Name of the Procedure:

Receptor Assay; Estrogen (ER Assay, Estrogen Receptor Test)

Summary

An estrogen receptor assay is a laboratory test that measures the presence of estrogen receptors in cancer tissue, typically breast cancer tissue. By analyzing these receptors, doctors can determine the best treatment approach.

Purpose

This test helps in diagnosing hormone receptor-positive breast cancer and in deciding the most effective treatment. It aims to examine whether the cancer cells grow in response to estrogen.

Indications

• Patients with a breast cancer diagnosis.
• Suspected cases of hormone receptor-positive cancer.
• Patients considering hormone therapy as a treatment option.

Preparation

• No special preparation is usually required.
• The biopsy or surgical tissue sample must be obtained beforehand.

Procedure Description

1. A sample of cancer tissue (usually from a biopsy or surgery) is collected.
2. The sample is sent to a laboratory.
3. The tissue is then treated with specific antibodies that attach to estrogen receptors if they are present.
4. The sample is analyzed under a microscope to detect and measure the amount of estrogen receptors.

No anesthesia or sedation is required for the assay itself, but may be needed for the tissue sample collection.

Duration

• Tissue sample collection: 30 minutes - 1 hour
• Laboratory analysis: Several days to a week

Setting

• Tissue sample collection: Outpatient clinic or hospital
• Laboratory analysis: Specialized pathology lab

Personnel

• Surgeon or interventional radiologist (for sample collection)
• Pathologist or lab technician (to perform the assay)

Risks and Complications

• Tissue sample collection may involve typical biopsy risks such as infection or bleeding.
• There are minimal risks associated with the laboratory test itself.

Benefits

• Identifies hormone receptor-positive cancers.
• Helps tailor hormone therapy, potentially leading to better treatment outcomes.
• Non-invasive testing of tissue samples with no additional physical risk to the patient.

Recovery

• No recovery needed from the lab test itself.
• Recovery from biopsy or surgery follows usual protocols, typically involving rest and limited physical activity.
• Follow-up visits may be necessary based on treatment decisions.

Alternatives

• Progesterone receptor assay (PR assay) for additional hormone receptor information.
• Genetic testing (e.g., Oncotype DX) to assess cancer aggressiveness.
• Each alternative offers different data and may complement rather than replace ER assay.

Patient Experience

• The patient will not feel anything during the lab test itself.
• Any discomfort or pain is associated with the initial tissue sample collection and can be managed with pain medication if necessary.
• Results consultation might involve discussing treatment options with the oncologist.