Total neoadjuvant therapy in rectal cancer: the evidence and expectations

Postoperative urinary dysfunction following lateral lymph node dissection for rectal cancer via minimally invasive surgery

BACKGROUND

Lateral lymph node dissection (LLND) for locally advanced rectal cancer (LARC) is performed widely since it reduces local recurrence. However, there are some disadvantages to LLND, including technical difficulties and association with postoperative urinary dysfunction. Procedures for LARC have also become more minimally invasive: laparoscopic surgery (LS) has become more common, and use of robot-assisted LS (RALS) is increasing. The purpose of this study is to assess differences in postoperative urinary dysfunction after LLND for LARC between LS and RALS, and to identify risk factors for postoperative urinary dysfunction.

METHODS

The subjects were 100 patients with LARC (≥ cT3) with the inferior border of the tumor reaching the peritoneal reflection who underwent LS or RALS with LLND between 2009 and 2023 at Juntendo University Hospital. After LLND, the urinary catheter was usually removed on or before postoperative day 5. The duration of urinary catheterization (DUC) was used to evaluate postoperative urinary dysfunction. The standard (S) and long-term (L) groups were defined as cases with urinary catheter removal at ≤ 5 and > 5 days, respectively. DUC was examined for LS vs. RALS and clinicopathological factors were identified that adversely affect DUC.

RESULTS

Of the 100 subjects, 72 underwent LS and 28 received RALS. LLND was bilateral in 65 cases and unilateral in 35 cases. The median DUC was 5 days, with 74 cases in group S and 26 in group L. The most frequent postoperative complication (Clavien-Dindo Grade 2 or higher) was urinary dysfunction, followed by ileus and surgical site infection (SSI), and none differed by procedure (LS vs. RALS). Univariate analysis showed significant differences in LLND laterality (p = 0.02) and SSI (p = 0.04) between groups S and L. In multivariate analysis, bilateral LLND (p < 0.01, HR 7.37) and SSI (p = 0.01, HR 15.36) were independent factors that worsened DUC.

CONCLUSIONS

There was no difference in urinary dysfunction after LLND between LS and RALS. Bilateral LLND and SSI were risk factors for lengthening DUC. Compared to bilateral LLND, unilateral LLND can reduce urinary dysfunction; therefore, selective LLND, which is overwhelmingly unilateral LLND, and prevention of perioperative SSI may be important for maintenance of urinary function.

A randomized phase 3 trial of total neoadjuvant therapy (induction chemotherapy, neoadjuvant chemoradiation, neoadjuvant chemotherapy, and surgery) vs. standard long-term chemoradiation therapy (neoadjuvant chemoradiation, surgery, and adjuvant chemotherapy) in locally advanced rectal cancer

Purpose

The management of rectal adenocarcinoma has evolved during the last decade, shifting from a conventional neoadjuvant chemoradiotherapy, surgery, and adjuvant chemotherapy in all cases to a total neoadjuvant approach, especially in locally advanced tumors when a sphincter-sparing surgery has been planned. However, the exact indications and the neoadjuvant regimen with the highest response remain unresolved. We aimed to assess whether administering neoadjuvant chemotherapy before and after preoperative chemoradiotherapy could increase the pathological complete response (pCR) rates.

Methods

We conducted a phase 3, multicenter, randomized trial at four hospitals in Iran. Adult patients with a newly diagnosed, biopsy-proven, locally advanced non-metastatic rectal adenocarcinoma with an ECOG performance status of 0-2 were randomly assigned (2:2) to either the total neoadjuvant treatment (TNT) or the standard-of-care groups using a block randomized design. Investigators and participants were not masked to treatment allocation and groups. The TNT group received neoadjuvant chemotherapy with FOLFOX6 (intravenous 85 mg/m2 oxaliplatin and 400 mg/m2 leucovorin, followed by intravenous 400 mg/m2 fluorouracil bolus and then continuous infusion at a dose of 2,400 mg/m2 over 46 h every 14 days for four cycles before and four cycles after chemoradiotherapy), chemoradiotherapy (50.4 Gy during 28 fractions and 800 mg/m2 concurrent oral capecitabine twice daily 5 days per week), and total mesorectal excision. The standard-of-care group received neoadjuvant chemoradiotherapy, total mesorectal excision, and adjuvant chemotherapy (eight cycles). The primary endpoint was the pathological complete response. Safety analyses were conducted on treated patients.

Results

Overall, 25 and 27 patients were enrolled in the TNT and standard-of-care groups, respectively. Both groups were similar in terms of gender, age, and tumor differentiation. The tumors in the standard-of-care group were significantly located closer to the anal verge compared with those in the TNT group (9.4 ± 3.7 cm in TNT vs. 6.8 ± 4 cm in standard, p = 0.02). A pCR was reached in 48% (12/25) and 25.9% (7/27) of patients in the TNT and standard-of-care groups, respectively (p = 0.4). The R0 resection rates were identical between the two groups (92% vs. 88.9%, p = 0.3). Moreover, the toxicity rates were similar between the two groups.

