Survival Trends of Metastatic Lung Cancer in California by Age at Diagnosis, Gender, Race/Ethnicity, and Histology, 1990-2014

Abstract

Background: We analyzed the survival trends for patients with metastatic lung cancer in California.

Materials and methods: We identified patients first diagnosed with primary lung cancer at distant (metastatic) stage in the California Cancer Registry between 1990 and 2014, with follow-up through end of 2015. Race/ethnicity was categorized into non-Hispanic white, non-Hispanic black, Hispanic, and Asian/Pacific Islander. One-year and 5-year relative survival rates were calculated overall and by age at diagnosis, gender, race/ethnicity, and histology during the study period. Joinpoint regression was used to evaluate the trends and to calculate the annual percentage changes (APCs).

Results: A total of 186,156 adults were identified for analysis. Between 1990 and 2014, 1-year relative survival significantly improved from 18.4% to 29.4%, with most improvement observed between 1993 and 2012 (APC, 2.60%; 95% confidence interval, 2.41-2.79; P < .01). Five-year relative survival significantly improved from 2.2% to 5.0%, with an APC of 4.05% (95% confidence interval, 3.47-4.64; P < .01). All age groups experienced an improvement in survival rates. The greatest increases in relative survival were observed among females, Asian/Pacific Islanders, and patients with adenocarcinoma. Yearly survival rates increased for all histologic types over the study period, with adenocarcinoma having the most improvement after 2000.

Conclusions: Survival for patients with metastatic lung cancer in California steadily improved during the 1990 to 2014 period, before the era of lung cancer screening and cancer immunotherapy. The greatest increase in relative survival was observed in those patients who have the most clinical benefit from the history- and biomarker-based precision oncology drugs during the study period.

Keywords: Annual percentage change; California Cancer Registry; Lung cancer; Metastatic; Relative survival rate.

Figure 1.. Trends in one-year survival rates in patients with metastatic lung cancer in California, 1990 to 2014.

One-year survival rates and prominent APCs for all lung cancer types combined (A) and by age (B), sex (C), race/ethnicity (D), and histology (E) between 1990 and 2014 are illustrated. Abbreviation: APC, annual percent change.

Figure 2.. Trends in yearly cancer specific survival rates by lung cancer types in California, 1990 to 2014.

The 1-year, 2-year, 3-year, 4-year and 5-year overall survival rates of all lung cancer cases (A), SCLC (B), LUSC (C), and LUAD (D) in consecutive five-year periods between 1990 and 2014 are illustrated. Furthermore, the 1-year, 2-year, 3-year, 4-year and 5-year overall survival rates of each subtype and all lung cancer combined in the 1990–1994 and 2005–2009 periods are showed in (E) and (F), respectively. Red stars highlight the trends with significant changes in (D) and (F).

Figure 3.. The chronological milestones for metastatic lung cancer.

Over the past 3 decades, many advances have contributed to the improved overall survival for patients with metastatic lung cancer, which includes first line platinum-based combination chemotherapy, second line single agent chemotherapy or unselected molecularly targeted therapy, histology-directed chemotherapy and tumor genotyping for molecular biomarkers, first- and second-generation molecularly targeted therapies in the United States. Notably, patients with metastatic LUAD benefited most from these therapeutic advances. The first generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib was approved in 2004[40], bevacizumab in combination with carboplatin and paclitaxel chemotherapy for the first-line treatment of patients with unresectable, locally advanced, recurrent or metastatic non-squamous NSCLC in October 2006 [36, 41], pemetrexed for non-squamous NSCLC in September 2008 [42], first generation TKI crizotinib for anaplastic lymphoma kinase (ALK)-rearranged tumors 2011 [43], and second generation EGFR TKI afatinib was approved in 2013[44] during the 1990–2014 study period. Patients with LUSC benefited from the docetaxel in 2000 and gemcitabine-containing regimen in 2008 [42]. Abbreviations: SCLC, small cell lung cancer; NSCLC, non-small cell lung cancer; LUSC, squamous cell lung cancer; Non-LUSC, non-squamous cell lung cancer; LUAD, lung adenocarcinoma; LCC, large cell carcinoma.