Your Pathology Report

Tumor tissue is routinely removed (or “biopsied”) and analyzed to confirm or rule out a cancer diagnosis. A pathologist performs such analysis on fresh tissue, frozen tissue, or tissue that has been fixed in formalin (a preservative).The pathologist then performs the “histological examination;” (histology refers to the anatomical study of the microscopic cellular structure and function of tissues).

Histological examination may determine:

• Whether the tissue sample is sufficient to make a diagnosis. For example, does the sample contain a necessary number of tumor cells and not just normal fat cells and supporting tissue (stroma)
• Whether the tissue sample is benign, pre-cancerous, or cancerous
• What specific cancer type is found
• Tumor grade, based on a system that classifies cancer cells according to how abnormal they appear under the microscope as well as the likelihood of tumor growth and spread.
• Histological grade, based on how closely the tumor cells resemble normal cells
• Nuclear grade, based on the rate of cell division and the shape and size of the nucleus in the abnormal cells
• Whether there are areas of degenerating cancer cells (necrosis)
• Whether additional tissue will need to be removed (margin status)
• Other characteristics of the tissue requiring identification by assays

Medicare, Medicaid, and most insurance policies require that such analysis be performed in a CLIA-certified laboratory. The objective of “CLIA,” or Clinical Laboratory Improvement Amendments, is “to ensure quality laboratory testing” and covers approximately 225,000 laboratory entities throughout the United States.

The pathologist documents the above information in a report, called a pathology report so that you and your medical team can use this to determine your individualized treatment plan.

The pathologist stores remaining formalin-fixed tissue that is not needed for your diagnosis and embeds it in a small paraffin (wax) block. The storage of these blocks ensures their availability for outside consultations, medical-legal cases, and any necessary subsequent testing.

(The following two photos are taken from the website of the National Surgical Adjuvant Breast and Bowel Project.)

		Should a patient require additional studies, the pathologist can slice additional formalin-fixed, paraffin-embedded sections for this use. It is possible that the newly-cut slices may not capture exactly the same cellular picture that was seen in the initial slide sample.

In addition, a hospital may not keep the blocks after a certain length of time, although it is possible that they may still be useful to the patient should subsequent treatment become necessary. State regulations determine the length of time that is required for archiving tissue samples, and such regulations vary from state to state. Generally, academic medical centers archive tissues longer than community hospitals do so. Some facilities never discard tissue samples.

Formalin-fixed, paraffin-embedded (FFPE) tissue is one of the most widely used methods of preserving and archiving clinical samples. Hospitals, tissue banks, and research laboratories worldwide currently hold over a billion tissue samples. (1)

Organizations like the Joint Commission and the College of American Pathologists issue guidelines and recommendations for the storage of tissue samples at hospital pathology units.

		This photo shows pathologist S. Paik in the National Surgical Adjuvant Breast and Bowel Project (NSABP) Tissue Repository. Tumor blocks are held in similar archives in hospital laboratories around the world.

Moving Forward

The work performed by today’s cancer research scientists has moved far beyond the histological examination performed by the clinical pathologist. They focus their efforts on the diagnoses and treatments of the future. They use sophisticated technology to conduct molecular analysis and to analyze the genetic makeup of normal and tumor tissue, the proteins expressed, specific genes, and proteins that drugs can target. They need tissue to make this research possible.

Common Misunderstandings

Many clinical studies that require tissue involve studying genes. The term “genetic research” is not restricted to research on gene changes that cause inherited cancers. Unfortunately, some patients may refuse to participate in studies or to donate tissue due to this misunderstanding.

Rather, genetic research is an umbrella term that can include research into inherited genetic mutations, acquired (somatic) genetic mutations, and common genetic variants that may predict risk of disease, response to treatment, risk of side effects from a treatment, or confer protection from a disease.

Hereditary genetic mutations, such as mutations of the BRCA1 or BRCA2 gene associated with increased risk of breast, ovarian, and other cancers, can be passed down from parent to child over generations. In contrast, a somatic or acquired genetic mutation occurs during a person’s lifetime and is not passed down to children.

In addition, people often do not understand that tissue donated by patients with a specific disorder may be used in the future not only for research on the disease in question, but also for research on other diseases and by researchers at different institutions. (See “Consensus Statement: Informed Consent for Genetic Research on Stored Tissue Samples,” JAMA 1995). Informed consents for patients who are interested in participating in clinical studies, undergoing surgery, and/or donating tissue include information about the future use of donated biospecimens.

“Content Developed September 1, 2012”