# Minimally invasive surgical resection reduces one-year mortality, especially in high-risk colon cancer patients: an emulated trial

## TL;DR

Minimally invasive surgery for colon cancer reduces one-year mortality, especially in high-risk patients, but access to this surgery is unequal.

## Contribution

The study uses an emulated trial to show that minimally invasive surgery lowers mortality in high-risk colon cancer patients compared to open surgery.

## Key findings

- MIS resection was associated with a 3.8% reduction in one-year mortality compared to open surgery.
- High-risk patients, including the elderly and those with comorbidities, experienced the largest mortality reductions with MIS.
- Higher-risk patients were less likely to receive MIS resection despite greater potential benefits.

## Abstract

Comorbidity, older age, frailty and socioeconomic deprivation are associated with higher risk of complications and death following resection for colon cancer. Minimally invasive surgical (MIS) resection is associated with earlier recovery, fewer postoperative complications and potentially lower early mortality than open surgical (OS) resection. We investigated the likelihood of receiving MIS vs OS resection by patient characteristics, and whether MIS resection reduces mortality after elective resection for colon cancer.

We analysed cancer registration data linked to secondary care records of 21,931 patients diagnosed with stage I-III colon cancer in NHS Trusts in England, in 2021 and 2022. We focused on elective operations completed as either MIS resections or OS resections. We used an emulated trial to estimate the impact of MIS resection on one-year mortality (expressed as Average Treatment Effect) compared with OS resection. Inverse-probability-weights with regression adjustment ensured comparability between the surgical groups.

MIS resection was attempted in 18,264 (83.3% of 21,931) patients and completed in 16,271 (74.2% of 21,931), among whom higher levels of deprivation, frailty, comorbidity and stage at diagnosis were independently associated with lower odds of receiving MIS resection. Observed one-year mortality was 7.7% after OS resection (436 deaths among 5660) vs 2.9% after MIS resection (472 deaths among 16,271). In the emulated trial, the average treatment effect of MIS resection was a reduction in one-year mortality from 6.8% to 3.0%; with the largest absolute reductions among patients aged 85 years or more, frail patients, and those with major comorbidities.

The emulated trial confirms that MIS resection for colon cancer reduces mortality at one year, compared with OS resection. However, patients in higher-risk groups, who were most likely to benefit from MIS resection, were less likely to receive it. The NHS needs to eliminate ongoing inequalities in optimal surgery for colon cancer.

10.13039/501100000289Cancer Research UK C7923/A29018; 10.13039/501100000265Medical Research Council MR/T032448/1 and MR/W021021.