eP352 - Is Rectal Cancer More Aggressive in the Very Young (Age < 40)? Results of a Large Population Health Based Cohort

Sunday, June 2, 2024

10:27 AM – 10:32 AM ET, USA

Location: Baltimore Convention Center, Room 318-320

ePoster Presenter(s)

Vanessa Wiseman, MD

General Surgery Resident
Queen's University
Queen’s University
Kingston, ON, Canada

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Senior Author(s)

SP

Sunil Patel, MD

Associate Professor
Queens University
Kingston, Ontario, Canada

Disclosure information not submitted.

Author(s)

AF

Ameer Farooq, MD MPH FRCSC

Assistant Professor (Colorectal Surgeon)
Queen's University
Kingston, Ontario, Canada

Disclosure information not submitted.
SM

Shaila Merchant, MSc, MHSc, MD, FRCSC

Associate Professor
Queen's University
Kingston, Ontario, Canada

Disclosure information not submitted.
WK

Weidong Kong, MSc

Biostatistician
Queens University
Kingston, Ontario, Canada

Disclosure information not submitted.
TH

Timothy P. Hanna, MD PhD

Associate Professor
Queen’s University
Kingston, Ontario, Canada

Disclosure information not submitted.
Alessandro Ricci, MD

General Surgery Resident
Queen's University
Queen's University
Kingston, ON, Canada

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.
Tyler McKechnie, MD, MSc (he/him/his)

Resident Physician
McMaster University
McMaster University
Hamilton, ON, Canada

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.
Kelly Brennan, MSc, MD

General surgery resident physician
Queen's University
Queen's University
Kingston, ON, Canada

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Purpose/Background: The very young (age < 40) are a group of particular interest as they may have more aggressive rectal cancer. This group has typically been understudied due to very low incidence. To describe treatment and outcomes in the very young with rectal cancer from a population-based cohort.Methods/Interventions: This study includes those diagnosed between 2010 and 2019 in Ontario, Canada. We compared receipt of guideline adherent care (staging investigations, treatment and surveillance) and survival between those who were very young at diagnosis and other age groups. Appropriate statistical methods were applied.Results/Outcomes: A total of 18,632 individuals had rectal cancer during the study period, with those less than 40 represented 3% of this cohort (n = 575). This group had similar stage of presentation to the overall cohort (Stage I 25% vs. 29%; Locally Advanced 58% vs. 58%, missing 17% vs. 13%). Stage at presentation was similar between those less than 40 and the rest of the cohort (Stage I 18.6% vs. 22.8%; Locally Advanced 41% vs. 44%; Stage IV 24% vs. 19%; Missing 16% vs. 13%). Guideline adherent staging investigations was negatively associated with increasing age on adjusted analysis (OR 0.91, 95%CI 0.89 – 0.93 per 10 year increase), as was guideline adherent treatment (i.e. receipt of radiation, surgery and chemotherapy) in those with locally advanced disease. (OR 0.61, 95%CI 0.58 – 0.64 per 10 year increase). Five year overall survival was 92% in those with early stage disease (vs. 96% in those aged 40 – 49; 93% in those aged 50 – 59; 91% in those aged 60 – 69, P < 0.001) and 81% in those with locally advanced disease (vs. 85% in those aged 40 – 49; 85% in those aged 50 – 59; 79% in those aged 60 – 69, P < 0.001). Cox regression analysis, which included age at surgery, chemotherapy, sex, surgery year, preoperative radiation and income quintile demonstrated an association between age and survival. In those with locally advanced disease, age < 40 had similar hazards (referent group) as those age 60 – 69 (HR 1.11, 95%CI 0.72 – 1.69), which were worse than those age 40 – 49 (HR 0.86, 95%CI 0.53 – 1.4) and those age 50 – 59 (HR 0.70, 95%CI 0.45 – 1.09) (test of significance, P < 0.0003).Conclusion/

Discussion: The very young represents a small minority of those diagnosed with rectal cancer. The majority of those diagnosed had locally advanced disease with higher rates of radiation and chemotherapy then the rest of the cohort. Despite more aggressive treatment, survival in those with locally advanced disease was worse than those aged 40 – 49 or 50 – 59. Rectal cancer in the very young may be predisposed to genetically more aggressive forms of cancer compared to other age cohorts.