The role of maintenance therapy in the first line treatment of metastatic colorectal cancer
Authors: D. Gridnev, A. Popov, E. Vozny, V. Makarov, D. Islamova, A. Kudryavtseva, A. Zhevelyuk, M. Trandofilov
Journal: Annals of Oncology (2018)

Introduction: The first line of chemotherapy is decisive in the treatment of colorectal cancer. Choosing the right one allows you to increase PFS and improve long-term results. Surgical treatment and maintenance therapy (MT) increase PFS and OS, as they can be prescribed at any stage of treatment. Methods: The analysis included 100 patients diagnosed with mCRC who received treatment between 2014 and 2018. The average age of the patients was 62.4 years. At the beginning of treatment, the overall condition of all patients was ECOG1. Primary mCRC had 67 (67%) patients. In 33 (33%) patients, locally advanced disease was first diagnosed, which were included in the study after progression. Only 27 (82%) of the patients received adjuvant therapy. PFS and OS for all patients were calculated from the start of the 1-line. Localization of the primary tumor in 19 patients (19%) was in the right part of the colon, and in the left part - in 81 (81%). Among the patients with primary metastatic disease 41 (61%) had isolated metastases, the remaining 26 (39%) had 2 or more localizations. Different types of surgical treatment of metastases in the liver received 20 (20%) patients. MT was performed in 58 (58%) patients by de Gramont regimen. The remaining 42 (42%) did not receive MT and made a comparison group. Evaluation of the effect was performed using RECIST criteria, at intervals of 3 months or the appearance of clinical symptoms of progression. The treatment was carried out before the progression. At the time of analysis, 39 patients are alive and continue to receive treatment. MT was provided in the second and subsequent chemotherapy lines. Results: In the general population in the group of patients receiving MT in the first line (group A) PFS-10 months that twice exceeds the same figure in the control group (group B) 5 months. OS in both groups was 29.6 months. When the primary tumor was localized in the left parts of the large intestine in group A (44 patients), PFS-10.5 months, OS-29.3 months VS group B (38 patients) PFS-6 months, OS-30.4 months. When the primary tumor was localized in right in group A (14 patients), PFS-9 months, OS-20.8 months VS group B (5 patients) PFS-4 months, OS-27.8 months. At metastatic lesion of only a liver in group A (41 patients) PFS-10 months, OS-29.0 months VS group B (33 patients) PFS-6 months, OS-31.0 months. With metastatic lesion of more than one organ in group A (17 patients) PFS-11 months, OS-27.4 months VS group B (9 patients) PFS-4 months, OS-9.3 months. In the presence of the primary disseminated disease in group A (44 patients) PFS-10.5 months, OS-25.8 months VS group B (23 patients) PFS-6 months, OS-14.2 months. With the progression of initially locally advanced disease in group A (14 patients) PFS-9 months, OS-33.0 months VS group B (19 patients) PFS 5 months, OS-34.3 months. Pre-existing chemotherapy (adjuvant) patients in group A (13 patients) PFS-8 months, OS-34.5 months VS group B (14 patients) PFS-10 months, OS-32.5 months. Untreated chemotherapy patients in group A (45 patients) PFS -11 months, OS-25.3 months VS group B (28 patients) PFS-6 months, OS-22.6 months. Conclusion: PFS increases with the inclusion of MT on the first line, without increasing the OS. A significant increase in PFS and OS during MT in the first line is observed in the group of those who did not receive chemotherapy before the first line. The appointment of MT in the first line is important for patients who have not received previous chemotherapy.