Gastrointestinal Stromal Tumors of Peritoneum and Retroperitoneum

Primary Site Histology Staging Type
C480-C482, C488 8935-8936 TNM 7 and Summary Stage

If you are working with a site/histology that only summary stages and you need to directly code it, please use the SEER Summary Stage 2000 manual

Notes

C480 Retroperitioneum C481 Specified parts of peritoneum (including omentum and mesentery) C482 Peritoneum, NOS C488 Overlapping lesion of retroperitoneum and peritoneum **Note 1:** This schema is based on the UICC chapter *Gastrointestinal Stromal Tumour (GIST),* pages 78-81. * Primary sites C480, C482, and C488 are not listed in this chapter of the UICC manual; however, they are included in this schema in and TNM staged **Note 2:** In addition to directly assigning TNM, Summary Stage 2000 (SS2000) must be captured. If directly assigning SS2000, use the *Retroperitoneum & Peritoneum* chapter on page 188 of the [SS2000 on-line manual](https://seer.cancer.gov/tools/ssm/ssm2000/SSSM2000-122012.pdf#page=188).

Main Data Items

Name Default Value Used for Staging NAACCR Item Required By Metadata
Clinical T <BLANK> Yes NAACCR #940 None
Clinical N <BLANK> Yes NAACCR #950 None
Clinical M <BLANK> Yes NAACCR #960 None
TNM Clin Stage Group 99 Yes NAACCR #970 None
Pathologic T <BLANK> Yes NAACCR #880 None
Pathologic N <BLANK> Yes NAACCR #890 None
Pathologic M <BLANK> Yes NAACCR #900 None
TNM Path Stage Group 99 Yes NAACCR #910 None
SSF5: Mitotic Count 999 Yes NAACCR #2920 All None
SSF6: KIT Gene Immunohistochemistry (IHC) 988 No NAACCR #2930 CCCR/Canada
COC
None
SSF7: KIT Gene Mutations 988 No NAACCR #2861 None None
SSF8: PDGFRA Gene Mutation 988 No NAACCR #2862 None None
SSF9: Tumor Multiplicity 988 No NAACCR #2863 None None
SSF10: Location of Primary Tumor 999 Yes NAACCR #2864 All None

Additional Data Items

Name Default Value Used for Staging NAACCR Item Required By Metadata
Year of Diagnosis <BLANK> No NAACCR #390 None
Primary Site <BLANK> Yes NAACCR #400 None
Histology <BLANK> Yes NAACCR #522 None
RX Summ Systemic/Surgery Sequence <BLANK> Yes NAACCR #1639 None
RX Summ Surgery/Radiation Sequence <BLANK> Yes NAACCR #1380 None
Regional Nodes Positive <BLANK> Yes NAACCR #820 None

Initial Context

Staging Methods

Expand All | Collapse All

TNM 7 Stage

Inclusion Table

Histology
8935-8936

Start

Additional Context
Pathologic Stage Group = 90
Clinical Stage Group = 90

Next Step

  1. Parse T
  2. clin_t_prefix
    tmp_clin_t

Next Step

  1. Parse N
  2. clin_n_prefix
    tmp_clin_n

Next Step

  1. Parse M
  2. tmp_clin_m
    clin_m_prefix

Next Step

  1. Parse T
  2. tmp_path_t
    path_t_prefix

Next Step

  1. Parse N
  2. tmp_path_n
    path_n_prefix

Next Step

  1. Parse M
  2. tmp_path_m
    path_m_prefix

Next Step

  1. Determine Default T
  2. Source T
    tmp_path_t
    tmp_clin_t
    tmp_combined_t

Next Step

  1. Determine Default N
  2. tmp_combined_n
    tmp_clin_n
    tmp_path_n
    Source N

Next Step

  1. Determine Default M
  2. tmp_path_m
    tmp_combined_m
    tmp_clin_m
    Source M

Next Step

  1. Mitotic Rate Calculation
  2. mitotic_rate

Next Step

  1. SSF10 Stage Group Selection
  2. stage_table
    Clinical Stage Group

Next Step

  1. SSF10 Path Stage Group Selection
  2. stage_table
    Pathologic Stage Group

Next Step

  1. Adjustments for No Clin or No Path
  2. tmp_combined_n
    tmp_combined_m
    Source T
    Clinical Stage Group
    Pathologic Stage Group
    Source N
    tmp_combined_t
    Source M

End

Combined Stage

Inclusion Table

Histology
8935-8936

Start

Additional Context
Combined Stage Group = 90
Combined N = 90
Combined M = 90
Combined T = 90

Next Step

  1. Stop if No Clin and No Path
  2. Combined M
    Combined N
    Source T
    tmp_continue
    Combined T
    Combined Stage Group
    Source N
    Source M

Next Step

  1. Combined T No Tis
  2. Source T
    tmp_combined_t

Next Step

  1. Combined N No Tis, Path N=cN0 allowed
  2. tmp_combined_n
    Source N

Next Step

  1. Combined M
  2. tmp_combined_m
    tmp_source_m
    Source M

Next Step

  1. Determine Combined Prefix
  2. cmb_t_prefix

Next Step

  1. Determine Combined Prefix
  2. cmb_n_prefix

Next Step

  1. Determine Combined Prefix
  2. cmb_m_prefix

Next Step

  1. Concatenate T
  2. Combined T

Next Step

  1. Concatenate N
  2. Combined N

Next Step

  1. Concatenate M
  2. Combined M

Next Step

  1. SSF10 Path Stage Group Selection
  2. stage_table
    Combined Stage Group

End

Outputs

Name Default Value Description NAACCR Item Metadata
Derived Version {{ctx_alg_version}} None None
Derived SEER Clin Stage Group 88 NAACCR #3610
None
None
Derived SEER Path Stage Group 88 NAACCR #3605
None
None
Derived SEER Combined Stage Group 88 NAACCR #3614
None
None
Derived SEER Combined T 88 NAACCR #3616
None
None
Derived SEER Combined N 88 NAACCR #3618
None
None
Derived SEER Combined M 88 NAACCR #3620
None
None
Derived SEER Combined T Source <BLANK> NAACCR #3622
None
None
Derived SEER Combined N Source <BLANK> NAACCR #3624
None
None
Derived SEER Combined M Source <BLANK> NAACCR #3626
None
None