Association Between Adjuvant Chemotherapy and Overall Survival in Patients With Rectal Cancer and Pathological Complete Response After Neoadjuvant Chemotherapy and Resection

Economic Evaluation of Neoadjuvant Versus Adjuvant Chemotherapy in Cancer Treatment: A Systematic Review and Meta-Analysis

OBJECTIVES

In the absence of evidence on whether neoadjuvant (NAC) or adjuvant chemotherapy (AC) is more beneficial for various tumor treatments, economic evaluation (EE) can assist medical decision making. There is limited evidence on their cost-effectiveness and their prospective evaluation is less likely in the future. Therefore, a systematic review and meta-analysis about EE for NAC versus AC in solid tumor help compare these therapies from various perspectives.

METHODS

Various databases were searched for studies published from inception to 2021. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines and economic-specific guidelines. The data were pooled using a random effects model when possible.

RESULTS

The retrieval identified 15 EE studies of NAC versus AC in 8 types of cancer. NAC is the dominant strategy for pancreatic, head and neck, rectal, prostate cancers and colorectal liver metastases. For ovarian cancer, NAC is cost-effective with a lower cost and higher or similar quality-adjusted life-year. There were no significant differences in cost and outcomes for lung cancer. For stage IV or high-risk patients with ovarian or prostate cancer, NAC was cost-effective but not for patients who were not high risk.

CONCLUSIONS

The EEs results for NAC versus AC were inconsistent because of their different model structures, assumptions, cost inclusions, and a shortage of studies. There are multiple sources of heterogeneity across EEs evidence synthesis. More high-quality EE studies on NAC versus AC in initial cancer treatment are necessary.

The clinical relevance of adjuvant chemotherapy in locally advanced rectal cancer patients achieving near pathological complete response following neoadjuvant chemoradiotherapy: Insights from ypT stage

BACKGROUND

Near-pathological complete response (Near-pCR) patients constitute a distinct subgroup with limited research attention. The clinical relevance of adjuvant chemotherapy (ACT) in this patient cohort remains uncertain.

METHODS

We conducted a retrospective analysis of 245 patients with locally advanced rectal cancer (LARC) who achieved near-pCR following neoadjuvant chemoradiotherapy (NCRT) between 2011 and 2018. Based on their receipt of ACT or not (non-ACT), patients were divided into two groups. We examined their characteristics, treatment modalities, and survival outcomes, particularly focusing on 5-year disease-free survival (DFS) and 5-year overall survival (OS).

RESULTS

Among the 245 near-pCR patients, 191 (77.96%) received ACT, and 42 (17.14%) experienced disease recurrence. All 54 (22.04%) Patients in the non-ACT group exhibited a lower 5-year DFS rate (72.2% vs. 85.9%, P = 0.014) and a similar 5-year OS rate (87.0% vs. 91.1%, P = 0.351). Interestingly, those with ypT3-T4 stage tumors demonstrated a worse DFS (76.8% vs. 89.9%, P = 0.010) and OS (87.5% vs. 97.0%, P = 0.004) compared to their counterparts with ypT1-T2 stage tumors. Patients with Non-Downstage tumors showed inferior DFS (76.9% vs. 88.3%, P = 0.025) and OS (87.2% vs. 93.0%, P = 0.166) in comparison to patients with Downstage tumors. The ACT subgroup in patients with Downstage demonstrated statistically better 5-year DFS (93.0% vs. 71.4%, P = 0.001) but analogous survival rates for 5-year OS (OS: 94.0% vs. 89.3%, P = 0.402). Pathological T stage 3-4, perineural invasion (PNI) (positive) and ACT were independent factors influencing 5-year DFS in multivariate analysis. Both univariate and multivariate analysis demonstrated a link between serum carcinoembryonic antigen (CEA) before treatment ≥5 ng/ml and shorter 5-year OS. Notably, near-pCR patients with positive lymph nodes experienced notably diminished 5-year DFS in the absence of ACT post-surgery (61.1% vs. 93.2%, P < 0.001).

CONCLUSIONS

ACT demonstrated a significant positive impact on the prognosis of select near-pCR patients, particularly those with ypT1-T2 stage tumors and positive lymph nodes. ypT staging may emerge as a valuable criterion for precise post-surgical ACT guidance in near-pCR patients.

