Survival analysis in lung cancer patients with interstitial lung disease

Lung Cancer and Interstitial Lung Diseases

Lung cancer continues to be one of the leading causes of cancer-related death worldwide. There is evidence of a complex interplay between lung cancer and interstitial lung disease (ILD), affecting disease progression, management strategies, and patient outcomes. Both conditions develop as the result of common risk factors such as smoking, environmental exposures, and genetic predispositions. The presence of ILD poses diagnostic and therapeutic challenges in lung cancer management, including difficulties in interpreting radiological findings and increased susceptibility to treatment-related toxicities, such as acute exacerbation of ILD after surgery and pneumonitis after radiation therapy and immunotherapy. Moreover, due to the lack of large, phase III randomized controlled trials, the evidence-based therapeutic options for patients with ILDs and lung cancer remain limited. Antifibrotic treatment may help prevent pulmonary toxicity due to lung cancer treatment, but its effect is still unclear. Emerging diagnostic modalities and biomarkers and optimizing personalized treatment strategies are essential to improve outcomes in this patient population.

Subsolid Nodules: Significance and Current Understanding

Subsolid nodules are heterogeneously appearing and behaving entities, commonly encountered incidentally and in high-risk populations. Accurate characterization of subsolid nodules, and application of evolving surveillance guidelines, facilitates evidence-based and multidisciplinary patient-centered management.

Clinical characteristics and outcome of lung cancer in patients with fibrosing interstitial lung disease

BACKGROUND

Lung cancer (LC) is an important comorbidity of interstitial lung disease (ILD) and has a poor prognosis. The clinical characteristics and outcome of each ILD subtype in LC patients have not been sufficiently investigated. Therefore, this study aimed to evaluate the difference between idiopathic pulmonary fibrosis (IPF) and non-IPF ILD as well as prognostic factors in patients with ILD-LC.

METHODS

The medical records of 163 patients diagnosed with ILD-LC at Asan Medical Center from January 2018 to May 2023 were retrospectively reviewed. Baseline characteristics and clinical outcomes were compared between the IPF-LC and non-IPF ILD-LC groups, and prognostic factors were analyzed using the Cox proportional-hazard model.

RESULTS

The median follow-up period was 11 months after the cancer diagnosis. No statistically significant differences were observed in clinical characteristics and mortality rates (median survival: 26 vs. 20 months, p = 0.530) between the groups. The independent prognostic factors in patients with ILD-LC were higher level of Krebs von den Lungen-6 (≥ 1000 U/mL, hazard ratio [HR] 1.970, 95% confidence interval [CI] 1.026-3.783, p = 0.025) and advanced clinical stage of LC (compared with stage I, HR 3.876 for stage II, p = 0.025, HR 5.092 for stage III, p = 0.002, and HR 5.626 for stage IV, p = 0.002). In terms of treatment, surgery was the significant factor for survival (HR 0.235; 95% CI 0.106-0.520; p < 0.001).

CONCLUSIONS

No survival difference was observed between IPF-LC and non-IPF ILD-LC patients. A higher level of Krebs von den Lungen-6 may act as a prognostic marker in ILD-LC patients.

An Accelerated Failure Time Model to Predict Cause-Specific Survival and Prognostic Factors of Lung and Bronchus Cancer Patients with at Least Bone or Brain Metastases: Development and Internal Validation Using a SEER-Based Study

BACKGROUND

This study addresses the significant challenge of low survival rates in patients with cause-specific lung cancer accompanied by bone or brain metastases. Recognizing the critical need for an effective predictive model, the research aims to establish survival prediction models using both parametric and non-parametric approaches.

METHODS

Clinical data from lung cancer patients with at least one bone or brain metastasis between 2000 and 2020 from the SEER database were utilized. Four models were constructed: Cox proportional hazard, Weibull accelerated failure time (AFT), log-normal AFT, and Zografos-Balakrishnan log-normal (ZBLN). Independent prognostic factors for cause-specific survival were identified, and model fit was evaluated using Akaike's and Bayesian information criteria. Internal validation assessed predictive accuracy and discriminability through the Harriel Concordance Index (C-index) and calibration plots.

