Breast Schema for 1988-2015 based on AJCC 6th edition

• T0: Cases with no primary found but either distant mets or regional/distant positive nodes.
• EOD: T0 was not a separate category. Cases with no primary but either distant mets or regional/distant positive nodes would have been coded to TX. Cases with distant mets in extension were moved to the T with mets category.
• CS: T0 cases with distant mets excluding nodes were moved to T with Mets. The T0 cases remaining have regional/distant lymph nodes involved.
• T0 with positive N: no cases for EOD and small number of cases for CS.

• Paget disease with no underlying tumor is considered Tis in AJCC but is considered malignant (/3) in ICD-O-3 unless specified as in situ Paget disease.
• For Paget disease with an underlying in situ tumor:
• EOD: The T value is assigned based on size and would not be assigned to Tis.
• CS: Tis

• The term T1mic was used in AJCC 6th and T1mi in AJCC 7th. Since they both have the same definition, we chose to only use T1mi for both.

• CS: Additional size categories to capture non-specific size information such as “Described as less than 2 cm” and the result is that a few more cases may have a T in CS rather than EOD. This applies to several T categories.

• CS: In case the only information in the medical record is a “T1” and there is no size information, then a T1NOS was assigned in derived AJCC 6th ed. T. These cases are included with T1c for 2004-2015, which had the largest number of cases in the T1 subcategories.

• CS: Besides tumors based on size alone, it also includes size categories 993-995.

• In addition to more than 5 cm, it includes breast cancers labeled as diffuse.

• In case the only information available is a “T4” in the record, then the record is assigned a T4NOS code in Derived AJCC 6th T. But for this Adjusted T variable, these cases are included with T4b for 2004-2015, which had the largest number of cases in the T4 subcategories.
• Additional information is available in CS for the percentage of skin involvement, but the definition of T4b is the same.

• Additional information is available in CS for the percentage of skin involvement, but the percentage is not necessary to derive T4c.

• Additional information is available in CS for the percentage of skin involvement with a diagnosis of inflammatory.
• Per AJCC 6th edition, inflammatory carcinoma is a clinicopathologic entity characterized by diffuse erythema and edema of the breast and involves over one-half of the breast.
• EOD: The specific percentage of skin involvement was not collected in EOD. EOD also included cases where there was diffuse, dermal lymphatic permeation or infiltration as inflammatory carcinoma and CS did not.
• CS: The derivation of T4d was broadened to include all cases documented in the medical record as inflammatory.

• There is a decrease in the percentage of cases which map to TX over time. Whenever there is a percentage decrease in one category there will be a compensating in increase in one or more other categories.
• TX cases with distant mets were moved to T with Mets category see definition below.
• TX Adjusted is a combination of TX plus all unstaged cases. For the unstaged cases, there was a disconnect between EOD and CS cases in that CS cases could have a known T and N with an MX, whereas, EOD cases had to have at least one unknown (TX or NX). Another way to look at it, is that for CS (2004-2015), MX was coded independent of the T value and N value.
• The T categories (T0, T1, T2, etc.) don’t exist for cases that stage to unknown or the M1 equivalent to stage usually Stage IV.

• EOD: Distant mets except distant nodes were collected in extension and derived a TX, M1.
• CS: Code for extension (T) is independent of distant mets (M). ‘T with Mets’ is not a recognized derived T for AJCC 6th ed. Separating T with Mets from the specific T categories does not affect stage because they are all stage IV cases by virtue of the M1.
• Impact: If the individual T codes remained in the different T categories, the frequencies of the individual T codes would show a sharp jump in 2004 due to the T code being coded independently for the M1 cases under CS.
• To equate the two systems, all EOD cases with extension codes that derived M1 and CS cases with Mets at Dx code positive for mets (except distant nodes), were defined as ‘T with Mets’.

• Not an AJCC category but designates the histologies that AJCC does not stage.

• EOD: only N0 category collected.
• CS: In AJCC 6th edition, subcategories for N0 were added to indicate positive IHC or molecular findings and are coded in CS site specific factors (SSF). Since all subcategories of N0 in AJCC 6th stage the same, they were collapsed to N0.
• SSF 4 and SSF 5 were introduced in CS to collect the IHC or molecular findings on negative lymph nodes to assign the N0 subcategories.
• There is a dramatic increase in N0 due to the decrease in NX between 2003 and 2004 and a smaller decrease over the entire time period. See NX for further details.

• For both includes cases with a microfocus in addition to those specified as less than or equal to 2 mm.

