EP201 - Characterizing Mid-Rectal Cancer Patients Managed with Total Neoadjuvant Therapy and Non-Operative Management

ePoster Presenter(s)

• 

  Ana Sofia Ore, MD MSc MPH (she/her/hers)

  Colon & Rectal Surgery Fellow
  Mayo Clinic Rochester
  Mayo Clinic - Rochester
  Rochester, Minnesota, United States

  All of the relevant financial relationships listed below have been mitigated.
  This individual has no financial relationships with ineligible companies.

Author(s)

• DC

  Dovile Cerkauskaite, MD

  Research Fellow
  Mayo Clinic
  Rochester, Minnesota, United States

  Disclosure information not submitted.
• JN

  Jyi Cheng Ng, MD

  General Surgery Resident
  Johns Hopkins University School of Medicine
  Baltimore, Maryland, United States

  Disclosure information not submitted.
• 

  Amit Merchea, MD (he/him/his)

  Associate Professor of Surgery
  Mayo Clinic Florida
  Jacksonville, FL, United States

  All of the relevant financial relationships listed below have been mitigated.
  This individual has no financial relationships with ineligible companies.
• 

  Justin Brady, MD

  Assistant Professor of Surgery
  Mayo Clinic Arizona
  Mayo Clinic Alix School of Medicine
  Scottsdale, Arizona, United States

  Disclosure information not submitted.
• NM

  Nicholas P. McKenna, M.D.

  Assistant Professor of Surgery
  Mayo Clinic
  Rochester, Minnesota, United States

  Disclosure information not submitted.
• 

  David w. Larson, MD MBA

  consultant
  Mayo Clinic
  Mayo Clinic
  rochester, MN, United States

  All of the relevant financial relationships listed below have been mitigated.
  This individual has no financial relationships with ineligible companies.

Senior Author(s)

• 

  Kellie L. Mathis, M.D. (she/her/hers)

  Professor of Surgery
  Mayo Clinic
  Mayo Clinic
  Oronoco, Minnesota, United States

  Disclosure information not submitted.

Purpose/Background: Management of rectal cancer has evolved significantly. Total neoadjuvant therapy (TNT) followed by watch and wait (W&W) for patients achieving a complete clinical response (cCR) with the goal of reducing treatment-related morbidity and preservation of anorectal function is an increasingly recognized alternative to surgery. Currently available survival data specifically targets low rectal tumors, while outcomes of mid and high rectal tumors with cCR and on W&W are scarce.

Methods/Interventions: Patients aged 18 and above, diagnosed with clinical TNM stage II or III rectal adenocarcinoma between 2017 and 2023, with tumors located ≥5cm from the anorectal junction, treated with TNT, who eventually achieved a cCR, were identified from a prospectively maintained, multistate institutional W&W database and included in the study. Patient demographics, tumor characteristics, treatment details and follow-up were analyzed. Primary outcomes were 3-year disease free survival (DFS) and distant metastasis free survival (DMFS). Survival analysis was performed using Kaplan-Meier method.

Results/Outcomes: A total of 22 patients with mid-/high rectal tumors who underwent TNT, achieved a cCR, and underwent W&W were identified. Of these patients, 72.7% (16) had an initial cCR and 27.3% (6) had an initial near-cCR that eventually achieved cCR. Median distance from the anorectal junction was 6.0cm (IQR 5-7.5). 72.7% (16) of patients underwent induction chemotherapy followed by long-course chemoradiation and 18.2% (4) underwent long-course chemoradiation followed by consolidation chemotherapy. Local regrowth rate for our cohort was 27.3% (6); distant metastasis rate was 18.2% (4). Local regrowth was identified by flexible sigmoidoscopy in 4 patients and MRI for 2 patients. 83.3% (5/6) patients with local regrowth underwent successful salvage surgery, with one patient refusing surgery. 3 underwent LAR and two underwent local excision. Median follow-up time was 32 months [interquartile range (IQR) 18-55)], The 3-year DFS was 74.5% (95% CI 48.3-88.7%) and 3-year DMFS was 82.3% (95% CI 53.5-94.1%).

Conclusion/Discussion: This descriptive study found that patients with mid-rectal tumors who underwent TNT with cCR and were managed with W&W achieved both 3-year DFS and DMFS similar to that of our current overall W&W cohort (3-year DFS 59%, 3-year DMFS 82.7%). Salvage surgery was successful in most cases of local regrowth. Further prospective studies looking at W&W and management of mid to high rectal cancer is warranted to further elucidate survival in these specific groups.

3-Year Distant Metastasis Free Survival
3-year DMFS was 82.3% (95% CI 53.5-94.1%)
3-Year Disease Free Survival
3-year DFS was 74.5% (95% CI 48.3-88.7%)