Simplifying Cancer Staging

Back in the 1940’s and 50’s, cancer was poorly understood.  It was believed back then (literally the dark ages!), that one medication would cure all cancers.  That cancer could be more advanced in one case than another, was totally unknown.  As research got more specific, stages were identified.  A simplified system used four stages, written in Roman numerals: Stage I and Stage II indicated the earliest stages, stage III was more advanced, and Stage IV demonstrated distant metastasis from the primary tumor.  As knowledge compiled through the decades, this system was modified with A, B and C, signifying the level of development in each stage.
As time and research progressed, a staging system was devised that provides more information at a glance. TNM stands for Tumor, Nodal involvement (lymph nodes) and Metastasis.  A T1 tumor is very small, and obviously a T4 tumor is much larger or has grown into nearby tissue.  The T1 tumor may be stage I and the T4 tumor may be Stage II.  N could be 1, 2 or 3, depending on the number of cancerous nodes.  M is 0 vs 1, depicting no metastasis versus metastasis (stage IV).  An x signifies unknown involvement (T1N1Mx).  Just to spice things up, a “c, p, or y” before the letters will tell you even more information.  It reads like this: cT1 would mean that a small tumor was identified per scans and physical exam (clinical); pT1 means the information came through a biopsy (pathology), and the yT1 means the staging information was AFTER treatment.