Abstract
Background/Aim: The usefulness of robot-assisted surgery for elderly colorectal cancer patients remains controversial. The aim of this study was to examine the impact of the surgical approach on short-term prognosis in patients aged ≥80 years.
Patients and Methods: A total of 1,115 colorectal cancer patients aged ≥80 years who underwent surgery at 6 hospitals between 2016 and 2024 were included in the study. Patients were divided into three groups according to surgical approach: robotic surgery (R group, n=55), laparoscopic surgery (L group, n=910), and open surgery (O group, n=150). Patient characteristics and surgical outcomes were compared among the three groups.
Results: The O group had higher proportions of patients with a body mass index (BMI) <25 kg/m2 (R vs. L vs. O: 72.7% vs. 80.8% vs. 87.3%, p=0.040), a performance status ≥3 (9.1% vs. 18.6% vs. 27.3%, p=0.006), an operation time <240 min (47.3% vs. 59.1% vs. 79.3%, p<0.001), and postoperative complications (9.1% vs. 23.0% vs. 27.3%, p=0.022). Multivariable analysis demonstrated that robotic surgery [odds ratio (OR)=0.243, 95% confidence interval (CI)=0.088–0.668, p=0.006] and BMI <25 kg/m2 (OR=0.626, 95% CI=0.419-0.936, p=0.032) were associated with a reduced risk of postoperative complications.
Conclusion: Robotic-assisted colorectal surgery in elderly patients is safe, with relatively few complications.
Introduction
The elderly proportion of the population is rapidly increasing worldwide. In the United States, individuals ≥65 years old will account for around 20% of the total population by 2030 (1). Compared to current demographics, the proportion of individuals ≥75 years old will triple and that of individuals ≥85 years old will double. The elderly are considered to show higher risk of various comorbidities and lower tolerance for hospitalization and stress, tending to result in greater rates of complications, prolonged hospitalization, and higher mortality rates (2, 3).
Compared to open surgery, laparoscopic surgery is reported to confer numerous advantages, including faster recovery of organ function, reduced postoperative pain, fewer infectious complications, and shorter hospitalization (4). Laparoscopic surgery for the elderly has been shown to significantly reduce morbidity and mortality (5-7), but also shows various limitations, such as an unstable field of view that is dependent on the assistant, shaking, and the limitations of ergonomics (8). For this reason, laparoscopic surgery is often switched to open surgery, which can negatively impact both short- and long-term prognoses (9). Robotic surgery has the potential to overcome the limitations of laparoscopy, such as by providing a stable field of view that can be controlled by the surgeon, anti-shake functions, 3-dimensional views, and expanded ranges of motion (10). However, while robotic surgery is associated with lower rates of conversion to open surgery compared to laparoscopy, some studies have reported longer operative time associated with robotic surgery (11). In addition, the effects on the elderly of maintaining the Trendelenburg position for prolonged periods of time and extending the duration of pneumoperitoneum have yet to be clarified. The aim of this study was to examine the impact of the surgical approach on short-term prognosis in colorectal cancer patients aged ≥80 years.
Patients and Methods
In this retrospective study, medical records of 5,160 consecutive patients who underwent colorectal surgery at Nagasaki University Hospital and 5 affiliated institutions (Sasebo City General Hospital, Isahaya General Hospital, Nagasaki Medical Center, Ureshino Medical Center, and Saiseikai Nagasaki Hospital) between April 2016 and March 2024 were reviewed. Patients with synchronous colon cancer, stoma construction alone, or emergency surgery were excluded. After these exclusions, the number of patients >80 years old was 1,115. This retrospective study was approved by the institutional review boards of each participating institution (approval no. 16062715-5), and the need to obtain informed consent was waived based on the retrospective design.
Patients were divided into three groups: a robotic surgery group (R group; n=55); a laparoscopic surgery group (L group; n=910); and an open surgery group (O group; n=150). The following data were collected: sex, age, body mass index (BMI), American Society of Anesthesiologists physical status classification (ASA-PS), comorbidities, preoperative treatment, tumor location, colonic stent insertion, multivisceral resection, clinical tumor/node/metastasis (T/N/M) status, operation time, estimated blood loss, postoperative complications, and length of postoperative stay. Postoperative complications were defined as any complications occurring within 30 days following the primary surgery and were recorded and classified according to the Clavien–Dindo classification system.
Data were analyzed using JMP software (SAS Institute, Cary, NC, USA). For comparisons of continuous variables among the three groups, one-way analysis of variance was used to determine the significance of differences. Multivariable analysis using logistic regression analysis was used to identify independent risk factors for postoperative complications. Variables showing a p-value of <0.05 in univariable analyses were included in the multivariable analysis. Differences with a p<0.05 were considered statistically significant.
