John H. Marks, MD

Headshot of John H. Marks, MD

Resident Faculty

Professor

Dr. Marks directs a colorectal surgical research team and a fellowship in advanced rectal cancer management, one of only four in the United States. His research and educational programs focus largely on minimally invasive laparoscopic and robotic colorectal surgery featuring radical sphincter preservation resection for rectal cancer after neoadjuvant therapy, one of the largest series of its kind in the world.

About

  • 1999–present: Professor, Lankenau Institute for Medical Research
  • 2001–present: Chief, Colorectal Surgery, Main Line Health
  • 2001–present: Director, Fellowship in Laparoscopic and Minimally Invasive Colorectal Surgery and Advanced Rectal Cancer Management, Main Line Health
  • 2019–present: Program Director, National Accreditation Program for Rectal Cancer
  • 2020–present: James Widener Ray Endowed Chair in Colorectal Surgery

Researcher Video

Research Descriptions

As one of the world’s most experienced colorectal surgeons, Dr. Marks has performed nearly 4,000 minimally invasive colorectal cancer surgeries, including more than 2,000 rectal cancer procedures. Dr. Marks’ research and educational programs focus largely on minimally invasive laparoscopic and robotic colorectal surgery featuring radical sphincter preservation resection for rectal cancer after neoadjuvant therapy, one of the largest series of its kind in the world.

He champions Full Thickness Local Excision (FTLE) by the Transanal Endoscopic Microsurgical (TEM) method following neoadjuvant therapy for rectal cancer and has performed over 450 TEMs to date. Dr. Marks remains on the leading edge of advancements in colorectal surgery, having performed over 350 single-incision laparoscopic surgeries (SILS).

He is currently collaborating on applications for robotic single port surgery to expand endoluminal and SILS for a variety of pathologies and Lankenau will be one of the first three centers in the world to have the new SP robot. With Dr. Marks leading Lankenau Medical Center, one of four academic colorectal robotic Epicenters in the country, he has performed over 300 surgeries with the da Vinci Surgical System Si and Xi robots and the newest SP robotic system.

Dr. Marks worked with Intuitive to develop colorectal operations using the SP robot. Examples of his leadership in this field include training surgeons in Hong Kong and performing the first SP robot cases in the western hemisphere. He and his colleagues frequently publish findings from a robust and rigorously maintained patient database, including a 2017 report of low local recurrence and excellent 5-year survival in 373 patients undergoing transanal total mesorectal excision (taTME) for rectal cancer.

Dr. Marks’ experience in advanced rectal cancer surgery led to Lankenau being selected in 2018 to participate in a 5-year multicenter phase II study of taTME.

Dr. Marks recently published a book “Surgical Techniques in Rectal Cancer – Transanal, Laparoscopic and Robotic Approach”, the first significant text dedicated to the surgical treatment of rectal cancer in over a decade. Dr. Marks is the Program Director of Lankenau Medical Center’s National Accreditation Program for Rectal Cancer (NAPRC).

He is the only colorectal surgeon in the United States currently utilizing the DaVinci Single Port (SP) robot for surgeries and has the most expansive experience with this technology in the world performing well over 100 surgeries.

