Minimally invasive rectal cancer surgery after neoadjuvant therapy in selected elderly and frail patients: A single-center real-world experience

Abstract

BACKGROUND

Management of elderly and frail patients with rectal cancer remains challenging after neoadjuvant therapy, as concerns about postoperative morbidity may influence treatment allocation. Evidence on the safety and oncologic adequacy of minimally invasive surgery in this setting remains limited. We hypothesized that, among highly selected elderly and frail patients completing neoadjuvant treatment, curative-intent minimally invasive surgery would provide acceptable postoperative and oncologic outcomes.

AIM

To evaluate postoperative and oncologic outcomes in selected elderly and frail patients undergoing minimally invasive rectal cancer surgery after neoadjuvant therapy.

METHODS

This retrospective single-center study analyzed a prospectively maintained database of patients with histologically confirmed rectal adenocarcinoma undergoing curative-intent minimally invasive surgery after neoadjuvant therapy from 2014 to 2025. Elderly patients were aged 80 years or older; frailty was defined as a 5-item modified frailty index score of at least 2. Postoperative outcomes, 90-day mortality, overall survival, cancer-specific survival, and disease-free survival were compared according to age and frailty status using appropriate comparative and survival analyses.

RESULTS

Among 142 patients, 23 (16.2%) were aged 80 years or older and 16 (11.3%) were frail. Elderly patients had more major postoperative complications than younger patients (30.4% vs 5.9%, P = 0.002) and more medical complications (60.9% vs 34.5%, P = 0.017). Surgical complications, anastomotic leak, reintervention, conversion to open surgery, and R0 resection rates were comparable between age groups. Overall survival was lower in elderly patients, whereas cancer-specific and disease-free survival were comparable. Frailty was not consistently associated with postoperative or survival outcomes.

CONCLUSION

In highly selected elderly and frail patients, minimally invasive rectal surgery after neoadjuvant therapy yields acceptable surgical and oncologic outcomes, supporting individualized multidisciplinary rather than age-based treatment decisions.

Key Words: Rectal neoplasms; Frailty; Octogenarians; Minimally invasive surgical procedures; Postoperative complications; Neoadjuvant therapy

Core Tip: In this single-center real-world cohort, elderly and frail patients with rectal cancer who completed neoadjuvant therapy and were selected for curative-intent minimally invasive surgery achieved acceptable technical and oncologic outcomes. Patients aged 80 years or older had more medical and major postoperative complications and poorer overall survival, whereas surgical complications, cancer-specific survival, and disease-free survival were broadly comparable with those of younger patients. These findings support individualized multidisciplinary assessment rather than age-based exclusion in appropriately selected candidates.

