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

Colorectal cancer: Recent advances in management and treatment

Colorectal cancer (CRC) is the third most common cancer worldwide, and the second most common cause of cancer-related death. In 2020, the estimated number of deaths due to CRC was approximately 930000, accounting for 10% of all cancer deaths worldwide. Accordingly, there is a vast amount of ongoing research aiming to find new and improved treatment modalities for CRC that can potentially increase survival and decrease overall morbidity and mortality. Current management strategies for CRC include surgical procedures for resectable cases, and radiotherapy, chemotherapy, and immunotherapy, in addition to their combination, for non-resectable tumors. Despite these options, CRC remains incurable in 50% of cases. Nonetheless, significant improvements in research techniques have allowed for treatment approaches for CRC to be frequently updated, leading to the availability of new drugs and therapeutic strategies. This review summarizes the most recent therapeutic approaches for CRC, with special emphasis on new strategies that are currently being studied and have great potential to improve the prognosis and lifespan of patients with CRC.

Construction and validation of a nomogram for predicting cancer-specific survival in middle-aged patients with advanced hepatocellular carcinoma: A SEER-based study

Hepatocellular carcinoma is the predominant form of primary liver cancer and is the leading cause of cancer-related death. The aim of this study was to construct a nomogram to predict cancer-specific survival (CSS) in middle-aged patients with advanced hepatocellular carcinoma. Clinical data were downloaded from the Surveillance, Epidemiology and End Results (SEER) database for middle-aged patients diagnosed with advanced hepatocellular carcinoma (AJCC stage III and IV) from 2000 to 2019. The patients were randomized in a 7:3 ratio into training cohort and validation cohort. Univariate and multivariate Cox regression analyses were performed in the training cohort to screen for independent risk factors associated with cancer-specific survival for the construction of nomogram. The nomogram was examined and evaluated using the consistency index (C-index), area under the curve (AUC), and calibration plots. The clinical application value of the model was evaluated using decision curve analysis (DCA). A total of 3026 patients were selected, including 2244 in the training cohort and 962 in the validation cohort. Multivariate analysis revealed gender, marital status, American Joint Committee on Cancer (AJCC) stage, tumor size, bone metastasis, lung metastasis, alpha-fetoprotein (AFP) level, surgery, radiotherapy, chemotherapy as independent risk factors, which were all included in the construction of the nomogram. In the training cohort, the AUC values were 0.74 (95% CI: 0.76-0.72), 0.78 (95% CI: 0.82-0.75), and 0.82 (95% CI: 0.86-0.78) at 1-, 3-, and 5-year CSS, respectively. The calibration plots showed good consistency between the actual and predicted values. The DCA curves indicated that the nomogram model could more accurately predict CSS at 1-, 3-, and 5-year in middle-aged patients with advanced hepatocellular carcinoma compared with the AJCC staging system. Highly similar results to the training cohort were also observed in the validation cohort. In the risk stratification system, good differentiation was shown between the 2 groups, and Kaplan-Meier survival analysis indicated that surgery could prolong patient survival. In this study, we developed a nomogram and risk stratification system for predicting CSS in middle-aged patients with advanced hepatocellular carcinoma. The prediction model has good predictive performance and can help clinicians in judging prognosis and clinical decision making.

Locally advanced mid/low rectal cancer with synchronous resectable liver metastases: systematic review of the available strategies and outcome

The management of patients with locally advanced mid/low rectal cancer with resectable liver metastases is complex because of the need to combine the optimal treatment of both tumors. This study aims to review the available treatment strategies and compare their outcome, focusing on radiotherapy (RT) and liver-first approach (LFA). A systematic review was performed in PubMed, Embase, and web sources including articles published between 2000 and 02/2023 and reporting mid-/long-term outcomes. Overall, twenty studies were included (n = 1837 patients). Three- and 5-year overall survival (OS) rates were 51-88% and 36-59%. Although several strategies were reported, most patients received RT (1448/1837, 79%; > 85% neoadjuvant). RT reduced the pelvic recurrence risk (5.8 vs. 13.5%, P = 0.005) but did not impact OS. Six studies analyzed LFA (n = 307 patients). LFA had a completion rate similar to the rectum-first approach (RFA, 81% vs. 79%) but the interval strategy-an LFA variant with liver surgery in the interval between radiotherapy and rectal surgery-had a better completion rate than standard LFA (liver surgery/radiotherapy/rectal surgery, 92% vs. 75%, P = 0.011) and RFA (79%, P = 0.048). Across all series, LFA achieved the best survival rates, and in one paper it led to a survival advantage in patients with multiple metastases. In conclusion, different strategies can be adopted, but RT should be included to decrease the pelvic recurrence risk. LFA should be considered, especially in patients with high hepatic tumor burden, and RT before liver surgery (interval strategy) could maximize its completion rate.

