Malignant colorectal obstruction: a university hospital 4-year retrospective case series

ABSTRACT

Background: In 2020, colorectal cancer (CRC) was the most diagnosed cancer and the 2nd leading cause of cancer related mortality in Portugal. Early detection and adequate treatment lead to improvements in mortality. Increasing participation in screening programs has been challenging and health authorities in Portugal reported that in 2018 only 40% of the target population had an up-to-date screening status. Not only screening but also access to specialized consultation and surgery seem to preclude timely treatment. The year 2020 brought forth another challenge as the SARS-CoV2 pandemic halted screening efforts and discouraged patients from seeking healthcare. We hypothesized that under these conditions an increase in colorectal obstruction and more advanced staging at diagnosis would be observed. Materials and Methods: We retrospectively identified the consecutive cases of malignant colorectal obstruction (MCO) that presented to the emergency department and demanded emergent surgery between January 1st 2017 and March 1st 2021. Recruitment was performed by reviewing operating room logbooks and electronic patient records. A total of 226 patients operated for colorectal obstruction were identified. Patients with benign disease or non-digestive primary were excluded and the 161 remaining cases were reviewed. Results: Median age of patients 72(29-97) years and female to male ratio of 11.3. Statistical analysis of complete years (2017-2020) observed an overall average of 39(±8.4) cases/year with no clear increasing trend. Previous CRC diagnosis had been established in 20.0%, 28.9%, 37.3% and 31.3% of cases in 2017, 2018, 2019 and 2020 respectively. Stage III or higher at pathological diagnosis was increasingly more frequent (62.9%, 76.3%, 76.5%, 81.3 %) but M status remained stable at an average of 42.7(±5.9)%. Surgical approach did not vary and in an average of 33.6(±2.7)% of patients, derivative surgery alone was indicated (palliation or bridge to therapy) and in 72.4(±1.0)% of patients, resection with ostomy was performed. Conclusions: The descriptive nature of this analysis hinders the accuracy of its conclusions but offers some insights. The incidence of MCO did not seem to vary, however our selection is biased as patients may have searched for emergent care in other hospitals. In the patients that evolve to obstruction, the delay in screening and treatment implementation seem to result in an increase in stage at surgery dependent on lymph node status as metastatic disease remained stable. It seems early to observe the effect of the pandemic on timely diagnosis and treatment, but it seems it contributed for a higher staging at diagnosis. It is possible we would find a similar effect on non-obstructive cases rather than an increase in MCO. A larger scope and prospective recruitment seem key to capturing this difference in outcomes.