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SEER Inquiry System - Report
Produced: 11/09/2025 6:01 PM
Question 20140062
Inquiry Details
References:
2007 MP/H Rules
Question:
MP/H Rules/Multiple Primaries--Lung: Does lung MP/H Rule M6 apply to synchronous tumors only, metachronous tumors only, or both? See discussion.
Discussion:
How many primaries should be reported when a patient has a history of RLL adenocarcinoma diagnosed on 10/8/2009 followed by diagnoses of LUL adenocarcinoma on 10/5/2012 and a RUL adenocarcinoma on 3/26/2014?
We applied Rule M6 to the 10/5/2012 diagnosis of LUL adenocarcinoma and reported an additional primary. However, we are unsure how to apply the MP/H rules for the 3/26/2014 RUL adenocarcinoma.
Should we apply Rule M8 because the RUL adenocarcinoma was diagnosed more than 3 years after the original RLL adenocarcinoma and then apply M6 because the RUL and LUL indicate a single tumor in each lung (resulting in a third primary); or does Rule M12 apply because there has been more than a single tumor in each lung (no new primary)?
Answer:
Assuming each of the three diagnoses is a single tumor and there are no other tumors in either lung, abstract two primaries: 1 in the RLL diagnosed on 10/8/2009 and 1 in the LUL diagnosed on 10/5/2012. Do not abstract the 3/26/2014 diagnosis as a new primary.
Rule M6 applies to the 2009 and 2012 diagnoses. Rule M12 applies to the 2012 and 2014 diagnoses. Do not compare the 2014 diagnosis to the 2009 diagnosis. Always compare the latest diagnosis to the most recent previous diagnosis in cases like this.
