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SEER Inquiry System - Report
Produced: 10/06/2026 8:56 PM
Question 20041100
Inquiry Details
References:
2004 SEER Manual, 72
Question:
Discussion:
In the case of two or more simultaneously diagnosed primary tumors, instructions in the SEER manual state that the tumor with the worse prognosis is to be assigned the lower sequence number. Prognosis decisions should be based on primary site, histology and extent of disease.
Stage as a criteria for decision making is fairly straightforward. On the other hand, decisions based on primary site seem to be more subjective than objective.
Answer:
For tumors diagnosed prior to 2007:
Compare the combination of the primary site, histology and extent of disease for each primary, and assign the lowest sequence number to the primary with the worst prognosis. Do not use primary site or histology alone to determine prognosis in the case of assigning sequence number. Survival is a component of prognosis.
If there is no difference in prognosis, assign the sequence numbers in any order.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
