A story map presented by geodesy, inc.

A collaborative effort by:

• John Cassels, Geo-Spatial Analyst, GEODESY, INC. 
• Andrew F. Olshan, Ph.D., Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina
• Marlana Orloff, MD, Department of Medical Oncology, Thomas Jefferson University Hospital
• Takami Sato, MD, PhD, Metastatic Uveal Melanoma Program, Jefferson Medical College
• Michael Brennan, MD, Retired Ophthalmologist

INTRODUCTION

The National Institute of Health Cancer Institute identifies a cancer cluster as. “the occurrence of a greater than expected number of cancer cases among a group of people in a defined geographic area over a specific time period”. Most suspected cancer clusters turn out, on detailed investigation, not to be true cancer clusters. That is, no cause can be identified, and the clustering of cases turns out to be a random occurrence. Cluster investigations are inherently difficult to study epidemiologically and statistically. 

This investigation is not trying to determine whether this is a cluster or not. It is recognized as an extremely unusual coincidental occurrence of a rare cancer in a very unusual demographic population (young women). This investigation is looking for environmental issues, near of the patient population, which have been documented in scientific literature to have possible associations with uveal melanoma cases.  

When medical professionals first noticed the coincidental occurrence of a rare cancer in North Carolina, the focus was on the four young women who lived near or attended Hopewell High School in Huntersville.  In April 2014, the North Carolina Division of Public Health's Occupational and Environmental Epidemiology Branch (OEEB) initiated an epidemiological investigation.  They included 8 cases of ocular melanoma diagnosed between 2009 and 2014 who lived in, work in, or frequently visited Huntersville prior to diagnosis.  OEEB staff not were able to identify any common environmental exposures specific to the Huntersville area that were likely to be associated with ocular melanoma.  They noted that the American Cancer Society recommends limiting exposure to intense sunlight, covering up with protective hats and clothing, using sunscreen, and wearing UV-protective sunglasses (UVA and UVB) when outside in strong sunlight.

The North Carolina Legislative Branch through the Department of Health and Human Services awarded the Huntersville Town Council $100,000 grant to further study the situation.  In 2016, a Phase I Environmental Site Assessment of the school property was performed by Hart & Hickman, PC (H&H). The assessment "revealed no recognized environmental conditions (RECs) in connection with this property".  However, the Town Council requested that samples be taken anyway.  After additional literature searches into chemical contaminants which could cause the outcome, H&H advised the Council that based on their review, they could not provide a list of chemicals for soil sample analysis.  In the absence of target chemicals, a soil testing work plan could not be prepared, and no soil sampling or other media testing was advised, based on currently available information.  It was then decided to conduct a geospatial investigation in hope of uncovering other details that might lead to further recommendations.

The term Geospatial can be thought of as the science of where.  Spatial analysis allows us to study complex location-oriented problems and better understand where and what is occurring in our world. It goes beyond mere mapping to let us understand the characteristics of places and the relationships between them. Spatial analysis lends new perspectives to decision-making. 

In this investigation we asked the patients or their surviving relatives to tell us where they spent their time in the Huntersville area.  When we add the time frame for which those locations were occupied, we can look for correlations in both space and time.  Once this information is compiled we can start to look for spatial and temporal patterns. Emerging hot spots will help us focus on environmental features which may lead us to recommendation for further study.