ARUP's Laboratory Test Directory

DNA Content/Cell Cycle Analysis, Colon : 0095140

Mnemonic: DNA COL

Methodology: Quantitative Flow Cytometry
Performed: Sun, Tue
Reported: 3-9 days
Specimen Required: Collect: Colon tumor tissue.

Specimen Preparation: Paraffin embed tissue block enriched with colon tumor. If no normal tissue is included in the block, supply a control tissue block to be processed in parallel.

Storage/Transport Temperature: Room temperature.

Remarks: Include H&E stained slide and surgical pathology report.

Unacceptable Conditions: No tumor tissue remaining on block. Specimens fixed in Bouin's solution (picric acid), mercuric chloride containing fixatives (e.g., B5, Zenker's solution), or ethanol-based fixatives containing ethylene glycol, acetic acid or zinc chloride. Decalcified specimens.

Stability (collection to initiation of testing): Paraffin block: Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable

Reference Interval:
Report components include: DNA content, S-phase interpretation, and copy of histogram.
Interpretive Data: In one review of 14 studies of colon cancer with a total of 2,090 patients, 60% were aneuploid and 40% were diploid.1 Tetraploid tumors were included with aneuploid tumors. In two reviews of 18 large series of colon cancer, aneuploidy usually correlated with poor survival, especially in higher stages.1,2 Low S-phase may correlate with better survival. 3

References:
1. Virchow Arch B Cell Pathol 60:123-131, 1991.
2. J Surg Onc 48:4-10, 1991.
3. Cancer Res 51:2403-2409, 1991.

See Compliance Statement B: www.aruplab.com/CS
Note: A thin section of each tissue submitted is stained with H & E to verify the presence of tumor. The DNA content of each tumor is classified as diploid or aneuploid. The DNA index is the ratio of tumor G0-G1 cells to normal G 0-G1 cells.

The tumor-specific S-phase is used when possible. An average histogram S-phase is used for diploid and aneuploid tumors where the tumor and host S-phases cannot be separated. An average histogram S-phase is also used when the percentage of aneuploid cells in the histogram is low (less than 25%). The S-phase interpretation is based on comparison to other colon tumors and is controlled for histogram type (diploid, aneuploid). The appropriate population is divided into thirds and compared to the sample S-phase for an interpretation of low, moderate, or high S-phase.
CPT Code(s): 88182
Cross References: DNA Ploidy and S-Phase (Paraffin Block) (DNA Content/Cell Cycle Analysis, Colon)