ASCO GI Coverage: Study Finds Tumor Characteristics Correlate With Survival in Stomach, Esophageal Cancers

An analysis of the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) database showed that advanced gastric or esophageal cancer confers a poor prognosis, although outcomes varied by stage at diagnosis, location, and histologic subtype.

The study helps shed light on an area where data are limited and provides insights that researchers can use when designing clinical development programs and interpreting results. Lisa Wang, PhD, an epidemiologist at Genentech in South San Francisco, California, and colleagues reported that during 2004 to 2006, more than 15,500 newly diagnosed cases of gastric cancer and more than 9800 cases of esophageal cancer were entered into the SEER registry. For gastric cancer, the stages at diagnosis were stage I (24%), stage II (11%), stage IIIa (9%), stage IIIb/ IV (41%), and unknown (15%). For esophageal cancers, the stages at diagnosis were stage I (17%), stage II (16%), stage III (17%), stage IV (31%), and unknown (19%). The distribution of stomach cancer was cardia (29%) and noncardia/ other (71%). Histology was diffuse (24%), intestinal (66%), and other (10%).

More than half (58%) of esophageal cancers occurred in the upper esophagus, upper/ middle (26%), overlapping (5%), and not otherwise specified (10%). Histologic subtype was adenocarcinoma (57%), squamous cell (34%), and other (9%).

Median survival in patients with gastric cancer ranged from 25 months for stage I/II cardia to 7 months and 4 months for stage IIIb/IV cardia and noncardia, respectively. Analysis by histologic subtype showed a median survival of 15 months for stage IIa diffuse disease and 6 months for stage IIIb/IV. The range for intestinal disease was 32 months for stage I/II, 15 months for stage IIIa, and 5 months for stage IIIb/IV.

Among patients with esophageal cancer, median overall survival was 11 months for adenocarcinoma and 9 months for squamouscell histology. Separated by stage, median survival was 19 months for stage I/III adenocarcinoma and 13 months for squamous cell. Patients with stage IV disease at diagnosis had a median survival of 5 to 6 months, regardless of histology.

In their conclusion, Wang and colleagues noted that a better understanding of survival, stage, and patient/tumor characteristics might provide needed context for developing and optimizing therapies for these diseases.

________________________________________________________

Wang L, Chu L, Shing M, Dong W. Survival by anatomic site, histologic type, and tumor stage in stomach and esophageal cancer patients from the US SEER Cancer Registry. Paper presented at: 2011 Gastrointestinal Cancers Symposium; January 2011; San Francisco, CA.

Published in Oncology & Biotech News. February 2011.