Comparison of oncologic outcomes of metastatic rectal cancer patients with or without neoadjuvant chemoradiotherapy

Efficacies of radiotherapy in rectal cancer patients treated with total mesorectal excision or other types of surgery: an updated meta-analysis

Background

An updated meta-analysis was conducted to evaluate the efficacy of radiotherapy in rectal cancer patients treated with total mesorectal excision (TME) or other types of surgery (non-TME-only).

Methods

The PubMed, Cochrane Library, and CNKI databases were searched. Data on overall survival (OS) were extracted.

Results

Hazard ratios (HRs) for OS associated with preoperative radiotherapy, preoperative long-course concurrent chemoradiotherapy (LCCRT), preoperative radiotherapy alone, and postoperative radiotherapy in patients treated with TME were 1.02 [95% CI: 0.92-1.14, P = 0.65], 1.04 [95% CI: 0.93-1.16, P = 0.47], 0.87 [95% CI: 0.61-1.25, P = 0.46], and 1.18 [95% CI: 0.91-1.52, P = 0.20], respectively. HRs for OS associated with preoperative radiotherapy, preoperative LCCRT, preoperative radiotherapy alone, preoperative long-course RT (LCRT), and preoperative short-course radiotherapy (SCRT) in patients treated with non-TME-only surgery were 0.85 [95% CI: 0.79-0.90, P < 0.00001], 0.77 [95% CI: 0.63-0.94, P = 0.009], 0.86 [95% CI: 0.80-0.92, P < 0.0001], 0.83 [95% CI: 0.73-0.95, P = 0.005], and 0.84 [95% CI: 0.77-0.91, P= <0.0001], respectively. The HR for postoperative radiotherapy in patients treated with non-TME-only surgery was 1.08 [95% CI: 0.84-1.39, P = 0.57].

Conclusion

Preoperative radiotherapy, regardless of the regimen, improves the OS in patients treated with non-TME-only surgery, but not in those treated with TME. Postoperative radiotherapy does not improve OS.

Advances in knowledge

This meta-analysis will serve as a reference for decision-making in multidisciplinary approaches for rectal cancer patients.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Efficacy of concurrent radiotherapy in patients with locally advanced rectal cancer and synchronous metastasis receiving systemic therapy

BACKGROUND

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is the standard treatment for patients with nonmetastatic locally advanced rectal cancer (LARC). However, for patients with LARC and synchronous metastasis, the optimal treatment strategy and sequence remain inconclusive. In the present study, we evaluated the efficacy and safety of concurrent radiotherapy in patients with de novo metastatic rectal cancer who received chemotherapy and targeted therapy.

METHODS

We retrospectively reviewed the data of 63 patients with LARC and synchronous metastasis who received intensive therapy at the study hospital between April 2015 and November 2018. The included patients were divided into two groups: RT-CT, those who received systemic chemotherapy with targeted therapy and concurrent radiotherapy (for primary rectal cancer), and CT, those who received only systemic chemotherapy with targeted therapy.

RESULTS

Treatment response was better in the RT-CT group than in the CT group. The rate of primary tumor resection (PTR) was higher in the RT-CT group than in the CT group (71.4% and 42.9%, respectively; P = .0286). The RT-CT group exhibited considerably longer local recurrence-free survival (P = .0453) and progression-free survival (PFS; from 13.3 to 22.5 months) than did the CT group (P = .0091); however, the groups did not differ in terms of overall survival (OS; P = .49). Adverse events were almost similar between the groups, except frequent diarrhea, the prevalence of which was higher in the RT-CT group than in the CT group (59.5% and 23.8%, respectively; P = .0075).

CONCLUSIONS

In the era of biologics, radiotherapy may increase the resectability of primary rectal tumors, reducing the risk of locoregional failure and prolonging PFS. Concurrent pelvic radiotherapy may not substantially improve OS, which is indicated by metastasis. Hence, the resection of the distant metastases may be essential for improving long-term OS. To further determine the efficacy of concurrent radiotherapy, additional prospective, randomized studies must combine preoperative pelvic radiotherapy with PTR and metastectomy to treat patients with stage IV LARC.

