Breast Schema for 1988+ based on AJCC 6th edition

The following adjusted variables are available for the Breast Schema for 1988+ based on AJCC 6th edition. These adjusted variables are based on EOD (1988-2003) and CS (2004+)

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Overall Assumptions

  • The changes to the Adjusted T, N, M do not affect stage except for the move of the distant lymph nodes to N3 rather than M1. That is, the derived AJCC 6th stage should be the same as the Adjusted AJCC 6th except for combinations with distant nodes.
  • Stage 0 includes more than just in situ tumors. It also includes Paget disease with no underlying tumor or an in situ underlying tumor. If malignant cases are chosen, there still may remain some Stage 0 cases since Paget disease is considered malignant in ICD-O-3.
  • NA is not an AJCC stage category. It is used as a placeholder to eliminate histologies that AJCC does not stage.
  • For the T category, Tumor Size is the primary measure used for T1, T2 and T3 breast tumors confined to the breast or pectoral fascia. CS has additional 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.
  • Subcategories for N0, N1, N2 and N3 were available in the derived AJCC 6th N code but for comparability to EOD data, the subcategories may have been folded into the main N categories N0, N1, N2 and N3.
  • NX Adjusted: one of the contributing factors to the decrease in NX Adjustedmay be the increased use of sentinel lymph node biopsies.

Breast - Adjusted AJCC 6th Stage (1988+) Variable

For the definitions of each stage, see AJCC 6th edition or the CS website: http://web2.facs.org/cstage0204/breast/Breast_qad.htmlExternal Web Site Policy

Value Comments
Stage 0 See discussion on Tis.
Stage I  
Stage IIA T0 N1 M0 is missing for EOD and included for CS; this affects a very small number of cases.
Stage IIB  
Stage IIINOS Not an AJCC stage but a placeholder in that there is enough information to know that it is stage III but not enough information to code to the specific sub-group. This group is not consistent between EOD and CS.
Stage IIIA T0 N2 M0 is missing for EOD and included for CS; this affects a very small number of cases.
Stage IIIB  
Stage IIIC Artificial increase in IIIC due to distant nodes (M1) moved to N3 (Stage IIIC when no other mets) for consistency with EOD over time.
Stage IV Stage IV will be slightly lower than the derived AJCC 6th ed stage since all of the distant lymph nodes were moved to N3 for consistency with EOD over time.
NA Not an AJCC category but designates the histologies that AJCC does not stage. For example, sarcomas are excluded.
Unk Stage Cases that do not have enough information to be staged.

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Breast - Adjusted AJCC 6 T (1988+) Variable

For the T category, Tumor Size is the primary measure used for T1, T2 and T3 breast tumors confined to the breast or pectoral fascia. CS has additional 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.

Value Definition Comments
T0 No evidence of primary tumor (2004+ only). These are cases where there were either positive lymph nodes or distant mets found but no tumor was found within the breast.
  • 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.
Tis In situ and Paget’s disease with no invasive underlying tumor
  • 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
T1mi Microinvasion 0.1 cm or less in greatest dimension
  • 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.
T1a Tumor more than 0.1 cm but not more than 0.5 cm in greatest dimension  
T1b Tumor more than 0.5 cm but not more than 1 cm in greatest dimension
  • 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.
T1c Tumor more than 1 cm but not more than 2 cm in greatest dimension
  • 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+, which had the largest number of cases in the T1 subcategories.
T2 Tumor more than 2 cm but not more than 5 cm in greatest dimension
  • CS: Besides tumors based on size alone, it also includes size categories 993-995.
T3 Tumor more than 5 cm in greatest dimension
  • In addition to more than 5 cm, it includes breast cancers labeled as diffuse.
T4a Direct extension to the chest wall  
T4b Edema (including peau d’ orange) or ulceration of the skin of the breast, or satellite skin nodules confined to the same breast
  • 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+, 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.
T4c Both T4a and T4b
  • Additional information is available in CS for the percentage of skin involvement, but the percentage is not necessary to derive T4c.
T4d Inflammatory carcinoma
  • 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.
TX Adjusted Primary tumor cannot be assessed or case information maps to unknown stage
  • 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+), 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.
T with Mets T with Mets (1988+)

