Nocardia Rubra Cell Wall Skeleton in Combination With Prior Second- or Third-line Regimens for the Treatment of Potentially Hazardous Colorectal Cancer SD Status

This is a prospective interventional clinical trial investigating the efficacy and safety of Nocardia rubra cell wall skeleton in combination with prior second- or third-line regimens for the treatment of potentially hazardous colorectal cancer SD (Stable Disease) status in the real world. Enrollment requirements were patients who had received prior second- or third-line therapy for advanced or metastatic colorectal cancer and presented with a potentially harmful SD status. The potentially hazardous SD (Stable Disease) state is defined as an increase in SLD (Sum of Longest Diameters) by less than 20% according to RECIST 1.1 criteria, with an absolute increase of SLD ≤ 5mm from the nadir; a serum CEA (Carcinoembryonic Antigen) level below 10.0 ng/ml during stable disease, with two consecutive measurements of 10 ng/ml or more (with a testing interval of at least one month); or a serum CEA level of 10 ng/ml or more during stable disease, with a gradual increase in CEA after two consecutive measurements (with a testing interval of at least one month); a serum CA19-9 level below 60.0 ng/ml during stable disease, with two consecutive measurements of 60 ng/ml or more (with a testing interval of at least one month); or a serum CEA level of 60 ng/ml or more during stable disease, with a gradual increase in CEA after two consecutive measurements (with a testing interval of at least one month). Meeting any one of the above criteria can be considered as the presence of a potentially hazardous SD state.