Tool May Enable Prognosis Prediction in Patients With NSCLC, Liver Metastases

Using information from the Surveillance, Epidemiology, and End Results (SEER) database, researchers developed a prognostic nomogram for patients with non–small cell lung cancer (NSCLC) and liver metastases to help personalize prognoses.

Writing in Scientific Reports, the authors explained the nomogram has satisfactory accuracy and that their findings serve as a guide for development of patient treatment plans.

Although NSCLC accounts for around 85% of lung cancer cases, signs of the condition are not obvious and between 40% and 55% of patients are in advanced stages at the time of diagnosis.

Previous research has revealed liver metastasis serves as an independent poor prognostic factor for this patient population, as “the risk of death in patients with NSCLC in the presence of liver metastases is 1.53 to 2.41 times higher than that of distant metastases from other sites.”

Tumor, nodes, and metastases (TNM) staging is widely used to predict NSCLC prognosis, but several factors can have an impact on its effective implementation. In addition, there is currently no effective model to predict prognosis of patients with NSCLC and liver metastases.

“The nomogram is a simple statistical tool that can meet our needs for a comprehensive clinical model,” the authors wrote. “Nomograms enable rapid calculations as well as higher accuracy and easier-to-understand prognosis compared to traditional TNM staging to assist physicians in clinical decision-making.”

Data from patients included in the SEER database between 2010 and 2015 were used to create the model. All included individuals were at least 18 years old and had a primary site tumor pathologically diagnosed as NSCLC.

Patient factors that could be associated with prognosis were extracted from the data, and individuals were randomly divided into a training group (n = 1375) and a validation group (n = 588) in a ratio of 7:3.

In the training group, the majority of patients were older than 66 years, White, and male. “For tumor characteristics, 54.6% of them were adenocarcinoma, 59.2% were upper lobe, 68.4% were histologic grade 3, and 50.2% were N2,” the researchers said. Throughout the follow-up window, most patients did not receive surgical treatment (97%), 55.7% received chemotherapy, and 42.9% received radiation therapy.

Analyses revealed:

• Independent prognostic factors for patients with NSCLC and liver metastases included age, race, gender, grade, T stage, N stage, brain metastases, bone metastases, surgery, chemotherapy, and tumor size (P < .05 for all)
• The area under the curve predicting overall survival at 6, 9, and 12 months was 0.793, 0.787, and 0.784 in the training cohort and 0.767, 0.771, and 0.773 in the validation cohort, respectively
• Calibration curves of the nomogram showed high agreement between the outcomes predicted by the nomogram and the actual observed outcomes, and the decision curve analysis further demonstrated the value of the clinical application of the nomogram

Results showed that females with NSCLC and liver metastases had a better prognosis compared with males, while more advanced T and N stages and larger tumor size were linked with worse prognosis. The researchers hypothesized this could be due to the fact that sensitivity of the tumor cells to treatments like radiotherapy decreases as the tumor grows.

Patients with adenocarcinoma are also more likely to develop liver metastases compared with those with squamous carcinoma and other histological types. “However, the histologic type is not one of the poor prognostic factors for NSCLC patients with liver metastases, which may be due to different chemotherapy regimens for patients with different histologic types,” the authors wrote.

Specific information on targeted therapies and immunotherapies was not available in the SEER database, marking a limitation to the study. Data were also only representative of the US population and findings may not be generalizable.

Reference

Zhao R, Dai Y, Li X, Zhu C. Construction and validation of a nomogram for non small cell lung cancer patients with liver metastases based on a population analysis. Sci Rep. Published online March 7, 2022. doi:10.1038/s41598-022-07978-8