The New AJCC Pathologic T4 Classification Does Not Have a Better Correlation with Outcome.
Sara Hafezi, Patricia Shaw, Stefano Serra, Hala El-Zimaity. University Health Network, Toronto, ON, Canada
Background: The 7th edition of the AJCC changed its recommendations in January 2010 for stage 4 large colonic carcinomas. The AJCC guidelines recommend classifying tumors invading other organs (previously classified as stage 4a – AJCC 6th edition) as stage 4b. Tumors with serosal involvement (previously classified as stage 4b – AJCC 6th edition) are classified as stage 4a. The AJCC commission based their recommendation on data deposited in the SEER data bank.
Design: One pathologist reviewed all slides for patients diagnosed with “n”pT4 colon cancer at Toronto General Hospital between1999-2008. Clinical data was retrieved from electronic patient record and patients' charts. We grouped tumors by serosal involvement or invasion of other organs. We also grouped tumors by histology type, tumor grade, location and lymph node involvement. The study end points were overall and disease-free survivals. We analyzed differences using Kaplan-Meier survival log rank test.
Results: The study included 140 patients (90 with serosa involvement, and 50 with tumors invading other organs). Overall survival was 22 months for tumors involving the serosa and 24 months for tumors invading other organs, p = 0.45,. Disease free survival was not affected by tumor site (right sided vs left sides), tumor grade, age, or gender.
Conclusions: In this series of operable patients survival is similar between patients with serosal involvement and those with invasion of other organs. Dividing stage T4 into T4a and T4b did not show significant differences in overall survival between the subgroups.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 42, Wednesday Morning