First a quick reminder on the four stages of cancer diagnosis: 

• Stage 1 - this usually means that a cancer is relatively small and contained within the organ it started in.

• Stage 2 - this usually means the cancer has not started to spread into surrounding tissue but the tumour is larger than in stage 1. Sometimes stage 2 means that cancer cells have spread into lymph nodes close to the tumour. This depends on the particular type of cancer.

• Stage 3 usually means the cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes in the area.

• Stage 4 means the cancer has spread from where it started to another body organ. This is also called secondary or metastatic cancer.

This is very hard to write but it's really important that my family and friends understand this reality. I'm getting a little tired of the "you'll be fine" and "oh my friend had that and he's fine now" emails. Stage 4 is a different ball game because the cancer is deemed to be "metastatic".

Not very long ago, a stage 4 colon cancer would be deemed terminal. Today there are odds for survival, but I need you to understand that the official published odds are not good...at all. 

Survival rates are provided on curves that look like this: 

As you can see from this particular study, only 10% of people with my stage 4 diagnosis are alive after 5 years. 

Now I am guy who likes data and I need it to process a situation, and I'll confess that this data scares the crap out of me. However I've learned that there are several factors that make the interpretation of these medical stats for the purpose of deducing my individual prognosis very problematic. 

• New innovations - innovation in cancer treatment is proceeding at a rapid pace. For example one of the chemo drugs I'll be on has only recently become available. Therefore these stats, which are generally always at least 5 years old, don't reflect the latest treatment technologies.

• I'm not the average bowel cancel patient - Bowel cancer normally hits people much later in life and so the stats are generally based on a very different average patient profile. This is significant because, for example, I'm able to tolerate more aggressive chemotherapy.

• Every case is unique - The characteristics of every cancer are unique to each patient. For example while I'm am technically in stage 4 my liver tumours are very small.

So, how should you think about my prognosis. Well, you should know that the published odds are very bad, but my doctors are encouraging me to think about my odds of surviving this more as a 50/50 bet (I'll talk more about what "survival" of a stage 4 cancer really means in a future post, but think of it simply as being alive in 5 years....not forever). 

I've been discussing my personal strategy a lot with my family over the last week. I'll write more about this later but I'm essentially developing a dual track mental model to get through the next few months. On the one hand I have to be optimistic (studies show your mental attitude has a huge impact on treatment success), but on the other hand I need to be pragmatic and prepared for the worst, given there is at least a 50% chance of it eventuating. Going down that path of thought is profoundly challenging for a father of three beautiful young children, but I personally think I must go there to get through this.