Conclusion

Our results showed that TNT is a safe and feasible treatment approach in patients with rectal cancer and may improve the overall pCR rate compared with standard treatment.

Clinical trial registration

https://irct.behdasht.gov.ir/trial/65666, identifier IRCT20220723055527N1.

The role of PIK3CA gene mutations in colorectal cancer and the selection of treatment strategies

PIK3CA gene encodes the p110α catalytic subunit of PI3K, which regulates the PI3K/AKT/mTOR signaling pathway. PIK3CA gene mutation is one of the most common mutations in colorectal cancer (CRC), affecting about 15%-20% of CRC patients. PIK3CA gene mutation leads to the persistent activation of the PI3K/AKT/mTOR signaling pathway, which promotes the proliferation, invasion, metastasis, and drug resistance of CRC. This article provides a summary of the key detection methods for PIK3CA gene mutation, and provides an introduction to the existing colorectal cancer treatments and their practical applications in the clinic. Besides, this article summarizes the role and mechanism of PIK3CA gene mutation in the occurrence and development of CRC. It also explores the relationship between PIK3CA gene mutation and the clinical features and prognosis of CRC. This article focuses on the influence and mechanism of PIK3CA gene mutation on the targeted therapy and immunotherapy of CRC, and discusses the potential value and future direction of PIK3CA gene mutation in the personalized therapy of CRC. We aim to provide new perspectives and ideas for the precise diagnosis and treatment of CRC.

Can yStage Ⅰ/Ⅱ rectal cancer patients be treated in the same way as stage Ⅰ/Ⅱ patients?

Background

Neoadjuvant therapy (NAT) before radical surgery are effective treatments for locally advanced rectal cancer. However, the treatment strategy after NAT and surgery is still unclear. It is difficult to accurately evaluate the stage before NAT, as some cases are downstaged by NAT.

Objective

We investigated the treatment strategies based on the postoperative pathology of patients with yStage Ⅰ or Ⅱ rectal cancer who underwent NAT and radical resection.

Design

They patients were retrospectively evaluated the long-term outcomes. They were divided into patients with yStage I/II receiving NAT and patients with stage I/II patients without NAT (non-NAT). Disease-free survival (DFS) and overall survival (OS) were examined, and the prognosis was compared. Cox proportional hazard model was used to examine the recurrence risk factors in all patients or NAT. We compared the effects of adjuvant therapy in NAT.

Patients

Overall, 521 patients histologically diagnosed with yStage I/II or stage I/II who underwent surgery for rectal cancer between April 2001 and July 2019 were eligible.

Results

The NAT and non-NAT groups included 80 and 441 patients, respectively. DFS was significantly lower in NAT, but there was no difference in OS between the two groups. All patients had several recurrence risk factors, but none of the NAT had such risk factors. No significant difference in DFS and OS was found between NAT with and without adjuvant chemotherapy.

Limitation

This is a single-center retrospective study.

Conclusions

NAT had lower DFS than non-NAT, but no difference in OS was observed. No significant recurrence risk factors were observed in NAT. Adjuvant chemotherapy for NAT may have no benefit.

Pelvic exenteration for locally advanced rectal cancer and associated outcomes in England between 1995 and 2016: Analysis of a national database

AIM

The clinical burden of pelvic exenteration (PE) for locally advanced rectal cancer (LARC) is nationally under-reported. The widespread use of pelvic MRI since 2005 has increased the accuracy of local staging and awareness of the need for 'beyond TME (total mesorectal excision)' surgery. The aim of this study was to assess the volume of patients undergoing PE within England, which factors affected survival outcomes and whether the use of MRI has influenced these outcomes.

METHOD

The volume of patients undergoing PE and associated survival outcomes across England between 1995 and 2016 was evaluated from Public Health England Hospital Episode Statistics data.

RESULTS

A total of 2996 patients were recorded as undergoing PE. The 5-year overall survival rate improved after 2005 compared with prior to 2005 (61.7% vs. 37%, p < 0.001), with no significant difference between cancer registries throughout England. After 2005, the volume of patients undergoing PE and undergoing preoperative MRI increased, as did the number of non-T4 cancers operated on. After 2005, age, preoperative MRI and preoperative radiotherapy were the significant factors influencing 5-year overall survival on multivariate analysis.

CONCLUSION

This review of national data confirms that PE outcomes are under-reported. MRI staging aids with the identification of patients suitable for perioperative treatment, surgery or palliation and facilitates treatment planning. Since 2005, MRI, likely in combination with advances in surgery and perioperative treatment, has improved survival outcomes. It is imperative that detailed information from patients with LARC undergoing PE is captured and reported in order to optimize care and future service provision.