Neoadjuvant chemotherapy without radiation as a potential alternative treatment for locally advanced rectal cancer: A meta-analysis

BACKGROUND

Neoadjuvant chemoradiotherapy (Neo-CRT) is the current standard strategy for treating locally advanced rectal cancer. However, it delays the administration of optimal chemotherapy and increases toxicity.

AIM

To compare the feasibility and efficacy of neoadjuvant chemotherapy (Neo-CT) and Neo-CRT for patients with locally advanced rectal cancer.

METHODS

The Cochrane, EMBASE, and PubMed databases were searched for relevant articles using MESH terms and free words. The hazard ratio of overall survival and the risk ratio (RR) for the pathological complete response, the sphincter preservation rate, and treatment-related adverse events were analyzed.

RESULTS

A total of 19 studies of 60870 patients were included in the meta-analysis. There was no significant difference in overall survival [hazard ratio = 1.09, 95% confidence interval (CI) = 0.93-1.24; P = 0.19] or the pathological complete response (RR = 0.79, 95%CI = 0.61-1.03; P = 0.086) between the Neo-CT and Neo-CRT groups. As compared to the Neo-CRT group, the incidences of anastomotic fistula (RR = 0.49, 95%CI = 0.35-0.68; P = 0.000) and temporary colostomy (RR = 0.69, 95%CI = 0.58-0.83; P = 0.000) were significantly lower in the Neo-CT group, with a simultaneous increase in the sphincter preservation rate (RR = 1.07, 95%CI = 1.01-1.13; P = 0.029). However, there was no significant difference in the tumor downstaging rate, overall complications, and urinary complications.

CONCLUSION

Neo-CT administration can lower the incidences of anastomotic fistula and temporary colostomy and increase the sphincter preservation rate as to compared to Neo-CRT and could provide an alternative to chemoradiotherapy for locally advanced rectal cancer.

Neoadjuvant Pelvic Radiotherapy in the Management of Rectal Cancer with Synchronous Liver Metastases: Is It Worth It?

BACKGROUND

The use of neoadjuvant pelvic radiotherapy was a major advance in oncologic care for locally advanced rectal cancer in the twentieth century. The extrapolation of the care of locally advanced rectal cancer to the management of rectal cancer with treatable liver metastases is controversial. The aim of this review is to examine the available data on the role of pelvic radiotherapy and chemoradiation in the setting of treatable metastatic liver disease.

METHODS

A systematic search of MEDLINE was performed to report the landmark randomized controlled trials between 1993 and 2021.

RESULTS

Attaining liver clearance and total mesorectal excision with R0 margin remains the mainstay of cure. There is uncertainty regarding the sequencing of treatment. The literature lacks randomized clinical trials comparing the rectal first, liver first, interval strategy, and simultaneous surgical approaches. A multidisciplinary discussion regarding the utility of radiotherapy is emphasized to achieve the goals of treatment. Short-course radiotherapy has proved comparable disease-control outcomes to long-course chemoradiation with a significantly improved cost-performance. The implementation of short-course radiotherapy in the interval strategy and simultaneous surgical approach is promising. Neoadjuvant pelvic radiotherapy can be omitted in patients with metastatic rectal cancer if adequate margin clearance is achievable.

CONCLUSION

The use of radiotherapy in metastatic rectal cancer is popular but is based on limited data. Treatment should be tailored to the local extent of rectal cancer and priority of liver metastasis management. The optimal treatment strategy in patients with rectal cancer and synchronous liver metastatic disease needs to be studied in randomized trials.

No benefit after neoadjuvant chemoradiation in stage IV rectal cancer: A propensity score-matched analysis on a real-world population

BACKGROUND

Stage IV rectal cancer occurs in 25% of patients and locoregional control of primary tumor is usually poorly considered, since priority is the treatment of metastatic disease.

