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Question 20071051

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References:

2007 MP/H Rules. Lung (M6)

Question:

MP/H Rules/Multiple Primaries--Lung: Please clarify the multiple primary rule M6 and the explanatory note that states when there is a single tumor in each lung, they are to be reported as multiple primaries unless stated or proven to be metastasis. See Discussion.

Discussion:

Single tumor in left lung, single tumor in right lung. The rules take you to M6. Suppose the tumor in left lung is biopsied and there is a physician statement that right lung tumor is metastatic from left lung tumor. The note under M6 is "When there is a single tumor in each lung, abstract as multiple primaries unless stated or proven to be metastatic." In this case, is it a single primary or multiple primaries?

Answer:

For cases diagnosed 2007 or later:

When there is a single tumor in one lung and a single tumor in the other lung, apply rule M6 and abstract as multiple primaries. Use this rule whenever there is a single tumor in each lung, even when neither tumor is biopsied or resected.

This rule is unique to lung. Our physician advisors emphasized that it is very unlikely that a single tumor in one lung could be metastatic from a single tumor in the opposite lung. Therefore, the default is to abstract as multiple primaries.

The note at M6 means that there must be proof that one tumor is metastatic in order to abstract as a single primary. For example, a biopsy of the tumor proving that it is metastatic. An opinion or belief that one tumor is metastatic is not sufficient. In the absence of proof, use rule M6 and abstract as multiple primaries.

A list of MP/H clarifications will be available. This issue will be included on the list.

Cancer Site Category:

Lung

Data Item Category:

N/A

Other Category:

Multiple primaries

Year:

2007