Different distant metastasis patterns based on tumor size could be found in extensive-stage small cell lung cancer patients: a large, population-based SEER study

Abstract

Background Small-cell lung cancer (SCLC) is a malignant cancer with the ability to metastasize quickly. The relationship between tumor size and the distant metastasis patterns of Extensive-Stage Small Cell Lung Cancer (ES-SCLC) has not been reported.ObjectivesThe aim of this study was to determine the different distant metastasis patterns as they related to tumor size in ES-SCLC.Patients and MethodsWe used Surveillance, Epidemiology, and End Results (SEER) population-based data collected from 2010 through 2013 to identify 11058 ES-SCLC patients with definite evidence of distant metastases. Multivariate logistic regression analysis was used to demonstrate the association between tumor size and distant metastasis patterns including bone, liver, brain, and lung metastases. Age, race, sex, and N stage were also selected in the logistic regression model.ResultsSubtle differences in metastasis patterns were found among patients based on different tumor sizes. Patients with tumors 3–7 cm have a higher risk of bone metastasis compared with those that have tumors ≤3 cm (OR 1.165, 95% CI [1.055–1.287], P = 0.003) and patients with tumors ≥7 cm have a higher risk of lung metastasis (OR 1.183, 95% CI [1.039–1.347], P = 0.011). In addition, patients with tumors ≥7 cm had a lower risk of brain metastasis and liver metastasis than patients with tumors ≤3 cm (OR 0.799, 95% CI [0.709–0.901], P < 0.001; OR 0.747, 95% CI [0.672–0.830], P < 0.001). Interestingly, there was no correlation between a larger tumor and a higher risk of metastasis. However, the tumor metastasis pattern did have some correlation with age, gender, race and N-status.ConclusionThe pattern of distant metastasis of ES-SCLC is related to the tumor size and the tumor size is indicative of the metastatic site. Larger tumor sizes did not correlate with a higher risk of distant metastasis, but the size is related to the pattern of distant metastasis. The study of different distant metastasis patterns based on tumor size and other clinical features (e.g., age, race, sex, and N stage) in ES-SCLC is clinically valuable.

Association of Race, Socioeconomic Factors, and Treatment Characteristics With Overall Survival in Patients With Limited-Stage Small Cell Lung Cancer

“…8 , 15 , 16 Notably, most of these studies were limited by institutional experiences or statewide databases and mainly focused on NSCLC and extensive-stage SCLC. 17 , 18 , 19 As a result, the validity of race, among other factors, for limited-stage (stages I-III) SCLC (L-SCLC) is not well understood. Unlike extensive-stage SCLC, which is incurable and primarily treated with systemic chemotherapy with or without immunotherapy, L-SCLC is potentially curable and treated primarily with concurrent chemoradiotherapy or surgery followed by adjuvant chemotherapy.…”

Efficacy and safety of PD‐1/PD‐L1 inhibitor plus chemotherapy versus chemotherapy alone as first‐line treatment for extensive‐stage small cell lung cancer: A systematic review and meta‐analysis

“…Approximately 10%-25.8% of patients with SCLC at diagnosis had symptomatic or asymptomatic brain metastases. [26][27][28][29][30] The effects of chemotherapy in patients with brain metastasis are limited, and whole brain radiotherapy is the current therapeutic model for SCLC with brain metastasis. Recently, a Phase II study reported the preliminary efficacy of pembrolizumab for patients with NSCLC with untreated brain metastases.…”

“…In total, 20.3%-44.8% of SCLC patients presented with liver metastases at the time of diagnosis. 30,32,33 It has previously been reported that the one-year survival rate of SCLC patients with liver metastasis is less than 20%. 33 In the KEYNOTE-189 study (2019 AACR), pembrolizumab plus chemotherapy improved PFS and OS in nonsquamous NSCLC patients with liver metastases unlike chemotherapy alone.…”

“…Brain metastasis is associated with a poor SCLC prognosis. Approximately 10%–25.8% of patients with SCLC at diagnosis had symptomatic or asymptomatic brain metastases 26–30 . The effects of chemotherapy in patients with brain metastasis are limited, and whole brain radiotherapy is the current therapeutic model for SCLC with brain metastasis.…”

“…Another factor affecting the prognosis of SCLC is liver metastasis. In total, 20.3%–44.8% of SCLC patients presented with liver metastases at the time of diagnosis 30,32,33 . It has previously been reported that the one‐year survival rate of SCLC patients with liver metastasis is less than 20% 33 .…”