RESULTS

A total of 20,412 patients were included, with 14,290 (70%) as the training cohort and 6122 (30%) validation. Independent prognostic factors selected for the study were age, race, sex, primary tumor site, disease grade, total malignant tumor in situ, metastases, treatment modality, and histology. Among the accelerated failure time (AFT) models considered, the ZBLN distribution exhibited the most robust model fit for the 3- and 5-year survival, as evidenced by the lowest values of Akaike's information criterion of 6322 and 79,396, and the Bayesian information criterion of 63,495 and 79,396, respectively. This outperformed other AFT and Cox models (AIC = [156,891, 211,125]; BIC = [158,848, 211,287]). Regarding predictive accuracy, the ZBLN AFT model achieved the highest concordance C-index (0.682, 0.667), a better performance than the Cox model (0.669, 0.643). The calibration curves of the ZBLN AFT model demonstrated a high degree of concordance between actual and predicted values. All variables considered in this study demonstrated significance at the 0.05 level for the ZBLN AFT model. However, differences emerged in the significant variations in survival times between subgroups. The study revealed that patients with only bone metastases have a higher chance of survival compared to only brain and those with bone and brain metastases.

CONCLUSIONS

The study highlights the underutilized but accurate nature of the accelerated failure time model in predicting lung cancer survival and identifying prognostic factors. These findings have implications for individualized clinical decisions, indicating the potential for screening and professional care of lung cancer patients with at least one bone or brain metastasis in the future.

Clinical characteristics and prognostic impact of acute exacerbations in patients with interstitial lung disease and lung cancer: A single-center, retrospective cohort study

BACKGROUND

Although acute exacerbation (AE) after treatment for lung cancer (LC) is a poor prognostic factor in patients with interstitial lung disease associated with lung cancer (ILD-LC), the risk of AE according to cancer treatment type remains unclear. Therefore, in the present study, we aimed to investigate the association between AE and treatment received for LC in patients with ILD-LC.

METHODS

We conducted a retrospective study of patients with ILD-LC who had undergone treatment for LC between January 2018 and December 2022. The primary study outcome was the incidence of AE within 12 months of treatment for LC according to treatment type. The association between AE and all-cause mortality was evaluated as a secondary outcome.

RESULTS

Among a total of 137 patients, 23 (16.8%) developed AE within 12 months of treatment for LC. The incidence of AE according to treatment type was 4.3% for surgery, 16.2% for radiotherapy, 15.6% for chemotherapy, and 54.5% for concurrent chemoradiation therapy (CCRT). Patients who received CCRT were more likely to develop AE, even after adjustment for covariables (hazard ratio [HR], 15.39; 95% confidence interval [CI]: 4.00-59.19; p < 0.001). In addition, AE within 12 months of treatment for LC was associated with an increased risk of all-cause mortality (HR, 2.82; 95% CI: 1.13-7.04; p = 0.026).

CONCLUSION

Among treatment options for patients with ILD-LC, CCRT was associated with an increased risk for AE. In addition, patients with AE had a higher mortality rate than patients without AE.

Clinical significance of KL-6 in immune-checkpoint inhibitor treatment for non-small cell lung cancer

PURPOSE

Krebs von den Lungen-6 (KL-6) functions as a tumor marker, as well as a diagnostic tool for interstitial pneumonia (IP). However, the significance of KL-6 in the immune-checkpoint inhibitor (ICI) treatment of non-small cell lung cancer (NSCLC), especially in patients without IP, is unknown.

METHODS

This multicenter, retrospective study, which included patients with advanced NSCLC who received ICI therapy, analyzed the association between serum KL-6 values and ICI efficacy and the association between serum KL-6 values and ICI-induced interstitial lung disease (ILD) occurrence, focusing primarily on patients without IP.

RESULTS

In total, 322 patients had available KL-6 values before ICI therapy. Among 202 patients without IP who received ICI monotherapy, the high-KL-6 group (≥ 500 U/mL) showed significantly shorter progression-free survival (PFS) and overall survival (OS) than the low-KL-6 group (< 500 U/mL) (median: 2.1 vs. 3.6 months, p = 0.048; median: 9.2 vs. 14.5 months, p = 0.035). There was no significant difference in response rate between the KL-6 high and low groups (19% vs. 29%, p = 0.14). In the multivariate analysis, high KL-6 was a significant predictor of poor PFS (hazard ratio [HR], 1.52; 95% confidence interval [CI] 1.10-2.11, p = 0.012) and OS (HR, 1.51; 95% CI 1.07 - 2.13, p = 0.019) for patients treated with ICI monotherapy. There was no significant difference in the occurrence rate of ILD between the high KL-6 and low KL-6 groups in patients with (20% vs. 15%, p = 1.00) or without IP (12% vs. 12%, p = 1.00).

CONCLUSION

In ICI monotherapy for NSCLC without IP, elevated serum KL-6 levels were associated with poorer outcomes.

