Colorectal cancer (CRC) continues to be one of the leading causes of cancer-related deaths worldwide, prompting research aimed at identifying reliable prognostic indicators. A recent study from Teikyo University Hospital has found the systemic inflammation response index (SIRI) to be significantly associated with patient outcomes following curative surgery.
The retrospective study analyzed data from 406 patients who underwent surgery for Stage I-III colorectal cancer between 2012 and 2017. Prior to surgery, the patients' SIRI levels were determined based on their neutrophil, monocyte, and lymphocyte counts. The researchers categorized patients as having low SIRI (≤ 1700) or high SIRI (> 1700), with the aim of establishing the index as a prognostic factor for recurrence-free survival (RFS) and overall survival (OS).
Patients with high SIRI levels exhibited statistically significant poorer 5-year RFS and OS when compared to their low SIRI counterparts. Specifically, the study found high SIRI to be independently predictive of 5-year RFS (p = 0.045) and OS (p = 0.048). According to the results, 5-year RFS rates were 65.9% for high-SIRI patients compared to 81.9% for low-SIRI patients, with 79.4% OS for the former versus 90.1% for the latter.
These findings stress the relevance of SIRI as part of the clinical assessment for CRC patients after surgery. "The high-SIRI level is significantly associated with a poorer prognosis for patients diagnosed with CRC," the authors communicated. They emphasized the need for incorporating inflammatory markers like SIRI to refine prognostic predictions beyond standard structural classifications like tumor stages and grades.
While traditional TNM staging has been the cornerstone of cancer prognosis, the disparities observed among patients with the same stage motivate the search for additional predictive indicators. The authors pointed out, "SIRI may complement the use of TNM staging by providing insight what was not captured by standard pathological assessments." This study encourages the integration of inflammatory response assessments alongside established staging systems.
Introduced relatively recently, SIRI is calculated using the formula: SIRI = (neutrophil count × monocyte count) / lymphocyte count. It reflects the host's inflammatory status and its effects on tumor progression, presenting important information about the systemic inflammatory response following surgery. The study highlighted several mechanisms by which inflammation can influence cancer prognosis, advocating for the use of SIRI as it encompasses the complexity of immune interactions with tumors.
Despite the compelling evidence, the authors noted concerns about the study's retrospective nature and the single-institution design, which can influence broader applicability. Different surgical approaches and the validity of the established SIRI cut-off values across wider cohorts require evaluation through future prospective, multi-center studies.
Overall, this promising research on SIRI as a biomarker emphasizes the importance of addressing inflammation to improve prognostic assessments. Such innovations can drive more personalized and effective treatment strategies for colorectal cancer patients.