Smoking Cessation After Lung Cancer Diagnosis and the Risk of Second Primary Lung Cancer: The Multiethnic Cohort Study

Background Smoking cessation reduces lung cancer mortality. However, little is known about whether diagnosis of lung cancer impacts changes in smoking behaviors. Furthermore, the effects of smoking cessation on the risk of second primary lung cancer (SPLC) have not been established yet. This study aims to examine smoking behavior changes after initial primary lung cancer (IPLC) diagnosis and estimate the effect of smoking cessation on SPLC risk following IPLC diagnosis. Methods The study cohort consisted of 986 participants in the Multiethnic Cohort Study who were free of lung cancer and active smokers at baseline (1993-1996), provided 10-year follow-up smoking data (2003-2008), and were diagnosed with IPLC in 1993-2017. The primary outcome was a change in smoking status from “current” at baseline to “former” at 10-year follow-up (ie, smoking cessation), analyzed using logistic regression. The second outcome was SPLC incidence after smoking cessation, estimated using cause-specific Cox regression. All statistical tests were 2-sided. Results Among 986 current smokers at baseline, 51.1% reported smoking cessation at 10-year follow-up. The smoking cessation rate was statistically significantly higher (80.6%) for those diagnosed with IPLC between baseline and 10-year follow-up vs those without IPLC diagnosis (45.4%) during the 10-year period (adjusted odds ratio = 5.12, 95% confidence interval [CI] = 3.38 to 7.98; P < .001). Incidence of SPLC was statistically significantly lower among the 504 participants who reported smoking cessation at follow-up compared with those without smoking cessation (adjusted hazard ratio = 0.31, 95% CI = 0.14 to 0.67; P = .003). Conclusion Lung cancer diagnosis has a statistically significant impact on smoking cessation. Quitting smoking after IPLC diagnosis may reduce the risk of developing a subsequent malignancy in the lungs.

High Rate of Epidermal Growth Factor Receptor-Mutated Primary Lung Cancer in Patients with Primary Breast Cancer

Background With increased survival in breast cancer, resulting from advances in treatment, patients incur the possibility of subsequent primary malignancies, especially lung cancer. The aim of this study was to assess the frequency of CT-detected pulmonary ground-glass nodules and lung cancer following breast cancer diagnosis, the associations between breast cancer and lung cancer, the pathological features of double primary cancer, and the status of epidermal growth factor receptor (EGFR) mutations in second primary lung cancer. Methods Clinical data from more than 8000 individuals who were diagnosed with primary breast cancer at Jiangsu Province Hospital (Jiangsu, China) between January 2008 and December 2020 were retrospectively analyzed. Results Of the 8048 patients, 55 (0.7%) were diagnosed with a second primary lung cancer, which accounted for approximately 14.8% of the pulmonary ground-glass opacity (GGO) detected. The incidence was higher than in the general female population (standardized incidence ratio 1.4 [95% confidence interval (CI): 1.25–1.55]). Patients who experienced a second primary lung cancer exhibited a significantly higher rate of EGFR mutation (78.5%) than those with lung adenocarcinoma alone, with most exhibiting low-grade malignancy, older age, estrogen receptor negativity, low Ki67, and no lymph node metastasis. Conclusions Breast cancer patients, especially those with low-grade malignancy, were at high risk for developing primary lung cancer. For isolated GGO in patients with high-risk factors, clinicians should insist on close follow-up. Furthermore, EGFR may play an important role in primary lung adenocarcinomas and breast cancer.

Routine follow-up after surgical treatment of lung cancer: is chest CT useful?

Objective: To report the experience of a routine follow-up program based on medical visits and chest CT. Methods: This was a retrospective study involving patients followed after complete surgical resection of non-small cell lung cancer between April of 2007 and December of 2015. The follow-up program consisted of clinical examination and chest CT. Each follow-up visit was classified as a routine or non-routine consultation, and patients were considered symptomatic or asymptomatic. The outcomes of the follow-up program were no evidence of cancer, recurrence, or second primary lung cancer. Results: The sample comprised 148 patients. The median time of follow-up was 40.1 months, and 74.3% of the patients underwent fewer chest CTs than those recommended in our follow-up program. Recurrence and second primary lung cancer were found in 17.6% and 11.5% of the patients, respectively. Recurrence was diagnosed in a routine medical consultation in 69.2% of the cases, 57.7% of the patients being asymptomatic. Second primary lung cancer was diagnosed in a routine medical appointment in 94.1% of the cases, 88.2% of the patients being asymptomatic. Of the 53 patients who presented with abnormalities on chest CT, 41 (77.3%) were diagnosed with cancer. Conclusion: Most of the cases of recurrence, especially those of second primary lung cancer, were confirmed by chest CT in asymptomatic patients, indicating the importance of a strict follow-up program that includes chest CTs after surgical resection of lung cancer.