Clinical spectrum of Chinese hospitalized lung cancer patients with concomitant interstitial lung disease: before and after the new era of LC treatment

This study aimed to explore the general characteristics and spectrum of hospitalized Chinese patients suffering from lung cancer with concomitant interstitial lung disease (LC-ILD). Furthermore, we compared their features before and after the period of immunotherapy for lung cancer. A retrospective analysis of the clinical characteristics of hospitalized LC patients with definite pathological diagnoses was performed from 2014 to 2021. ILD was defined after the review of chest CT imaging. There were 13,085 hospitalized LC patients. Among them, 509 patients (3.89%) had 551 cases of ILD. There were variable underlying causes of ILD, including idiopathic interstitial pneumonia (360 patients), LC treatment-associated ILD (134 cases), and connective tissue disease-associated ILD (55 patients). Although most LC-ILD patients were suffering from adenocarcinoma (204/40.1%), SCLC patients were prone to concomitant ILD (10.8% of all SCLC cases), followed by SCC (9.6% of all SCC cases). All but 10 LC-ILD patients received anti-LC treatment; however, only 39 (10.8%) LC-IIP patients received anti-ILD treatment. There were more LC-ILD patients in the 2018-2021 group than in the 2014-2017 group (5.16% vs. 2.03%, p < 0.001). The underlying causes of ILD were significantly different between the 2018-2021 group and the 2014-2017 group (p < 0.001). After adjusting for the number of hospitalized patients having the same LC pathological pattern, SCLC was determined to be the most likely to be concomitant with ILD, followed by SCC. Most LC-ILD patients were scheduled for anti-LC therapy; however, treatments for concomitant IIP were usually ignored. LC treatment-associated ILD should receive more attention than before.

Is pulmonary fibrosis a precancerous disease?

Idiopathic pulmonary fibrosis (IPF) is the most common type of interstitial lung disease (ILD) characterized by a histopathological pattern of usual interstitial pneumonia with progressive fibrosis of the pulmonary epithelium. The incidence of IPF is increasing worldwide as the population ages and with that, there is a concomitant increase in the incidence of lung cancer in these patients who are living longer with the disease. The average length of time for lung cancer development following an IPF diagnosis is 3 years. Given the high prevalence of lung cancer among patients with pulmonary fibrosis, we wondered if pulmonary fibrosis could be classified as a precancerous disease. We provided support from the Pubmed published literature to investigate whether pulmonary fibrosis meets the five criteria of the National Cancer Institute's definition of premalignant conditions for classification as a precancerous disease. We found out pulmonary fibrosis meets the five criteria of the National Cancer Institute's definition of a premalignant condition and can be considered a precancerous disease. To identify early lung cancer in patients with pulmonary fibrosis, regular screening with HRCT and PET-CT scans is highly recommended for these patients.

Management of Lung Cancer in the Patient with Interstitial Lung Disease

Patients with interstitial lung disease (ILD), especially those with pulmonary fibrosis, are at increased risk of developing lung cancer. Management of lung cancer in patients with ILD is particularly challenging. Diagnosis can be complicated by difficulty differentiating lung nodules from areas of focal fibrosis, and percutaneous biopsy approaches confer an increased risk of complications in those with pulmonary fibrosis. Lung cancer treatment in these patients pose several specific considerations. The degree of lung function impairment may preclude lobectomy or surgical resection of any type. Surgical resection can trigger an acute exacerbation of the underlying ILD. The presence of ILD confers an increased risk of pneumonitis with radiotherapy, and many of the systemic therapies also carry an increased risk of pneumonitis in this population. The safety of immunotherapy in the setting of ILD remains to be fully elucidated and concerns remain as to triggering pneumonitis. The purpose of this review is to summarize the evidence regarding consideration for tissue diagnosis, chemotherapy and immunotherapy, radiotherapy, and surgery, in this patient population and discuss emerging areas of research. We also propose a multidisciplinary approach and practical considerations for monitoring for ILD progression during lung cancer treatment.

Molecular Mechanisms and Cellular Contribution from Lung Fibrosis to Lung Cancer Development

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease (ILD) of unknown aetiology, with a median survival of 2-4 years from the time of diagnosis. Although IPF has unknown aetiology by definition, there have been identified several risks factors increasing the probability of the onset and progression of the disease in IPF patients such as cigarette smoking and environmental risk factors associated with domestic and occupational exposure. Among them, cigarette smoking together with concomitant emphysema might predispose IPF patients to lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer development. To this purpose, IPF and LC share several cellular and molecular processes driving the progression of both pathologies such as fibroblast transition proliferation and activation, endoplasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target molecular pathway. In this review our aim is to describe the updated studies on common cellular and molecular mechanisms between IPF and lung cancer, knowledge of which might help to find novel therapeutic targets for this disease combination.