Survey results of US radiation oncology providers' contextual engagement of watch-and-wait beliefs after a complete clinical response to chemoradiation in patients with local rectal cancer.

Background: Watchful waiting in rectal cancer patients with a complete clinical response (cCR) to chemoradiation therapy (CRT) forgo upfront resection has been proposed. Growing evidence suggests that a watch-and-wait approach using resection for salvage of local recurrence may improve quality of life without jeopardizing outcomes. The current acceptance of watch-and-wait by US radiation oncologists (ROs) is unknown.

Methods: US ROs completed our IRB-approved anonymous e-survey regarding non-surgical management of patients who achieved a cCR to neoadjuvant CRT. Self-ranked knowledge of the OnCoRe Project-UK prospective observational study of watch-and-wait-was tested for its association with ROs' attitudes using the Chi-squared or Fisher's test, as indicated. Supporters of observation are self-identified.

Results: Of the 220 respondents, 48% (n=106) of respondents support watchful waiting and 48% claimed familiarity with the OnCoRe Project. Respondents supporting observation were more likely to be familiar with the publication (P=0.029). Among watch-and-wait supporters, 59% (n=62) felt comfortable discussing this approach and 41% preferred the conversation be initiated by other specialists. There was no association between comfort level in discussing watch-and-wait and familiarity with the OnCoRe Project. ROs treating more than 10 locally advanced rectal cancer (LARC) patients annually felt more comfortable discussing watch-and-wait (P=0.015) compared to ROs seeing fewer patients.

Conclusions: Almost half of surveyed US ROs support watch-and-wait, though many do not feel comfortable discussing this paradigm with patients. Knowledge of the OnCoRe Project is associated with support of watch-and-wait, yet not comfort level in leading the discussion. These results inform provider attitudes toward future clinical study participation.