Symptom clusters and sentinel symptoms in colorectal cancer patients during post-operative chemotherapy.

Objective: This study aimed to identify the distribution characteristics, dynamic changes, and sentinel symptoms of symptom clusters in colorectal cancer patients undergoing post-operative adjuvant chemotherapy, providing a scientific basis for optimizing symptom management strategies. Methods: A prospective longitudinal study design was employed, using convenience sampling to recruit 220 colorectal cancer patients receiving their first post-operative chemotherapy from a tertiary hospital in Chifeng City, Inner Mongolia, from July 2024 to July 2025. The M.D. Anderson Symptom Inventory-Gastrointestinal Cancer Module (MDASI-GI) was used to assess symptoms after the 1st, 2nd, and 3rd chemotherapy cycles. Exploratory factor analysis was used to identify symptom cluster structures, generalized estimating equations were applied to analyze longitudinal changes in symptom severity, and the Apriori algorithm with association rule mining was employed to identify sentinel symptoms within each symptom cluster based on temporal precedence criteria. A total of 182 patients completed all follow-ups, with a loss-to-follow-up rate of 12.50% (calculated from 208 patients with valid T1 data). Results: Symptom burden increased progressively across chemotherapy cycles, with the average number of symptoms rising from 8.32 at T1 to 13.3 at T3. Fatigue, decreased appetite, and disturbed sleep were consistently the most prevalent symptoms, all reaching 96.7% by T3. Symptom cluster structure evolved from three clusters at T1 (gastrointestinal-nutritional, emotional-psychological, and sensory-neurological) to four clusters at T2 and T3, with the emergence of a distinct fatigue-pain cluster. All symptom severities increased significantly over time (P<0.001), with fatigue and constipation showing the most pronounced progression. Seven sentinel symptoms were identified across the three time points: in the gastrointestinal-nutritional cluster - taste changes (T1), nausea and diarrhea (T2), and abdominal bloating (T3); in the emotional-psychological cluster - disturbed sleep (T2), distress and sadness (T3). Conclusion: Colorectal cancer patients undergoing post-operative chemotherapy experience cumulative increases in symptom burden, with symptom cluster structures evolving dynamically throughout the treatment course. The identified sentinel symptoms represent potential monitoring targets that may inform proactive symptom management strategies, though further intervention studies are needed to validate their clinical utility.