Results
Table I presents clinicopathological characteristics of patients. The O group showed a higher proportion of lower BMI (R group vs. L group vs. O group: BMI ≥25 kg/m2, 27.3% vs. 19.2% vs.12.7%; p=0.040), poorer ASA-PS (PS ≥3: 9.1% vs. 18.6% vs. 27.3%; p=0.006), greater frequencies of right-side colon cancer (25.5% vs. 48.7% vs. 44.7%; p=0.003), multivisceral resection (3.6% vs. 5.4% vs. 16.7%; p<0.001), and clinical T4 (12.7% vs. 21.5% vs. 37.3%, p<0.001), lower frequency of operation time ≥240 min (52.7% vs. 40.9% vs. 27.3%; p<0.001), higher frequency of postoperative complications (9.1% vs. 23.0% vs. 27.3%; p=0.022), and longer hospital stay (13 days vs. 14 days vs. 21 days; p<0.001).
Comparison of demographic and clinicopathological characteristics among surgical groups.
Table II lists the details of postoperative complications. The frequency of grade 2 postoperative complications was 5.4% (3/55) in the R group, 16.4% (149/910) in the L group, and 17.3% (26/150) in the O group (p=0.088). Grade 3 complications were seen in 3.6% (2/55) of the R group, 5.4% (49/910) of the L group and 7.3% (11/150) of the O group (p =0.511). Grade 4 complications observed seen in 0% (0/55) of the R group, 1.0% (49/910) of the L group, and 2.0% (3/150) of the O group (p=0.393). Grade 5 complications were seen in 0% (0/55) of the R group, 0.2% (2/910) of the L group, and 1.3% (2/150) of the O group (p=0.096).
Details of postoperative complications.
In univariable analyses, female sex, use of robotic surgery, low BMI, poor PS, and long operation time were significantly associated with postoperative complications (Table III). Multivariable analysis identified female sex [odds ratio (OR)=1.577, 95% confidence interval (CI)=1.180-2.106, p=0.002), poor PS (OR=1.675, 95% CI=1.197-2.343, p=0.003), and long operation time (OR=1.625, 95%CI=1.204-2.193, p=0.002) as factors associated with an increased risk of postoperative complications. Robotic surgery (OR=0.243, 95% CI=0.088-0.668, p=0.006) and BMI ≥25 kg/m2 (OR=0.626, 95% CI=0.419-0.936, p=0.032) were associated with a reduced risk of postoperative complications,
Univariable and multivariable logistic regression analyses of clinical factors associated with infectious complications in colorectal cancer patients.
Discussion
With the continuing aging of the population, increases have been seen in the number of elderly patients with colorectal cancer who undergo surgery. Treatment strategies are important for elderly patients, who show a wide variety of backgrounds compared to younger patients, but very limited data are available on this issue, because elderly patients have been excluded or underrepresented in previous clinical trials (12, 13). This study examined the impact of robotic-assisted, laparoscopic, and open surgeries on the short-term prognosis of colorectal cancer patients ≥80 years old. Open surgery was associated with higher BMI, poorer PS, shorter operation time, and a higher frequency of postoperative complications. In the multivariable analysis of postoperative complications, robotic-assisted surgery emerged as an independent protective factor.
Elderly patients reportedly display a higher proportion of poor PS (PS ≥3) and cardiovascular comorbidities than younger patients (14-18). In previous reports, the proportion of elderly patients with colorectal cancer showing poor PS was high, ranging from 29.2% to 49.5% (16-18). Xue et al. examined the usefulness of minimally invasive surgery for elderly patients, and found that 68.5% of patients had comorbidities, including hypertension (51.4%), coronary heart disease (20.7%), diabetes (16.2%) and pulmonary disease (7.6%) (16). In the current study of colorectal cancer patients aged ≥80 years, the proportion showing PS 3 was 19.3%, slightly lower than in previous reports. However, the comorbidity rate was high (79.3%), with hypertension present in 52.2%, cardiovascular disease in 15.0%, pulmonary disease in 4.3%, and diabetes mellitus in 15.8%. This may be due to fact that the decision to operate on elderly patients was made by the attending physician at each facility, potentially introducing selection bias.
The ROLARR randomized clinical trial compared robotic-assisted and laparoscopic surgeries for patients with rectal cancer, revealing a trend towards a reduction in the open conversion rate, with 8.1% of patients in the robotic-assisted group and 12.2% in the laparoscopic group undergoing conversion to open surgery (11, 19). In the current study, open conversion was performed for 20 cases (2.3%) in the laparoscopic group, whereas no conversions (0%) occurred in the robotic surgery group. This suggests that robotic surgery may also reduce the open conversion rate in elderly patients.
