• All IHC stains will include a positive control tissue

• PR is used to determine if a tumor expresses estrogen receptor (i.e. for classification purposes)
• PR positivity is used to determine if a patient would be a candidate for anti-estrogen therapy

Submit a formalin-fixed, paraffin embedded tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• PR is a nuclear protein that binds progesterone hormone
• PR expression is seen in a variety of tumors from breast or gynecologic origin
• PR expression can also be seen in tumors of lung, stomach, thyroid, and very rarely colorectal origin (PR is less specific than ER)

  Staining

• Nuclear staining

References

1. Aziz DC: Quantitation of estrogen and progesterone receptors by immunocytochemical and image analyses. Am J Clin Pathol 1992; 98:105-111.
2. Wilbur DC et al: Estrogen and progesterone receptor detection in archival formalin-fixed, paraffin-embedded tissue from breast carcinoma: A comparison of immunohistochemistry with the dextran-coated charcoal assay. Mod Pathol, 5(1), 1992.
3. Esteban JM et al: Improvement of the quantification of estrogen and progesterone receptors in paraffin-embedded tumors by image analysis. Am J Clin Pathol, 1993; 99:32-38.
4. Taylor CR: Paraffin section immunocytochemistry for estrogen receptor; the time has come. Cancer 77(12), 1996.