Incidence Trends and Main Features of Gastro-Intestinal Stromal Tumours in a Mediterranean Region: A Population-Based Study

Abstract

Gastro-Intestinal Stromal Tumours (GISTs) are a kind of neoplasm whose diagnosis in common clinical practice just started in the current century, implying difficulties for proper registration. Staff from the Cancer Registry of Murcia, in southeastern Spain, were commissioned by the EU Joint Action on Rare Cancers into a pilot study addressing GIST registration that also yielded a population-based depiction of GISTs in the region, including survival figures. We examined reports from 2001 to 2015 from hospitals as well as cases already present in the registry. The variables collected were sex, date of diagnosis, age, vital status, primary location, presence of metastases, and risk level according to Joensuu's Classification. In total, 171 cases were found, 54.4% occurred in males, and the mean age value was 65.0 years. The most affected organ was the stomach, with 52.6% of cases. Risk level was determined as "High" for 45.0%, with an increment of lower levels in recent years. Incidence for the year 2015 doubled that of 2001. Overall, the 5-year net survival estimation was 77.0%. The rising incidence magnitude is consistent with trends in other European countries. Survival evolution lacked statistical significance. A more interventional approach in clinical management could explain the increase in the proportion of "Low Risk GISTs" and the first occurrence of "Very Low Risk" in recent years.

Keywords: GIST; cancer; incidence; malignant; population-based; survival.

Figure 1

Standardized Incidence Rate Ratios (SIRs) (and their 95% CI) between subgroups of GIST patients. Subgroups evaluated are Joensuu’s risk level, period of diagnosis, and sex. Reference categories are those with value = 1.

Figure 2

Kaplan–Meier survival curves of OS by sex, age period, level risk, and site group of GIST patients. Because of scarcity of cases, only the two site groups with more incidences and age groups of 40 years and over are presented.