Increasing tumor stage predicts local regrowth of rectal cancer during watch-and-wait management

Last Updated: 2018-11-13

By Reuters Staff

NEW YORK (Reuters Health) - Increasing tumor stage is associated with greater risk of rectal-cancer local regrowth in patients with a clinical complete response following chemoradiotherapy who are managed by watch-and-wait, according to a new meta-analysis.

Watch-and-wait management allows patients with rectal cancer who have clinical complete responses after neoadjuvant chemoradiotherapy to avoid major pelvic surgery. But it is not yet standard care because of uncertainties regarding local regrowth compared with patients managed by surgical resection.

Dr. Andrew G. Renehan from The Christie NHS Foundation Trust, in Manchester, UK, and colleagues used data from 11 published studies within the International Complete Response consortium to perform an individual-participant-data meta-analysis with the aim of identifying factors affecting local regrowth after clinical complete response to chemotherapy.

The study included 602 patients with median follow-up of 38 months (range, 12.4 months to 60 months). The two-year cumulative incidence of local regrowth was 21%, with a high level of heterogeneity between studies, the researchers report in The Lancet Gastroenterology & Hepatology, online October 11.

The only factor associated with increased risk of local regrowth was increasing clinical T (cT) stage. Among patients managed after 2008, two-year cumulative incidence of local regrowth increased from 19% for stage cT1 and cT2 tumors to 31% for cT3 and 37% for cT4.

Among the 137 patients who had salvage surgery, 131 achieved R0 status. Three-year survival after local regrowth was 80% for those who had salvage surgery, compared to 55% for those not undergoing salvage therapy.

Overall, five-year survival was 87% and five-year non-regrowth disease-free survival was 81%. The three-year incidence of distant metastasis was 9%.

"Regarding the clinical relevance of this study, we have not identified a patient subgroup that is unsuitable for watch and wait," the researchers note. "Going forward, there is a need to validate the associations between cT stage and local regrowth on the basis of standardized MRI-based pretreatment staging protocols."

"Another clinical question is whether there should be a stratified approach to follow-up," they add. "Conceivably, one might argue that cT3 and cT4 tumors are at high risk of local regrowth, but given the high proportions of patients undergoing salvage surgery and attaining R0 status, it is questionable whether more intensive surveillance in this patient subgroup would substantially affect long-term outcomes. Similarly, the rate of distant metastases in all these patients is low, arguing that more regular CT surveillance is unlikely to have a major clinical impact."

"Shared decision making requires the clinician to provide sufficiently accurate information to patients," writes Dr. Rob Glynne-Jones from Mount Vernon Center for Cancer Treatment, in London, in a linked editorial. "For this reason, data provided by this study could give confidence to clinicians to consider watch and wait more widely. Yet much of the experience still reflects treatment of earlier, smaller cancers than those treated routinely in randomized trials."

Dr. Renehan did not respond to a request for comments.

SOURCE: https://bit.ly/2DyTWLj and https://bit.ly/2K155Vo

Lancet Gastroenterol Hepatol 2018.