AIMS

This study evaluates impact of neoadjuvant chemoradiation followed by surgery (nCHRTS) vs. upfront surgery on locoregional control and overall survival in stage IV rectal cancer.

METHODS

All patients diagnosed with stage IV rectal carcinoma between 2009 and 2019, undergone elective surgery at the National Cancer Institute of Milan (Italy), were included. Propensity score-based matching was performed between the two study groups. Loco-regional recurrence-free survival (LRRFS) and overall survival (OS) were analysed using Kaplan-Meyer method.

RESULTS

A total of 139 patients were analyzed. After propensity score matching, 88 patients were included in the final analysis. The 3-yr LRRFS rates were 80.3% for nCHRTS vs. 90.4% for upfront surgery patients (p = 0.35). The 3-yr OS rates were respectively 81.8% vs. 58% (p = 0.36). KRAS mutation (HR 2.506, p = 0.038) and extra-liver metastases (HR 4.308, p = 0.003) were both predictive of worse OS in univariate analysis.

CONCLUSION

The present study failed to demonstrate a significant impact of nCHRTS on LRRFS or OS in stage IV rectal cancer.

Population-based assessment of the National Comprehensive Cancer Network recommendations for baseline imaging of rectal cancer

Aim: To examine the performance characteristics of alternative criteria for baseline staging, in a cohort of contemporary rectal cancer patients from the Surveillance, Epidemiology and End Results (SEER) database. Methods: The SEER database (2010-2015) was accessed and patients with rectal cancer plus complete information on clinical T and N stages as well as metastatic sites were evaluated. We examined various performance characteristics of baseline imaging, including specificity, sensitivity, number needed to investigate (NNI), positive predictive value (PPV), negative predictive value and accuracy. Results: A total of 15,836 rectal cancer patients were included. Based on current guidelines that suggest cross-sectional chest and abdominal imaging for all cases of invasive rectal cancer, these recommendations would yield a PPV of 11.9% for the detection of liver metastases and 6.2% for the detection of lung metastases. This would translate to an NNI of 8.4 for liver metastases and an NNI of 16.1 for lung metastases. When patients with T1N0 were excluded from routine imaging, this resulted in a PPV of 6.4% and an NNI of 15.6 to identify one case of lung metastasis. Likewise, this resulted in a PPV of 12.3% and an NNI of 8.0 to detect one case of liver metastasis. Similarly, when patients with either T1N0 or T2N0 were excluded from routine imaging, the PPV and NNI for lung metastases improved to 6.6% and 15.1, respectively, and the PPV and NNI for liver metastases improved to 12.6 and 7.9%, respectively. Conclusion: Our study suggests that the specificity of the current imaging approach for rectal cancer staging is limited and that the omission of chest and abdominal imaging among selected early stage asymptomatic cases may be reasonable to consider.

Survival Benefit of Preoperative Versus Postoperative Radiotherapy in Metastatic Rectal Cancer Treated With Definitive Surgical Resection of Primary Tumor: A Population Based, Propensity Score-Matched Study

Preoperative chemoradiation followed by surgery has been recommended as a standard treatment for patients with stage II/III rectal cancer. However, the optimal sequencing of radiotherapy for metastatic rectal cancer remains unclear. Between 2004 and 2014, patients diagnosed with metastatic rectal cancer who underwent the resection of primary site and received radiotherapy were retrospectively selected using the Surveillance, Epidemiology, and End Results (SEER) database. The propensity score matching analyses were used to lessen the effects of confounding factors including age, sex, race, marital status, serum carcinoembryonic antigen level, histologic type, differentiation status, tumor size, T stage, N stage and resection of the distant lesions. The cancer-specific survival (CSS) were compared based on the sequencing of radiotherapy. Ultimately, 686 matched pairs were formed for comparison of preoperative versus postoperative radiotherapy. The 5-year CSS estimates were 33.4% (95% CI: 28.9%-37.9%) and 26.8% (95% CI: 22.7%-30.9%) for patients underwent preoperative radiotherapy followed by resection of primary lesion and postoperative radiotherapy after surgery, respectively. Patients underwent preoperative radiotherapy had better CSS as compared to patients received postoperative radiotherapy (p<0.001 for log-rank test). Multivariate analysis demonstrated that preoperative radiotherapy group was associated with significantly decreased risk for cancer death (HR=0.820, 95% CI: 0.712-0.945, p=0.006). Preoperative radiotherapy was superior to postoperative radiotherapy in patients with metastatic rectal cancer. Therapeutic strategy for these patients should be further explored.

