Table 1.

Definition of Breast Cancer Cases

Case Type	Definition
Inflammatory breast cancer (IBC)	Morphology: 2001-2015  • ICD-O-3 (converted from ICD-O-2 for 1988-2000) = 8530 “Inflammatory Carcinoma” or Stage: 2001-2015  • AJCC TNM, T = T4d “Inflammatory Carcinoma” or Extent of Disease: 2001-2003 (Historic)  • 70: “Inflammatory carcinoma, including diffuse (beyond that directly overlying the tumor) dermal lymphatic permeation or infiltration.” 2004-2010 (Collaborative Staging)  • 71: “Diagnosis of inflammatory carcinoma WITH a clinical description of inflammation, erythema, edema, peau d’ orange, etc., involving not more than 50% of the skin of the breast, or percent of involvement not stated, WITH or WITHOUT dermal lymphatic infiltration. Inflammatory carcinoma, NOS.”  • 73: “Diagnosis of inflammatory carcinoma WITH a clinical description of inflammation, erythema, edema, peau d’orange, etc., of more than 50% of the breast, WITH or WITHOUT dermal lymphatic infiltration.” 2011-2015 (Collaborative Staging)  • 600: “Diagnosis of inflammatory carcinoma WITH a clinical description of inflammation, erythema, edema, peau d’orange, etc., involving less than one-third (33%) of the skin of the breast, WITH or WITHOUT dermal lymphatic infiltration.”  • 725: “Diagnosis of inflammatory carcinoma WITH a clinical description of inflammation, erythema, edema, peau d’orange, etc., involving one-third (33%) or more but less than or equal to one-half (50%) of the skin of the breast, WITH or WITHOUT dermal lymphatic infiltration.”  • 730: “Diagnosis of inflammatory carcinoma WITH a clinical description of inflammation, erythema, edema, peau d’orange, etc., involving more than one-half (50%) of the skin of the breast, WITH or WITHOUT dermal lymphatic infiltration.”  • 750: “Diagnosis of inflammatory carcinoma WITH a clinical description of inflammation, erythema, edema, peau d’orange, etc., but percent of involvement not stated, WITH or WITHOUT dermal lymphatic infiltration. Diagnosis of inflammatory carcinoma WITHOUT a clinical description of inflammation, erythema, edema, peau d’orange, etc., WITH or WITHOUT dermal lymphatic infiltration. Inflammatory carcinoma, NOS.”  • 780: “Stated as T4d with no other information on extension.”
Non-inflammatory locally advanced breast cancer (LABC)	Stage: 2001-2015 Not an IBC case as defined above and:  • AJCC TNM, T = T4a (extension to the chest wall, not including only pectoralis muscle adherence/invasion), or  • AJCC TNM, T = T4b (ulceration and/or ipsilateral satellite nodules and/or edema (including peau d’orange) of the skin, which do not meet the criteria for inflammatory carcinoma), or  • AJCC TNM, T = T4c (both T4a and T4b)
Other localized breast cancer	SEER Historic Stage A = “localized”
Other regional/distant/unstaged other breast cancer	SEER historic stage A = “regional/distant/unstaged”