Nevertheless, robotic surgery has been reported to have longer operating times compared to laparoscopic surgery (11). Concerns have been raised that complications after surgery may increase due to factors such as extension of the duration of general anesthesia in line with extension of the duration of surgery, increased intra-abdominal pressure, and hypercapnia due to prolonged use of the Trendelenberg position.
A recent meta-analysis that examined the utility of robot surgery for elderly patients with rectal cancer found no significant difference in the incidence of complications after robot surgery between elderly and young patients (20). A previous study comparing robotic-assisted and laparoscopic surgeries for colorectal cancer patients ≥80 years old reported no statistically significant difference in complication rates between the two approaches.
In the present study, complications were significantly lower in the R group (9.1%) than in the L group (23.0%) or O group (27.3%). In addition, the multivariable analysis of complications identified the use of robotic-assisted surgery as an independent protective factor for reducing postoperative complications. In a previous report, the overall complication rate for robotic-assisted rectal surgery was lower in the elderly group than in the younger group (21). This suggests that the minimally invasive nature of robotic-assisted surgery may be beneficial for elderly patients with physical frailty.
Compared to younger patients, elderly patients have lower levels of cardiopulmonary and organ function, and are considered more likely to suffer from cardiac, pulmonary, and infectious complications (22). In addition, elderly patients appear more likely to suffer from postoperative delirium due to declines in activity of daily living and problems with levels of consciousness (22). However, robotic-assisted surgery may help mitigate some of these risks by reducing fluid movement and preventing hypothermia (23, 24). Moreover, the use of narcotics and antiemetics can be reduced with more minimally invasive approaches, which may further reduce the risk of postoperative delirium and disorders of consciousness (23, 24).
This study found no significant difference in the incidence of cardiopulmonary complications between the three groups. However, 2.0% of patients in O group developed postoperative delirium, compared to none of the patients in R group.
In addition, compared to younger patients, elderly individuals are more likely to have reduced organ function and reduced ADL. Organ recovery and shorter duration of hospitalization are thus important not only for achieving long-term improvements in ADL, but also from a medical economic perspective. Jayne et al. reported that robotic-assisted surgery significantly reduced the organ recovery period and hospital stay compared to laparoscopic surgery (11). In addition, a study of 12,790 people in the United States also showed that, although the cost of robotic-assisted surgery was relatively high, the duration of hospitalization was short (25). Studies on robotic-assisted surgery and the duration of hospitalization for elderly colorectal cancer patients remain limited, but some have reported equivalence to laparoscopy (16). In this study, the median duration of hospitalization was 21 days for O group, compared to 13 days for R group and 14 days for L group.
Study limitations. First, its retrospective design and the limited number of patients may affect the generalizability of the findings. Second, indications for surgery were determined by the discretion of individual surgeons, potentially introducing selection bias.
In conclusion, robotic-assisted colorectal surgery can be safely performed in elderly patients with colorectal cancer, with a low rate of complications. As the aging population continues to grow, the need for less invasive surgical approaches will become increasingly important. Robotic surgery has the potential to play a crucial role in the treatment of elderly patients, who often present with lower performance status compared to younger individuals, by providing a minimally invasive option that may help preserve quality of life in this vulnerable population.
Footnotes
Authors’ Contributions
Shoko Tei and Tetsuro Tominaga was primarily responsible for the study design. Keisuke Noda, Yuma Takamura, Hiroki Katayama, Shintaro Hashimoto, Rika Ono, Mitsutoshi Ishii, Makoto Hisanaga, Kaido Oishi, Masaaki Moriyama, Fumitake Uchida, and Toshio Shiraishi performed the surgeries. Takashi Nonaka supervised the study. Tetsuro Tominaga wrote the first draft of the manuscript, and all authors commented on previous versions of the manuscript. All Authors read and approved the final version of the manuscript.
Conflicts of Interest
The Authors have no conflicts of interest to declare.
Artificial Intelligence (AI) Disclosure
No artificial intelligence (AI) tools, including large language models or machine learning software, were used in the preparation, analysis, or presentation of this manuscript.
- Received September 7, 2025.
- Revision received September 24, 2025.
- Accepted October 1, 2025.
- Copyright © 2026 The Author(s). Published by the International Institute of Anticancer Research.
This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY-NC-ND) 4.0 international license (https://creativecommons.org/licenses/by-nc-nd/4.0).