• EOD: only N1 category collected
• CS: In the AJCC 6th edition, subcategories for N1 were added and are coded in CS. All subcategories of N1 in AJCC 6th stage the same, so they were collapsed to N1.

• EOD: only N2 category collected. Information did not include the clinical and pathologic evaluation.
• CS: In the AJCC 6th edition, subcategories for N2 were added and are coded in CS. All subcategories of N2 in AJCC 6th stage the same, so they were collapsed to N2.

• EOD: The supraclavicular lymph nodes are grouped in the same code as distant lymph nodes. Therefore, the supraclavicular lymph nodes and all of the distant lymph nodes have to be in the same category: either N3 or M1 even though in AJCC 6th the supraclavicular nodes are N3 and the rest of the distant lymph nodes are M1. Infraclavicular are grouped with the regional nodes and can’t be separated from the regional nodes. N3 will not include cases with infraclavicular nodes and they would instead be N1 or N2 unless there were some other criteria such as 10+ regional nodes involved to bump it to an N3.
• CS: N3 has three components in AJCC 6th edition: Infraclavicular nodes, Supraclavicular nodes, and 10 or more nodes involved. In addition, internal mammary nodes plus positive axillary lymph nodes were coded separately, whereas in EOD the internal mammary nodes would override the positive axillary lymph nodes and be coded as N2.
• In AJCC 6th, there are definitions based on sentinel node biopsy with or without axillary node dissection. This information is not in EOD. In CS the count of the lymph nodes positive is limited to axillary regional nodes level I/II whereas for EOD, the positive lymph nodes would be based on any regional nodes including infraclavicular and level III nodes.
• In order that the N3 category is as similar over time as possible, all distant nodes were moved to N3 for CS. Therefore this N3 code includes all distant lymph nodes and is different from the definition in AJCC 6th edition

• The data show a dramatic decrease in the NX category over time and between 2003 and 2004. While a particular rule change between EOD and CS is not evident, there are some differences in NX between 2003 and 2004. NX Adjusted is a combination of NX plus all unstaged cases. For the unstaged cases, there was a disconnect between EOD and CS cases in that CS cases could have a known T and N with an MX, whereas, EOD cases had to have at least one unknown (TX or NX). Another way to look at it, is that for CS (2004-2015), MX was coded independent of the T value and N value.
• The increase of sentinel lymph node biopsies may have contributed to the overall decrease in NX over time.

• EOD: Distant lymph nodes were moved to N3 and no cases will derive to ’N with Mets’
• CS: Distant lymph nodes were moved to N3 and no cases will derive to Any N, Mets.
• Therefore, there are no cases for this category.

• Not an AJCC category but designates the histologies that AJCC does not stage.

• Recording ‘no distant metastases’ have changed over time leading to a steady increase in M0 and subsequent decrease in MX, which has resulted in more cases being staged.
• These changes cannot be totally resolved between EOD and CS. Caution is advised when comparing M0 and MX over time.
• Distant mets coded to unknown: in AJCC 7th, treated as M0 and in AJCC 6th treated as MX.
• Due to the change in AJCC 7th to handle MX as M0, some registrars and medical professionals may no longer make the distinction between MX and M0 and record that there are no mets automatically assigning a M0, which affects the staging for AJCC 6th.

• All distant lymph nodes from EOD and CS have now been moved to N3. In CS, if the only distant mets were distant lymph nodes, the case is N3 and M0. In CS, if there were distant lymph nodes and mets, the case is N3 and M1.

• The definition of MX did change for CS in that under CS, MX can be coded independent of the values for T and N but for EOD it is dependent on those values One possible reason for decrease in MX is the realization that in the next version of AJCC, there isn’t an MX category.
• See M0 for additional information about the decline in MX.

• Not an AJCC category but designates the histologies that AJCC does not stage.

• EOD: The total number of positive regional lymph nodes was coded in Regional nodes positive and is included in the algorithm to compute the N category. This includes axillary, intramammary, infraclavicular, and internal mammary lymph nodes.
• CS: SSF 3 collects the number of positive AXILLARY lymph nodes instead of the total number of positive regional lymph nodes. The number of regional nodes positive is still collected but may be larger than the number recorded in SSF 3. SSF 3 is included in the algorithm to compute the N category.
• Some EOD cases will have a higher N than they should since the information wasn’t limited to axillary nodes in comparison to CS cases.

Distant lymph node(s):
    Cervical, NOS
    Contralateral/bilateral axillary and/or internal mammary
    Other than above

Distant lymph node(s), NOS