PR negative

Progesterone Receptor Negative (PR Negative) refers to a characteristic of certain types of cancer cells, particularly in the context of breast cancer, where the cancer cells do not have receptors for the hormone progesterone. This attribute is crucial for determining the course of treatment and understanding the prognosis of the disease.

Overview

Progesterone, along with estrogen, plays a significant role in the development and regulation of the reproductive system in females. In the context of breast cancer, the presence or absence of progesterone receptors (PR) on the surface of cancer cells is a critical factor in classifying the disease and deciding on treatment options. Breast cancers are tested for hormone receptors using a process called immunohistochemistry.

Classification

Breast cancers can be classified based on the presence or absence of hormone receptors:

• PR Positive: Cancer cells have progesterone receptors and may grow more slowly.
• PR Negative: Cancer cells lack progesterone receptors, indicating that the cancer may be more aggressive and less responsive to hormone therapy.

Diagnosis

The determination of PR status is part of a broader hormone receptor test, which also includes testing for estrogen receptor (ER) status. The results of these tests are typically reported as positive or negative, guiding the treatment approach. A biopsy sample of the tumor is used for this testing.

Treatment Implications

The absence of progesterone receptors (PR Negative) has significant implications for treatment. PR Negative tumors are not likely to respond to hormone therapy, which targets these receptors to slow down or stop the growth of cancer. Therefore, treatment options may include:

• Chemotherapy
• Radiation therapy
• Targeted therapy, depending on the presence of other receptors or proteins, such as HER2.

Prognosis

Generally, PR Negative breast cancers may have a poorer prognosis than PR Positive cancers because they tend to be more aggressive and have fewer treatment options. However, the outcome can vary greatly depending on a combination of factors, including the cancer's stage, grade, and overall health of the patient.

Research and Future Directions

Ongoing research aims to better understand the biology of PR Negative breast cancers and to develop new treatments that can target these tumors more effectively. This includes exploring the role of other molecular markers and finding ways to make these cancers more responsive to existing therapies.

See Also

• Breast cancer classification
• Hormone receptor positive breast cancer
• Triple-negative breast cancer