Primary tumor resection does not improve survival among patients with unresectable colorectal cancer metastases-But who determines resectability?

Phase angle as a prognostic biomarker in metastatic colorectal cancer: A prospective trial

BACKGROUND

Colorectal cancer (CRC) represents a major global public health issue, ranking as the third most common cancer worldwide. Given the substantial prevalence of CRC, there is a critical need to identify precise prognostic and predictive biomarker tools for better treatment outcomes. Phase angle (PA) has been proposed as a prognostic marker in various non-malignant and malignant clinical conditions.

AIM

To investigate the relationship between PA and survival outcomes in the first-line treatment of metastatic CRC (mCRC).

METHODS

In this prospective observational study, we obtained data on patients who started first-line systemic chemotherapy from the beginning of 2020 until the end of 2022. The PA, assessed by the bioelectrical impedance analysis scale, was evaluated as a possible prognostic factor for treatment outcomes, which were measured as progression-free survival (PFS) and objective response rate (ORR).

RESULTS

Using the cut-point value for PA set at 4.60°, 144 patients were divided into two cohorts. The high PA group of patients exhibited a significantly longer median PFS than the low PA group, 14.8 vs 10.5 months, respectively. No difference in ORR was observed. However, patients with PA ≥ 4.60° had a higher disease control rate.

CONCLUSION

PA represents a novel and objective pre-chemotherapy prognostic factor to identify mCRC patients who are at increased risk of a worse survival outcome.

Primary tumor resection in stage IV unresectable colorectal cancer: what has changed?

Most current guidelines do not recommend primary tumor resection in stage IV unresectable colorectal cancer. Rapid chemotherapy development over the last decade has substantially changed the decision making. However, results of recently published trials and meta-analyses suggest that primary tumor resection may in fact be beneficial, principally in terms of prolonged survival. Additional factors, such as use of minimally invasive approach or protocols of enhanced recovery after surgery, affect clinical outcomes as well, but are often neglected when discussing the state of the art in this area. There are still no randomized studies determining the legitimacy of upfront surgery in asymptomatic patients. Also, quality of life also plays an important role in choosing appropriate treatment. Having said that, there is no data that would prove whether primary tumor resection has an advantage on that issue. With all the uncertainty, currently decision making in unresectable stage IV colorectal cancer is primarily up to clinicians' knowledge, common sense and patients' preferences.