An official website of the United States government

SEER*Explorer

Cancer Sites

The cancer sites available in SEER*Explorer are primarily defined using the SEER Site Recode ICD-O-3/WHO 2008 variable. However, there are additional sites included that are defined below and are based on specific behaviors and/or histologies, and only valid for specific years.
All definitions below include Malignant Behavior only unless noted.

Special Cancer Site Definitions

Chronic Myelomonocytic Leukemia (CMML)
  • Only valid for diagnosis years 2001+
  • ICD-O-3 Histology (Type) = 9945

Chronic myeloproliferative disorders (CMD)
  • Only valid for diagnosis years 2001+
  • ICD-O-3 Histology (Type) = 9950-9964

Myelodysplastic syndromes (MDS)
  • Only valid for diagnosis years 2001+
  • ICD-O-3 Histology (Type) = 9980-9989

Cancer Subtype Definitions for SEER*Explorer

Brain and Other Nervous System Cancer


Diffuse Astrocytoma and Anaplastic Astrocytoma of the Brain and ONS 
  • SEER Brain and CNS Recode = 1.1.1

Glioblastoma of the Brain and ONS
  • SEER Brain and CNS Recode = 1.1.2

Other Glioma of the Brain and ONS 
  • SEER Brain and CNS Recode = 1.1.3-1.1.10

Embryonal Tumors of the Brain and ONS
  • SEER Brain and CNS Recode = 1.2

Meningioma of the Brain and ONS 
  • SEER Brain and CNS Recode = 1.3

Other Tumors of Brain and ONS
  • SEER Brain and CNS Recode = 1.4-1.6

Non-Malignant Brain and Other Nervous System
  • Only valid for years of diagnosis 2004+
  • Site recode ICD-O-3/WHO 2008 = Brain and Other Nervous System
  • Behavior code ICD-O-3 = Benign or Borderline malignancy

Non-malignant Meningioma of the Brain and ONS 
  • Only valid for years of diagnosis 2004+
  • SEER Brain and CNS Recode = 2.1

Non-malignant Tumors of the Cranial and Paraspinal Nerves
  • Only valid for years of diagnosis 2004+
  • SEER Brain and CNS Recode = 2.2

Refer to the documentation for Brain/CNS Recode

Breast Cancer


HR+/HER2+ Breast Cancer
  • Site recode ICD-O-3/WHO 2008 = Breast
  • Breast Subtype (2010+) = Her2+/HR+

HR-/HER2+ Breast Cancer
  • Site recode ICD-O-3/WHO 2008 = Breast
  • Breast Subtype (2010+) = Her2+/HR-

HR+/HER2- Breast Cancer
  • Site recode ICD-O-3/WHO 2008 = Breast
  • Breast Subtype (2010+) = Her2-/HR+

HR-/HER2- Breast Cancer
  • Site recode ICD-O-3/WHO 2008 = Breast
  • Breast Subtype (2010+) = Triple Negative

Refer to the documentation for Breast Subtype (2010+)

Esophagus Cancer


Adenocarcinoma of the Esophagus 
  • Site recode ICD-O-3/WHO 2008 = Esophagus
  • ICD-O-3 Histology (Type) = 8140-8573
  • Diagnostic Confirmation = Microscopically confirmed

Squamous Cell Carcinoma of the Esophagus
  • Site recode ICD-O-3/WHO 2008 = Esophagus
  • ICD-O-3 Histology (Type) = 8050-8082
  • Diagnostic Confirmation = Microscopically confirmed

Lung & Bronchus


Adenocarcinoma of the Lung and Bronchus
  • Site recode ICD-O-3/WHO 2008 = Lung and Bronchus
  • ICD-O-3 Histology (Type) = 8015, 8050, 8140, 8141, 8143, 8144, 8145, 8147, 8190, 8201, 8211, 8250, 8251, 8252, 8253, 8254, 8255, 8260, 8290, 8310, 8320, 8323, 8333, 8401, 8440, 8470, 8471, 8480, 8481, 8490, 8503, 8507, 8550, 8570, 8571, 8572, 8574, 8576
  • Diagnostic Confirmation = Microscopically confirmed

Small cell carcinoma of the Lung and Bronchus
  • Site recode ICD-O-3/WHO 2008 = Lung and Bronchus
  • ICD-O-3 Histology (Type) = 8002, 8041, 8042, 8043, 8044, 8045
  • Diagnostic Confirmation = Microscopically confirmed

Squamous Cell Carcinoma of the Lung and Bronchus
  • Site recode ICD-O-3/WHO 2008 = Lung and Bronchus
  • ICD-O-3 Histology (Type) = 8051, 8052, 8070, 8071, 8072, 8073, 8074, 8075, 8076, 8078, 8083, 8084, 8090, 8094, 8120, 8123
  • Diagnostic Confirmation = Microscopically confirmed

Large Cell Carcinoma of the Lung and Bronchus
  • Site recode ICD-O-3/WHO 2008 = Lung and Bronchus
  • ICD-O-3 Histology (Type) = 8012, 8013, 8014, 8021, 8034, 8082
  • Diagnostic Confirmation = Microscopically confirmed

Thyroid


Papillary Subtype of the Thyroid
  • Site recode ICD-O-3/WHO 2008 = Thyroid
  • ICD-O-3 Histology (Type) = 8050, 8052, 8260, 8340, 8341, 8342, 8343, 8344
  • Diagnostic Confirmation = Microscopically confirmed

Follicular Subtype of the Thyroid 
  • Site recode ICD-O-3/WHO 2008 = Thyroid
  • ICD-O-3 Histology (Type) = 8290, 8330, 8331, 8332, 8335
  • Diagnostic Confirmation = Microscopically confirmed