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Deriving Disease Extent from TNM in EPISODE table


I think Disease Extent can be derived from TNM but I just wanted to check that.

Is this a correct algorithm to derive Disease Extent?:

  • If M = 0 and N = 0 then Disease Extent = Confined Disease
  • If M = 0 and N > 0 then Disease Extent = Invasive Disease
  • If M = 1 then Disease Extent = Metastatic Disease
    What should be done with NX and MX?

Alternatively, can the disease extent also be derived from the staging groups?:

  • If Stage = I then Disease Extent = Confined Disease
  • If Stage = II, III then Disease Extent = Invasive Disease
  • If Stage = IV then Disease Extent = Metastatic Disease

Thanks for your help,


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Thank you, Peter!

The presence of TX/NX/MX indicate unknown tumor extent. We will add this to the recommendation.

Problem is that not all cancers are following this logic.

  • Stage IVA prostate cancer is Any T, N1, M0. No metastasis here. We cannot categorize them as metastatic disease
  • Stage IVA bladder cancer: T4b, Any N, M0 OR Any T, Any N, M1a. A mix of metastatic and non-metastatic bladder cancer. We cannot tell who is metastatic and who is not based on the stage.
  • Stage II thyroid cancer: Any T, Any N, M1 (in patients <55 years old). Metastatic but using stage categories, we would categorize it as invasive disease.

ENCR has tumor specific recommendation for deriving disease extent from T, N and M values. We have considered this options as well. We are still evaluating this option and other options including SEER Summary stage as potential options. Please bring any recommendation/suggestion to the Onc WG meetings and help us finalize the recommendations.

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Thanks, Asieh!

I wasn’t sure whether this was a straightforward thing or whether it was more complicated (and maybe still under discussion). I see that it is the latter :slight_smile: . I will have a look at it with Chiara and we’ll bring any suggestions we have to the Onc WG meeting.


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Looking forward to hearing your thoughts on this. :slight_smile: