Our study aims to estimate the incidence of metachronous second primary lung cancer(SPLC) in initial primary lung cancer(IPLC) survivors and to determine whether radiotherapy affects the risk of metachronous SPLC in the first five years after the diagnosis of lung cancer. Incidence data of IPLC individuals who survived ≥2 years were obtained from SEER-18 database in 2004–2007. Joinpoint regression analysis and competing risk analysis were used to calculate the incidence of metachronous SPLC. Propensity score matching and decision analysis were available to estimate the effect of radiotherapy on metachronous SPLC. 264 of 11657 IPLC survivors with radiotherapy and 1090 of 24499 IPLC survivors without radiotherapy developed metachronous SPLC during 5-year follow-up, respectively. In joinpoint regression analysis, the 5-year incidence of metachronous SPLC in the radiotherapy group was lower than that in the nonradiotherapy group(2385 per 100,000 vs 4748 per 100,000, HR = 0.43,95% CI:0.39–0.47). Competing risk analysis showed that the survivors with radiotherapy were associated with the lower 5 year incidence of metachronous SPLC compared with those without radiotherapy(2.28% vs 4.47%, HR = 0.49,95% CI:0.43–0.57). Through propensity score matching, 4077 pairs of survivors were available to further study that radiotherapy potentially decreased the risk of developing metachronous SPLC with the adjustment of various factors(2.5% vs 3.3%, HR = 0.72, 95% CI:0.55–0.96). Decision analysis suggested that radiotherapy was a negative independent risk factor of metachronous SPLC with clinical net benefit in a range of risk thresholds (2% to 5%). Survivors of IPLC with radiotherapy likely had a low risk of metachronous SPLC during the first five years follow-up, especially non-small cell lung cancer.

Background The prognosis of lung cancer with malignant pericardial effusion is very terrible owing to the impact of cardiac tamponade. The aim of our study seeks to identify prognostic factors and establish a prognostic nomogram of non small cell lung cancer (NSCLC) with malignant pericardial effusion. Methods NSCLC patients with malignant pericardial effusion between 2010 and 2014 are searched from SEER database.Cancer-specific death of these patients are analyzed through the Kaplan–Meier method, Cox proportional hazard model and competing risk model. Prognostic nomogram of cancer-specific death is performed and validated with concordance index (C-index), calibration plots and internal validation population. Propensity score matching is used to evaluate whether chemotherapy affected the survival of study population. Results 696 eligible NSCLC patients are involved in the study population, with 22.7% of 1-year survival rate and 8.9% of 2-year survival rate. Laterality, AJCC N, AJCC T, and chemotherapy are regarded as independent prognostic factors of cancer-specific death in the Cox proportional hazards model and competing risk model. The C-index of established nomogram is 0.703(95%CI:0.68–0.73) for cancer-specific death in the study population with acceptable calibration, which is significantly higher than classical TNM stage(C-index = 0.56, 95%CI:0.52–0.60). After 1:1 propensity score matching, chemotherapy potentially reduces the risk of cancer-specific death (HR = 0.42 95%CI: 0.31–0.58) of NSCLC with pericardial effusion. Conclusions NSCLC with malignant pericardial effusion harbors low overall survival. One prognostic nomogram based on laterality, AJCC N, AJCC T and chemotherapy is developed for cancer-specific death to predict 1-year and 2-year survival rate with good performance.

BackgroundThis study was designed to estimate the trends in 5-year incidence of metachronous second primary lung cancer(SPLC) and to establish a risk prediction model to identify candidates who were at high risk of developing metachronous SPLC.MethodsIncidence data between 2004 and 2007 were obtained from SEER database, including 42453 participants who survived ≥ 2 years after the initial diagnosis of lung cancer. Joinpoint regression analysis was used to calculate the 5-year incidence rates of metachronous SPLC per 100 000 population. Related risk factors of the survivors who developed MSPLC during five years were identified through logistic regression analysis, followed by establishment of risk prediction nomogram. Discrimination (C-index), calibration and decision analysis were further performed to assess the validation and clinical net benefit of risk prediction nomogram.ResultsA total of 1412 survivors with lung cancer developed MSPLC during five years, with 3546 per 100 000 population of age-adjusted 5-year incidence. Age, histology, tumor stage, and radiation were recognized as risk factors of metachronous SPLC, as indicated by logistic regression analysis. The risk prediction nomogram of metachronous SPLC harbored moderate discrimination(C-index = 0.67) and good calibration, with the risk of 0.01 to 0.11.The decision curve analysis showed that clinical net benefit of this risk prediction nomogram in a range of risk thresholds (0.01 to 0.06) was higher compared to all-screening or no-screening strategies.ConclusionsCollectively, the cumulative risk of metachronous SPLC of the survivors increased over time. The risk prediction nomogram was available to select high-risk survivors who should regularly undergo computed tomography screening.