Trends in esophageal cancer survival in United States adults from 1973 to 2009: A SEER database analysis

Abstract

Background and aim: The rise in incidence of esophageal cancer (EC) in the USA over the last four decades has been well documented; however, data on trends in long-term survival and impact on modern therapies associated with survival are lacking.

Methods: The Surveillance, Epidemiology, and End Results database was queried to identify patients with confirmed EC. Cox proportional hazard regression was used to determine independent mortality factors.

Results: Of 93 167 patients diagnosed with EC between 1973 and 2009, 49% had a histologic diagnosis of esophageal adenocarcinoma (EAC). There was an increase (almost double) in the proportion of patients with adenocarcinoma from the 1970s to 2000s (n = 2,350; 35% to n = 32,212; 61%, P < 0.001). Surgery was performed for localized disease in a majority of EC regardless of type (n = 46 683; 89%). Use of surgical treatment increased significantly over the study period (49% to 64%, P < 0.001). There was also an increase in overall median survival (6 months versus 10 months, P < 0.001) and 5-year survival rate (9% to 22%, P < 0.001). Median survival increased consistently for EAC and squamous cell carcinoma (SCC) until the 1990s. After this period, median survival of EAC continued to increase more rapidly while SCC remained relatively stable.

Conclusion: A significant survival improvement in esophageal cancer was seen from 1973 to 2009, largely because of earlier detection at a curative stage and greater utilization of treatment modalities (especially surgery). Despite the rising prevalence, patients with EAC have better long-term survival outcomes than those SCC.

Keywords: adenocarcinoma; carcinoma; esophagus; squamous.

Figure 1

Trend graph depicts stage distribution of diagnosed cases with earlier diagnosis at a localized stage increasing over the study period

Figure 2

Trend graph of cancer-directed therapy showing increasing utilization of surgery and radiotherapy over four decades. The p-values reported for trend analysis refers to comparison among all of the four decade quartiles.

Figure 3A

Kaplan-Meier Analysis: Localized EC. Graph shows increasing survival from 1970's to 2000's with largest improvement in survival seen from the 1990's to 2000's. The p-values reported for trend analysis refers to comparison among all of the four decade quartiles.

Figure 3B

Kaplan-Meier Analysis: Regional EC. Graph shows increasing survival from 1970's to 2000's with largest improvement in survival seen from the 1990's to 2000's. The p-values reported for trend analysis refers to comparison among all of the four decade quartiles.

Figure 3C

Kaplan-Meier Analysis: Metastatic EC. Graph shows small but statistically significant increase in survival (4 to 6 months, p=0.01) from 1970's to 2000's. The p-values reported for trend analysis refers to comparison among all of the four decade quartiles.

Figure 4

shows overall better median survival of EAC compared to SCC over four decades. The median survival increased consistently for both EAC and SCC until the 1990's. After this period, the median survival of EAC continued to increase at a more rapid rate while that of SCC has remained relatively stable. The p-values reported for trend analysis refers to comparison among all of the four decade quartiles.

Figure 5

EAC had a better median survival than SCC. The most noticeable increase was seen in Localized disease.