INTRODUCTION

Colorectal cancer is the third most common malignancy worldwide, with the incidence of rectal cancer increasing progressively with age and peaking around 80 years[1]. At the same time, life expectancy in Europe continues to rise, currently reaching 84.1 years for women and 78.9 years for men, leading to a growing population of elderly patients diagnosed with rectal cancer[2]. Surgery remains the cornerstone of curative treatment; however, real-world decision-making in this population remains unclear and current guidelines provide limited specific recommendations for elderly patients, as high-quality evidence from clinical trials in this setting remains scarce[3]. This population is highly heterogeneous, ranging from fit individuals to those with significant frailty and reduced physiological reserve. Advanced age has been reported as a potential risk factor for postoperative morbidity after minimally invasive colorectal surgery[4]. Frailty has emerged as a key concept to better capture the biological heterogeneity of aging, reflecting a state of reduced physiological reserve and increased vulnerability to stressors. A growing body of evidence has shown that frailty is associated with worse postoperative outcomes, including higher rates of major complications, prolonged hospital stay, and increased mortality[5], and may represent a more accurate predictor of surgical risk than chronological age or traditional comorbidity indices such as the American Society of Anesthesiologists (ASA) score or the Charlson Comorbidity Index[6]. Aging and frailty are closely related but distinct processes: While the prevalence of frailty increases with advancing age, their respective impact on clinical outcomes may differ, with frailty potentially exerting a stronger influence on short-term postoperative outcomes and chronological age reflecting, at least in part, the burden of competing risks affecting long-term survival[7,8]. Despite this variability, chronological age alone is insufficient to adequately characterize older patients or to guide clinical decision-making. Whether age alone should preclude surgical treatment remains controversial, particularly in the context of modern perioperative care and minimally invasive approaches. In parallel, the adoption of enhanced recovery after surgery (ERAS) protocols and structured preoperative optimization strategies has improved perioperative outcomes and may expand surgical eligibility to selected elderly and frail patients[9]. Evidence suggests that the implementation of multidisciplinary preoperative evaluation in frail patients with colorectal cancer improves risk stratification and enables targeted prehabilitation, resulting in postoperative outcomes comparable to those of non-frail individuals, although overall survival (OS) may remain impaired[10]. In this context, the aim of the present study was to evaluate postoperative and oncologic outcomes in a highly selected real-world cohort of elderly and frail patients undergoing curative-intent minimally invasive rectal cancer surgery after neoadjuvant therapy within a real-world clinical setting, and to explore whether structured patient selection and multidisciplinary perioperative optimization may mitigate the detrimental impact of aging and frailty on postoperative outcomes while preserving oncologic adequacy.

MATERIALS AND METHODS

Study design and data collected

Data were retrospectively collected from a prospectively maintained institutional database and reclassified according to standardized definitions applied throughout the study period. The study included patients with histologically confirmed rectal adenocarcinoma who underwent neoadjuvant therapy followed by curative-intent surgery from 2014 to 2025. Surgical procedures consisted of minimally invasive low anterior resection or abdominoperineal resection, performed using either robotic or laparoscopic approaches. Patients undergoing synchronous liver resection for hepatic metastases were also included. All cases were preoperatively discussed within a dedicated multidisciplinary team, including at least one oncologist, one radiologist, two surgical oncologists, and one endoscopist. Patients were managed within a structured perioperative pathway based on ERAS principles, incorporating multidisciplinary evaluation and systematic preoperative optimization. This included assessment and management of modifiable risk factors, with particular attention to nutritional status, functional reserve, and comorbidities, along with preadmission counseling. Nutritional screening was routinely performed, with targeted interventions implemented when indicated, including immunonutrition and preoperative carbohydrate loading according to institutional protocols. A structured prehabilitation program was applied, comprising respiratory and physical training following physiatric evaluation, with the aim of improving functional capacity and reducing postoperative pulmonary complications. In addition, elderly patients underwent preoperative geriatric assessment focusing on functional autonomy, comorbidity burden, and frailty status, contributing to individualized treatment planning. Therefore, the study population represents a highly selected cohort of patients who completed neoadjuvant therapy and were considered suitable for curative-intent minimally invasive surgery. Data included demographic and clinical characteristics, as well as preoperative variables such as body mass index (BMI), ASA score, comorbidities, and previous surgical history. Frailty was assessed using the 5-item modified frailty index (mFI-5)[11], with patients categorized as frail (mFI-5 ≥ 2) or non-frail (mFI-5 < 2). Neoadjuvant treatment strategies were classified according to institutional protocols as short-course chemoradiotherapy, long-course chemoradiotherapy with concomitant capecitabine, or total neoadjuvant therapy (TNT). Chemotherapy regimens within TNT were grouped as fluoropyrimidine-, oxaliplatin-, or irinotecan-based, with biologic agents administered in selected patients according to clinical indication. Disease-related variables included tumor location, clinical and pathological staging before and after neoadjuvant treatment, and tumor regression grade. Pathological data comprised tumor size, grading, and nodal status, reported according to the American Joint Committee on Cancer 8^th edition[12]. Surgical variables and postoperative outcomes were collected. Complications were classified according to the Clavien-Dindo system, with major complications defined as grade > 2, and further categorized as medical or surgical. Additional outcomes included intensive care unit (ICU) admission, reoperation, length of hospital stay, and readmission. Short-term outcomes were defined as complications and mortality within 90 days after surgery, while long-term outcomes included recurrence, survival status, and cause of death (cancer-related vs other).

