Modified CXI predicts survival in CRC after surgery

The modified cachexia index (mCXI) is effective in predicting the survival outcomes in patients with colorectal cancer (CRC) following radical surgery, reports a study.

“Moreover, in the context of predicting the prognosis following radical surgery for CRC, the mCXI demonstrated outstanding predictive ability to that of the CXI, signifying its effectiveness as a valuable prognostic indicator in the clinic,” the researchers said.

A retrospective analysis was conducted in 215 patients with newly diagnosed CRC. The receiver operating characteristic (ROC) curves were used to establish an optimal cutoff value of mCXI for predicting prognosis.

The researchers used Kaplan–Meier curves and Cox regression analysis to examine the prognostic implications of mCXI. They also performed a comparative assessment of the predictive ability between mCXI and CXI using time-dependent ROC analysis.

Patients were grouped into two based on the cutoff value of mCXI: the low mCXI group (n=60) and the high mCXI group (n=155). At 3 years, patients in the low mCXI group had significantly worse overall survival (76.6 percent vs 96.7 percent; p<0.01) and recurrence survival (68.3 percent vs 94.1 percent; p<0.01) than those in the high mCXI group. [Eur J Clin Nutr 2024;78:880-886]

Results of the multivariate analysis supported the above findings, with mCXI shown to be independently associated with overall survival (hazard ratio, 8.951, 95 percent confidence interval, 3.105–25.807; p<0.01). In addition, mCXI (AUC, 0.801) demonstrated better predictive efficacy than CXI (AUC, 0.723), indicating that mCXI was “more suitable for prognostic assessment.”

“The mCXI significantly correlated with survival outcomes for colorectal cancer patients after radical surgery,” the researchers said.

Biomarker

Regarded as a potential biomarker of cancer cachexia, CXI is determined using the formula SMI*ALB/NLR, with SMI derived from measuring the skeletal muscle area in the L3 slice level of the abdominal CT, serum albumin, and NLR dependent on the preoperative blood draw. [J Cachexia Sarcopenia Muscle 2021;12:2211-2219; Ann Surg 2015;261:345-352]

“The assessment of skeletal muscle in the third lumbar spine cross-section on preoperative abdominal CT scan was widely recognized as a reflection of the skeletal muscle mass in the body,” according to the researchers. Moreover, research has demonstrated the usefulness of SMI as a prognostic factor for patients with CRC.” [JAMA Surg 2020;155:942-949; Arch Med Sci 2021;17:361-367]

Cancer cachexia, a multifactorial syndrome, is marked by weight loss and depletion of skeletal muscle and adipose tissue. The depletion of skeletal muscle mass is a major characteristic of this syndrome, while malnutrition and systemic inflammation due to tumour progression are common among patients with cancer cachexia. [Trends Cancer 2018;4:849-860; Cancer Manag Res 2020;12:5597-5605]

“It is noteworthy that cancer cachexia contributes indirectly to the mortality of 20 percent of cancer patients, with its incidence reported to be approximately 50 percent in CRC patients,” the researchers said. [Nat Rev Cancer 2014;14:754-762]

“CRC patients’ prognosis and quality of life are substantially affected by cancer cachexia,” they added. [Int J Mol Sci 2021;22:1565]