RIOT, CIOT, and the Surgeon's Role in Optimizing Oncologic Outcomes
Authors
Shaun McKenzie, MD, FACS
Texas Oncology Surgical Specialists
Dennis Begos MD, FACS
Medical Director @ Lexington Medical, Inc.
Introduction
Most patients with solid organ malignancies will require surgical resection at some point in their treatment course. This is especially true in gastrointestinal and thoracic oncology, where surgery remains the cornerstone of curative-intent therapy. At the same time, the proportion of patients receiving neoadjuvant or adjuvant therapy continues to rise—driven by increasing incidence, novel therapeutics, and improving evidence for multimodal approaches [1].
This intersection of surgery and systemic therapy raises a critical but often underappreciated question: does the quality of the surgical episode itself affect whether a patient actually completes their intended oncologic treatment—and ultimately, their survival?
Defining the Metrics
RIOT (Return to Intended Oncologic Treatment) — a quality metric first described at MD Anderson in 2014, measuring whether and how quickly a patient begins planned adjuvant or systemic therapy following surgical resection.
CIOT (Completion of Intended Oncologic Therapy) — the downstream extension of RIOT: not just starting treatment but completing it.
Both are now recognized as oncologic quality indicators [4].
The Evidence: Surgery Directly Affects Oncologic Outcomes
The landmark 2014 MD Anderson study by Aloia et al. examined RIOT in hepatic malignancy patients and found a striking result: while 75% of open resection patients went on to RIOT, 100% of minimally invasive patients did. Postoperative complications were the primary barrier in the open group, with an odds ratio of 2—patients with complications were half as likely to receive planned postoperative therapy. The minimally invasive surgery (MIS) group began adjuvant treatment at a median of 15 days vs. 42 days in the open group and had superior disease-free and overall survival [2].
These findings have been replicated across other organ systems—gastric, colorectal, endometrial, lung, and prostate cancer—establishing RIOT as a robust, generalizable metric [3]. Postoperative complications consistently reduce RIOT rates by 50% or more [3,4].
Modifiable Surgical Factors: Where You Have Control
1. Preoperative Optimization
- Prehabilitation and nutritional optimization—particularly in patients who have received neoadjuvant therapy—have been shown to improve RIOT rates [3].
- Smoking cessation improves RIOT rates in mesothelioma and likely other thoracic malignancies [5].
2. Complication Avoidance
- Postoperative complications are the leading modifiable cause of failure to RIOT, with as few as half of patients who experience them going on to receive planned therapy [6,7].
- Operative time is an under-recognized driver of complications: complication rates and surgical site infection rates double after 2 hours of operative time, with a dose-response relationship increasing approximately 14% for every additional 30 minutes [8,9].
- Implication for training environments: while surgical education is essential, trainees should not lengthen cases beyond the threshold where complications begin to climb.
- Minimizing transfusion requirements reduces immunosuppression, infection risk, and delays to adjuvant therapy.
3. Technology Selection
Device selection is a direct, modifiable variable in surgical outcomes. The published data on the AEON™ surgical stapling platform is illustrative:
| Procedure | Finding | Reference |
|---|---|---|
| Laparoscopic Distal Pancreatectomy | POPF rate 20% (AEON) vs. 65% (EndoGIA) | [10] |
| Sleeve Gastrectomy | Superior staple-line hemostasis (non-buttressed) vs. EndoGIA with buttress | [11] [12] |
| Lung Volume Reduction Surgery | Reduced air leak rate vs. Echelon Flex | [13] |
| GI Surgery (Multi-Procedure) | Favorable early clinical experience across GI applications | [14] |
- Eliminating the need for adjunctive hemostasis—suture, clip, or buttress on staple lines—directly reduces operative time and complexity.
- Although not all these studies were in cancer patients, it is logical that the lower complication rate would extend to oncologic surgery.
- Minimizing the need for adjunctive hemostasis such as buttressing, suturing, clipping, etc. on staple lines can decrease OR time.
4. Anesthetic Technique
- Intermediate-acting neuromuscular blockade has been associated with improved RIOT in gastric cancer surgery [15].
- Epidural analgesia blunts the inflammatory and immunosuppressive stress response to surgery, with potential implications for tumor biology in the perioperative window [16].
5. Minimally Invasive Approach
- Substantial evidence across GI, thoracic, and gynecologic oncology demonstrates that MIS improves RIOT rates—consistent with shorter recovery times and lower complication rates [3,4,17].
- MIS is associated with reduced perioperative immunosuppression and inflammatory response, which may have direct oncologic implications beyond just recovery [18].
6. Enhanced Recovery After Surgery (ERAS) Adherence
- ERAS protocols—multimodal, specialty-specific, and applied from prehabilitation through discharge—consistently reduce length of stay, complication rates, and total cost of care [19].
