Clinical Significance Of Postoperative Change Patterns Of Tumor Marker In Colorectal Cancer Patients

Objective: To investigate the correlation between tumor marker change patterns and the characteristics of relapse, the recurrence time and prognosis in colorectal cancer patients after surgery, and guiding clinical treatment and follow-up, and discuss the timing of early treatment for colorectal cancer patients after surgery, by building the model of slope.Methods: 1. Inclusion criteria:(1) Patients were initially diagnosed with primary colorectal adenocarcinoma through pathological examination and underwent surgery in our hospital to remove the tumors.(2) Postoperative TNM classification was defined as stages I – III.(3) CEA testing was routinely performed every three months, at least four consecutive times.(4) No other primary cancer was found in the first five years after operation;(5) No neoadjuvant chemotherapy was performed before operation.(6) Patients had complete follow-up data.(7) Patients received fluorouracil-based adjuvant chemotherapy after operation. 2. For the 165 patients, curve estimation was applied to each patient to obtain a linear model Y = ax + b, where ‘a’ represents the slope and ‘b’ represents a constant. The slopes of 165 patients were analyzed using the receiver operating characteristic(ROC) curve to obtain the area under ROC curve, the sensitivity, and the specificity. The index of correct diagnosis is equal to the difference between the corresponding sensitivity and(1-specificity). The corresponding value of the maximum index of correct diagnoses was determined as the best diagnostic cut-off point. 3. According to the index of correct diagnosis, the patients(n = 165) were divided into two groups, we compared the correlation between carcinoembryonic antigen(CEA) change patterns and the characteristics of relapse, the recurrence time and prognosis in colorectal cancer patients after surgery. 4. Statistical analysis: SPSS 17.0 was used for statistical analysis. The t-test was used to compare measurement data; the χ2-test was used to compare enumeration data. The Kaplan-Meier method was used in survival analysis. The log rank test was used to compare the differences in survival between groups. The testing standard was represented as α = 0.05.Results 1. According to the ROC curve(area under the curve > 0.5), the corresponding slope of the maximum index of correct diagnosis was 0.85. The patients(n = 165) were divided into two groups: the rapid elevation group(slope >= 0.85; n = 45; with 31 males and 14 females) and the slow elevation group(slope <0.85, n = 120; with 72 males and 48 females). 2. No significant differences were found for gender, age, tumor diameter, tumor location, and tumor differentiation, T stage(P> 0.05). The lymph node metastasis rates,the TNM stage,preoperative CEA, postoperative CEA with a significant difference between groups(P< 0.05). 3. At the end of the follow-up, a total of 106 people(64.2%) survived in the two groups. Ninety-six people(58.2%) had no recurrence and metastasis. There were significant differences in OS and DFS between the two groups(P< 0.01).In the stage I/II and stage III patients, There were significant differences in five-year survival and The median survival time between the two groups(P < 0.01) 4. Thirty-nine people(86.7%) in the rapid elevation group and 30 people(25.0%) in the slow elevation group experienced recurrence and metastasis, with a statistically significant difference between the two groups(P< 0.01). There was no statistically significant difference between local recurrence and distant metastases in the two groups. But there was significant statistically significant difference between single metastasis and multiple metastases, especially stage III(P=0.04). 5. There were 42 disease progression patients with first CEA raised before diagnosed, included 28 rapid elevation group patients and 14 slow elevation group patients with statistically significant difference(P=0.04).Conclusion: 1. No significant differences were found for gender, age, tumor diameter, tumor location, and tumor differentiation, T stage. The lymph node metastasis rates,the TNM stage,preoperative CEA,postoperative CEA with a significant difference between groups. 2. We found that the slope of postoperative CEA change was negatively correlated with the prognosis of colorectal cancer patients. The patients with steeper slope were more likely to experience the recurrence and metastasis of colorectal cancer, no matter in stage I/II patients or stage III patients.3. The slope size of CEA was associated with the number of tumor recurrences. The patients in the rapid elevation group had larger slopes than the patients in the slow elevation group and were prone to multiple metastases, whereas patients in the slow elevation group had smaller slopes and were more likely to have a single metastasis compared to patients in the rapid elevation group. Especially for stage III patients. 4. More patients of the slow elevation group received topical treatments than the rapid elevation group, so as the radical surgery. We recommend shorten the interval of recheck for the slow elevation group, and extend the rapid elevation group. 5. The time of first CEA raised in the rapid elevation group usually before diagnosed with high CEA of the first postoperative. The patients in rapid elevation group whether be the proper patients to chemotherapy with elevated tumor markers with negative imaging remains, and still need clinical trials to confirm.