#1: Solid Tumor Rules (2018)
Source 1: 2018 Solid Tumor Rules
Solid Tumor Rules (2018)/Recurrence--Breast: Does any recurrence within the multiple primaries-stated timeframe count, not those just in the primary site? See Discussion.
A patient has a left breast cancer diagnosed in 2011; then has a "recurrence" in her lymph nodes in 2017. In 2018, she has a new left breast mass that is the same histology and behavior as the 2011 cancer. Based on the 2017 "recurrence" in the lymph nodes, this is not a new breast primary, is that correct?
This is a single primary using 2018 Breast Solid Tumor Rule M11. Rule M8 does not apply because the patient was not clinically disease free for 5 years. We are interpreting the 2017 diagnosis as lymph node metastasis from the 2011 breast cancer diagnosis.