Researchers investigated the association between chronic obstructive pulmonary disease (COPD) phenotypes and the prognosis of different histological subtypes of lung cancer and found that COPD, especially emphysema-predominant phenotype, was an independent prognostic risk factor for squamous carcinoma only.
Lung cancer and chronic obstructive pulmonary disease (COPD) affect a significant population of the world and impose significant burdens on patients and healthcare. Both diseases are heterogeneous with different pathological changes, clinical manifestations, and outcomes. When researchers investigated the association between COPD phenotypes and the prognosis of different histological subtypes of lung cancer in a new study, they found that COPD, especially emphysema-predominant phenotype, was an independent prognostic risk factor for squamous carcinoma only.
The researchers had speculated that the heterogeneous nature of the 2 diseases played an important role in the relationship between COPD and lung cancer prognosis.
The study enrolled subjects with a newly and pathologically confirmed diagnosis of lung cancer who were preparing for lung cancer surgery. The participants also underwent a pulmonary function test (PFT) and diagnosis of COPD was determined based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Guidelines. Furthermore, WHO classification of lung tumors was utilized to categorize lung cancer subtypes and COPD phenotypes.
Of the 2222 lung cancer patients, 32.6% coexisted with COPD, according to the results.
After adjustment for age, sex, body mass index (BMI), smoking status, and therapy method, COPD was significantly associated with the decreased overall survival (OS) of lung cancer (HR 1.28, 95% CI 1.05—1.57). With the increased severity of COPD, the OS of lung cancer was gradually worsened (HR 1.23, 95% CI 1.08–1.39). But surgical treatment and high BMI were independent prognostic protective factors (HR 0.46, 95% CI 0.37–0.56; HR 0.96, 95% CI 0.94–0.99).
In terms of disease heterogeneity, emphysema-predominant phenotype of COPD was an independent prognostic risk factor for squamous carcinoma (HR 2.53, 95% CI 1.49—4.30). No significant relationship between COPD phenotype and lung cancer prognosis was observed among adenocarcinoma, small cell lung cancer, large cell lung cancer, and other subtype patients.
There have been conflicting results from previous studies about whether or not COPD affects lung cancer survival. The researchers said that to their knowledge, their study is the largest study to date to examine this issue. The 5-year OS rates of lung cancers with COPD were significantly lower than that of lung cancers without COPD. The results were higher than the overall 5-year survival in overall lung cancer population but were consistent with OS rates in patients undergoing surgery
The authors concluded that these results offer new implications for the research of the relationship between lung cancer and COPD and demonstrate clinical identification of patients with higher risk for lung cancer prognosis.
Wang W, Dou S, Dong W, et al. Impact of COPD on prognosis of lung cancer: from a perspective on disease heterogeneity. Int J Chron Obstruct Pulmon Dis. [published online November 20, 2018]. doi: 10.2147/COPD.S168048.