In Memoriam: David A. Ahlquist, MD

Our esteemed colleague and friend, David A. Ahlquist, MD, passed away on November 1, 2020 due to complications from amyotrophic lateral sclerosis (ALS). Dr Ahlquist was a visionary leader, compassionate clinician, dedicated mentor, exemplary friend. Dave also an imaginative innovator, with unique ability deconstruct complex challenges define elegant solutions, guided by his “North Star” of reducing the cancer burden through novel research, practical application, mission-driven entrepreneurialism. started finished illustrious medical career in Rochester, MN. He earned degree Mayo Medical School (1977; as part second-ever graduating class) completed Internal Medicine residency (1980) Gastroenterology fellowship (1983) training Clinic College Medicine. subsequently joined & Hepatology faculty (1983), serving numerous internal leadership positions (eg, Director Endoscopy; President Staff; Director, Department Development) receiving multiple prominent institutional awards Research Career Achievement Award, Investigator Year Distinguished Inventor Award) before retiring 2018. Ahlquist’s seminal contributions were further recognized externally highly prestigious William Beaumont Prize American Gastroenterological Association (for achievement innovation that has affected practice), designation Exemplar Translational National Cancer Institute, induction Fellow Academy Inventors, many other distinguished honors. His scholarly productivity includes more than 25 years continuous funding Institutes Health, 200 peer-reviewed manuscripts book chapters, 80 issued patents. In addition clinical research activities, passionate about working trainees at all levels, sharing expertise 40 mentees who have established successful careers across broad array professional disciplines. frequently invited speak top-tier scientific conferences, delivering presentations 400 national international meetings. interactions, immediately connected whomever involved conversation, building lasting collaborations founded exceptional inspire creativity respect diversity pursuit common goals. As gastroenterologist, convinced biggest impact he could make colorectal (CRC) improved early detection. team their talents discovery tumor-associated molecular markers be applied screen-detect localized cancers advanced precancerous neoplasia. The defined optimized probes separate relatively scant fragments human DNA massive amounts bacterial DNA, maximize performance efficiency resulting assay. Dave’s laboratory observations ultimately translated into Food Drug Administration–approved, multi-target stool (mt-sDNA) test, commercially marketed Cologuard, deep partnership Exact Sciences. mt-sDNA test is endorsed major guideline groups noninvasive option for average-risk CRC screening, been used screen 5 million people date. later career, expanded pursue approaches detection beyond colorectum. among first recognize tissue-specific methylation patterns health inform signatures cancer. Although this concept had previously proposed thought leaders, meaningful advances hindered lack compelling candidate markers. To discover methylated site arising different organs, directed explore then emerging tool, next-generation sequencing. contrast existing hybridization arrays, sequencing provided huge information without bias known This insightful approach now widely tests treatment response, post-treatment monitoring. new investigation coupled rational scientifically justified hypothesis biomarkers efficiently population. sharp departure traditional practice single-organ screening cardinal focus along researchers recruited mentored over last decade. Single-organ practiced population level few malignancies are not only prevalent but can found stage or state often treated minimally invasive means. Currently, breast, uterine cervix, colorectum meet these conditions. However, unscreened solid general population, such lung, esophageal, gastric, liver, pancreatic, ovarian, account most fatalities each year when counted together. raised consciousness transformative biomarker might capable screen-detecting several diseases same time. If screened aggregate using multicancer low prevalence individual target condition would no longer pose barrier application adoption. Along stellar reputation specialist, expert occult gastrointestinal bleeding. mid-1990s, contacted Centers Disease Control Prevention assist pervasive, unexplained, iron-deficiency anemia Alaska Native Through series arctic investigators, tribal elders, study participants, identified hemorrhagic gastritis, atypical manifestation Helicobacter pylori infection, etiology long-standing mystery. experience marked beginning connection developed which higher risk race/ethnicity United States. During 2 decades, stayed actively researchers, including visits remote outposts learn from, work with, indigenous peoples. Not surprisingly, quickly welcomed traditionally tight-knit communities trusted colleague. Alaska’s environmental splendor ecological tremendous Dave, prompting memorable trips family friends share beauty “the frontier.” Beyond Alaska, wanderlust took him spectacular places like Greenland, Ecuador, Patagonia, Costa Rica. Yet, despite extensive travel exotic locations, northern Minnesota remained spiritual center (Figures 2, 3, 4). always keen observer world around him, stalwart steward environment. For those privilege taking walk woods trip trout stream intoxicating sense nature’s wonders evident. While relaxing streamside, expertly identify surrounding flora, explain subtle differences between varieties nearby spring warblers, deftly cast fly line barely visible pod lurking just beneath water’s surface.Figure 3Enjoying Rica.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 4On water daughter, Brooke Carlson, Hudson Bay.View (PPT) some occasionally find courage embark “road less travelled” during life’s journey, made it habit, reveling every chance chart own course, undaunted unknown. Whether traversing forest near cabin north shore Lake Superior, problem-solving conundrum laboratory, routinely blazed trails uncharted territory. Paraphrasing Waking Theodore Roethke, learned going where needed go. Admittedly, “short cuts” successful, deciphered way achieve goal, pausing congratulate contributed success moving next quest, whether hill within tumor profile. inspired us, so others, join cancer-prevention mission, moved think ways forward-looking yet well-argued evidence-based vision. skilled nurturing relationships personally well. collegial impressive networking sparked deepening dialogues bench scientists, clinicians, epidemiologists, patient advocates, industry regulatory authorities ever-more committed advancing accelerating movement, drawing horizon unsolvable problems out reach, innovative experiments creative collaborations. Indeed, enormous potential meaningfully improve prevention control launched entire commercial academic programs, viewed beacons era patient-centered prevention, shining light ultimate goal vanquishing “emperor maladies.” It natural wonder how one respond if broadsided diagnosis lethal disease. Characteristically, did progressive limitations imposed ALS. Instead, chose describe end-of-life journey adventure, intense moment. time pursuing extraordinary heartfelt conversations friends, while continuing guide support grateful colleagues long possible. devoted above else. survived loving wife Susan, daughter Carlson (Bryant), sons Aaron (Elizabeth) Daniel (Amanda Flaim), grandchildren. Now bend, doubt waiting, usual, rest us catch up. life well lived, we better it. memorial material published Letter. Limburg serves Chief Officer Screening Sciences contracted services agreement Clinic. contractual rights receive royalties agreement. intellectual property under Dr. Kisiel listed inventor may royalties.