Active involvement of patients, radiation oncologists, and surgeons in a multidisciplinary team approach: Guiding local therapy in recurrent, metastatic rectal cancer

BACKGROUND

Despite the extensive implementation of an organized multidisciplinary team (MDT) approach in cancer treatment, there is little evidence regarding the optimal format of MDT. We aimed to investigate the impact of patient participation in MDT care on the actual application rate of metastasis-directed local therapy.

METHODS

We identified all 1211 patients with locally advanced rectal cancer treated with neoadjuvant radiochemotherapy at a single institution from 2006 to 2018. Practice patterns, tumor burden and OMD state were analyzed in recurrent, metastatic cases.

RESULTS

With a median follow-up of 60.7 months, 281 patients developed metastases, and 96 (34.2%), 92 (32.7%), and 93 (33.1%) patients had 1, 2-5, and >5 lesions, respectively. In our study, 27.1% were managed in the MDT clinic that mandated the participation of at least four to five board-certified multidisciplinary experts and patients in decision-making processes, while the rest were managed through diverse MDT approaches such as conferences, tumor board meetings, and discussions conducted via phone calls or email. Management in MDT clinic was significantly associated with more use of radiotherapy (p = 0.003) and more sessions of local therapy (p < 0.001). At the time of MDT clinic, the number of lesions was 1, 2-5, and >5 in 9 (13.6%), 35 (53.1%), and 19 (28.8%) patients, respectively. The most common states were repeat OMD (28.8%) and de novo OMD (27.3%), followed by oligoprogression (15%) and induced OMD (10.6%).

CONCLUSION

Our findings suggest that active involvement of patients and radiation oncologists, and surgeons in MDT care has boosted the probability of using local therapies for various types of OMD throughout the course of the disease.

Staged or Simultaneous Surgery for Colon or Rectal Cancer with Synchronous Liver Metastases: Implications for Study Design and Clinical Endpoints

In patients presenting with colorectal cancer and synchronous liver metastases, the disease burden related to the liver metastasis is the driving cause of limited longevity and, eventually, risk of death. Surgical resection is the potentially curative treatment for colorectal cancer liver metastases. In the synchronous setting where both the liver metastases and the primary tumor are resectable with a relative low risk, the oncological surgeon and the patient may consider three potential treatment strategies. Firstly, a "staged" or a "simultaneous" surgical approach. Secondly, for a staged strategy, a 'conventional approach' will suggest removal of the primary tumor first (either colon or rectal cancer) and plan for liver surgery after recovery from the first operation. A "Liver first" strategy is prioritizing the liver resection before resection of the primary tumor. Planning a surgical trial investigating a two-organ oncological resection with highly variable extent and complexity of resection as well as the potential impact of perioperative chemo(radio)therapy makes it difficult to find the optimal primary endpoint. Here, we suggest running investigational trials with carefully chosen composite endpoints as well as embedded risk-stratification strategies to identify subgroups of patients who may benefit from simultaneous surgery.

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.

The value of diffusion kurtosis imaging and intravoxel incoherent motion quantitative parameters in predicting synchronous distant metastasis of rectal cancer

BACKGROUND

The incidence and mortality rate of rectal cancer are still high, the metastasis of rectal cancer are main causes of death. The control of the distant metastasis is one of the main concerns in the treatment of locally advanced rectal cancer, but there are few studies on predicting synchronous distant metastasis (SDM) of rectal cancer.

METHOD

The data of patients with rectal adenocarcinoma confirmed by endoscopic biopsy or postoperative pathology from September 2015 to May 2020 in hospital A (center 1) and hospital B (center 2) were analyzed retrospectively, including age, sex, carcinoembryonic antigen, carbohydrate antigen 19-9, tumor location, tumor length, image staging and characteristics. The average age of the 169 patients consisting of 105 males and 64 females in study is 61.2 years. All patients underwent rectal routine rectal MRI, DKI and IVIM examinations on a 3.0-T scanner. Two radiologists sketched regions of interest (ROIs) on b = 1000 s/mm² DKI and IVIM images to obtain quantitative parameters with FireVoxel manually. We evaluated the difference of histogram analysis, clinical and image data between SDM group and non-SDM group, and evaluated the efficacy of each index in predicting SDM of rectal cancer.