 

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

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Breast - Adjusted AJCC 6th N (1988+) Variable

For the N category, the AJCC 6th is much more complicated than the simple codes used in EOD. We have tried to make it as comparable as possible. One problem is that EOD does NOT include all combinations of the regional node categories and does not separate clinical from pathologic information while CS is able to collect this. Te subcategories for N0, N1, N2 and N3, are available in the derived AJCC 6th N code but for comparability to EOD data, the subcategories have been folded into the main N categories of N0, N1, N2 and N3. This has no affect on stage because the specific sub categories for N0, N1, N2, or N3 are not used to determine stage. NX decreases over time and other categories show increases that are artifacts of the decrease in NX. The increase of sentinel lymph node biopsies may have contributed to the overall decrease in NX over time.

Value Definition Comments
N0 No regional lymph node metastases
  • 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.
N1mi Micrometastasis (greater than 0.2 mm, none greater than 2.0 mm)
  • For both includes cases with a microfocus in addition to those specified as less than or equal to 2 mm.
N1 Clinical: Metastasis to movable ipsilateral axillary lymph node(s)
Pathologic: Metastasis in 1 to 3 axillary lymph nodes, and/or in internal mammary nodes with microscopic disease detected by sentinel lymph node dissection but not clinically apparent
  • 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.
N2 Clinical: Metastases in ipsilateral axillary lymph nodes fixed or matted, or in clinically apparent ipsilateral internal mammary nodes in the absence of clinically evident axillary lymph node metastasis
Pathologic: Metastasis in 4 to 9 axillary lymph nodes, or in clinically apparent internal mammary lymph nodes in the absence of axillary lymph node metastasis
  • 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.
N3 Clinical: Metastasis in ipsilateral infraclavicular lymph node(s) with or without axillary lymph node involvement, or in clinically apparent ipsilateral internal mammary lymph node(s) and in the presence of clinically evident axillary lymph node metastasis; or metastasis in ipsilateral supraclavicular lymph node(s) with or without axillary or internal mammary lymph node involvement
Pathologic: Metastasis in 10 or more axillary lymph nodes, or in infraclavicular lymph nodes, or in clinically apparent ipsilateral internal mammary lymph nodes in the presence of 1 or more positive axillary lymph nodes; or in more than 3 axillary lymph nodes with clinically negative microscopic metastasis in internal mammary lymph nodes; or in ipsilateral supraclavicular lymph nodes
  • 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
NX Adjusted Regional lymph nodes cannot be assessed or case information maps to unknown stage
  • 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+), 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.
N with Mets N with Mets (1988+)

 

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

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Breast - Adjusted AJCC 6 M (1988+)

Value Definition Comments
M0 No distant mets
  • 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.
M1 Distant metastasis
  • 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.
MX Distant metastasis cannot be assessed
  • 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.
NA Not Applicable
  • Not an AJCC category but designates the histologies that AJCC does not stage.
Additional staging data items EOD: Regional Nodes Positive
CS: Number of Positive Ipsilateral Level I-II Axillary Lymph nodes
  • 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.

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Implementation Details

Summary of Mapping Changes to AJCC 6th Edition

CS Mets at DX

Code Description Original TNM 6 Map Mapping Change Change to stage
10

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

Distant lymph node(s), NOS

M1 N3c M0 IIIC
50 (40 - 44) + 10 M1 N3c M1 No change - Remains stage V

Notes:

  • Since all N3c M0 go to Stage IIIC, the T value does not have to be taken into account.
  • There isn't any 'Any N with Mets' for this schema.
  • Document change for 'Any T with Mets'

Coding Extent of Disease (EOD) 1988-2003

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