Chromosome 1p Status (CNS Other (V9 2023+))

Organization	Field Name	ID#	ID Name	Required

Organization	Field Name	ID#	ID Name	Required
KCR	Chromosome 1p: Loss of Heterozygosity (LOH)	34019	Chromo1pLOH	yes
SEER	Chromosome 1p Status	3801	chromosome1pLossHeterozygosity	yes

Note 1 Physician Statement

Physician statement of Chromosome 1p deletion/LOH can be used to code this data item when no other information is available.

Note 2 Applicable histologies

Below is a list of histologies/terms for which the Chromosome 1p test is commonly done. If the test was done, record the results, regardless of the histology. If the histology is not listed among those for which the Chromosome 1p test is commonly done, and the test result is not readily available, assume it was not done and code 9 for unknown.
9382/3 Oligoastrocytoma (anaplastic, or NOS)
9400/3 Diffuse astrocytoma (IDH mutant, IDH wild type, or NOS)
9401/3 Anaplastic astrocytoma (IDH mutant, IDH wild type, or NOS)
9411/3 Gemistocytic astrocytoma, IDH mutant
9424/3 Anaplastic pleomorphic xanthoastrocytoma
9430/3 Astroblastoma
9440/3 Glioblastoma (epithelioid, IDH wild type, or NOS)
9441/3 Giant cell glioblastoma
9442/3 Gliosarcoma
9445/3 Glioblastoma, IDH mutant
9450/3 Oligodendroglioma (IDH mutant and 1p/19q codeleted, or NOS)
9451/3 Anaplastic oligodendroglioma (IDH mutant and 1p/19q codeleted, or NOS)
9505/3 Anaplastic ganglioglioma
9530/3 Anaplastic (malignant) meningioma

Note 3 Related data item

Code	Description

Code	Description
0	Chromosome 1p deletion/LOH not identified/not present
1	Chromosome 1p deletion/LOH identified/present
6	Benign or borderline tumor
7	Test ordered, results not in chart
8	Not applicable: Information not collected for this case (If this item is required by your standard setter, use of code 8 will result in an edit error.)
9	Not documented in medical record Cannot be determined by the pathologist Chromosome 1p deletion/LOH not assessed or unknown if assessed