The following is the summary of “Postoperative survival of pulmonary invasive mucinous adenocarcinoma versus non-mucinous invasive adenocarcinoma” published in the January 2023 issue of Pulmonary medicine by Cui, et al.

The World Health Organization reclassified mucinous bronchioloalveolar adenocarcinoma as pulmonary invasive mucinous adenocarcinoma (IMA) in 2015. Previous studies have shown conflicting survival outcomes due to its low prevalence and uncertainty with surgical treatment. By comparing IMA to non-mucinous invasive adenocarcinoma, researchers  hoped to learn more about the variations in the surgical outcome and prognosis-related risk variables between the 2 cancer types (NMA). Through the use of the Surveillance, Epidemiology, and End Results database, a total of 20,914 patients diagnosed with IMA or NMA between the years 2000 and 2014 were evaluated. 

To investigate the differences in survival rates between patients with IMA and NMA and the factors affecting prognosis, propensity score matching (PSM) was performed on the screened patients in a 1:4 ratio. As a result, patients with IMA were more likely to have their cancer begin in the lower lobes of the lungs (P<0.0001), have a well-differentiated histology (P<  0.0001), have fewer lymph node metastases (94.4% vs 72.0%, P<0.0001), and be diagnosed at an earlier pathological stage (P=0.0001). There were a total of 303 patients in the IMA cohort and a total of 1,212 patients in the NMA cohort following PSM. Overall survival (OS) did not differ between the IMA and NMA groups, as shown by Kaplan-Meier analysis (P=0.7). 

Tumor pathology was not a significant predictor of OS between the 2 groups, as determined by a Cox proportional hazards analysis (P=0.65). Independent predictors of patient OS included patient age (HR: 1.98, 95% CI 1.7-2.31, P<0.0001), gender (HR: 0.64, 95% CI 0.55-0.75, P<0.0001), and radiation treatment (HR: 2.49, 95% CI 1.84-3.37, P<0.0001). After surgery, there was no discernible difference in OS between patients with IMA and those with NMA. Independent predictors of OS include age, sex, and radiation therapy.