eP565 - Timing of Recurrence for Patients Diagnosed with Anal Squamous Cell Carcinoma Who Achieve a Complete Response Following Combined Modality Treatment

ePoster Presenter(s)

• 

  Roni Rosen, MD

  Research Fellow
  Memorial Sloan Kettering Cancer Center
  Memorial Sloan Kettering Cancer Center
  New York, NY, United States

  All relevant financial disclosures have been managed and will be listed below.
  This individual has no financial relationships with ineligible companies.

Author(s)

• PR

  Paul Romesser, MD

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  Aron P. Bercz, MD (he/him/his)

  Research Resident
  Memorial Sloan Kettering Cancer Center
  Memorial Sloan Kettering Cancer Center
  New York, NY, United States

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

  Maria Widmar, MD, MPH, FACS (she/her/hers)

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  Weill Cornell Medical Center
  New York, New York, United States

  All relevant financial disclosures have been managed and will be listed below.
  This individual has no financial relationships with ineligible companies.
• IW

  Iris Wei, MD

  Surgeon
  Memorial Sloan Kettering Cancer Center
  New York City, New York, United States

  Disclosure information not submitted.
• 

  Garrett M. Nash, MD, MPH

  Vice Chair, Department of Surgery
  Memorial Sloan Kettering
  New York, New York, United States

  Disclosure information not submitted.
• 

  Martin Weiser, MD

  Attending Surgeon and Professor
  Memorial Sloan Kettering Cancer Center
  Cornell Medical College
  New York, New York, United States

  All relevant financial disclosures have been managed and will be listed below.
  This individual has no financial relationships with ineligible companies.
• 

  Philip B. Paty, FASCRS, FACS

  Attending Surgeon, Colorectal Surgery Service
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  J. Joshua Smith, MD, PhD

  Associate Attending
  Memorial Sloan Kettering Cancer Center
  MSKCC, Weill Cornell Medical College
  New York, New York, United States

  Disclosure information not submitted.
• MG

  Mithat Gonen, PhD

  Attending Biostatistician
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.
• 

  Julio Garcia-Aguilar, MD, PhD (he/him/his)

  Chief Attending
  Memorial Sloan Kettering Cancer Center
  Memorial Sloan Kettering Cancer Center
  New York, New York, United States

  Disclosure information not submitted.

Senior Author(s)

• 

  Emmanouil Pappou, MD, PhD

  Assistant Attending
  Memorial Sloan Kettering Cancer Center
  new York, New York, United States

  All relevant financial disclosures have been managed and will be listed below.
  This individual has no financial relationships with ineligible companies.

Purpose/Background: Background: Anal squamous cell carcinoma (ASCC) is a rare cancer that represents an estimated 0.5% of all new cancer cases the US annually, however, the incidence has been rising over the past decade. Although current guidelines recommend surveillance with CT scan and anoscopy for the first 3 years after therapy, few studies exist to justify such a surveillance period. This is the largest single institutional study to describe the time to recurrence in patients who achieve a complete clinical response to neoadjuvant therapy.Methods/Interventions:

Methods: A retrospective review was conducted at a comprehensive cancer center that included patients diagnosed with anal squamous cell carcinoma treated with the Nigro protocol between January 2007 and December 2020. Patients with stage IV disease and persistent disease within 6 months of finishing neoadjuvant therapy were excluded. Data pertaining to patient demographics, risk factors, treatment course, surgery, pathologic traits and oncologic outcomes were extracted from the institutional database and patient charts. Rates of local and distant recurrence were calculated at two and three years. Rates of disease-free and overall survival were calculated using Kaplan-Meier estimates.Results/Outcomes:

Results: A total of 420 patients with anal squamous cell carcinoma were identified. The cohort included 307 females and 113 males with a median age of 60 years (IQR 53-67). Fifty-nine (14%) patients had stage I disease, 130 (31%) patients had stage II disease, 208 (50%) patients had stage III disease and 23 (5%) patients were stage indeterminate. Of the 374 patients alive and disease-free at 2 years, the probability of local and distant recurrence after two years was 3% (11/374) and 5% (17/374). The probability of both local (n=6) and distant (n=6) recurrence after 3-years was 2% (6/299; figure 1). The disease-free survival at 2-, 3- and 5-years (95%CI) was 89% (86-92%), 86% (82-89%) and 80% (76-85%), respectively. The overall survival was 97% (95-98%) at 2-years, 95% (93-97%) at 3-years and 89% (86-92%) at 5-years.Conclusion/

Discussion:

Conclusion: The majority of ASCC local recurrences occur within three years of finishing chemoradiation therapy in patients who achieve a clinical complete response, making this a reasonable period for endoscopic surveillance. Although prospective studies may not be feasible in such a rare cancer, further studies may be useful in defining predictors of complete response, optimal interval for surveillance and risk factors for recurrence.Time to Local Recurrence of ASCCKaplan-Meier estimate of the probability of local recurrence with time