ORLANDO – While esophageal cancer survival rates have improved over the past four decades, the prevalence of adenocarcinoma has also increased significantly, according to an analysis of a national database.
"Our study emphasized the importance of early detection of disease and increased utilization of locoregional therapies," said Dr. Basile Njei of the University of Connecticut, Farmington. He presented his abstract, which is not published, at the annual Digestive Disease Week.
Dr. Njei said that although the rise in the incidence of esophageal cancer in the United States has been well documented, there is a lack of data on trends in long-term survival and prognostic factors associated with esophageal cancer survival.
The authors analyzed the national Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2009. The database included 18 cancer registries representing about 26% of the U.S. population.
The majority of the 93,191 patients included in the analysis were older white males. Patients diagnosed by autopsy or death certificates were excluded.
The number of patients increased from 6,700 in the 1970s to 53,000 in the 2000s. In addition, the median age of patients at baseline increased significantly, from 63 years to 68 years, as did the percentage of white patients, from 74% to 86%, and the rate of adenocarcinoma, from 35% to 61% (P for trend less than .05 for all).
Dr. Njei said that while in the 1990s squamous cell carcinoma (SCC) was the most prevalent type of esophageal cancer, after the 1990s adenocarcinoma became more prevalent. He attributed the rise and fall of the two types of cancer to etiology.
The investigators divided the study population according to histology (adenocarcinoma, AC vs. squamous cell carcinoma, SCC), and by decade of diagnosis. They also analyzed independent predictors of mortality across subgroups. These factors included age, gender, ethnicity, tumor location, stage of disease, and treatment modality.
The results showed that the overall median survival was 9 months. There was a significant increase in overall median survival between the 1970s and the 2000s, from 6 months to 10 months (P less than .001). The overall 5-year survival rate was 15.5%, and there was a significant increase in overall 5-year survival, from 8.1% to 21.3%.
There were also significant improvements in survival for local, regional, and metastatic esophageal cancer during the 40 years, the authors found.
The diagnosis of esophageal cancer at a localized stage increased significantly during the study period, from 11% to 35% (P less than .001).
In addition, there were significant increases in surgical treatment (50% to 64%; P less than .05) and adjuvant radiotherapy (47% to 53%; P less than .05) during the four decades.
Meanwhile, age, sex, tumor histology, stage at diagnosis, node status, adjuvant radiotherapy, and surgery were independently associated with overall survival, the authors reported.
"There’s not much that’s really new in terms of the overall presentation here," said Dr. David C. Metz, professor of medicine at the University of Pennsylvania, Philadelphia. "But it does cement what we’ve been thinking over time, that the shift between squamous cell carcinoma and adenocarcinoma is real, and that we are starting to make an impact in terms of outcome," Dr. Metz said in an interview. "I think there are limitations on how much you can learn from databases, but I think this is a good study."
Although the study had a large sample size and was from a widely validated database, the data are retrospective, there were no chemotherapy data, there is a lead-time and length-time bias, and the findings cannot be generalized to populations in other countries, said Dr. Njei.
Dr. Njei had no disclosures. Dr. Metz is on the advisory committee/review panel for Eisai; has consulted for Novartis, Solesta, Fresenius, and Abbott; and has received grant/research support from Tercica and Lutethera.
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