Overall Survival After Treatment Failure Among Patients With Rectal Cancer

Dentate line invasion is a risk factor for locoregional recurrence and distant metastasis following abdominoperineal resection in rectal cancer: a single-centre retrospective cohort study based on 1854 cases

BACKGROUND

In the context of surgical treatment for rectal cancer, the dentate line is acknowledged as a critical anatomical landmark. However, the prognostic implications of dentate line invasion (DLI) remain elusive and warrant further investigation. This study aims to evaluate and compare the outcomes of patients with rectal cancer who underwent abdominoperineal resection (APR), distinguishing between those with and without DLI.

MATERIALS AND METHODS

Between January 2006 and December 2017, this study enrolled 1854 patients with rectal cancer who underwent APR. The cohort was divided into two groups, namely the DLI group (n = 340) and the non-DLI group (n = 1514). The primary endpoints were distant relapse-free survival (DRFS) and local recurrence-free survival (LRFS). Univariate and multivariate analyses were conducted to assess the impact of DLI on DRFS, LRFS, overall survival (OS), and disease-free survival (DFS).

RESULTS

The median follow-up duration for the patients was 92.9 months, with a 5-year OS rate of 92.0% for the entire cohort. Compared to the non-DLI group, patients in the DLI group showed significantly poorer outcomes, with 5-year DRFS at 57.4% vs. 73.9% (P < 0.001), DFS at 51.2% vs. 70.7% (P < 0.001), and LRFS at 71.7% vs. 88.5% (P = 0.018). OS was the only metric that showed no significant difference(89.0% vs. 92.6%, P = 0.064). Multivariate analysis demonstrated that DLI negatively impacted DRFS (hazard ratio HR 1.319, P = 0.029), LRFS (HR 2.059, P < 0.001), and DFS (HR 1.563, P < 0.001) as an independent prognostic factor. Furthermore, distant metastasis occurred more frequently in the DLI group (30.0% vs. 23.1%, P = 0.002), along with a higher rate of locoregional recurrence. (16.8% vs. 8.3%, P < 0.001).

CONCLUSIONS

DLI correlates with a heightened likelihood of locoregional recurrence and distant metastasis among rectal cancer patients treated with APR. This association underscores the significance of DLI as a crucial prognostic factor that should be considered when developing clinical management strategies.

Preoperative chemoradiotherapy with the TEGAFIRI regimen achieves significant local control in locally advanced rectal cancer

PURPOSE

This study aims to evaluate both the short- and long-term outcomes of preoperative chemoradiotherapy (CRT) using the tegafur-uracil/calcium folinate/irinotecan (TEGAFIRI) regimen in patients with locally advanced rectal cancer (LARC). While total neoadjuvant therapy (TNT) is becoming more common, CRT may still be the optimal approach in certain cases to improve prognosis and reduce adverse events.

METHODS

This single-center, retrospective cohort study included patients with histologically confirmed nonmetastatic primary adenocarcinoma of the lower rectum treated with preoperative CRT using the TEGAFIRI regimen (TEGAFIRI group). The control group comprised patients treated with tegafur-uracil/calcium folinate (UFT group). The primary endpoint was the pathologic complete response (pCR) rate. Secondary endpoints included adverse events, overall survival (OS), disease-free survival (DFS), distant recurrence-free survival (DRFS), and local recurrence-free survival (LRFS). The background was adjusted using inverse probability weighting (IPW) calculated with the propensity score.

RESULTS

The TEGAFIRI group consisted of 79 patients, while the UFT group included 264. The standardized pCR rates through the IPW were as follows: TEGAFIRI group: 24.3%, UFT group: 8.8%, and the difference in pCR was 15.4% (P = 0.01). Adverse events of grade 3 or higher were observed in 15.2% vs. 8.7% (adjusted) (13.6% vs. 9.1% crude) in the TEGAFIRI group and the UFT group. The standardized LRFS was significantly higher in the TEGAFIRI group (HR = 0.39, (95% CI 0.16-0.98), P = 0.045). There were no significant differences in OS, DFS, or DRFS between groups.

CONCLUSIONS

The TEGAFIRI regimen for preoperative CRT in LARC demonstrated a high pCR rate and reduced local recurrence, with manageable adverse events.

Economic Evaluation of 'Watch and Wait' Following Neoadjuvant Therapy in Locally Advanced Rectal Cancer: A Systematic Review

BACKGROUND

Owing to multimodal treatment and complex surgery, locally advanced rectal cancer (LARC) exerts a large healthcare burden. Watch and wait (W&W) may be cost saving by removing the need for surgery and inpatient care. This systematic review seeks to identify the economic impact of W&W, compared with standard care, in patients achieving a complete clinical response (cCR) following neoadjuvant therapy for LARC.

