An assessment of left-digit bias in the treatment of older patients with potentially curable rectal cancer

Left-digit bias in surgical decision-making for lumbar spinal stenosis

BACKGROUND CONTEXT

Left-digit bias is a behavioral heuristic or cognitive "shortcut" in which the leftmost digit of a number, such as patient age, disproportionately influences surgical decisions.

PURPOSE

To determine if left-digit bias in patient age influences the decision to perform arthrodesis with instrumentation vs decompression in lumbar spinal stenosis (LSS).

DESIGN

Retrospective cohort.

PATIENT SAMPLE

Patients with an ICD-10 diagnosis of lumbar stenosis or spondylolisthesis identified in the 2017-2021 National Surgical Quality Improvement Program (NSQIP) database.

OUTCOME MEASURES

The primary outcome was the percent of patients who underwent arthrodesis with instrumentation (AwI). Matched age group comparisons without left-digit differences (ie, 76/77 vs 78/79, 80/81 vs 82/83, etc.) were performed to isolate the effect of the heuristic. Secondary outcomes including peri-operative events and complications were also compared within AwI and decompression cohorts.

METHODS

Using CPT codes, procedures were classified as either AwI or decompression. Patients were grouped into 6 cohorts based on 2-year age windows (74/75, 76/77, 78/79, 80/81, 82/83, 84/85). The cohorts were propensity matched with neighboring age groups based on the presence of spondylolisthesis, demographics, and comorbidities. The primary comparison was between those aged 78/79 vs 80/81.

RESULTS

After matching, the primary cohort consisted of two groups of 1,550 patients (aged 78/79 and 80/81). Patients aged 80/81 were less likely to undergo AwI than patients aged 78/79 (23.5% vs 27.2%, p=.021). AwI procedures occurred at similar rates between age groups with the same left digit. Within the decompression and AwI cohorts, there were no differences in secondary outcomes between patients aged 78/79 and 80/81.

CONCLUSIONS

LSS patients aged 80/81 are less likely to undergo AwI than patients aged 78/79, regardless of comorbidities. This was not seen when comparing patients with similar left digits in age. Until objective measures of physiologic capacity are established, left-digit bias may influence clinical decisions.

Practice Patterns for Organ Preservation in US Patients With Rectal Cancer, 2006-2020

Importance

In March 2023, the National Comprehensive Cancer Network endorsed watch and wait for those with complete clinical response to total neoadjuvant therapy. Neoadjuvant therapy is highly efficacious, so this recommendation may have broad implications, but the current trends in organ preservation in the US are unknown.

Objective

To describe organ preservation trends among patients with rectal cancer in the US from 2006 to 2020.

Design, Setting, and Participants

This retrospective, observational case series included adults (aged ≥18 years) with rectal adenocarcinoma managed with curative intent from 2006 to 2020 in the National Cancer Database.

Exposure

The year of treatment was the primary exposure. The type of therapy was chemotherapy, radiation, or surgery (proctectomy, transanal local excision, no tumor resection). The timing of therapy was classified as neoadjuvant or adjuvant.

Main Outcomes and Measures

The primary outcome was the absolute annual proportion of organ preservation after radical treatment, defined as chemotherapy and/or radiation without tumor resection, proctectomy, or transanal local excision. A secondary analysis examined complete pathologic responses among eligible patients.

Results

Of the 175 545 patients included, the mean (SD) age was 63 (13) years, 39.7% were female, 17.4% had clinical stage I disease, 24.7% had stage IIA to IIC disease, 32.1% had stage IIIA to IIIC disease, and 25.7% had unknown stage. The absolute annual proportion of organ preservation increased by 9.8 percentage points (from 18.4% in 2006 to 28.2% in 2020; P < .001). From 2006 to 2020, the absolute rate of organ preservation increased by 13.0 percentage points for patients with stage IIA to IIC disease (19.5% to 32.5%), 12.9 percentage points for patients with stage IIIA to IIC disease (16.2% to 29.1%), and 10.1 percentage points for unknown stages (16.5% to 26.6%; all P < .001). Conversely, patients with stage I disease experienced a 6.1-percentage point absolute decline in organ preservation (from 26.4% in 2006 to 20.3% in 2020; P < .001). The annual rate of transanal local excisions decreased for all stages. In the subgroup of 80 607 eligible patients, the proportion of complete pathologic responses increased from 6.5% in 2006 to 18.8% in 2020 (P < .001).

Conclusions and Relevance

This case series shows that rectal cancer is increasingly being managed medically, especially among patients whose treatment historically relied on proctectomy. Given the National Comprehensive Cancer Network endorsement of watch and wait, the increasing trends in organ preservation, and the nearly 3-fold increase in complete pathologic responses, international professional societies should urgently develop multidisciplinary core outcome sets and care quality indicators to ensure high-quality rectal cancer research and care delivery accounting for organ preservation.