67 Background: in Mexico, Colorectal Cancer (CRC) is a leading cause of cancer death, yet population-based screening programs are lacking. In our center, a cohort was created to validate a risk calculator to detect advanced colorectal neoplasia, and to understand barriers to implement a CRC screening program. We aimed to determine frequency and reasons associated to rejection of CRC screening in our population. Methods: from August 2019 to March 2020 (early close owing to COVID-19 pandemic) asymptomatic individuals between 50 and 75 years-old with standard-risk for CRC, without previous screening for CRC, from the outpatient internal medicine clinic at a tertiary care center in Mexico City, received standardized information on the importance of CRC screening and were invited to perform both Fecal Immunochemical Test and a screening colonoscopy within a clinical study at no cost. Individuals who rejected participation were given a 10-item questionnaire to select reasons for refusal, as many items as applied. Here we present two groups: 1) individuals who refused to receive information and to perform screening studies, and 2) individuals who refused to participate after receiving information. Results: 162 patients were invited to participate, 77 (47%) refused: 48 rejected immediately (group 1) and provided 51 reasons, and 29 declined after having received standardized information about CRC screening (group 2) and provided 30 reasons. Demographics for 77 patients were: 54 (70.1%) women, median age 66 (IQR 58-71) years. Main reasons for rejection in both groups were: “I do not have time” in 24 (29.6%) times, “I am not interested” in 23 (28.4%) times, and “I am scared” in 14 (17.3%) times (Table). Conclusions: in our cohort, we identified that nearly half of the population invited to participate in a CRC screening program refused. Main reasons were lack of time, lack of interest and fear. This may translate poor understanding on the importance of measures to prevent CRC, and absence of education programs to recall its importance. In order to increment participation in CRC screening, education and awareness campaigns should be implemented.[Table: see text]

327 Background: Advanced gastric cancer (GC) is a disease with high morbidity and poor prognosis. We hypothesize that different sites of metastasis have different impact in terms of symptoms and complications. We sought to evaluate if site specific morbidity in our patients impacted treatment and survival. Methods: Medical records from patients with advanced GC treated from Jan 2005 to Dec 2015 were retrospectively reviewed. Morbidity was defined as having any symptom by metastases in a specific site. OS was estimated by Kaplan Meier method and compared by Log-rank test. P value < 0.05 was considered significant. Results: We included 180 consecutive patients, median age at diagnosis was 56 years (21-90), 55% were women. Most common sites of metastases were: peritoneum 76.1%, non-regional lymph nodes 38.9%, liver 22.8%, lung 26.7%, bone 9.4% and ovary 12.8%. Regarding morbidity, at diagnosis 68% of patients presented morbidity by the primary tumor: obstruction 56%, bleeding 27%, obstruction and bleeding 3%, other 14%. Disease by peritoneum caused morbidity in 30%, by lung in 8%, by ovarian in 4.4%, by lymph nodes in 3.3%, and by other sites in 5.6% of patients. OS in the global cohort was: 3.53 months (2.2 to 4.8), nevertheless by univariate analysis we found that OS was affected by morbidity at some sites as it is show in table. More patients with peritoneal morbidity could not receive treatment vs those without peritoneal morbidity (p = 0.042). Conclusions: We found that morbidity in peritoneum, lung and ovary adversely affected prognosis of patients with advanced GC. Moreover, peritoneal morbidity preclude patients from receiving oncological treatment. [Table: see text]

319 Background: gastric cancer is common in Mexico. Evaluation of treatment strategies is greatly important in early gastric cancer. National institutions rarely report their outcomes, limiting feedback and policy improvements. Methods: single-center retrospective review of patients with histologically confirmed localized gastric cancer diagnosed from Jan 2005 to Dec 2017. Overall survival (OS) and recurrence-free survival (RFS) were estimated by Kaplan-Meier curves and compared with log-rank rest. A p value < 0.05 was significant. Results: we included 78 cases, median age 63 years, 52.6% men. Surgery was the initial treatment in 46 patients (59%) and 87% achieved R0 resection. Adjuvant treatment was administered to 63% of patients. 29 patients (37.2%) started perioperative chemotherapy with 86.2% of them being resected, and 75.9% having R0 resection. 13 patients (44.8%) also received postoperative chemotherapy. Better performance status (p=0.036) and lower albumin levels (p=0.039) were found in patients with initial surgery vs those with perioperative chemotherapy. At the time of surgery, most patients had stage III disease in both groups but 5 patients had M1 disease despite negative initial laparoscopy in the chemotherapy group and 5 patients did not require aduvant tx given early stage in the surgery first group. Median OS and RFS are reported in table. Conclusions: Most patients in our center undergo initial surgery. We report a differential survival according to initial treatment. More advanced disease in chemotherapy first group may explain differences. Given non-random assignment, we could not show survival benefit of chemotherapy treated patients. [Table: see text]

