of 10,575 asymptomatic participants were enrolled in PRENEC. Participants with positive immunochemical fecal occult blood test (iFOBT) results or a family history of CRC underwent colonoscopy. The colonoscopy results from a similar, previous project in Chile (PREVICOLON) were compared with those from PRENEC. Furthermore, the initial colonoscopies of 1562 participants in PRENEC were analyzed according to whether the colonoscopists were from TMDU or Chile. RESULTS: The complete colonoscopy, adenoma detection, and cancer detection rates were 88.0%, 26.7%, and 1.1%, respectively, in PREVICOLON, while the corresponding values were 94.4%, 41.8%, and 6.0%, respectively, in PRENEC. In PRENEC, 107 cases of CRC were detected, amounting for 1.0% of all participants. Considering initial colonoscopies in PRENEC, the complete colonoscopy, adenoma detection, and cancer detection rates were 97.4%, 45.3%, and 9.3%, respectively, for physicians at TMDU and 93.3%, 41.5%, and 5.1%, respectively for Chilean physicians. The detection rates of intramucosal cancer were 7.3% and 3.7%, respectively, for TMDU and Chilean physicians. CONCLUSIONS: Quality indicators of colonoscopy substantially improved from PREVICOLON to PRENEC. The assessments made by Chilean physicians alone were improved in PRENEC, but remained better in the TMDU group. Moreover, physicians from TMDU detected more CRCs than Chilean physicians, especially at earlier stages. Cancer 2016;122:71-7. V C 2015 American Cancer Society.KEYWORDS: adenoma detection rate, colorectal cancer, colonoscopy, diagnostic techniques and procedures, international cooperation, screening, training programs. INTRODUCTIONColorectal cancer (CRC) is the third most common cancer and the fourth most common cause of mortality in the world, accounting for approximately 694,000 deaths in 2012. 1 Although CRCs have generally been more common in the countries of North America, Oceania, and Europe, the incidence of CRC in Asian and South American countries has increased considerably during the past decade. In Chile, mortality from CRC has increased rapidly over the past 15 years, 2 and the prevention of CRC has come to be recognized as an urgent issue that might be addressed through organized screening systems.Some studies have reported that screening with a fecal occult blood test (FOBT) has reduced CRC mortality and have suggested FOBT as a suitable population-based screening test for CRC. [3][4][5] Screening for CRC with FOBT not only leads to the detection of advanced CRCs, but also results in detection at earlier clinical stages. 6 Another advantage of screening with FOBT is that the removal of adenomatous, precancerous polyps can decrease the incidence of CRC 7,8 and consequently reduce mortality from CRC. 9 In particular, immunochemical FOBT (iFOBT) has been shown to be more sensitive than guaiac-based FOBT. 10 Reduced mortality and the detection of CRC in earlier stages results in high costeffectiveness and lowered health costs for both patients and the government. 11 In Chile, a prospective mult...

(Rev Med Chile 2018; 146: 685-692)

In Chile, the mortality from colorectal cancer has been on the rise. A national screening program based on a fecal immunochemical test was started in 2012 as an international collaboration with Japan. This case-control study was designed to identify the risk factors for colorectal cancer, with a goal of increasing the participation rate for colorectal cancer screening. In accordance with the Strengthening the Reporting of Observational Studies in Epidemiology guidelines, we conducted a case-control study from 2012 to 2017; 23 845 asymptomatic participants were enrolled in the study. Participants who were fecal immunochemical test-positive or had a family history of colorectal cancer underwent a colonoscopy. We analyzed the odds ratio of the risk factors for colorectal cancer, including sex, age, family history, BMI, hypertension, diabetes, regular use of nonsteroidal anti-inflammatory drugs, alcohol consumption, smoking, physical activity, and daily intake of certain food items. For the screening program, 202 cases of colorectal cancer were detected, and 195 of them were evaluated pathologically after resection. Of these, 173 cases (88.7%) had colorectal cancer stage 0/1, 151 (77.4%) of which were treated with endoscopic resection. In the multivariate analysis, male sex, family history of colorectal cancer, and low intake of cereals or fibers were closely related to a high colorectal cancer incidence. Moreover, participants in their 60s and 70s had a higher incidence of colorectal cancer than those in their 50s. These results suggest that intensive screening of the high-risk population can help in improving the detection of colorectal cancer, whereas higher consumption of cereals or fibers can be effective in preventing its onset.

Drilling exploratory wells in Campos Basin shallow water has been done before. However, if you put in place an aggressive exploratory campaign to drill 40 wells in less than 2 years, with more than 4 semi-submersible rigs new to the area and all for a recently created operating company, you are facing quite a challenge.The lithology of the wells in block C-M-592, pore pressure profiles and the requirement for formation evaluation while drilling are challenges that needed to be addressed in the design and drilling of these wells. In addition, multiple bit trips, low ROP, and high drilling vibrations have also contributed to increased non-productive time (NPT) with the associated costs.An integrated approach to engineering and real time monitoring has been the key to controlling the operations and understanding block C-M-592 in Campos basin. In addition, the application of appropriate new technologies along with standardized, fit-for-purpose practices that have been implemented since the beginning of the drilling campaign have resulted in performance improvements.

The Upper Cretaceous is a challenging drilling environment in Santos Basin, offshore Brazil. The lithology consists of highly intercalated layers of sandstone, siltstone and conglomerate from Santos and Jureia Formations. These formations are drilled vertically in 17 ½" intermediate hole and the length of the section varies from 1600 m up to 2000 m. Optimizing the drilling efficiency in this section is crucial to reducing drilling costs and non-productive time. During a recent exploratory campaign in Santos Basin, severe levels of shocks and vibrations were encountered while drilling this large and intercalated hole section, resulting in a low rate of penetration, premature bit wear, damaged tools, unplanned trips and drill string failures. Three to four bit runs were required to reach section TD. Post job information and drilling data were reviewed by an integrated operator-contractor team. A detailed engineering analysis of bit, BHA design and drilling mechanics was conducted to address the challenges of this section and propose a new approach to the drilling process. The key was the determination of the best combination of WOB and RPM to drill the different lithologies, together with more stable PDC bits, use of downhole motors and combined with specific operational procedures to mitigate shocks and vibrations. The proposed changes in bit selection and BHA configuration, drilling parameters and procedures, real-time monitoring and training have been successful. For the first time in the drilling campaign in Santos basin, it has proved possible to drill the 17 ½" hole in one bit run. The section was finished without any incident, under budget and under time. The improvement in drilling performance achieved with the implementation of this engineering study helped the operator to mitigate shocks and vibrations and save money, thus ensuring a more efficient drilling operation and preventing further drill string failures.