For patients with rectal cancer, the promise of sphincter-preserving surgery comes with an asterisk: a temporary diverting stoma, a surgical opening that reroutes stool while a delicate anastomosis heals deep in the pelvis. Closing that stoma is usually celebrated as the final step back to normal life. But a new long-term study from Japan suggests that closure is not the finish line many patients and clinicians assume it to be. In a cohort of 296 patients treated with radiation-based neoadjuvant therapy, nearly one in ten who achieved an apparently successful stoma closure later needed a second stoma, sometimes years afterward. The findings, published in Annals of Gastroenterological Surgery, offer some of the most detailed data yet on what researchers call delayed re-stoma-free survival — a measure of whether restored bowel continuity actually lasts.
The retrospective cohort study was conducted at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research in Tokyo, one of Japan’s leading oncology centers. The investigators reviewed consecutive patients who underwent definitive rectal cancer surgery between January 2011 and December 2024. To keep the population homogeneous, they included only patients who had sphincter-preserving rectal resection with double-stapling technique reconstruction and a diverting stoma, all following radiation-based neoadjuvant treatment. Patients with Stage IV disease at surgery, those undergoing additional major procedures, and those with other reconstructive methods were excluded. Treatment strategy for each patient was determined at a multidisciplinary team conference, reflecting real-world institutional practice rather than trial protocol conditions.
The cohort was divided into two treatment eras of evolving intensity. A total of 168 patients received radiotherapy without additional preoperative systemic chemotherapy — the non-TNT group — comprising 135 patients treated with long-course chemoradiotherapy and 33 with short-course radiotherapy alone. Another 128 patients received total neoadjuvant therapy, or TNT, in which systemic chemotherapy is delivered before surgery, either before or after radiotherapy: 94 with a long-course chemoradiotherapy-based regimen and 34 with a short-course radiotherapy-based approach. TNT has become increasingly standard for locally advanced rectal cancer because Phase III trials have shown higher pathological complete response rates and, in selected patients, the possibility of organ preservation. The median patient age was 61 years, about 70 percent were men, and 71 percent had clinical Stage III disease.
The results on closure itself were encouraging. Stoma closure was achieved in 287 of 296 patients, a rate of 97 percent, and only five of those 287 patients — 1.7 percent — needed a stoma again within 30 days, a signal of an anastomotic problem missed during pre-closure assessment. That left 282 patients with what the researchers defined as initially successful closure. Before every closure, patients underwent contrast enema and endoscopic examination of the anastomosis, and surveillance computed tomography was added when more than six months had elapsed since the original operation. Closure proceeded only when no leakage, fistula, sinus, severe stenosis, or recurrence was evident. Even with this careful gating, the story did not end there.
During a median follow-up of 63 months after closure, 25 of the 282 patients — 8.9 percent — required delayed re-stoma creation more than 30 days after closure. The Kaplan-Meier estimates of delayed re-stoma-free survival were 93.3 percent at three years and 90.3 percent at five years. At the final follow-up, 258 of all 296 patients, or 87.2 percent, were stoma-free, while 12.8 percent lived with a permanent stoma. Strikingly, the timing and cause of re-stoma creation followed two distinct patterns that carry different clinical implications, the authors report.
Structural anastomotic complications were the leading cause, accounting for 14 of the 25 delayed events. These included delayed leakage, pelvic abscess, fistula, chronic sinus, and clinically significant stenosis — objectively confirmed anatomical failures severe enough to demand renewed fecal diversion. The median interval from closure to re-stoma in this group was 11 months. The researchers attribute these late failures to a convergence of mechanisms: persistent pelvic sepsis, impaired tissue healing, and progressive radiation-related tissue changes such as fibrosis and microvascular injury. Radiation, while essential for tumor control, leaves behind tissue that is fibrotic, poorly vascularized, and slow to repair itself — a hostile environment for an anastomosis that must remain intact for decades. A delayed leak may represent either an occult abnormality that became apparent only after bowel continuity was restored or a genuinely new failure of the irradiated tissue.