From the Operating Room
In my personal experience at Texas Oncology, adopting the AEON stapling platform has meaningfully shortened our OR times. We have also seen a lower need for intra- and post-operative transfusions, which I attribute to more consistent staple-line hemostasis.
Shaun McKenzie, MD, FACS
Texas Oncology
The Bottom Line: Can a Stapler Affect Survival?
It may seem like a substantial claim—but the evidence supports it. Surgical staplers enable MIS approaches, reduce operative time, and, in the case of AEON, are associated with lower complication rates in pancreatic, gastric, and thoracic surgery. Each of these factors independently correlates with improved RIOT rates. And RIOT rates correlate with survival.
Of course there is no single variable that determines oncologic outcomes. But the evidence makes clear that surgical quality—including intraoperative decisions about technique and technology—is not a passive backdrop to cancer treatment. It is an active determinant of whether patients complete their treatment and, ultimately, whether they survive.
Each of the marginal gains described here—optimized prehabilitation, reduced operative time, hemostatic staple lines, MIS approach, ERAS adherence—compounds. The question worth asking before your next oncologic resection is not whether any single factor matters enough on its own. It’s whether you’re optimizing all of them.
Key Takeaways
- Surgical quality is an active determinant of cancer survival, not a passive backdrop. Intraoperative decisions about technique and technology directly influence whether patients complete their intended oncologic treatment.
- RIOT (Return to Intended Oncologic Treatment) measures whether and how quickly a patient begins planned therapy after surgery. It was first described at MD Anderson in 2014 and is now a recognized oncologic quality indicator across multiple cancer types.
- CIOT (Completion of Intended Oncologic Therapy) extends RIOT to measure whether patients finish treatment, not just start it. Both metrics correlate with disease-free and overall survival.
- Postoperative complications are the leading modifiable cause of failure to return to oncologic treatment. Patients who experience complications are roughly half as likely to receive their planned postoperative therapy.
- Operative time is an under-recognized driver of complications. Complication and surgical site infection rates double after two hours, rising approximately 14% for every additional 30 minutes.
- Device selection is a direct, surgeon-controlled variable in oncologic outcomes. In laparoscopic distal pancreatectomy, the AEON platform was associated with a postoperative pancreatic fistula rate of 20% versus 65% with a comparator (Sheen et al., 2023).
- Consistent staple-line hemostasis can reduce the need for adjunctive measures. Eliminating suture, clip, or buttress reinforcement on staple lines reduces operative time and complexity, which compounds into lower complication risk.
- Minimally invasive surgery improves return-to-treatment rates across GI, thoracic, and gynecologic oncology. Staplers that enable MIS approaches contribute to shorter recovery and reduced perioperative immunosuppression.
- Marginal gains compound. Prehabilitation, reduced operative time, hemostatic staple lines, an MIS approach, and ERAS adherence each independently support RIOT and combine to improve the odds a patient completes treatment.
- The question for your next oncologic resection is not whether one factor matters enough alone, but whether you are optimizing all of them.
Frequently Asked Questions
RIOT, or Return to Intended Oncologic Treatment, is a quality metric that measures whether and how quickly a patient begins planned adjuvant or systemic therapy after surgical resection. It was first described at MD Anderson in 2014 and is now a recognized oncologic quality indicator across multiple cancer types.
RIOT (Return to Intended Oncologic Treatment) measures whether a patient starts their planned therapy after surgery, while CIOT (Completion of Intended Oncologic Therapy) measures whether they finish it. CIOT is the downstream extension of RIOT, and both correlate with disease-free and overall survival.
The evidence supports that it can, indirectly. Surgical staplers enable minimally invasive approaches, reduce operative time, and, in the case of the AEON platform, are associated with lower complication rates in pancreatic, gastric, and thoracic surgery. Each of these factors independently correlates with improved RIOT rates, and RIOT rates correlate with survival. No single variable determines oncologic outcomes, but surgical quality is an active determinant, not a passive backdrop.
Postoperative complications are the leading modifiable cause of failure to return to intended oncologic treatment. Patients who experience complications are roughly half as likely to receive their planned postoperative therapy, and complications consistently reduce RIOT rates by 50% or more.
Yes. Complication rates and surgical site infection rates double after two hours of operative time, with a dose-response relationship that increases approximately 14% for every additional 30 minutes. This makes operative time an under-recognized but modifiable driver of complications.
Six evidence-based, surgeon-controlled variables affect RIOT rates: preoperative optimization including prehabilitation and smoking cessation, complication avoidance, technology and device selection, anesthetic technique, a minimally invasive approach, and adherence to Enhanced Recovery After Surgery (ERAS) protocols.