The study was approved by the local Ethics Committee (approval No. 5956/2020, I.5/262). Written informed consent for the collection and use of clinical data for research purposes was obtained from all patients. The study was conducted in accordance with the Declaration of Helsinki and complied with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016, as well as with the relevant Italian legislation on the use and protection of personal data.

Statistical analysis

Descriptive statistics were reported as means and SD for continuous variables and as n (%) for categorical variables. Continuous variables were reported as medians with interquartile range (IQR) and compared using the Mann-Whitney or the Kruskal-Wallis test, when necessary. Categorical variables were n (%) with percentages and were compared using the χ² or Fisher exact test, as appropriate. A two-sided significance level of α = 0.05 was adopted.

The primary endpoint was to evaluate short-term postoperative outcomes, including ICU admission, length of hospital stay, and postoperative complications (both surgical and medical) occurring within 90 days after surgery, comparing elderly (≥ 80 years) and younger patients, as well as frail (mFI-5 ≥ 2) and non-frail individuals, in order to assess whether outcomes were comparable across groups within a structured perioperative pathway. In the absence of a universally accepted definition of “elderly” in the surgical setting, a cut-off of ≥ 80 years was adopted. Frailty was defined as a mFI-5 ≥ 2. Associations between binary outcomes and independent variables were assessed using logistic regression models. To account for multiple testing in multivariable analyses, P values were adjusted using the Benjamini-Hochberg method and reported accordingly. Secondary endpoints included overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS), analyzed to compare long-term outcomes between age (≥ 80 vs < 80 years) and frailty (frail vs non-frail) groups, and to explore whether comparable oncologic outcomes were maintained despite differences in baseline risk. Survival analyses were performed using the Kaplan-Meier method, with comparisons between groups assessed by the log-rank test. Univariate Cox proportional hazards models were used to evaluate the association between covariates and time-to-event outcomes (OS, CSS, and DFS). Multivariable Cox regression was not performed, as no covariates reached statistical significance in univariate analyses. Hazard ratios (HR) with 95% confidence intervals (CI) were reported. All statistical analyses were performed using Jamovi (version 2.7; The Jamovi Project, Sydney, Australia).

RESULTS

Baseline characteristics

A total of 142 patients with rectal adenocarcinoma underwent curative-intent minimally invasive surgery following neoadjuvant therapy. Of these, 23 patients (16.2%) were aged ≥ 80 years and 16 (11.3%) were classified as frail (mFI-5 ≥ 2). Baseline preoperative characteristics are summarized in Table 1. Compared with younger patients, octogenarians presented a higher comorbidity burden, with higher ASA and Age-Adjusted Charlson Comorbidity Index scores and a greater prevalence of frailty. Neoadjuvant treatment strategies differed between age groups, with elderly patients more frequently receiving chemoradiotherapy and less commonly TNT. No major baseline differences were observed according to frailty status.

Table 1 Baseline characteristics stratified by age group, n (%)/mean ± SD.