[How to manage a rectal cancer with synchronous liver metastases? A question of strategy]

The prognosis of patients with rectal cancer and synchronous liver metastasis has improved thanks to chemotherapy and rectal and liver surgery progresses. However, there is no consensus about optimal management and practices remain heterogeneous. A curative treatment may be considered for 20 to 30% of patients with complete resection of metastasis and primary tumor after induction chemotherapy. To this end, a primary optimal evaluation by a multidisciplinary board including hepatic and colorectal surgeons is crucial. The therapeutic strategy associates chemotherapy, radiotherapy, hepatic and rectal surgery. The most threatening site guides the sequence of treatments. If hepatic resectability is uncertain, a "liver first" strategy associating induction chemotherapy and hepatic surgery is preferred. In non-resectable metastatic cases, chemotherapies with targeted therapies might lead to secondary resection for 30% of patients (conversion). This has changed our practice and triggers reconsidering resectability after chemotherapy. When metastases remain non-resectable, additional treatment focusing on primary tumor should control pelvic symptoms otherwise hardly impacting quality of life. Rectal surgery, short-course radiotherapy (5×5Gy), conformational long-course chemoradiotherapy or intensity-modulated radiation therapy with dose escalation are options discussed in this review.

The role of neoadjuvant radiotherapy for locally-advanced rectal cancer with resectable synchronous metastasis

BACKGROUND

Although neoadjuvant radiotherapy is typically administered for locally-advanced rectal cancer to reduce local recurrence (LR), its role for patients who present with synchronous resectable liver and/or lung metastasis is not well defined. The aim of this study was to evaluate the role of neoadjuvant radiotherapy for patients with stage IV rectal cancer undergoing curative-intent surgery.

METHODS

This study is a retrospective review of a prospectively maintained surgical registry of all consecutive adult patients who underwent curative-intent resection at Mayo Clinic in Rochester, MN, from January 1990 until December 2014 with a median follow-up time of 43 (IQR 16-67) months. Eligible patients had locally-advanced rectal cancer (T3, T4 and/or nodal involvement) with synchronous resectable liver and/or lung metastasis. Exclusion criteria were as follows: patients with primary tumor stage of T1N0 or T2N0, patients with metastasis to organs other than the liver or lung, patients who had palliative resection, patients who had non-surgical treatment of synchronous metastasis (e.g., radiofrequency ablation), patients who received postoperative radiotherapy, or absence of research authorization. Ninety three patients were included of which 47 received neoadjuvant radiotherapy and 46 did not. All patients received neoadjuvant chemotherapy +/- radiotherapy followed by curative-intent surgery with metastasectomy performed either simultaneously with resection of the primary tumor or as a planned staged resection. The primary outcomes of this study are LR, distant metastasis, overall and disease-specific survival (DSS).

RESULTS

LR was observed in 12 patients (26%) who did not receive radiotherapy, while no LR developed in those who received neoadjuvant radiotherapy, P<0.001. Univariate analysis showed that neither age, sex, ASA class, BMI, tumor location, procedure performed, or neoadjuvant chemotherapy were associated with subsequent LR. The 5-year overall survival (OS) rates were: 43.3% (95% CI: 30.1, 62.3) for no radiotherapy vs. 58.3% (95% CI: 43.4, 78.2) with radiotherapy.

CONCLUSIONS

Neoadjuvant radiotherapy should be considered in patients with locally-advanced stage IV rectal cancer. These data add to the evidence supporting neoadjuvant radiotherapy in the setting of resectable metastatic disease.