Nonoperative Management of Rectal Cancer: Is “Near-Complete” Response Safe to Surveil?

Catherine N. Zivanov; Nathan S. Kau; Harika Nalluri-Butz; Oluseye K. Oduyale; Ahmed A. Eltahir; Jared T. Yee; Austin R. Dosch; Lindsey Zhang; Hyun Kim; Michael D. Iglesia; Michelle L. Cowan; Kerri A. Ohman; Paul E. Wise; Steven R. Hunt; Matthew L. Silviera; Matthew G. Mutch; William C. Chapman

doi:10.1245/s10434-025-17033-1

Nonoperative Management of Rectal Cancer: Is “Near-Complete” Response Safe to Surveil?

Catherine N. Zivanov, Nathan S. Kau, Harika Nalluri-Butz, Oluseye K. Oduyale, Ahmed A. Eltahir, Jared T. Yee, Austin R. Dosch, Lindsey Zhang, Hyun Kim, Michael D. Iglesia, Michelle L. Cowan, Kerri A. Ohman, Paul E. Wise, Steven R. Hunt, Matthew L. Silviera, Matthew G. Mutch, William C. Chapman

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Background: Nonoperative management of rectal cancer in patients who achieve near-complete response following total neoadjuvant therapy remains controversial and understudied. Methods: This retrospective cohort study conducted at a tertiary National Cancer Institute-designated cancer center included patients with rectal cancer who initiated active surveillance after achieving near-complete response following induction radiotherapy and consolidation chemotherapy. Near-complete response was determined based on restaging endoluminal evaluation and pelvic magnetic resonance imaging. Time-to-event analyses were used to estimate regrowth-free, proctectomy-free, disease-free, and overall survival. Results: Of 61 patients who achieved near-complete response and initiated nonoperative management between February 2017 and March 2024, 36 (59.0%) maintained organ preservation with a median follow-up of 27.1 (interquartile range [IQR] 17.4–37.4) months. Twenty-five patients (41.0%) developed local regrowth by a median of 5.7 (IQR 3.2–8.2) months. All regrowths occurred within 17.5 months of initial restaging. Twenty-one patients with regrowth underwent salvage proctectomy, of which 20 (95.2%) achieved R0 resection margins. Following salvage proctectomy, four patients (19.0%) developed local recurrence. Disease-free and overall survival 2 years from restaging were 79.2% (95% confidence interval [CI] 67.0–93.6) and 93.3% (95% CI 86.3–100), respectively. Overall survival was not significantly different between patients with versus without local regrowth (log-rank p = 0.09). Conclusions: Nonoperative management achieves clinically significant organ preservation rates without compromising oncologic outcomes in patients with near-complete response to total neoadjuvant therapy. Active surveillance allows time for continued evolution of tumor response and may substantially expand organ preservation in a patient population who otherwise would undergo avoidable radical surgery.

Original language	English
Journal	Annals of Surgical Oncology
DOIs	https://doi.org/10.1245/s10434-025-17033-1
State	Accepted/In press - 2025

Keywords

Near-complete response
Nonoperative management
Organ preservation
Rectal cancer
Watch and wait

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10.1245/s10434-025-17033-1

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Zivanov, C. N., Kau, N. S., Nalluri-Butz, H., Oduyale, O. K., Eltahir, A. A., Yee, J. T., Dosch, A. R., Zhang, L., Kim, H., Iglesia, M. D., Cowan, M. L., Ohman, K. A., Wise, P. E., Hunt, S. R., Silviera, M. L., Mutch, M. G., & Chapman, W. C. (Accepted/In press). Nonoperative Management of Rectal Cancer: Is “Near-Complete” Response Safe to Surveil? Annals of Surgical Oncology. https://doi.org/10.1245/s10434-025-17033-1

@article{a3e7a0f5518147be9884170b8d7cae9a,

title = "Nonoperative Management of Rectal Cancer: Is “Near-Complete” Response Safe to Surveil?",

abstract = "Background: Nonoperative management of rectal cancer in patients who achieve near-complete response following total neoadjuvant therapy remains controversial and understudied. Methods: This retrospective cohort study conducted at a tertiary National Cancer Institute-designated cancer center included patients with rectal cancer who initiated active surveillance after achieving near-complete response following induction radiotherapy and consolidation chemotherapy. Near-complete response was determined based on restaging endoluminal evaluation and pelvic magnetic resonance imaging. Time-to-event analyses were used to estimate regrowth-free, proctectomy-free, disease-free, and overall survival. Results: Of 61 patients who achieved near-complete response and initiated nonoperative management between February 2017 and March 2024, 36 (59.0%) maintained organ preservation with a median follow-up of 27.1 (interquartile range [IQR] 17.4–37.4) months. Twenty-five patients (41.0%) developed local regrowth by a median of 5.7 (IQR 3.2–8.2) months. All regrowths occurred within 17.5 months of initial restaging. Twenty-one patients with regrowth underwent salvage proctectomy, of which 20 (95.2%) achieved R0 resection margins. Following salvage proctectomy, four patients (19.0%) developed local recurrence. Disease-free and overall survival 2 years from restaging were 79.2% (95% confidence interval [CI] 67.0–93.6) and 93.3% (95% CI 86.3–100), respectively. Overall survival was not significantly different between patients with versus without local regrowth (log-rank p = 0.09). Conclusions: Nonoperative management achieves clinically significant organ preservation rates without compromising oncologic outcomes in patients with near-complete response to total neoadjuvant therapy. Active surveillance allows time for continued evolution of tumor response and may substantially expand organ preservation in a patient population who otherwise would undergo avoidable radical surgery.",