A nomogram of anastomotic stricture after rectal cancer: a retrospective cohort analysis

BACKGROUND

Anastomotic stricture significantly impacts patients' quality of life and long-term prognosis. However, current clinical practice lacks accurate tools for predicting anastomotic stricture. This study aimed to develop a nomogram to predict anastomotic stricture in patients with rectal cancer who have undergone anterior resection.

METHODS

A total of 1542 eligible patients were recruited for the study. Least absolute shrinkage selection operator (Lasso) analysis was used to preliminarily select predictors. A prediction model was constructed using multivariate logistic regression and presented as a nomogram. The performance of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration diagrams, and decision curve analysis (DCA). Internal validation was conducted by assessing the model's performance on a validation cohort.

RESULTS

72 (4.7%) patients were diagnosed with anastomotic stricture. Participants were randomly divided into training (n = 1079) and validation (n = 463) sets. Predictors included in this nomogram were radiotherapy, diverting stoma, anastomotic leakage, and anastomotic distance. The area under the ROC curve (AUC) for the training set was 0.889 [95% confidence interval (CI) 0.840-0.937] and for the validation set, it was 0.930 (95%CI 0.879-0.981). The calibration curve demonstrated a strong correlation between predicted and observed outcomes. DCA results showed that the nomogram had clinical value in predicting anastomotic stricture in patients after anterior resection of rectal cancer.

CONCLUSION

We developed a predictive model for anastomotic stricture following anterior resection of rectal cancer. This nomogram could assist clinicians in predicting the risk of anastomotic stricture, thus improving patients' quality of life and long-term prognosis.

Compare clinical efficacy and safety of neoadjuvant therapy and neoadjuvant chemoradiotherapy for locally advanced rectal cancer: Meta-analysis

BACKGROUND

To compare the efficacy and safety of total neoadjuvant therapy (TNT) and neoadjuvant chemoradiotherapy (nCRT) in the treatment of middle and low locally advanced rectal cancer. Our study will systematically collect and integrate studies to evaluate the ability of these two treatments to improve tumor shrinkage rates, surgical resection rates, tumor-free survival, and severe adverse events.

AIM

To provide clinicians and patients with more reliable treatment options to optimize treatment outcomes and quality of life for patients with locally advanced rectal cancer by comparing the advantages and disadvantages of the two treatment options.

METHODS

A full search of all clinical studies on the effectiveness and safety of TNT and nCRT for treating locally advanced rectal cancer identified in Chinese (CNKI, Wanfang, China Biomedical Literature Database) and English (PubMed, Embase) databases was performed. Two system assessors independently screened the studies according to the inclusion and exclusion criteria. Quality evaluation and data extraction were performed for the included literature. We used RevMan 5.3 software to perform a meta-analysis of the pathologic complete response (pCR) rate, T stage degradation rate, resection 0 (R0) rate, anal grade 3/4 acute toxicity rate, perioperative complications, overall survival (OS), and disease-free survival (DFS) in the TNT and nCRT groups.

RESULTS

Finally, 14 studies were included, six of which were randomized controlled studies. A total of 3797 patients were included, including 1865 in the TNT group and 1932 in the nCRT group. The two sets of baseline data were comparable. The results of the meta-analysis showed that the pCR rate [odds ratio (OR) = 1.57, 95% confidence interval (CI): 1.30-1.90, P < 0.00001], T stage degradation rate (OR = 2.16, 95%CI: 1.63-2.57, P < 0.00001), and R0 resection rate (OR = 1.42, 95%CI: 1.09-1.85, P = 0.009) were significantly greater in the nCRT group than in the nCRT group. There was no significant difference in the incidence of grade 3/4 acute toxicity or perioperative complications between the two groups. The 5-year OS [hazard ratio (HR) = 0.84, 95%CI: 0.69-1.02, P = 0.08] and DFS (HR = 0.94, 95%CI: 0.03-1.39, P = 0.74) of the TNT group were similar to those of the nCRT group.

CONCLUSION

TNT has greater clinical efficacy and safety than nCRT in the treatment of locally advanced rectal cancer.

Prediction of liver metastasis and recommended optimal follow-up nursing in rectal cancer

We aimed to analyze and investigate the clinical factors that influence the occurrence of liver metastasis in locally advanced rectal cancer patients, with an attempt to assist patients in devising the optimal imaging-based follow-up nursing. Between June 2011 and May 2021, patients with rectal cancer at our hospital were retrospectively analyzed. A random survival forest model was developed to predict the probability of liver metastasis and provide a practical risk-based approach to surveillance. The results indicated that age, perineural invasion, and tumor deposit were significant factors associated with the liver metastasis and survival. The liver metastasis risk of the low-risk group was higher at 6-21 months, with a peak occurrence time in the 15th month. The liver metastasis risk of the high-risk group was higher at 0-24 months, with a peak occurrence time in the 8th month. In general, our clinical model could predict liver metastasis in rectal cancer patients. It provides a visualization tool that can aid physicians and nurses in making clinical decisions, by detecting the probability of liver metastasis.