RESULTS

The 90th percentile of f values in the SDM group is lower than that in the non-SDM group (29.4 ± 8.4% vs. 35 ± 17.8%, P = 0.005). CA19-9 in the SDM group is higher than that in the non-SDM group (P = 0.003). Low and high rectal cancer are more likely to develop SDM than middle rectal cancer (P = 0.05 and P = 0.047). The combination of these three indexes has a greater area under the curve (AUC) than any one index (0.801 vs. 0.685 (f (90th percentile)) and 0.627 (CA19-9), P = 0.0075 and 0.0058, respectively), and its specificity and sensitivity are 80.0% and 71.6%, respectively. When this combination is incorporated into the predictive nomogram model, the c-index is 0.801 (95% confidence interval (CI): 0.730-0.871).

CONCLUSIONS

IVIM quantitative parameters combine with CA19-9 and tumor location can better predict the risk of SDM of rectal cancer.

Novel Carbon Ion and Proton Partial Irradiation of Recurrent Unresectable Bulky Tumors (Particle-PATHY): Early Indication of Effectiveness and Safety

Background: We present the early results of a novel partial bulky-tumor irradiation using particles for patients with recurrent unresectable bulky tumors who failed previous state-of-the-art treatments. Methods: First, eleven consecutive patients were treated from March 2020 until December 2021. The targeted Bystander Tumor Volume (BTV) was created by subtracting 1 cm from Gross Tumor Volume (GTV) surface. It reflected approximately 30% of the central GTV volume and was irradiated with 30–45 Gy RBE (Relative Biological Effectiveness) in three consecutive fractions. The Peritumoral Immune Microenvironment (PIM) surrounding the GTV, containing nearby tissues, blood-lymphatic vessels and lymph nodes, was considered an organ at risk (OAR) and protected by highly conservative constraints. Results: With the median follow up of 6.3 months, overall survival was 64% with a median survival of 6.7 months; 46% of patients were progression-free. The average tumor volume regression was 61% from the initial size. The symptom control rate was 91%, with an average increase of the Karnofsky Index of 20%. The abscopal effect has been observed in 60% of patients. Conclusions: Partial bulky-tumor irradiation is an effective, safe and well tolerated treatment for patients with unresectable recurrent bulky disease. Abscopal effects elucidate an immunogenic pathway contribution. Extensive tumor shrinkage in some patients might permit definitive treatment—otherwise previously impossible.

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.

Short-course radiotherapy in stage IV rectal cancer with resectable disease

INTRODUCTION

Stage IV rectal cancer with resectable disease presents challenging issues, as the radical treatment of the whole disease is difficult. Surgery and chemotherapy (CT) play an unquestionable role, but the contribution of pelvic radiotherapy (RT) is not very clear.

METHODS

In 2009, we established a prospective treatment protocol that included CT, short-course preoperative radiotherapy (SCRT) with surgery of the primary tumour and all metastatic locations.

RESULTS

Forty patients were included. Eight (20%) patients did not receive CT due to significant comorbidities. Radical surgery treatment was possible in 22 (55%) patients. The mean follow-up was 42.81 months (3.63-105.97). Overall survival at 24 and 36 months was 71.4% and 58.2%, respectively. There was good local control of the disease, as 97.2% of pelvic surgeries were R0 and there were no local recurrences.

CONCLUSION

In stage IV with resectable metastatic disease, the proposed therapeutic regimen seems very appropriate in well selected patients able to tolerate the treatment. We bet on the role of pelvic RT, due to the good local control of the disease in our series.

Radiation therapy for rectal cancer

Radiotherapy (RT) has remained an important pillar in the multi-modality management of rectal cancer. Adjuvant RT with concurrent chemotherapy (chemo-RT) was once the standard of care for locally advanced rectal cancer, but with time, that has now changed and neoadjuvant chemo-RT followed by total mesorectal excision (TME) surgery is the new standard. Alternatively, neoadjuvant RT alone remains an option and clinicians are tasked to choose between the two. In an era of personalised oncological management, it is unsurprising that the treatment for rectal cancer is following suit and upcoming trials are studying ways to improve outcomes and minimise toxicity for patients while tailoring treatments specific to each patient's tumour. We review the evolution of the role of RT in rectal cancer and look forward to what the future holds.

A Concise Review of Pelvic Radiation Therapy (RT) for Rectal Cancer with Synchronous Liver Metastases

Background and Objective

Colorectal cancer is a major health concern as a very common cancer and a leading cause of cancer-related mortality worldwide. The liver is a very common site of metastatic spread for colorectal cancers, and, while nearly half of the patients develop metastases during the course of their disease, synchronous liver metastases are detected in 15% to 25% of cases. There is no standardized treatment in this setting and no consensus exists on optimal sequencing of multimodality management for rectal cancer with synchronous liver metastases.