Variable	Age ≥ 80 years (n = 23)	Age < 80 years (n = 119)	P value
Body mass index	26.3 ± 4.0	25.4 ± 4.2	-
ACCI	11.2 ± 1.9	6.7 ± 2.9	< 0.001
ASA score	3.0 ± 0.2	2.4 ± 0.6	< 0.001
Male sex	14 (60.9)	72 (60.5)	0.98
Comorbidities ≥ 1	18 (78.3)	54 (45.4)	< 0.01
Previous surgery	5 (21.7)	30 (25.2)	0.72
Smoking	3 (13.0)	36 (31.1)	0.10
Frail (mFI-5 ≥ 2)	5 (21.7)	11 (9.2)	0.09
Neoadjuvant treatment
CH-RT	21 (91.3)	79 (66.4)	0.02
TNT	2 (8.7)	40 (33.6)	0.02
Chemotherapy backbone
Fluoropyrimidine-based	16 (88.9)	67 (63.8)	-
Oxaliplatin-based	1 (5.6)	33 (31.4)	-
Irinotecan-based	1 (5.6)	5 (4.8)	-
Biologic therapy	2 (11.1)	14 (13.3)	-

ACCI: Age-Adjusted Charlson Comorbidity Index; ASA: American Society of Anesthesiologists; mFI: 5-item modified frailty index; CH-RT: Chemoradiotherapy; TNT: Total neoadjuvant therapy.

Intraoperative characteristics

Intraoperative characteristics are reported in Table 2. Surgical feasibility and oncologic adequacy appeared comparable across groups. Minimally invasive surgery was predominantly robotic, conversion to open surgery remained uncommon, and R0 resection rates were similar between elderly and younger patients. Elderly patients underwent abdominoperineal resection more frequently, while low anterior resection remained the predominant procedure overall. When stratified by age, liver resection was performed in one elderly patient (4.3%) vs seven (5.9%) younger patients. Both non-anatomic and anatomic resections were performed, although the number of cases was limited.

Table 2 Intraoperative characteristics stratified by age group, n (%)/mean ± SD.

Variable	Age ≥ 80 years (n = 23)	Age < 80 years (n = 119)	P value
Tumor distance (cm)	7.6 ± 3.0	8.7 ± 3.6	0.30
Tumor location
Low	7 (30.4)	24 (20.2)	0.40
Middle	13 (56.5)	65 (54.6)	0.95
High	3 (13.0)	30 (25.2)	0.20
Lymph nodes harvested, median (range)	23 (11-38)	17 (3-40)	0.01
R0 resection	21/22 (95.5)	115/119 (96.6)	0.85
Type of surgery
Low anterior resection	16 (69.6)	109 (91.6)	0.02
Abdominoperineal resection	6 (26.1)	9 (7.6)	0.02
Hartmann	1 (4.3)	1 (0.8)	-
Surgical approach
Robotic	19 (82.6)	104 (87.4)	0.60
Laparoscopic	4 (17.4)	15 (12.6)	0.60
Stoma
Ileostomy	3 (13.0)	88 (73.9)	< 0.001
Colostomy	20 (87.0)	20 (16.8)	< 0.001
Operative time (minutes)	366 ± 109	408 ± 127	0.15
Blood transfusion	3 (13.0)	1 (0.8)	0.10
Conversion	1 (4.3)	8 (6.7)	0.45
Pelvic drain	22 (95.7)	118 (99.2)	0.80
Mesorectal excision
TME	22 (95.7)	111 (93.3)	0.70
PME	1 (4.3)	8 (6.7)	0.70

TME: Total mesorectal excision; PME: Partial mesorectal excision.

Postoperative outcomes

Postoperative outcomes are summarized in Table 3. Ninety-day mortality was low overall, with no significant differences between the groups. Postoperatively, octogenarians had a slightly longer duration of ICU stay (median 1.5 day vs 1 day). When stratified by age, elderly patients showed higher rates of major complications (7/23, 30.4% vs 7/119, 5,9%, P = 0.002) and medical complications (60.9% vs 34.5%, P = 0.017). Surgical complications (26.1% vs 14.3%, P = 0.165) and anastomotic leak (26.1% vs 16.8%, P = 0.292) were numerically more frequent in octogenarians, although these differences did not reach statistical significance. Medical complications, particularly respiratory events such as pneumonia, represented the most frequently observed category, without a clear pattern associated with frailty. Frailty was not consistently associated with postoperative outcomes. Although major complications were numerically more frequent among frail patients, no statistically significant differences were observed. The reintervention rate was comparable between elderly and younger patients. Length of hospital stay was longer in elderly patients compared to younger patients (median 10 days vs 8 days), with a modest but significant difference (P = 0.044). A lower reversal rate was observed in elderly patients compared to younger patients (P < 0.001). In multivariable analysis including age ≥ 80 years, frailty, and ASA score, advanced age remained independently associated with major complications, whereas frailty and ASA did not.

