values in the survival graph were calculated using the log-rank test, and the P values in the table were assessed by multivariate Cox analysis.

HR = hazard ratio, MST = median survival time, n.a. = not available.

Fig. 6. Stage-specific Kaplan-Meier estimates of overall survival according to the operation period. Kaplan-Meier survival curve for (A) pathological stages I, (B) pathological stage II, (C) pathological stage III, and (D) pathological stage IV. The P values in the survival graph were calculated using the log-rank.