Investigation of factors affecting the efficacy of targeted therapies in patients with metastatic colorectal cancer

Aim: Colorectal cancer is one of the most frequent cancer type which has high mortality rate. Recently, with the improvement of cancer treatment, using targeted therapy give hope to metastatic colorectal cancer like as many other cancer types. With the use of targeted therapies for the treatment of metastatic colorectal cancer, the need to observe the effects of the disease on prognosis, mortality and morbidity has emerged. In this study, the aim is investigating effectiveness of targeted therapy to patients with metastatic colorectal cancer in cases of survival effect, progression free survival and caracteristics of tumors. Materials and Methods: In this study, patients which applied to Ankara Yıldırım Beyazıt University, Ankara Atatürk Training and Research Hospital, Department of Medical Oncology and gave colorectal cancer diagnosis between January 2010 and December 2018, older than eighteen years, evaluated as metastatic disease and took targeted therapy cure at least once. Patients files at Department of Medical Oncology archieve were uploaded to SPSS database retrospectively with information of demographical, clinical and patological with targeted therapy. Results: One hundred ten patients were included into the study. 67 (60.9%) of the patients were male and 43 (39.1%) were female. Tumor was located at right colon for 30 patient (27.3%), at left colon for 47 patient (42.7%), at rectum for 30 patient (27.3%) while for 3 patient (2.7%) tumor location was not specified. There were 63 patients diagnosed as metastatic disease (stage 4) at the time of diagnosis. Overall survival duration was measured as 40 months for patients who joined the study. Among targeted therapies, overall survival duration was measured as 28 month for patients who gave anti-VEGF while there is no survival time data for patients who gave anti-EGFR. There were 78 patients treated by targeted therapy at metastatic disease first step and there were 32 patients treated only by chemotheraphy. These patients has been progression free survival 12 and 9 months, respectively. Higher median value of PFS is more logical in terms of statistics for patients who took anti-EGFR at targeted therapy (p= 0.079). At first step targeted therapy, ortanca PFS values for 24 patients who receiving anti- EGFR was found 13 months while 48 patients who receiving anti-VEGF was found 9 months (p=0,068). At second step treatment, PFS estimated 7 months for 30 patients who receiving anti-VEGF and PFS estimated as 7 months for 26 patients who receiving anti-EGFR (p=0,283). Conclusion: In this study, overall survival time has been found as 40 months. With using targeted therapy, it has been investigated that average overall survival time was increased. In this study, patients who were treated by targeted therapies of median value of PFS was found 3 months higher than others.