So, you’ve just received a copy of your pathology report from the oncologist, and you’re totally mystified by the “medicalese” it contains. Where to turn?

If you’re up for studying and interpreting the entire report, check out our Guide to Understanding Your Pathology Report.

But if you want a quick, “down and dirty” explanation of the key numbers in the report; or if you don’t have your pathology report, but only a few scattered parts your oncologist has shared, read the following guide for a fast explanation of your pathology report’s key numbers.

Grade
This is a detailed examination of your cancer cells: what they look like, and how fast they’re growing. It all boils down to behavior: the more quickly the cells are growing and the farther they stray from normal cell behavior, the more aggressive your cancer.

Different pathologists use different scales to determine grade, but here’s the simple explanation: grades go from 1 to 3, with 1 the lowest (least aggressive), and 3 the highest (most aggressive).

Occasionally, the report will state grade a different way, giving it as a Scarff-Bloom-Richardson (SBR) grade of 1 to 9. In that case, 1 to 3 is low (grade 1); 4-6 is medium (grade 2); and 7-9 is high (grade 3).

Stage
Your cancer's stage is based heavily on three things: information about your tumor; information about your lymph nodes; and whether or not the cancer has metastasized to other parts of your body. The American Joint Committee on Cancer has developed shorthand for determining these three aspects of your breast cancer, called TNM. Here's how it works:

T = tumor size, the tumor diameter measured in centimeters; 1 centimeter = approx. 1/3 inch. Your T score can be any of the following:

TX: the tumor couldn’t be accessed;

T0: no tumor;

Tis: in situ; tumor hasn’t moved beyond its original ducts or lobules;

T1: less than 2cm;

T2: 2-5cm;

T3: more than 5cm;

T4: any size, but attached to the chest wall and spread to the chest lymph nodes.

N = palpable nodes, which indicates whether cancer has spread to the lymph nodes.

NX: the nodes couldn’t be accessed;

N0: no spread;

N1: cancer has spread to the “movable” nodes in your armpit (axillary nodes) on the same side as your breast cancer;

N2: cancer has spread to the “attached” lymph nodes on the same side as your breast cancer; these nodes are attached to one another, or to other structures in your armpit;

N3: cancer has spread to the lymph nodes in your breast.

M = metastasis; whether the cancer has spread to other parts of your body beyond the breast and lymph nodes (distant metastasis).

MX: metastasis can’t be assessed;

M0: no distant metastasis;

M1: distant metastasis.

So, here’s how to interpret the jumble of numbers and letters you may see in your pathology report, that look something like this: pT2, pN1, M0. Or this: T2N1M0.

The interpretation of either of these is as follows:
•Your tumor is 2-5cm;