Reading Your Pathology Report: Preventing And Treating Colorectal Cancer

Content provided by the Faculty of the Harvard Medical School

Reading your pathology report

Following surgery, the doctor often gives the patient a copy of the pathology report — the pathologist's diagnosis based on the examination of tissues and lymph nodes taken during biopsy or surgery. If you don't receive a copy, ask for it. It contains a good deal of useful information. Although you may have had a biopsy during colonoscopy or sigmoidoscopy, that tissue sample revealed only whether cancer cells were present. Samples taken during surgery give a more complete picture because far more tissue is available for examination in the laboratory and because lymph nodes can also be examined.

The pathology report is important because your physicians use it to determine the stage of your cancer and your treatment options. This report forms the basis for many decisions that you and your doctors will make regarding your treatment.

The report should contain the following information:

• type and size of the specimen removed for biopsy

• type, grade, and size of the cancer

• presence or absence of lymphatic vessel invasion

• presence or absence of blood vessel invasion

• degree of differentiation (how different the cancer cells look from normal colon or rectal cells)

• lymph node status.

Keep a copy of the pathology report at home to refresh your memory if necessary and because the report might be relevant at some future time.

In the report, a tumor is given a letter and a number code that is a standardized, shorthand way of describing it. This code indicates the depth of the tumor's infiltration into the colon or rectum, whether it has invaded any lymph nodes (and if so, how many), and the possibility of metastases (secondary tumors) elsewhere in the body. Unlike most other solid tumors, the size of the primary colorectal tumor is not a factor in the tumor's staging. The reason is that most studies show that the tumor's size alone does not significantly influence the likelihood of a person's survival. A large tumor that does not penetrate beneath the first layer of colon or rectal tissue is easier to cure than a smaller tumor that has infiltrated the deeper layers or lymph nodes. Survival depends mainly on the extent of the tumor's invasion into healthy tissue and lymph nodes.

The following letter designations are used (see further information in Table 3):

• T for extent of tumor infiltration into the colon or rectum

• N for extent of lymph node involvement

• M for extent of metastases (spreading to other parts of the body).

A number is assigned to each letter to quantify the extent of the cancer's presence. For example, N0 means that there is no sign of cancer in the lymph nodes (N for nodes, 0 meaning none).

These codes provide the basis for determining the stage of the cancer. The stages usually are given in Roman numerals, ranging from Stage 0 to Stage IV. The higher the number, the more advanced the cancer.

Last updated:	April 09, 2009