Methods

Herein, we review the use of pelvic radiation therapy (RT) as part of potentially curative or palliative management of rectal cancer with synchronous liver metastases.

Results

There is accumulating evidence on the utility of pelvic RT for facilitating subsequent surgery, improving local tumor control, and achieving palliation of symptoms in patients with stage IV rectal cancer. Introduction of superior imaging capabilities and contemporary RT approaches such as Intensity Modulated Radiation Therapy (IMRT) and Image Guided Radiation Therapy (IGRT) offer improved precision and toxicity profile of radiation delivery in the modern era.

Conclusion

Even in the setting of stage IV rectal cancer with synchronous liver metastases, there may be potential for extended survival and cure by aggressive management of primary tumor and metastases in selected patients. Despite lack of consensus on sequencing of treatment modalities, pelvic RT may serve as a critical component of multidisciplinary management. Resectability of primary rectal tumor and liver metastases, patient preferences, comorbidities, symptomatology, and logistical issues should be thoroughly considered in decision making for optimal management of patients.

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.

MRI radiomics analysis for predicting preoperative synchronous distant metastasis in patients with rectal cancer

OBJECTIVES

To investigate the value of MRI radiomics based on T2-weighted (T2W) images in predicting preoperative synchronous distant metastasis (SDM) in patients with rectal cancer.

METHODS

This retrospective study enrolled 177 patients with histopathology-confirmed rectal adenocarcinoma (123 patients in the training cohort and 54 in the validation cohort). A total of 385 radiomics features were extracted from pretreatment T2W images. Five steps, including univariate statistical tests and a random forest algorithm, were performed to select the best preforming features for predicting SDM. Multivariate logistic regression analysis was conducted to build the clinical and clinical-radiomics combined models in the training cohort. The predictive performance was validated by receiver operating characteristics curve (ROC) analysis and clinical utility implementing a nomogram and decision curve analysis.

RESULTS

Fifty-nine patients (33.3%) were confirmed to have SDM. Six radiomics features and four clinical characteristics were selected for predicting SDM. The clinical-radiomics combined model performed better than the clinical model in both the training and validation datasets. A threshold of 0.44 yielded an area under the ROC (AUC) value of 0.827 (95% confidence interval (CI), 0.6963-0.9580), a sensitivity of 72.2%, a specificity of 94.4%, and an accuracy of 87.0% in the validation cohort for the combined model. A clinical-radiomics nomogram and decision curve analysis confirmed the clinical utility of the combined model.

CONCLUSIONS

Our proposed clinical-radiomics combined model could be utilized as a noninvasive biomarker for identifying patients at high risk of SDM, which could aid in tailoring treatment strategies.

KEY POINTS

• T2WI-based radiomics analysis helps predict synchronous distant metastasis (SDM) of rectal cancer. • The clinical-radiomics combined model could be utilized as a noninvasive biomarker for predicting SDM. • Personalized treatment can be carried out with greater confidence based on the risk stratification for SDM in rectal cancer.

Repeating of local therapy of distant metastases increases overall survival in patients with synchronous metastasized rectal cancer-a monocentric analysis

PURPOSE

The aim was to evaluate the outcome of treatment-naive patients with synchronous metastatic rectal cancer after chemotherapy with FOLFOXIRI followed by local therapeutic procedures of all tumor lesions as complete as possible.

METHODS

We reviewed data of 30 patients with synchronous distant metastatic rectal cancer who underwent chemotherapy with FOLFOXIRI and subsequent local therapy in our institution.

RESULTS

Median follow-up was 28 months (range: 8; 74). Cumulative overall survival (OS) and progression-free survival (PFS) was 93.3, 76.9, 55.6% and 46.2, 29.7, 29.7% after 1, 2, 4 years. Non-response to chemotherapy with FOLFOXIRI was associated with a highly significant decreased OS (p < 0.0001). The consistent use of local ablative procedures led to a statistically significant increase in OS (p < 0.0001), but not in PFS (p = 0.635). Patients with ≤ 4 distant metastases showed a better OS (p = 0.033).

CONCLUSIONS

Response to intensified first-line chemotherapy with FOLFOXIRI, treatment of the primary rectal tumor, and repeated thorough local ablative procedures in patients with synchronous metastasized rectal cancer may lead to long-term survival, even in a subset of patients with unresectable disease at initial diagnosis.