Table 3 Postoperative outcomes stratified by age and frailty, n (%).

Variable	Age ≥ 80 years (n = 23)	Age < 80 years (n = 119)	P value (age)	Frail (n = 16)	Non-frail (n = 126)	P value (frail)
ICU admission	12 (52.2)	53 (44.9)	-
ICU stay (days), median	1.5	1	-
Medical complications	14 (60.9)	41 (34.5)	0.017	6 (37.5)	49 (38.9)	0.914
Surgical complications	6 (26.1)	17 (14.3)	0.165	4 (25.0)	19 (15.1)	0.165
Clavien-Dindo ≥ 3	7 (30.4)	7 (5.9)	0.002	3 (21.4)	13 (10.2)	0.205
Anastomotic leak	6 (26.1)	20 (16.8)	0.292	4 (25.0)	22 (17.5)	0.292
Reintervention	2 (8.7)	7 (5.9)	0.612	2 (12.5)	7 (5.6)	0.612
Length of stay (days), median (IQR)	10 (8.5)	8 (5.0)	0.044
Length of stay (days), range	6-27	5-33
90-day mortality	1 (4.3)	0 (0)	0.162	0 (0)	1 (0.7)	-
Stoma reversal	2 (8.7)	64 (54.7)	< 0.001	7 (43.8)	59 (47.6)	0.704

ICU: Included intensive care unit; IQR: Interquartile range.

Survival outcomes

Survival outcomes stratified by age and frailty are reported in Table 4. Survival analyses were available for 116 patients. The median follow-up duration was 38 months (95%CI: 33.0-49.0), estimated using the reverse Kaplan-Meier method. During follow-up, 31 deaths occurred, including 28 cancer-specific deaths, and 33 patients experienced local or distant recurrence. OS was significantly lower in elderly patients compared to younger individuals, while CSS and DFS did not significantly differ according to age group. Frailty did not demonstrate a consistent association with survival outcomes, although a non-significant trend toward worse OS was observed. Median OS across combined age and frailty subgroups ranged from 20 months (IQR: 9) in elderly frail patients to 33.5 months (IQR: 34.0) in younger non-frail patients. In contrast, frailty was not significantly associated with OS, although a trend toward worse survival was observed in frail patients (log-rank P = 0.058). Cox regression analysis showed that age ≥ 80 years was associated with reduced OS in both univariable (HR: 0.41, 95%CI: 0.19-0.89; P = 0.025) and multivariable models (HR: 0.44, 95%CI: 0.20-0.98; P = 0.044), while frailty did not retain statistical significance after adjustment. Kaplan-Meier curves for OS stratified by age and combined age-frailty status are shown in Figure 1. When considering CSS, differences between groups were attenuated, with no clear pattern across subgroups. Age showed a borderline association in univariable analysis (P = 0.040), which was not confirmed after adjustment (P = 0.051), while frailty was not associated with CSS. Similarly, DFS did not differ significantly according to age (log-rank P = 0.53). Overall, differences in survival outcomes appeared more pronounced for OS than for cancer-specific or recurrence-related endpoints.

Figure 1 Overall survival based on Kaplan-Meier estimates of overall survival stratified. A: Overall survival based on Kaplan-Meier estimates of overall survival stratified by age; B: Overall survival based on Kaplan-Meier estimates of overall survival stratified by age and frailty.

Table 4 Survival outcomes: Overall survival, cancer-specific survival, and disease-free survival stratified by age and frailty.