The second pathway was quieter and slower. Seven patients required re-stoma creation because of severe functional bowel dysfunction — defecatory impairment so disabling that patients elected fecal diversion despite having no structural abnormality on endoscopy or imaging. In these cases the median interval was 44 months, nearly four years after closure, and all seven stomas were permanent. This pattern echoes long-term randomized trial data showing that preoperative radiotherapy is associated with a higher prevalence of major low anterior resection syndrome even 14 years after surgery. Anatomical continuity, the study makes clear, does not guarantee functional success. One patient additionally developed dysmotility-related megacolon 46 months after closure, and three patients required re-stomas because of tumor recurrence at a median of 11 months.
Importantly, the intensification of treatment did not appear to worsen long-term stoma outcomes. Delayed re-stoma-free survival did not differ significantly between the non-TNT and TNT groups (log-rank p = 0.176), nor between long-course and short-course radiotherapy schedules within TNT. In an exploratory comparison, male sex was the only characteristic significantly associated with delayed re-stoma creation — 88 percent of re-stoma patients were men versus 67.7 percent of those who remained stoma-free (p = 0.040) — a finding the authors attribute cautiously to the narrower male pelvis and greater technical difficulty of deep pelvic reconstruction, while emphasizing it is hypothesis-generating given the small number of events. Age, diabetes, tumor height, anastomotic height, surgical approach, and lateral lymph node dissection showed no significant associations.
The study has limitations the authors acknowledge candidly. It was retrospective and conducted at a single high-volume center where treatment strategies evolved over 14 years. The number of delayed events was small, limiting statistical power, and the primary endpoint captured only clinically consequential deterioration requiring diversion — not the full spectrum of delayed anastomotic abnormalities or functional decline that patients may endure without a new stoma. Patient-reported bowel, urinary, and sexual function were not systematically collected, and the decision to create a re-stoma inevitably involves physician judgment and patient preference. Even so, the central message stands: approximately 90 percent of patients were ultimately stoma-free after radiation-based neoadjuvant treatment and sphincter-preserving surgery, and TNT was not associated with worse long-term stoma outcomes. The authors argue that sustained stoma-free status should be recognized as a clinically meaningful endpoint in its own right, tracked well beyond the day the diverting stoma is closed — with careful pre-closure imaging, continued vigilance for late anastomotic failure, and standardized assessment of bowel function in future studies.
Subject of Research: Long-term stoma-free outcomes after diverting stoma closure in rectal cancer patients treated with radiation-based neoadjuvant therapy
Article Title: Long‐Term Stoma‐Free Outcomes After Diverting Stoma Closure Following Radiation‐Based Neoadjuvant Treatment for Rectal Cancer
Article References: Ichikawa, H., Matsui, S., Sato, K., Noguchi, T., Sakamoto, T., Mukai, T., Yamaguchi, T., & Akiyoshi, T. (2026). Long‐Term Stoma‐Free Outcomes After Diverting Stoma Closure Following Radiation‐Based Neoadjuvant Treatment for Rectal Cancer. Annals of Gastroenterological Surgery, Article ags3.70279. https://doi.org/10.1002/ags3.70279
Image Credits: AI Generated
DOI: 10.1002/ags3.70279
Keywords: rectal cancer, diverting stoma, stoma closure, total neoadjuvant therapy, anastomotic complications, sphincter-preserving surgery, radiotherapy, low anterior resection syndrome, surgical outcomes, colorectal surgery, Long, Term
Cite Scienmag News
Nathaniel Bowman. (September 22, 2026). Nine in Ten Rectal Cancer Patients Stay Stoma-Free Years After Closure, Study Finds. Scienmag. https://scienmag.com/nine-in-ten-rectal-cancer-patients-stay-stoma-free-years-after-closure-study-finds/
Nathaniel Bowman. "Nine in Ten Rectal Cancer Patients Stay Stoma-Free Years After Closure, Study Finds." Scienmag, 22 September 2026, https://scienmag.com/nine-in-ten-rectal-cancer-patients-stay-stoma-free-years-after-closure-study-finds/. Accessed 22 September 2026.
Nathaniel Bowman. "Nine in Ten Rectal Cancer Patients Stay Stoma-Free Years After Closure, Study Finds." Scienmag. September 22, 2026. https://scienmag.com/nine-in-ten-rectal-cancer-patients-stay-stoma-free-years-after-closure-study-finds/

