J Cancer 2021; 12(6):1575-1582. doi:10.7150/jca.49681 This issue
1. Department of Respiratory Medicine, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
2. Department of Respiratory Medicine, Hwamei Hospital, University of Chinese Academy of Sciences, Ningbo 315010, China.
3. Ningbo Institute of Life and Health Industry, University of Chinese Academy of Sciences,Ningbo 315010, China.
4. Department of Neurology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.
5. Department of Tuberculosis, Pulmonary Hospital, Tongji University School of Medicine, Shanghai 200072, China.
6. Tongji University School of Medicine, Shanghai 200092, China.
7. Department of Cardio-Thoracic Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai200072, China.
8. Department of Interventional and Vascular Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai200072, China.
#These authors contributed equally to this work.
Background: Small cell lung cancer (SCLC) represents about 13% of lung cancer cases, which is highly invasive and has a high mortality rate, with the 5-year overall survival (OS) rate being only 6.3%. Age at diagnosis of advanced SCLC is much older, but studies describing the ageing factor for distant metastasis patterns and prognosis of extensive-stage SCLC (ES-SCLC) are limited.
Methods: Using the Surveillance, Epidemiology, and End Results (SEER) registry, we identified 18,682 patients with ES-SCLC (9,089 women and 9,053 men) who had complete clinical information between 2008 and 2015. Patients were classified into three groups (older group: ≥80 yrs, middle-aged group: 60-79 yrs, and younger group: ≤59 yrs). The role of different age at diagnosis of ES-SCLC (especially older group) in metastasis patterns was investigated, and OS and cancer-specific survival (CSS) of different age groups of metastatic ES-SCLC was assessed.
Results: The most metastasis of ES-SCLC patients in the three groups was multiorgan metastases (MOM) metastasis (71.2%, 70.3% and 66.3%, respectively), the most single organ metastasis in the younger group was the lung (3.3%), the middle-aged group and the older group were the brain (3.5%, 3.1%, respectively). The analysis revealed that older patients were less likely to have MOM, but more likely to have all organs metastases than other two groups (p<0.001). Older group had the worst OS (p<0.001) and CSS (p<0.001). Furthermore, Radiotherapy and chemotherapy can improve survival (p<0.001), but the rate of radiotherapy and chemotherapy in older patients is lower than that in middle-aged and younger patients (50.4% vs 38.6% vs 20.7%, p<0.05). Compared with other two group, older group (odds ratios, ORs) for lung, all organ metastases, and MOM were 0.43 (95% CI 0.27-0.67), 1.77 (95% CI 1.55-2.03), 0.68 (95% CI 0.6-0.77), respectively.
Conclusion: The mortality risk is highest with MOM and all organs metastasis followed by brain, lung, bone and liver metastases in elderly ES-SCLC patients. These results will be helpful for pre-treatment evaluation regarding the prognosis of ES-SCLC patients.
Keywords: age-related, small cell lung cancer, metastasis, survival, prognosis