Outcome	Variable	Median (months)	IQR/CI	Log-rank P value	HR univariable (95%CI)	P value	HR multivariable (95%CI)	P value
Overall survival	Age ≥ 80 years	47	29-NR	0.021	Ref		Ref
	Age < 80 years	NR			0.41 (0.19-0.89)	0.025	0.44 (0.20-0.98)	0.044
	Frail	32	22-NR	0.058	Ref		Ref
	Non-frail	NR			0.43 (0.17-1.06)	0.066	0.48 (0.19-1.22)	0.124
	Age ≥ 80 + frail	20	9
	Age ≥ 80 + non-frail	26.5	34.5
	Age < 80 + frail	32	13
	Age < 80 + non-frail	33.5	34.0
Cancer-specific survival	Age ≥ 80	26	18-47	0.14	Ref		Ref
	Age < 80	32	26-38		0.42 (0.18-0.96)	0.040	0.43 (0.19-1.00)	0.051
	Frail	NR		0.38	Ref		Ref
	Non-frail	NR			0.62 (0.21-1.82)	0.384	0.71 (0.24-2.12)	0.541
Disease-free survival	Age ≥ 80	NR	≥ 31	0.53	Ref
	Age < 80	NR	≥ 69		1.40 (0.49-4.00)	0.527
	Frail	NR	≥ 13	0.10	Ref
	Non-frail	NR	≥ 69		0.48 (0.20-1.18)	0.110

IQR: Interquartile range; HR: Hazard ratio; CI: Confidence interval; NR: Not reached; Ref: References.