e13518 Background: COVID-19 detection in a timely manner in patients (pts) undergoing anticancer treatment is essential. RT-PCR test for SARS-CoV2 is the diagnostic gold standard, however it is a potentially limited resource in our setting. As an alternative, clinicians have developed symptom-based questionnaires as a screening tool for the detection of COVID-19 to optimize resources. The predictive efficacy of these tools in pts with cancer and healthcare personnel (HCP) who treat them has not been evaluated. Our objective was to describe the findings of the follow-up through an online clinical tool in our cohort, and determine its predictive performance compared against the gold standard. Methods: Data was obtained from a follow-up cohort of HCP and pts attending the chemoradiotherapy unit of a tertiary hospital designated as a COVID-19 priority facility in Mexico City . The follow-up period was from June 12 to September 30, 2020, and consisted of a 10-item clinical questionnaire (CQ) on respiratory symptoms and contact with patients diagnosed with COVID-19, collected daily electronically or by telephone . In addition, RT-PCR for SARS-CoV2 was performed every two weeks. The CQ was considered as a positive screening test if in the period between the biweekly RT-PCRs the participants had reported symptoms or contact. Results: We included 130 asymptomatic participants. 44.6% (n = 58) were HCP and 55.3 % (n = 72) were pts. Within a median follow-up of 85 days (IQR 48-103) a total of 8970 CQ were completed, 48.3% (n = 4335) were answered by HCP and 51.6% (n = 4635) by pts. 4.03% (n = 175) of CQ returned positive in HCP and 0.77% (n = 36) in pts. 634 nasopharyngeal swabs for SARS-CoV-2 RT-PCR were performed, 13.5% (n = 18) of the participants tested positive for SARS-CoV2 infection. When we evaluate within the biweekly period, the CQ for symptoms or contact was found to be a positive screening test in 12% (n = 78). If we applied the standardized definition of COVID-19 suspicious case used at our center, the CQ was found to be positive just in 3.9% (n = 25). The CQ as a general screening tool gave a sensitivity (SN) of 33.3%, specificity (SP) of 88.3%, a positive predictive value (PPV) of 7.6% and a negative predictive value (NPV) of 97.8%. Using the standardized definition, CQ gave a SN of 38.8% and a SP of 97.07%, a PPV of 28% and a NPV of 98.1%. Conclusions: Screening based on self-reporting of symptoms and contact through a questionnaire demonstrated low sensivity but high specificity in our cohort. When we applied a standardized definition of COVID-19 suspicious case, the clinical performance improved. RT-PCR testing remains as the gold standard to detect COVID-19 and should be preferred in patients undergoing anticancer treatment. Nevertheless, clinical questionnaires are an accessible tool for follow-up.

e16105 Background: Regarding cancer care, health system in Mexico is characterized by heterogeneous medical and technical infrastructure among institutions. Limited access to specialized surgeons, radiation therapy and medications may differ and affect survival. Our institution has surgeons, medical oncologists and radiation therapy for the treatment of uninsured low-income patients with RC. The institution does not provide chemotherapy or biologic therapy. Our aim was to describe treatment modalities and outcomes in patients (pts) with RC treated in a referral center in Mexico. Methods: A retrospective database of all consecutive pts with histological diagnosis of rectal adenocarcinoma evaluated at our institution from January 2010 to December 2016 was created. Clinical and pathological variables at diagnosis and treatment modalities were recorded. Overall survival (OS) was estimated using Kaplan-Meier method and compared by log rank test. Results: 99 pts were included, 61.6% male gender. Median age was 61 y/o (range 19 – 97). EGOG PS 0 – 1: 86%. 69% were moderately differentiated. Tumor location: lower (25%), middle (57%), and upper third (18%). Clinical stage (CS) was localized (T1-2, N0 M0) 5%, locally advanced (T3-4, or N+) 71% and advanced (M1) 24%. Treatment modalities (TM) by stage are presented in the Table. For those with advanced disease, 58% had metastasis in one site. RAS and BRAF mutation determination was performed in 21%. 5-year survival rate: 56%. Median OS (months): 25.3 for localized, 103.1 for locally advanced and 18.6 for advanced disease (P = 0.001). Conclusions: In our center, pts with local and regional RC had treatment according to international guidelines and survival was not compromised. On the contrary, limited access to systemic therapy affected patients with advanced disease and decreased survival was documented. To improve survival in patients with advanced disease, health policy adjustments to incorporate systemic treatment coverage are required. [Table: see text]