Publications

  • Perioperative outcomes for single-port robotic versus single-incision laparoscopic surgery: a comparative analysis in colorectal cancer surgery. Keller DS, Reif de Paula T, Ikner TP, Saidi H, Schoonyoung H, Marks JH. Surg Endosc. 2024 Jan 4. doi: 10.1007/s00464-023-10629-2
  • Longitudinal Analysis of Local Recurrence and Survival After Transanal Abdominal Transanal Radical Proctosigmoidectomy for Low Rectal Cancer Treated With Neoadjuvant Chemoradiation. Marks JH, Reif de Paula T, Saidi H, Ikner TP, Schoonyoung H, Marks G, et al. Dis Colon Rectum. 2023 Dec 7. doi: 10.1097/DCR.0000000000003146
  • A prospective phase II clinical trial/IDEAL Stage 2a series of single-port robotic colorectal surgery for abdominal and transanal cases. Marks JH, Yang J, Spitz EM, … de Paula TR, Schoonyoung HP, Keller DS. Colorectal Dis. 2023 Oct 31. doi: 10.1111/codi.16788
  • Multicenter phase II trial of transanal total mesorectal excision for rectal cancer: preliminary results. Sylla P, Sands D, … Marks J, et al. Surg Endosc. 2023 Sep 12. doi: 10.1007/s00464-023-10266-9
  • International standardization and optimization group for intersphincteric resection (ISOG-ISR): modified Delphi consensus on anatomy, definition, indication, surgical technique, specimen description and functional outcome. Piozzi GN, Khobragade K, … Marks J, et al. Colorectal Dis. 2023 Sep;25(9):1896-1909.
  • Discordance in Total Mesorectal Excision Specimen Grading in a Prospective Phase 2 Multicenter Rectal Cancer Trial: Are We Overestimating the Quality of Our Resections? Sylla P, Berho M, … Marks J, et al. Ann Surg. 2023 Sep 1;278(3):452-463. doi: 10.1097/SLA.0000000000005948.
  • Robotic right colectomy with robotic-sewn anastomosis: a pilot case series. Huscher CGS, Lazzarin G, … Marks J. J Robot Surg. 2023 Apr;17(2):427-434. doi: 10.1007/s11701-022-01435-4
  • Genomics of Black American colon cancer disparities: An RNA sequencing (RNA-Seq) study from an academic, tertiary referral center. Haskins IN, Wang BD, … Marks J, et al. Surgery. 2021 May 17:S0039-6060(21)00223-3.
  • First Clinical Experience with Single-Port Robotic Transanal Minimally Invasive Surgery: Phase II Trial of the Initial 26 Cases. Marks JH, Kunkel E, Salem JF, et al. Dis Colon Rectum. 2021 May 11. doi: 10.1097/DCR.0000000000001999
  • SP rTaTME: initial clinical experience with single-port robotic transanal total mesorectal excision (SP rTaTME). Marks JH, Salem JF, Adams P, et al. Tech Coloproctol. 2021 Jun;25(6):721-726.
  • Initial clinical experience with Single-Port robotic (SP r) left colectomy using the SP surgical system: description of the technique. Salem JF, Agarwal S, Schoonyoung H, Martin C, Marks JH. Surg Endosc. 2021 Jul;35(7):4022-4027.
  • First clinical experience with single-port robotic transanal minimally invasive surgery (SP rTAMIS) for benign rectal neoplasms. Marks JH, Kunkel E, et al. Tech Coloproctol. 2021 Aug 1;64(8):1003-1013.
  • rSILS: initial clinical experience with single-port robotic (SPr) right colectomy. Marks JH, Kunkel E, Salem J, Martin C, Schoonyoung HP, Agarwal S. Tech Coloproctol. 2020 May 25. doi: 10.1007/s10151-020-02218-5.
  • Transanal Surgery: A History of taTME Ancestry. Izquierdo KM, Salem JF, Cha E, Unal E, Marks JH. Clin Colon Rectal Surg. 2020 May;33(3):128-33.
  • Single-port robotic left colectomy: first clinical experience using the SP robot (rSILS). Marks JH, Salem JF, Anderson BK, et al. Tech Coloproctol. 2019 Dec 12.
  • Cannabinoids: A Guide for Use in the World of Gastrointestinal Disease. Unal E, Anderson B, Helber A, Marks JH. J Clin Gastroenterol. 2019 Nov 27.
  • Laparoscopic left colectomy: modern technique based on key anatomical landmarks reported by giants of the past. Hüscher CGS, Lirici MM, Marks JH, et al. Minim Invasive Ther Allied Technol. 2019;16:1-11.
  • Natural orifice specimen extraction in colorectal surgery: patient selection and perspectives. Izquierdo KM, Unal E, Marks JH. Clin Exp Gastroenterol. 2018;11:265-79.
  • Minimally Invasive Surgical Approaches to Colon Cancer. Salem JF, Gummadi S, Marks JH. Surg Oncol Clin N Am. 2018;27(2):303-18.
  • Full-thickness neorectal prolapse after transanal transabdominal proctosigmoidectomy for low rectal cancer: a cohort study. Guraieb-Trueba M, Helber AR, Marks JH. Colorectal Dis. 2018;20(7):593-6.
  • The three approaches to the colonic splenic flexure mobilization - a video vignette. Dapri G, Bascombe NA, Cadière GB, Marks JH. Colorectal Dis. 2017;19(10):948-9.
  • Long-term outcomes by a transanal approach to total mesorectal excision for rectal cancer. Marks JH, Myers EA, Zeger EL, Denittis AS, Gummadi M, Marks GJ. Surg Endosc. 2017;31(12):5248-57.
  • Quality of Life and Functional Outcome After Transanal Abdominal Transanal Proctectomy for Low Rectal Cancer. Marks JH, Salem JF, Valsdottir EB, et al. Dis Colon Rectum. 2017;60(3):258-65.
  • Transanal TATA/TME: a case-matched study of taTME versus laparoscopic TME surgery for rectal cancer. Marks JH, Montenegro GA, Salem JF, et al. Tech Coloproctol. 2016;20(7):467-73.
  • True NOTES TME resection with splenic flexure release, high ligation of IMA, and side-to-end hand-sewn coloanal anastomosis. Marks JH, Lopez-Acevedo N, Krishnan B, et al. Surg Endosc. 2016;30(10):4626-31.
  • Outcomes in 132 patients following laparoscopic total mesorectal excision (TME) for rectal cancer with greater than 5-year follow-up. Marks JH, Huang R, McKeever D, Greenfield M. Surg Endosc. 2016;30(1):307-14.

Education and Training

Education

  • MD
    Jefferson Medical College

Academic Titles

  • 1999–present: Professor, Lankenau Institute for Medical Research
  • 2001–present: Chief, Colorectal Surgery, Main Line Health
  • 2001–present: Director, Fellowship in Laparoscopic and Minimally Invasive Colorectal Surgery and Advanced Rectal Cancer Management, Main Line Health
  • 2019–present: Program Director, National Accreditation Program for Rectal Cancer
  • 2020–present: James Widener Ray Endowed Chair in Colorectal Surgery