Please contact the undersigned immediately if you have received this document in error and destroy the original. [...] Interpretation of results: In cancer incidence investigations such as these, we assess four attributes in combination to help us determine whether cancer incidence is changing (and, therefore, what our next steps are): 1) Value of the ISIR The ISIR is the ratio of the number of new cancer cases observed in a geographic area to that which would be expected if the incidence rates for the reference p [...] To interpret the value of the ISIR it is critical to evaluate the location of the 95% confidence interval relative to the number ‘1’. [...] This action is taken if the ISIRs in the most recent time period are not statistically significant, and the ISIRs are not increasing over time. [...] This action is taken if the 95% confidence intervals are narrow and the following applies: the ISIRs in the most recent time period are not statistically significant but there is an increasing trend over time.