Abstract 254P
Background
The watch-and-wait (WW) strategy has become increasingly adopted in the management of locally advanced rectal cancer (LARC), extending even to patients with clinical T4 (cT4) tumors. However, the efficacy and safety of this approach in patients with cT4 LARC, who face increased risks of both local and distant recurrences, lack substantial supporting data.
Methods
LARC patients with cT4 tumors were selected from the US National Cancer Database (2010-2020), comparing outcomes with surgical (Sx) versus non-surgical (NOM) treatment. Inclusion criteria: age 18-65 years, Charlson comorbidity index (CCI) 0 or 1, cT4cN+/- rectal cancer, receipt of neoadjuvant multi-agent chemotherapy, and radiation ≥ 45 Gray. These criteria aimed to reflect real-world scenarios of patients pursuing the WW strategy. Overall survival (OS) was compared between Sx and NOM cohorts using Kaplan-Meier methodology, both overall and after propensity score matching. Additionally, a multivariable Cox proportional hazard model was employed to explore the association between NOM and OS in the entire cohort.
Results
The analysis included 2,402 patients, of whom 2,071 (86.2%) underwent surgery. The median age was 54 years, with a predominant representation of non-Hispanic White individuals (73.2%), Charlson-Deyo scores of 0 (85.2%), and private insurance coverage (61.6%). The majority received treatment at academic (38.0%) or comprehensive community (29.4%) cancer centers. Patients in the NOM cohort demonstrated significantly lower OS compared to those undergoing surgery, with a 5-year OS rate of 44.5% (95% confidence interval [CI], 37.0-51.8) versus 72.5% (95% CI, 69.9-74.8; p < 0.001). NOM was associated with a median OS of 51.4 months (95% CI, 43.4-67.2) versus 131.5 months (95% CI, 122.4-not reached) in the Sx group (p < 0.001). These findings persisted in propensity score-matched analysis. Finally, multivariable regression analysis revealed NOM to be significantly associated with worse OS than Sx (Hazard Ratio, 2.73; 95% CI, 2.24-3.32).
Conclusions
In patients with LARC and cT4 tumors, a non-surgical strategy appears to confer significantly inferior overall survival compared to surgery.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.