Trends in survival for both histologic types of esophageal cancer in Switzerland

Data from Sweden1 as well as from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program2 indicate an improvement in relative survival rates (RSRs) for patients diagnosed with both adenocarcinoma and squamous cell esophageal cancer over the last 3 decades. To provide further information on the issue, we considered trends in survival by histotype of esophageal cancer for cases diagnosed between 1974 and 1998 from the cancer registries of Vaud and Neuchâtel in the French-speaking part of Switzerland.3, 4 Information on survival has been published only for the Vaud Cancer Registry until 1993 for all esophageal cancers combined. Overall, 5-year relative survival rates increased in males from 0.08 in 1974–8 to 0.10 in 1989–93, and in females from 0.06 to 0.08.5 We decided therefore to consider trends in survival for both histologic types of esophageal cancer to 1998 for the registries of Vaud and Neuchâtel combined. The data were abstracted from the Vaud and Neuchâtel Cancer Registries files, which include incident cases of malignant neoplasms in the cantons, whose populations, according to the December 2000 census, were about 620,300 and 165,700, respectively. Information collected comprises general demographic characteristics of each case (age, sex, municipality of residence), site and histologic type of the tumor according to standard International Classification of Diseases for Oncology (ICD-O)6 and time of diagnostic confirmation. The present report includes 810 squamous cell carcinomas (ICD-O-1 M codes 8070-8076) and 221 adenocarcinomas (ICD-O-1 M 8140-8570) of the esophagus registered from 1974 to 1998.7 Information on survival is integrated from mortality statistics into the incidence data file and, for patients who are apparently alive, through an active follow-up based on verification of vital status from registries of current residence. The vital status of each case has been verified up to 30 December 2002. Relative survival rates were computed after allowance for the general life tables of the cantons. No information was available on tumor stage or treatment. Table I gives the number of registered cases and 1-, 3- and 5-year RSRs in 5 subsequent calendar periods (from 1974–8 to 1994–8) for squamous cell carcinomas, and in 4 calendar periods for adenocarcinomas, due to small absolute numbers in earlier calendar years. For squamous cell cancer, RSRs steadily increased from 25.1% to 46.7% at 1 year, from 7.6% to 19.7% at 3 years and from 5.2% to 13.9% at 5 years. Due to smaller absolute numbers, the pattern was less consistent for adenocarcinomas, but an improvement over calendar years (from 27.7% to 37.0% at 1 year, from 16.4% to 22.2% at 3 years, from 12.9% to 21.0% at 5 years) was observed for adenocarcinomas, too. Thus, the present analyses confirm the existence of appreciable improvements in RSRs for both histologic types of esophageal cancer over the last 3 decades.1, 2 Possible explanations of these findings include earlier diagnosis and detection through wider adoption of endoscopy for squamous cell and also for adenocarcinomas potentially related to Barrett's esophagus and gastroesophageal reflux,8 as well as potential advancements in (surgical) treatment of the disease.9, 10 Yours sincerely, The contribution of the Vaud and Neuchâtel Cancer Registry's staff is gratefully acknowledged. Fabio Levi, Van-Cong Te, Lalao Randimbison, Carlo La Vecchia