Nottingham Prognostic Index (NPI): Applications & Validity

Question
Thanks for responding so quickly to my earlier question about the Elston score.  Now that I have done some internet googling, I have discovered the Nottingham Prognostic Index (NPI).  

    Is the NPI only used in conjunction with primary cancers?  Is it at all valid for recurrences?  The medical literature seems to use it only for primary cancers, or at least does not mention locally recurrent cancer.

    Using the NPI, I have clearly exceeded the odds for my primary cancer (2 cm tumor, 10 positive nodes, etc).  The NPI score back in 1991 would have been about 6.4 (poor prognosis).   But I am still here 14 years later.  I know I'm very lucky.

    If the NPI can be used for recurrent cancers, am I to apply the >4 lymph node status from 14 years ago, or the current lymph nodes status (no axillary adenopathy seen on PET scan).   Using the current lymph node status (0 lymph node involvement), I would end up with a NPI of 3.4, based on:

Tumor size 2 cm X 0.2 + Grade 3 histology + 0 lymph nodes.

So I guess the question is, is the NPI useful for recurrent cancers or only for primary cancers?

Thanks again,
Jean


Answer
NPI is - as far as I know - only defined for use with primary cancers. Its goal was to provide a tool for deciding which primary cancers should have chemo therapy by evaluating their risk of relapsing (= spreading to become secondary cancers elsewhere). So (almost) already by that definition secondary cancers are excluded.  Yes it took a long time, you are certainly correct, but breast cancers and malignant melanomas are tricky. In most cancers you can use a rule of thumb that if the patient has survived 5 years apparently cancer free it is very probable that the patient is cured. Not so with these 2 tumors. With them you can have a relapse after 30 cancer free years. As it is now your cancer has relapsed so it is a different ball game. In your favour though is probably still the fact that it took such a long time to come back. But that is just a finger tip feeling I have. I have no real studies to back it up, none that I know of anyway. Good luck!