METHODS

The PubMed, OVID Medline, OVID Embase, and Cochrane CENTRAL databases were systematically searched from inception to 26 April 2024. All economic evaluations (EEs) that compared W&W with standard care were included. Reporting and methodological quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS), BMJ and Philips checklists. Narrative synthesis was performed. Primary and secondary outcomes were (incremental) cost-effectiveness ratios and the net financial cost.

RESULTS

Of 1548 studies identified, 27 were assessed for full-text eligibility and 12 studies from eight countries (2016-2024) were included. Seven cost-effectiveness analyses (complete EEs) and five cost analyses (partial EEs) utilized model-based (n = 7) or trial-based (n = 5) analytics with significant variations in methodological design and reporting quality. W&W showed consistent cost effectiveness (n = 7) and cost saving (n = 12) compared with surgery from third-party payer and patient perspectives. Critical parameters identified by uncertainty analysis were rates of local and distant recurrence in W&W, salvage surgery, perioperative mortality and utilities assigned to W&W and surgery.

CONCLUSION

Despite heterogenous methodological design and reporting quality, W&W is likely to be cost effective and cost saving compared with standard care following cCR in LARC. Clinical Trials Registration PROSPERO CRD42024513874.

Tumor Response and Its Impact on Treatment Failure in Rectal Cancer: Does Intensity of Neoadjuvant Treatment Matter?

Objectives: Additional adjuvant treatment in patients with rectal cancer with limited response to neoadjuvant treatment to mitigate their higher risk of treatment failure remains controversial. Methods: This is a post hoc analysis of a cohort study of 3 randomized phase 2 or 3 trials (CAO/ARO/AIO-94, -04, and -12 trial) that included 1948 patients with locally advanced rectal adenocarcinoma. After excluding patients with missing information, 1788 patients (1254 men and 524 women; median age: 62.6 years, age range: 19-84 years) were eligible. We analyzed the extent of tumor response and its association with the incidence of treatment failure after different neoadjuvant treatment approaches. Results: Tumor response was significantly enhanced with more intensive neoadjuvant treatment. After a median follow-up of 55 months for the entire cohort (IQR: 37 months-62 months), the incidence of treatment failure (TF) stratified by tumor response or post-neoadjuvant pathological outcome was not significantly affected by the intensity of neoadjuvant treatment, whereas the ypTNM stage was significantly associated with the risk of treatment failure. Conclusions: In this cohort study, we provide evidence that limited or no response to intensified neoadjuvant treatment protocols is not likely to be more strongly associated with an extensive risk of TF after 5-FU CRT+/- adjuvant chemotherapy.

Persistent Lymph Node Metastases After Neoadjuvant Chemoradiotherapy for Rectal Cancer

Importance

Patients with locally advanced rectal cancer and persistent lymph node metastases (PLNM) after neoadjuvant treatment are at high risk of developing locoregional and distant metastasis, yet optimal postsurgical treatment of these patients is limited.

Objective

To analyze the association of PLNM with pretreatment clinical parameters, intensity of neoadjuvant treatment, and long-term oncological outcomes.

Design, Setting, and Participants

This cohort study is a post-hoc analysis of 3 randomized clinical trials (Surgical Oncology Working Group of Germany [CAO], Radiological Oncology Working Group of Germany [ARO], and Working Group for Internal Oncology in the German Cancer Society [AIO]) conducted in Germany in 1994, 2004, and 2012 that included 1948 patients with locally advanced rectal cancer recruited between February 1995 and January 2018. Statistical analysis was conducted between September 2023 and February 2024.

Exposures

Receiving preoperative fluorouracil-based chemoradiotherapy (CRT, comprising the preoperative group of CAO/ARO/AIO-94 and the control group of CAO/ARO/AIO-04), fluorouracil-based CRT plus oxaliplatin (experimental group of CAO/ARO/AIO-04), or total neoadjuvant treatment (TNT) with fluorouracil-based CRT plus oxaliplatin with induction or consolidation leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin chemotherapy within the CAO/ARO/AIO-12 trial.

Main Outcome and Measures

The associations of PLNM with clinical parameters, intensity of neoadjuvant treatment, and cumulative incidences of LR, DM, and overall survival were assessed.

