Over past decades, scientists have collected a large amount of information on cancer in our society.

Through these efforts, information on types of cancers, characteristics of patients, environmental conditions, types of treatments provided, and survival has been accumulated. Review of this information

has allowed us to identify factors that we believe increase or decrease cancer risk.

This document focuses on cancer in Appalachia. It is a companion to another document titled

‘The Cancer Burden in Appalachia, 2009,’ and it is designed to provide descriptions and explanations

to help clarify technical information. This document is divided into four main sections. The first provides background on cancer risk. The second section focuses on clinical trials. The third describes

cancer in Appalachia, and the fourth reviews important information on different types of cancer that

are commonly diagnosed in Appalachia.

Understanding Cancer Risk

Cancer risk is the chance of developing cancer over a certain time period, such as within the next 10 years, or during a lifetime.

A person’s cancer risk can be estimated based on a combination of their behavioral, environmental, biological and genetic factors. In this report, incidence rates are used to represent the cancer burden of Appalachian residents (as well as non-Appalachian

residents).

Incidence and Mortality Rates

Incidence (new cancers) and mortality rates (cancer deaths) provide a useful way to measure the cancer burden in any size population. Rates can be used to compare demographic groups (e.g., males have higher colorectal cancer incidence rates than females),

race/ethnic groups (e.g., African American males have higher prostate cancer mortality rates than white males), or geographic

areas (e.g., Appalachian females have a higher cervical cancer mortality rate than non-Appalachian females). The cancer rates in

this document represent the number of new cancer cases and new cancer deaths per 100,000 population during a year. Incidence

and mortality rates are calculated using invasive cancers only, with the addition of in situ urinary bladder cancers. Cancers that are

invasive have spread beyond the layer of tissue in which the tumor began growing.

The number of cancers diagnosed in a specific part of the population or geographic area can be determined from a rate if the

population is known. For example, if a county’s average annual lung cancer incidence rate is 40.0 per 100,000, this means an

average of 40 new cases of lung cancer were diagnosed in the county per year for every 100,000 people.

Five-year Relative Survival

Five-year relative survival is a measure of survival that is calculated by comparing the observed survival of a group of people diagnosed with cancer with the expected survival from a comparable set of people who do not have cancer. Five-year relative survival

measures the excess mortality resulting from the cancer diagnosis. Five-year survival rates are useful for many reasons including:

comparing the effects of treatments and comparing the survival of different groups of people.