Factors associated with one-year mortality after curative surgery for primary clinical T4 and locally recurrent rectal cancer in elderly patients

Introduction: Despite advancements in colorectal cancer care, one-year post-operative mortality rates remain high for elderly patients who have undergone curative surgery for primary clinical T4 rectal cancer (cT4RC) or locally recurrent rectal cancer (LRRC). This study aimed to identify factors associated with one-year mortality and to evaluate the causes of death. Materials & methods: This retrospective cohort study included patients aged >= 70 years who underwent surgery with curative intent for cT4RC or LRRC between January 2013 and December 2020. Clinical and follow-up data were collected and analyzed to determine survival rates and investigate factors associated with mortality within one year after surgery. Results: A total of 183 patients (94 cT4RC, 89 LRRC) were included. One-year mortality rates were 16.0% for cT4RC and 28.1% for LRRC (P = 0.064). In cT4RC patients, factors associated with one-year mortality were preoperative anemia (OR 3.83, P = 0.032), total pelvic exenteration (TPE) (OR 7.18, P = 0.018), multivisceral resections (OR 5.73, P = 0.028), pulmonary complications (OR 13.31, P < 0.001) and Clavien-Dindo grade >= III complications (OR 5.19, P = 0.025). In LRRC patients, factors associated with one-year mortality were TPE (OR 27.00, P = 0.008), the need for supported care after discharge (OR 3.93, P = 0.041) and Clavien-Dindo grade >= III complications (OR 3.95, P = 0.006). The main causes of death in cT4RC and LRRC patients were failure to recover (cT4RC 26.6%, LRRC 28.0%) and disease recurrence (cT4RC 26.6%, LRRC 60.0%). Conclusion: In order to tailor treatment in elderly with cT4RC and LRRC, factors associated with increased oneyear mortality (e.g. pre-operative anemia, TPE) should be incorporated in the decision-making process. Clinical trial registration: Not applicable.