Results

A total of 1888 patients (1333 male participants [70.6%]; median [range] age, 62 [19-84] years) with locally advanced rectal adenocarcinoma (clinical tumor stage 3 to 4 and/or clinically node-positive) treated within 3 consecutive clinical trials were analyzed. A total of 522 (29%) experienced PLNM; 378 had lymph node stage (ypN) 1 (20%) after neoadjuvant treatment (ypN) 1 (20%), and 174 had ypN2 (9%). Age, clinical T-stage, N-stage, grading, carcinoembryonic antigen levels, and time interval from completion of CRT to surgery were significantly associated with PLNM, whereas sex and tumor location were not. The percentage of patients with ypN2 stage was almost halved after TNT (18 of 293 patients [6%]) compared with patients treated with fluorouracil-based CRT (114 of 1009 patients [11.3%]; χ26 = 16.693; P = .01). After a median (IQR) follow-up of 54 (37-62) months, 5-year overall survival was 86.1% (95% CI, 83.9%-88.4%) for ypN0, 74.0% (95% CI, 83.9%-88.4%) for ypN1, and 43% for ypN2 (95% CI, 35.4%-52.2%) (P < .001). The 5-year cumulative incidences of locoregional and distant metastases were, respectively, 3% (95% CI, 2.1%-4.2%) and 20% (95% CI, 18%-23%) for ypN0, 6% (95% CI, 3.4%-8.8%) and 40% (95% CI, 34%-46%) for ypN1, and 19% (95% CI, 13%-26%) and 72% (95% CI, 63%-79%) for ypN2 (both P < .001).

Conclusions and Relevance

In this cohort study, PLNM unmasked an unfavorable phenotype of rectal cancer at high risk for treatment failure. More aggressive adjuvant treatment might be considered; however, risk-adapted surveillance strategies and early recurrence-directed surgery, if feasible, are important strategies in this group of patients with CRT- and/or chemotherapy-resistant disease.

Oncological risks associated with the planned watch-and-wait strategy using total neoadjuvant treatment for rectal cancer: A narrative review

Overall survival benefit of total neoadjuvant treatment (TNT) remains unconfirmed. Thus, in our opinion, the main rationale for using TNT is a planned watch-and-wait (w&w) strategy to improve patients' long-term quality of life through organ preservation. The OPRA randomized trial, which examined a planned w&w strategy using TNT, showed a higher organ preservation rate but also a higher regrowth rate compared to studies on the opportunistic w&w strategy. Higher rates of complete clinical response with TNT did not improve disease-free survival compared to historical controls. Therefore, the gain in organ-sparing capability might not be balanced by the increased oncological risk. The ultimate local failure rate in the intention-to-treat analysis of the OPRA trial was 13% for induction chemotherapy and 16% for consolidation chemotherapy, which seems higher than expected compared to 8% in a meta-analysis of w&w studies or 12% after TNT and surgery in the PRODIGE-23 and RAPIDO trials, which enrolled patients with more advanced cancers than the OPRA trial. Other studies also suggest worse local control when surgery is delayed for radio-chemoresistant cancers. Our review questions the safety of the planned w&w strategy using TNT in unselected patients. To reduce the oncological risk while maintaining high organ preservation rates, we suggest that the planned w&w strategy using TNT requires a two-tier patient selection process: before treatment and after tumor response assessment at the midpoint of consolidation chemotherapy. These robust selections should identify patients who are unlikely to achieve organ preservation with TNT and would be better managed by preoperative chemoradiotherapy (without consolidation chemotherapy) and surgery, or by discontinuing consolidation chemotherapy and proceeding directly to surgery.

Patient-Relevant Costs for Organ Preservation versus Radical Resection in Locally Advanced Rectal Cancer

Total neoadjuvant therapy (TNT) is an evolving treatment schedule for locally advanced rectal cancer (LARC), allowing for organ preservation in a relevant number of patients in the case of complete response. Patients who undergo this so-called "watch and wait" approach are likely to benefit regarding their quality of life (QoL), especially if definitive ostomy could be avoided. In this work, we performed the first cost-effectiveness analysis from the patient perspective to compare costs for TNT with radical resection after neoadjuvant chemoradiation (CRT) in the German health care system. Individual costs for patients insured with a statutory health insurance were calculated with a Markov microsimulation. A subgroup analysis from the prospective "FinTox" trial was used to calibrate the model's parameters. We found that TNT was less expensive (-1540 EUR) and simultaneously resulted in a better QoL (+0.64 QALYs) during treatment and 5-year follow-up. The average cost for patients under TNT was 4711 EUR per year, which was equivalent to 3.2% of the net household income. CRT followed by resection resulted in higher overall costs for ostomy care, medication and greater loss of earnings. Overall, TNT appeared to be more efficacious and cost-effective from a patient's point of view in the German health care system.