The role of adjuvant chemotherapy in rectal cancer patients with ypT0-2N0 after neoadjuvant chemoradiotherapy

Background

Neoadjuvant chemoradiotherapy has emerged as the established treatment for locally advanced rectal cancer. Nevertheless, there remains a debate regarding the necessity of adjuvant chemotherapy for patients with locally advanced rectal cancer who exhibit a favorable tumor response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery. Thus, the objective of this study is to investigate the impact of adjuvant chemotherapy on the oncological prognosis of rectal cancer patients who have a good response to neoadjuvant chemoradiotherapy.

Materials and methods

The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Articles were searched in the Web of Science, PubMed, and Cochrane Library databases. The primary outcomes assessed were 5-year overall survival, disease-free survival, cancer-specific survival, recurrence-free survival, local recurrence, and distant metastasis. The data was summarized using a random effects model.

Results

A meta-analysis was conducted using 18 retrospective studies published between 2009 and 2023. The studies included 9 from China and 5 from Korea, involving a total of 6566 patients with ypT0-2N0 rectal cancer after neoadjuvant chemoradiotherapy. The pooled data revealed that adjuvant chemotherapy significantly improved 5-year overall survival (OR=1.75, 95% CI: 1.15-2.65, P=0.008), recurrence-free survival (OR=1.73, 95% CI: 1.20-2.48, P=0.003), and reduced distant metastasis (OR=0.68, 95% CI: 0.51-0.92, P=0.011). However, adjuvant chemotherapy did not have a significant effect on disease-free survival, cancer-specific survival, and local recurrence in ypT0-2N0 rectal cancer. Subgroup analysis indicated that adjuvant chemotherapy was beneficial in improving overall survival for ypT1-2N0 rectal cancer (OR=1.89, 95% CI: 1.13-3.19, P=0.003).

Conclusion

The findings of the meta-analysis suggest that adjuvant chemotherapy may provide benefits in terms of oncological outcomes for rectal cancer patients with ypT0-2N0 after neoadjuvant chemoradiotherapy and radical surgery. However, further prospective clinical studies are needed to confirm these findings.

Effect of adjuvant chemotherapy on the oncological outcome of rectal cancer patients with pathological complete response

BACKGROUND

Locally advanced rectal cancer is typically treated using a combination of neoadjuvant chemoradiotherapy and total mesorectal resection. While achieving pathological complete response following neoadjuvant chemoradiotherapy has been recognized as a positive prognostic factor in oncology, the necessity of adjuvant chemotherapy for locally advanced rectal cancer patients with pathological complete response after surgery remains uncertain. The objective of this meta-analysis was to examine the impact of adjuvant chemotherapy on the oncological outcomes of rectal cancer patients who attain pathological complete response after neoadjuvant chemoradiotherapy.

METHODS

This meta-analysis followed the guidelines outlined in the preferred reporting items for systematic review and meta-analysis (PRISMA). The Web of Science, PubMed, and Cochrane Library databases were systematically searched to identify relevant literature.

RESULTS

A total of 34 retrospective studies, including 9 studies from the NCBD database, involving 31,558 patients with pathological complete response rectal cancer, were included in the meta-analysis. The included studies were published between 2008 and 2023. The pooled analysis demonstrated that adjuvant chemotherapy significantly improved overall survival (HR = 0.803, 95% CI 0.678-0.952, P = 0.011), and no heterogeneity was observed (I2 = 0%). Locally advanced rectal cancer patients with pathological complete response who underwent adjuvant chemotherapy exhibited a higher 5-year overall survival rate compared to those who did not receive adjuvant chemotherapy (OR = 1.605, 95% CI 1.183-2.177, P = 0.002). However, the analysis also revealed that postoperative ACT did not lead to improvements in disease-free survival and recurrence-free survival within the same patient population. Subgroup analysis indicated that pathological complete response patients with clinical stage T3/T4, lymph node positivity, and younger than 70 years of age may benefit from adjuvant chemotherapy in terms of overall survival.

CONCLUSIONS

The findings of this meta-analysis suggest that adjuvant chemotherapy has a beneficial effect on improving overall survival among rectal cancer patients with pathological complete response. However, no such association was observed in terms of disease-free survival and recurrence-free survival.

