Abstract 580P
Background
Primary tumor location (PTL) is a well-established prognostic factor in stage III and IV colorectal cancer (CRC), with right-sided CRC (RSCC) showing a worse prognosis compared to left-sided CRC (LSCC). However, the impact of PTL on stage II CRC remains uncertain. One explanation for these inconsistencies is the potential confounding effect of molecular biomarkers, such as MMR status. Therefore, there is a need to elucidate the prognostic value of PTL, as well as the role of biomarkers in this effect.
Methods
This study utilized observational data from a retrospective cohort obtained from the Belgian Cancer Registry (BCR). The study population comprised all patients diagnosed with pathologically confirmed stage II CRC in Belgium from January 1st, 2015, to December 31st, 2016 (n= 3,278). Information on PTL, demographics, pathologic T category (pT category), and molecular biomarkers (including MMR status, BRAF and KRAS mutations) was collected from the registry, along with vital status to calculate overall survival (OS). The primary aim of this study was to investigate the independent prognostic value of PTL in stage II CRC. Additionally, we assessed whether potential confounding factors, such as biomarkers and demographics, influenced the prognostic effect of PTL.
Results
In the univariate analysis, patients with stage II RSCC had a significantly worse OS compared to those with LSCC (including rectal cancer; p-value=0.0055 and excluding rectal cancer; p-value=0.0035). Higher age and pT4 were also significantly associated with worse OS. However, in the multivariable analysis, only gender, age, and pathologic T-stage were found to be significant predictors of OS. PTL was not a significant factor in multivariable analysis. Furthermore, biomarkers such as MMR-status, BRAF-, and KRAS mutations did not show a significant effect on OS in either analysis.
Conclusions
Our analysis led us to the conclusion that PTL is not an independent prognostic factor in stage II. Notably, we observed confounding effects between patient characteristics and the prognostic impact of PTL, such as older age at diagnosis and shorter OS in patients with RSCC. Furthermore, molecular biomarkers did not have a statistically significant effect on OS in stage II CRC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
University of Antwerp.
Funding
Antwerp University Hospital.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
548P - Diffuse midline gliomas H3K27-altered in adults, the experience of an oncology center
Presenter: Carolina Trabulo
Session: Poster session 10
561P - Risk of colorectal cancer and premalignant lesions after kidney transplantation
Presenter: Koen Zwart
Session: Poster session 10
562P - Quantifying the effect of colonoscopy and polypectomy rates in stage shift of colorectal cancer and reduced need for adjuvant chemotherapy
Presenter: Mina Sarofim
Session: Poster session 10
563P - The impact of participation in colorectal cancer screening: A population-based results from Lithuania
Presenter: Tomas Poskus
Session: Poster session 10
564P - A large-scale real-world study for colorectal cancer screening
Presenter: Song LIU
Session: Poster session 10
565P - Real-world data of early-onset colon cancer (early-onset CC) from the AIO colopredict plus (CPP) registry: Clinical and molecular characteristics, treatment and outcome
Presenter: Doreen Gisder
Session: Poster session 10
566P - Long-term survivorship outcomes of adolescents and young adults (AYA) with cancer of the lower gastrointestinal tract
Presenter: Winette Van Der Graaf
Session: Poster session 10
567P - Impact of concomitant medication on recurrence, survival and tolerability of chemotherapy in early colon cancer patients: Results from the PETACC 8 study
Presenter: Elisabeth Bergen
Session: Poster session 10
568P - Single cell AI-based detection of DNA mismatch repair deficiency in 1,988 colorectal cancers reveals prognostic and predictive value in the SCOT trial
Presenter: Faiz Jabbar
Session: Poster session 10
569P - Artificial intelligence for detection of mismatch repair deficiency in colon carcinomas (alliance)
Presenter: Frank Sinicrope
Session: Poster session 10