Device selection is a direct, modifiable variable in surgical outcomes. Published data on the AEON surgical stapling platform is illustrative: in laparoscopic distal pancreatectomy, the AEON surgical stapler was associated with a postoperative pancreatic fistula rate of 20% compared with 65% for a comparator (Sheen et al., 2023). These results represent findings from individual studies and should be interpreted in clinical context, with larger prospective trials ongoing.
Eliminating the need for adjunctive hemostasis, such as suture, clip, or buttress reinforcement on staple lines, directly reduces operative time and surgical complexity. Because operative time and complications are linked, more consistent staple-line hemostasis can contribute to a lower overall complication burden.
Yes. Substantial evidence across gastrointestinal, thoracic, and gynecologic oncology shows that minimally invasive surgery improves RIOT rates, consistent with shorter recovery times and lower complication rates. MIS is also associated with reduced perioperative immunosuppression, which may carry oncologic implications beyond recovery alone.
ERAS, or Enhanced Recovery After Surgery, refers to multimodal, specialty-specific protocols applied from prehabilitation through discharge. These protocols consistently reduce length of stay, complication rates, and total cost of care, which supports a patient’s ability to return to intended oncologic treatment.
References
- Wagle NS, et al. Cancer treatment and survivorship statistics, 2025. CA Cancer J Clin. 2025;75(4):308–340.
- Aloia TA, et al. Return to intended oncologic treatment (RIOT): a novel metric for evaluating the quality of oncosurgical therapy for malignancy. J Surg Oncol. 2014;110(2):107–14.
- Cortes-Mejia NA, Lillemoe HA, Cata JP. Return to intended oncological therapy: state of the art and perspectives. Curr Oncol Rep. 2024;26(11):1420–1430.
- Koo A, et al. Effect of minimally invasive gastrectomy on return to intended oncologic therapy for gastric cancer. Ann Surg Oncol. 2025;32(1):230–239.
- Nelson DB, et al. Return to intended oncologic treatment after surgery for malignant pleural mesothelioma. J Thorac Cardiovasc Surg. 2019;158(3):924–929.
- Merkow RP, et al. Effect of postoperative complications on adjuvant chemotherapy use for stage III colon cancer. Ann Surg. 2013;258(6):847–853.
- Kim BJ, et al. The impact of postoperative complications on a timely return to intended oncologic therapy (RIOT): the role of enhanced recovery in the cancer journey. Int Anesthesiol Clin. 2016;54(4):e33–46.
- Cheng H, et al. Prolonged operative duration is associated with complications: a systematic review and meta-analysis. J Surg Res. 2018;229:134–144.
- Procter LD, et al. General surgical operative duration is associated with increased risk-adjusted infectious complication rates and length of hospital stay. J Am Coll Surg. 2010;210(1):60–65.
- Sheen AJ, et al. Preliminary experience in laparoscopic distal pancreatectomy using the AEON™ endovascular stapler. Front Oncol. 2023;13:1146646.
- Redmann JG, et al. Improving hemostasis in sleeve gastrectomy with alternative stapler. JSLS. 2020;24(4).
- Hogan G, et al. Comparative analysis of hemostasis and staple-line integrity between Medtronic Tri-Staple™ with preloaded buttress material and the AEON™ stapler in bariatric surgery. JSLS. 2024;28(2).
- Macharia-Nimietz EF, et al. Efficacy of non-powered stapler in lung volume reduction surgery of severe lung emphysema: a prospective randomized single-blinded monocentric study. Interdiscip CardioVasc Thorac Surg. 2026.
- Sheen AJ. The validity of the AEON™ stapler in gastrointestinal surgery: early clinical experience and translational rationale. Front Oncol. 2026;16.
- Niu L, et al. Association between intermediate-acting neuromuscular-blocking agents and short-term postoperative outcomes in patients with gastric cancer. Cancer Manag Res. 2020;12:11391–11402.
- Vicente D, et al. Impact of epidural analgesia on the systemic biomarker response after hepatic resection. Oncotarget. 2019;10(5):584–594.
- Leitao MMJ, et al. The RECOURSE study: long-term oncologic outcomes associated with robotically assisted minimally invasive procedures for endometrial, cervical, colorectal, lung, or prostate cancer. Ann Surg. 2023;277(3):387–396.
- Lee SW, Whelan RL. Immunologic and oncologic implications of laparoscopic surgery: what is the latest? Clin Colon Rectal Surg. 2006;19(1):5–12.
- Lau CSM, Chamberlain RS. Enhanced recovery after surgery programs improve patient outcomes and recovery: a meta-analysis. World J Surg. 2017; 41(4):1.
