New Ultrasonic Techniques for Colorectal Cancer Imaging

Colorectal cancer (CRC) is the third most common cancer diagnosed in the world and the second cancer-related cause of mortality in both men and women [1]. Despite of being about three times more incident in transitioned countries, the mortality rates for CRC are higher in transitioning countries, and these two discrepancies reflect that improvements in survival are due to the adoption of best practices in cancer treatment and management [2]. CRC presents a variation of incidence trends in different geographic regions: increasing incidence in some countries (such as China, Russia, Canada, The United Kingdom and Brazil) and decreasing incidence in others (including The United States, France and Japan) [3]. However, the overall declines in CRC incidence in countries such as The United States are masking an increasing incidence in young adults: from the mid1980 through 2013, rates of CRC incidence increased by 2.4% per year in adults aged 20-29 years and by 1.0% per year in adults aged 30-39 years [4]. It is estimated that by 2030 the incidence rates for colon and rectal cancer in the US population will increase by 90% and 124%, respectively, for patients 20 to 34 years of age [5]. The declining CRC incidence in groups aged older than 50 years may be a reflect from the widespread screening in this population, which rose from 38% in 2000 to 59% in 2013 [6]. Fecal occult blood tests, flexible sigmoidoscopy and colonoscopy were the most common screening test modalities among older adults in The United States until 2005 [7]. By 2005, colonoscopy had become the most common imaging screening test modality for CRC in older adults [7], with its use among US adults aged 50 years and older reaching 60% in 2015 [8].