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the treatments to specific subtypes of cancer, control of symptoms resulting from treatment, and palliation of advanced breast cancer. Nevertheless, most breast cancer patients, even some diagnosed with early stage disease, must endure surgery, chemotherapy, radiation therapy, and multiyear courses of hormone therapy, each with attendant physical, psychological, and social costs.a Survivors continue to experience the consequences of the disease years beyond the initial diagnosis. These consequences include risk of recurrence and new primary cancers, long-term physical and psychological effects of the treatment and disease Survivors experience physical and psychological consequences of the disease and require long-term medical monitoring. 3.5 Survival, Recurrence, and Second Breast Cancers Relative survival is a way of comparing the survival of people in the general population who have a specific disease with those who do not. The percentage of survivors is usually determined at specific times, such as 5 years after diagnosis or treatment. The relative survival rate shows whether the disease shortens life. Five-year relative survival from breast cancer is 90 percent for women diagnosed in the years 2002 to 2008. Survival, however, depends on the stage at diagnosis. Sixty percent of invasive breast cancers are localized (confined to the breast), 33 percent are regional, and 5 percent are metastatic when they are diagnosed. When cancer is confined to the breast, the 5-year relative survival is 98.4 percent. When breast cancer has metastasized (spread) to other organs, however, the 5-year relative survival is only 23.8 percent.33 Even if they survive for 5 years after diagnosis, breast cancer patients continue to be at risk of breast cancer recurrence and of developing cancer in the opposite breast.34 Cancer recurrence is defined as cancer that has returned, usually after a period of time during which the cancer could not be detected. The cancer recurs because not all of the breast cancer cells present in the body were completely eradicated by the therapies used to treat the cancer. It may come back in the same place as the original breast tumor or to another place in the body to which it spread from the primary site. One national study of women with breast cancer diagnosed at ages 65 through 80 found that the cancer recurred in 36.8 percent of these cases over 10 years.35 The rate of breast cancer recurrence varies by breast cancer subtype, stage at diagnosis of the first primary cancer, treatment, and the screening modality used to identify the recurrence.36-38 Women with specific tumor subtypes, such as HER2+ and TNBC, are more likely to experience a recurrence.39, 40 a Breast Cancer and the Environment: Prioritizing Prevention 3 countries, but continue to increase in many parts of the world. Incidence rates in Asia and Africa have seen dramatic increases in recent years, which have been attributed to changes in reproductive patterns, increased obesity, decreased physical activity, and limited increases in screening rates. Mortality from breast cancer in most of the developed countries has remained stable or decreased slightly during the past 25 years, primarily due to earlier detection and improvements in treatments. Breast cancer death rates continue to increase in the rest of the world, probably due to the increased incidence of breast cancer in developing countries.55 The percent of women surviving breast cancer ranges from 73 percent in all developed countries, with a high of 81 percent in the United States, to 57 percent in all developing areas, with a low of 32 percent in SubSaharan Africa.56 3.8 The Importance of Surveillance in Monitoring the Cancer Burden The United States has a nationwide cancer surveillance system and several other surveillance systems that that collect demographic, health behavior, and other data needed to measure the cancer burden and identify factors that may affect that burden. These surveillance systems are described in Chapter 7. Research on breast cancer and the environment would benefit from a national cancer surveillance system that provides more detail about cancer subtypes and is linked to more sociodemographic, economic, environmental, and geographic data. A major gap in the U.S. cancer surveillance system is that recurrence data are not collected routinely. Improved methods for monitoring the global burden of cancer also are needed, as existing data indicate increasing rates of breast cancer with global modernization and suggest that the global burden of breast cancer will grow substantially. Scientists will need to monitor the global changes in the burden of this disease and conduct studies to rapidly ascertain the causes. and, for many survivors, long-term or life-long treatment and increased medical screening and monitoring.47 Late physical effects of treatment are common and can include cardiotoxicity,48 lymphedema,49 and fertility concerns.50 Psychological consequences of breast cancer can include psychosocial distress and depression.51 The most recent projected 2012 national cost of cancer care for breast cancer was $17.35 billion.52 These costs are only a small part of the overall social, economic, and medical burden of breast cancer. Despite declines in mortality, the economic value of