Regional anesthesia not linked to recurrence of colorectal cancer after surgery, suggests study

General or regional anesthesia's effect on colorectal cancer recurrence after surgery

The research study evaluated the recurrence of colorectal cancer (CRC) under general anaesthesia (GA) or regional anaesthesia (RA) in patients undergoing CRC surgery, along with the impact of anaesthetic agents on the immune system, neuroendocrine response, and the metastatic process. The study also discussed the implications of primary tumour location and tumour stage on the recurrence rate and the overall survival of patients with early-stage CRC.

Systematic Review Methodology

The authors performed a systematic review following PRISMA and SWiM guidelines, including studies that evaluated the effects of GA or RA on CRC recurrence. They conducted an electronic literature search and selected six studies for the review, with a total of 58,075 patients undergoing CRC surgery. The included studies utilized various anaesthetic agents and techniques, such as total intravenous anaesthesia (TIVA), inhalational anaesthesia, epidural anaesthesia, and spinal anaesthesia. The risk of bias and quality assessment for the included studies were evaluated using the Newcastle-Ottawa Scale (NOS).

Primary and Secondary Outcomes

The primary outcome of interest was cancer recurrence after surgery, while secondary outcomes included disease-free survival (DFS), overall survival, and mortality. The review revealed no significant association between anaesthesia type and CRC recurrence. Additionally, no conclusive improvement was found in DFS. The evidence quality was deemed very low for cancer recurrence and low for DFS, thus leaving scope for further studies with larger sample sizes and longer follow-up periods to determine the association between CRC recurrence and anaesthesia.

Factors Contributing to Recurrence

The authors discussed the potential factors contributing to recurrence or metastasis after cancer surgery, including minimal residual disease, surgical stress, and the use of anaesthetic agents and techniques, which may affect the immune and inflammatory responses. Furthermore, they highlighted the conflicting findings on the impact of different anaesthetic agents on cancer recurrence in various types of cancer and the need for further prospective clinical trials to elucidate the role of anaesthetic agents on cancer recurrence and prognosis.

Concluding Remarks on CRC Recurrence

In conclusion, the review found no significant association between regional anaesthesia and CRC recurrence. However, the authors emphasized the limitations of the existing studies, including various confounding factors, and highlighted the need for further well-designed randomized controlled trials to establish the relationship between CRC recurrence and anaesthesia.

The study identified limitations in the existing literature and suggested the need for larger prospective clinical trials to address these limitations and provide clearer insights into the impact of anaesthesia on CRC recurrence.

Reference –

Chachra, Alisha; Gunashekar, Satheesh; Kumar, Ajit; Thakur, Nitish; Jagath, Arun. Impact of general or regional anaesthesia on recurrence of colorectal cancer after surgery: Systematic review. Indian Journal of Anaesthesia 67(12):p 1061-1070, December 2023. | DOI: 10.4103/ija.ija_478_23