Geospatial heterogeneity of hotspots for incidence and late-stage diagnosis of breast, colorectal, and lung cancer

Purpose Cancer control relies on the identification of populations at risk (hotspots) of new or late-stage cancer diagnoses. However, the extent to which hotspots differ between cancer sites or between outcome measures has been poorly characterized. We sought to determine the geospatial heterogeneity of hotspots of breast, colorectal, and lung cancer incidence and late-stage diagnoses. Methods We identified adult patients diagnosed with female breast, colorectal, and lung cancer between 2010 and 2019 in Indiana. To identify hotspots for incidence and late-stage diagnoses, we disaggregated the patient residential location information from the Census block group level to the approximated individual point level. Statistically significant hotspots were identified with kernel ratio estimation. Total areas of hotspots and overlap between hotspots were compared. Results 117,305 patients diagnosed with breast (n=51,623), colorectal (n=25,160), and lung (n=37,522) cancer were included. Geospatial visualization demonstrated marked spatial deviation, with little overlapping area between incidence and late-stage hotspots for all three cancer sites (32km ² – 165km ² ). However, there was greater overlap in late-stage hotspots between the different cancer sites, with total overlapping hotspot areas ranging from 408km ² – 1046km ² . Conclusions Our results demonstrate considerable geospatial heterogeneity of hotspots between different outcome measures and different sites of cancer. However, there are greater overlapping areas of late-stage hotspots, especially for breast and lung cancer. The use of disaggregated spatial data enables more granular, precise comparison of cancer hotspots. Greater overlap between late-stage breast and lung cancer suggests similar spatial drivers and the potential for coordinated cancer control interventions.