keywords = "Near-complete response, Nonoperative management, Organ preservation, Rectal cancer, Watch and wait",

author = "Zivanov, {Catherine N.} and Kau, {Nathan S.} and Harika Nalluri-Butz and Oduyale, {Oluseye K.} and Eltahir, {Ahmed A.} and Yee, {Jared T.} and Dosch, {Austin R.} and Lindsey Zhang and Hyun Kim and Iglesia, {Michael D.} and Cowan, {Michelle L.} and Ohman, {Kerri A.} and Wise, {Paul E.} and Hunt, {Steven R.} and Silviera, {Matthew L.} and Mutch, {Matthew G.} and Chapman, {William C.}",

note = "Publisher Copyright: {\textcopyright} Society of Surgical Oncology 2025.",

year = "2025",

doi = "10.1245/s10434-025-17033-1",

language = "English",

journal = "Annals of Surgical Oncology",

issn = "1068-9265",

}

TY - JOUR

T1 - Nonoperative Management of Rectal Cancer

T2 - Is “Near-Complete” Response Safe to Surveil?

AU - Zivanov, Catherine N.

AU - Kau, Nathan S.

AU - Nalluri-Butz, Harika

AU - Oduyale, Oluseye K.

AU - Eltahir, Ahmed A.

AU - Yee, Jared T.

AU - Dosch, Austin R.

AU - Zhang, Lindsey

AU - Kim, Hyun

AU - Iglesia, Michael D.

AU - Cowan, Michelle L.

AU - Ohman, Kerri A.

AU - Wise, Paul E.

AU - Hunt, Steven R.

AU - Silviera, Matthew L.

AU - Mutch, Matthew G.

AU - Chapman, William C.

PY - 2025

Y1 - 2025

N2 - Background: Nonoperative management of rectal cancer in patients who achieve near-complete response following total neoadjuvant therapy remains controversial and understudied. Methods: This retrospective cohort study conducted at a tertiary National Cancer Institute-designated cancer center included patients with rectal cancer who initiated active surveillance after achieving near-complete response following induction radiotherapy and consolidation chemotherapy. Near-complete response was determined based on restaging endoluminal evaluation and pelvic magnetic resonance imaging. Time-to-event analyses were used to estimate regrowth-free, proctectomy-free, disease-free, and overall survival. Results: Of 61 patients who achieved near-complete response and initiated nonoperative management between February 2017 and March 2024, 36 (59.0%) maintained organ preservation with a median follow-up of 27.1 (interquartile range [IQR] 17.4–37.4) months. Twenty-five patients (41.0%) developed local regrowth by a median of 5.7 (IQR 3.2–8.2) months. All regrowths occurred within 17.5 months of initial restaging. Twenty-one patients with regrowth underwent salvage proctectomy, of which 20 (95.2%) achieved R0 resection margins. Following salvage proctectomy, four patients (19.0%) developed local recurrence. Disease-free and overall survival 2 years from restaging were 79.2% (95% confidence interval [CI] 67.0–93.6) and 93.3% (95% CI 86.3–100), respectively. Overall survival was not significantly different between patients with versus without local regrowth (log-rank p = 0.09). Conclusions: Nonoperative management achieves clinically significant organ preservation rates without compromising oncologic outcomes in patients with near-complete response to total neoadjuvant therapy. Active surveillance allows time for continued evolution of tumor response and may substantially expand organ preservation in a patient population who otherwise would undergo avoidable radical surgery.

AB - Background: Nonoperative management of rectal cancer in patients who achieve near-complete response following total neoadjuvant therapy remains controversial and understudied. Methods: This retrospective cohort study conducted at a tertiary National Cancer Institute-designated cancer center included patients with rectal cancer who initiated active surveillance after achieving near-complete response following induction radiotherapy and consolidation chemotherapy. Near-complete response was determined based on restaging endoluminal evaluation and pelvic magnetic resonance imaging. Time-to-event analyses were used to estimate regrowth-free, proctectomy-free, disease-free, and overall survival. Results: Of 61 patients who achieved near-complete response and initiated nonoperative management between February 2017 and March 2024, 36 (59.0%) maintained organ preservation with a median follow-up of 27.1 (interquartile range [IQR] 17.4–37.4) months. Twenty-five patients (41.0%) developed local regrowth by a median of 5.7 (IQR 3.2–8.2) months. All regrowths occurred within 17.5 months of initial restaging. Twenty-one patients with regrowth underwent salvage proctectomy, of which 20 (95.2%) achieved R0 resection margins. Following salvage proctectomy, four patients (19.0%) developed local recurrence. Disease-free and overall survival 2 years from restaging were 79.2% (95% confidence interval [CI] 67.0–93.6) and 93.3% (95% CI 86.3–100), respectively. Overall survival was not significantly different between patients with versus without local regrowth (log-rank p = 0.09). Conclusions: Nonoperative management achieves clinically significant organ preservation rates without compromising oncologic outcomes in patients with near-complete response to total neoadjuvant therapy. Active surveillance allows time for continued evolution of tumor response and may substantially expand organ preservation in a patient population who otherwise would undergo avoidable radical surgery.

KW - Near-complete response

KW - Nonoperative management

KW - Organ preservation

KW - Rectal cancer

KW - Watch and wait

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U2 - 10.1245/s10434-025-17033-1

DO - 10.1245/s10434-025-17033-1

M3 - Article

C2 - 39982548

AN - SCOPUS:85218705811

SN - 1068-9265

JO - Annals of Surgical Oncology

JF - Annals of Surgical Oncology

ER -

Nonoperative Management of Rectal Cancer: Is “Near-Complete” Response Safe to Surveil?

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