Gastrointestinal cancers: cachexia associated with more complications after surgery, with very uncertain evidence

A review focused on treatment outcomes

Cachexia is a major nutritional problem in patients with gastrointestinal cancers. The researchers wanted to determine whether it was associated with adverse outcomes related to surgery, chemotherapy or radiotherapy.

They searched five databases for studies. The 34 included studies were cohorts, not trials testing an intervention for cachexia. The review also examined length of hospital stay and readmissions. The supplied abstract does not specify follow-up durations.

An association after surgery, not an estimate of individual risk

Cachexia was associated with higher odds of postoperative complications: the odds ratio was 1.38, with a 95% confidence interval of 1.11 to 1.72. This finding does not mean that every patient has a 38% higher risk of complications. Without a baseline frequency of complications, which is missing from the abstract, the increase in absolute risk cannot be calculated.

Hospital stays were also longer in patients with cachexia. The abstract reports a mean difference but does not specify its unit, so this finding cannot be translated into a number of days.

Chemotherapy and radiotherapy remain blind spots

No statistically significant association was observed for chemotherapy-related adverse effects. However, the estimate remains imprecise: the odds ratio was 1.42, with a confidence interval of 0.57 to 3.54. This lack of a significant finding therefore does not demonstrate the absence of an association.

No study on the adverse effects of radiotherapy met the inclusion criteria. Only one study addressed readmissions, preventing a quantitative synthesis of these two outcomes.

A clinical signal, not proof of a nutritional solution

All pooled analyses showed considerable to substantial heterogeneity: results varied widely between studies. With very low overall certainty, the authors consider their conclusions inconclusive.

This review draws attention to the association between cachexia and adverse postoperative outcomes. It does not show that a supplement, diet or nutritional intervention reduces these complications: none of these strategies was tested by the research question examined.

What we can take away

Cachexia is associated with less favorable postoperative outcomes in gastrointestinal cancers. The evidence remains too uncertain to establish causation or infer the effectiveness of a nutritional intervention.