DISCUSSION

The main finding of the present study is that carefully selected elderly and frail patients undergoing neoadjuvant therapy followed by minimally invasive rectal surgery achieved acceptable surgical and oncologic outcomes despite increased medical morbidity. Although octogenarians experienced a higher incidence of postoperative medical complications and worse OS, technical-surgical and oncologic outcomes remained broadly comparable. Rates of surgical complications, anastomotic leak, reintervention, conversion to open surgery, and radical resection were similar across age groups, while differences in CSS and DFS were attenuated. Taken together, these findings suggest that, within a structured perioperative pathway, highly selected elderly patients who successfully completed neoadjuvant treatment and were considered suitable for curative-intent minimally invasive surgery may achieve acceptable technical and oncologic outcomes. These findings should be interpreted within this selected clinical context. A key aspect in interpreting the present findings is the highly selected nature of the study population. In real-world clinical practice, many elderly or frail patients with rectal cancer never proceed to radical surgery. Alternative strategies, including exclusive radiotherapy, watch-and-wait approaches after neoadjuvant treatment, palliative management, or less aggressive surgical strategies, are frequently adopted, particularly in patients with limited functional reserve or high competing-risk burden. Previous studies have highlighted the increasing use of individualized treatment strategies in older patients with rectal cancer, emphasizing that treatment allocation often reflects physiological reserve rather than chronological age alone[13]. Therefore, the present cohort should not be interpreted as representative of the overall elderly rectal cancer population. Rather, it reflects a real-world subset of elderly and frail patients who successfully completed multidisciplinary evaluation, preoperative optimization, neoadjuvant therapy, and ultimately reached minimally invasive radical surgery. In this sense, the composition of the cohort itself represents one of the main messages of the study: Elderly and frail patients who actually undergo curative-intent surgery are inherently ultra-selected. Importantly, the excess risk observed in elderly patients was primarily driven by medical rather than technical-surgical complications. Elderly patients experienced higher rates of postoperative medical morbidity, while rates of surgical complications, including anastomotic leak and reintervention, remained broadly comparable to those observed in younger patients. This distinction is clinically relevant. Rectal surgery after neoadjuvant therapy is technically demanding, and concerns regarding older patients frequently focus on the risk of postoperative failure or impaired surgical recovery. Importantly, these findings suggest that, in carefully selected elderly patients who successfully complete neoadjuvant treatment and reach minimally invasive surgery, the major residual vulnerability may no longer be the technical complexity of rectal cancer surgery itself, but rather the burden of perioperative medical morbidity. In contemporary clinical practice, the management of elderly and frail patients with colorectal cancer is evolving toward a more individualized approach, aiming to balance oncologic benefit with preservation of functional status and quality of life. Preoperative risk stratification in this population is complex and has led to the increasing adoption of multi-disciplinary team-based decision-making and structured perioperative pathways. Although high-level evidence supporting multi-disciplinary team-driven strategies in this setting remains limited, multidisciplinary care is widely recognized as a cornerstone of modern oncologic management and has been associated with improved outcomes, including quality of life and survival[10,14]. These findings are also consistent with the growing adoption of minimally invasive approaches and ERAS-based perioperative care, which may partially mitigate the burden of surgical stress in vulnerable populations. Frailty, as measured using the mFI-5, did not demonstrate a consistent association with either postoperative or long-term outcomes. While frail patients showed numerically higher complication rates, these differences were not statistically significant and no independent prognostic effect emerged across survival analyses. These findings should be interpreted cautiously and should not be construed as evidence of no association. The small number of frail patients and the limited number of outcome events substantially reduced statistical power, particularly for survival analyses, increasing the risk of type II error. In addition, the absence of a clear association may reflect the highly selected nature of the study population, in which only patients deemed suitable for neoadjuvant therapy and surgery were ultimately included. The mFI-5 was selected because of its simplicity, reproducibility, and feasibility in retrospective surgical datasets. However, it is primarily a comorbidity-based screening tool and cannot fully capture the multidimensional nature of frailty, including functional dependence, cognitive impairment, nutritional status, psychosocial vulnerability, and geriatric syndromes. Although simplified frailty indices have shown predictive ability for postoperative complications comparable to that of the original 11-item mFI[15], their correspondence with phenotypic frailty has been questioned, particularly because relevant domains such as cognition may remain insufficiently represented[16]. More comprehensive geriatric assessments, or multidomain risk tools such as the Risk Analysis Index, may provide more granular risk stratification and have shown superior discrimination for postoperative morbidity and mortality in surgical populations[17-19]. In the present cohort, a more comprehensive assessment might have identified specific vulnerability profiles not captured by the mFI-5, potentially improving the interpretation of postoperative medical complications and the apparently limited association between frailty and long-term outcomes. The present study has several limitations. Its retrospective single-center design inherently exposes the analysis to selection bias and limits external generalizability. In particular, the study population represents a highly selected subgroup of elderly and frail patients considered suitable for curative-intent treatment following multidisciplinary evaluation and perioperative optimization. The extended study period represents an additional limitation. From 2014 to 2025, rectal cancer management evolved substantially, including changes in neoadjuvant treatment strategies, the increasing adoption of TNT, the progressive implementation of robotic surgery, and refinement of perioperative care pathways. These temporal changes may have introduced historical confounding and may have influenced treatment allocation and postoperative outcomes. Consequently, these findings should not be generalized to all older patients with rectal cancer. The relatively limited sample size, particularly within the elderly and frail subgroups, together with the low number of outcome events, may have reduced statistical power for both postoperative and survival analyses and increased the risk of type II error. Accordingly, non-significant findings, particularly those concerning frailty, should not be interpreted as evidence of the absence of an association.

CONCLUSION

This study does not address the broader population of elderly or frail patients with rectal cancer, but rather a highly selected subgroup who completed neoadjuvant therapy and were considered suitable for curative-intent minimally invasive surgery. Within this selected cohort, acceptable surgical and oncologic outcomes were observed. Although elderly patients experienced increased medical morbidity, technical-surgical and cancer-related outcomes remained largely comparable, supporting individualized multidisciplinary assessment rather than age-based exclusion among appropriately selected candidates.