Retrospective evaluation of patients diagnosed with colorectal cancer

Aim: Our study was conducted to evaluate the general characteristics, clinical and laboratory findings, histopathological features, treatments received and survival data of colorectal cancer patients. Materials and Methods: This study was conducted retrospectively by scanning the file archives of patients who applied to the Oncology Polyclinic of Zonguldak Bülent Ecevit University (ZBEU) Faculty of Medicine Hospital between January 2015 and December 2020 via HBYS (Hospital Information Management System). The study included patients with available file data, over the age of 18, and diagnosed with colorectal cancer. Patients under the age of 18 and pregnant women were not included in the study. The patients' age, gender, epicrisis information, radiological images, laboratory results, pathology and treatment reports were evaluated. Results: A total of 172 patients were included in the study. The mean age at diagnosis was calculated as 59.82±13.72 years. 62 (36.00%) of the patients were female and 110 (64.00%) were male. While 64 (37.2%) of the patients had a history of smoking, 108 (62.8%) did not. 110 (64%) of the patients had comorbidities, while 62 (36%) had no comorbidities. The mean survival time of patients with a history of coronary artery bypass grafting (CABG) and heart failure (HF) was significantly lower compared to those without (p=0.001, p=0.039, respectively). In our study, the rate of anemia was significantly higher in right-sided colon tumors compared to left-sided colon (p=0.008). The rate of hematochezia and changes in bowel habits was significantly higher in the left colon compared to the right (p=0.004, p=0.030). At the time of diagnosis, 17 (9.9%) patients were stage 1, 70 (41.9%) were stage 2, 38 (22%) were stage 3, and 45 (26.2%) were stage 4. Staging could not be performed in 2 (1.2%) patients. Metastases were present in 45 (26.2%) of the patients at the time of diagnosis, while no metastases were present in 127 (73.8%) patients. According to the metastasis sites, 37 (82.2%) had liver metastases, 15 (8.72%) had multiple metastases, 13 (28.8%) had peritoneal metastases, 9 (20%) had lung metastases, 5 (11.11%) had bone metastases, and 1 (2.2%) had brain metastases. Adenocarcinoma was detected in 154 (89.5%) of the patients, mucinous carcinoma in 13 (7.6%), neuroendocrine tumor in 2 (1.2%), signet ring cell carcinoma in 2 (1.2%), and malignant mesenchymal tumor in 1 (0.58%). The mean survival time of patients with lymphovascular invasion (LVI) was 79.29±5.90 months, while the mean survival time of those without LVI was 85.82±3.55 months. There was no significant difference in mean survival times between patients with and without LVI (p=0.375). The mean survival time of patients with perineural invasion (PNI) was 73.40±5.62 months, while the mean survival time of those without PNI was 89.85±3.44 months. There was a significant difference in survival times between patients with and without PNI (p=0.014). 24% of the patients in our study had K-ras mutations, 20% had wild-type K-ras, and the ras mutation status was unknown in 56%. There was no significant relationship between K-ras mutation and gender (p=0.873). Preoperative CEA levels were high in 71 (46%) of the 152 patients whose preoperative CEA levels were available, and normal in 81 (54%). The mean survival time of patients with high CEA levels was significantly lower compared to those with normal CEA levels (p=0.000). Preoperative CA 19-9 levels were high in 33 (19%) of the 164 patients whose preoperative CA 19-9 levels were available, and normal in 133 (81%). The mean survival time of patients with high preoperative CA 19-9 levels was significantly lower compared to those with normal CA 19-9 levels (p=0.000). In the 113-month follow-up period of the patients, 133 (77%) of the 172 patients in our study received adjuvant chemotherapy. 22 (48%) of the 46 rectal cancer patients received neoadjuvant radiotherapy, and 10 (22%) received adjuvant radiotherapy. 14 (30%) did not receive radiotherapy due to comorbidities and advanced stage disease. 7 (15%) of the stage 4 colorectal cancer patients received palliative radiotherapy. Palliative radiotherapy was found to have no statistically significant effect on survival. The mean survival time of patients who did not receive palliative radiotherapy was 17.33±5.05 months and the median survival time was 12.00±4.90 months. In those who received palliative radiotherapy, the mean survival time was 30.31±4.08 months, and the median survival time was 23.00±3.64 months Conclusion: In our study, as in the literature data, it was determined that the stage at diagnosis, the presence of comorbidities such as heart failure and coronary bypass, high CEA and CA 19-9 levels, and the presence of perineural invasion play an important role in the prognosis of patients. The most common histological type is adenocarcinoma. Considering that rectum and rectosigmoid involvement are predominant, rectosigmoidoscopy will be beneficial in many cases during the diagnosis phase. Key words: Colorectal cancer, prognosis, survival rate, retrospective study.