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Clinical outcomes in patients age 40 or younger at diagnosis of synchonous metastatic colorectal cancer.

531 Background: The impact of age ≤ 40 at diagnosis of colorectal cancer on outcome is unclear. The higher incidence of tumor microsatellite instability (MSI) in young patients may confound the estimation of survival in this population due to the more favorable biology associated with MSI cancers.


METHODS
All pts diagnosed with metastatic colorectal adenocarcinoma at ≤ 40 years old between Jan 2000-Jan 2010 were identified from the institutional database with prior IRB approval. Clinical and pathology records were reviewed. Only patients with synchronous metastases at presentation were included. Immunohistochemistry for DNA mismatch repair proteins (MMR) was performed in 40 pts of whom 5 had loss of MMR and were excluded from the analysis.


RESULTS
185 pts were identified; median age at diagnosis was 36 years (range 18-40) Primary site was in the right colon in 50 cases (27%). All pts received at least one line of systemic chemotherapy. For pts receiving systemic therapy median survival was 23.4 months and for those receiving hepatic arterial infusion (HAI) plus systemic the median survival was 48.2 months. Median survival for those who underwent liver resection (78 pts) was 54.6 months. Other factors such as race, post partum and KRAS mutation impacted on survival as shown below.


CONCLUSIONS
Overall survival in this cohort of young pts is similar to that observed in clinical trials of modern combination therapy for metastatic CRC. African American race, presence of a KRAS mutation, and presentation following pregnancy may be associated with reduced survival in this group. [Table: see text] No significant financial relationships to disclose.