Oxidative Stress Induced by Chemotherapy: Evaluation of Glutathione and Its Related Antioxidant Enzyme Dynamics in Patients with Colorectal Cancer

One of the mechanisms of chemotherapy is to increase the oxidative stress of cancer cells, leading to their apoptosis. Glutathione (GSH) and its related antioxidant enzymes might be stimulated to cope with increased oxidative stress during chemotherapy. Here, we studied the fluctuation in oxidative stress and GSH-related antioxidant capacities before tumor resection, after tumor resection, and after resection either with or without chemotherapy in patients with colorectal cancer (CRC). This was a cross-sectional and follow-up design. We followed patients before having tumor resection (pre-resection), one month after tumor resection (post-resection), and after the first scheduled chemotherapy (post-chemo). If patients were required to receive chemotherapy after tumor resection, they were assigned to the chemotherapy group. Eligible patients were scheduled to undergo six to twelve cycles of chemotherapy at 2-week intervals and received single, double, or triple chemotherapeutic drugs as required. Those patients who did not require chemotherapy were assigned to the non-chemotherapy group. Indicators of oxidative stress and GSH-related antioxidant capacities were determined at the above three time points. We found in 48 patients of the chemotherapy group and in 43 patients of the non-chemotherapy group different fluctuations in levels of oxidative stress indicators and GSH-related antioxidant capacities starting from pre-resection, post-resection through the post-chemo period. Both groups showed significantly or slightly increased levels of advanced oxidation protein products (AOPP), GSH, and its related enzymes in tumor tissues compared to adjacent normal tissues. Patients in the chemotherapy group had significantly lower plasma levels of GSH and glutathione disulfide (GSSG), but had significantly higher plasma glutathione peroxidase and glutathione reductase activities than patients in the non-chemotherapy group post-chemo. Plasma levels of malondialdehyde and AOPP were positively or negatively associated with GSH and GSSG levels post-chemo after adjustment for age, sex, and histological grading in patients receiving chemotherapy. These significant associations were, however, not seen in patients without chemotherapy. Patients with CRC may require higher GSH demands to cope with a greater oxidative stress resulting from chemotherapy.

A large-scale study integrating nutritional indicators and clinicopathological parameters to evaluate prognosis, follow-up, and postoperative chemotherapy decisions in rectal cancer patients

OBJECTIVE

The aim of this study was to evaluate the role of nutritional indicators and clinicopathological parameters in predicting the progression and prognosis for pathological stage II-III rectal cancer (RC) patients without neoadjuvant radiotherapy. In addition, we sought to explore the high-risk population who may require postoperative chemotherapy.

METHODS

A total of 894 consecutive RC patients were enrolled in this study. Univariate and multivariate Cox analysis were performed to identify the independent risk factors for PFS and OS. The nomogram and calibration curves were conducted according to multivariable analysis result. Kaplan-Meier survival curves and log-rank tests were performed for different groups. Finally, random survival forest (RSF) model was developed to predict the probability of progression.

RESULTS

Our results revealed that CEA level, pathological stage, tumor deposit, and PNI were independently associated with PFS in RC patients. Similarly, the results indicated that CEA level, pathological stage, tumor deposit, PNI, and NRI were independently associated with OS. RSF model revealed that group 1 had the highest risk of progression at the 12th month of follow-up, group 2 had the highest risk of progression at the 15th month of follow-up, while group 3 had the highest risk of progression at the 9th month of follow-up. Besides, subgroup analysis suggested that the high-risk group needs postoperative adjuvant chemotherapy, while patients in the low- and moderate-risk groups may not need postoperative adjuvant chemotherapy. Finally, we validated our results with the SEER database.

CONCLUSIONS

In conclusion, we demonstrated that preoperative nutritional indicator and clinicopathological parameters could act as auxiliary prognostication tools for RC patients without neoadjuvant radiotherapy. We also established follow-up strategies for different groups of patients. Collectively, incorporating nutritional assessment into risk stratification for RC resection is crucial and should be an integral part of preoperative planning.

Recent advances and applications of peptide-agent conjugates for targeting tumor cells

BACKGROUND

Cancer, being a complex disease, presents a major challenge for the scientific and medical communities. Peptide therapeutics have played a significant role in different medical practices, including cancer treatment.

METHOD

This review provides an overview of the current situation and potential development prospects of anticancer peptides (ACPs), with a particular focus on peptide vaccines and peptide-drug conjugates for cancer treatment.

RESULTS

ACPs can be used directly as cytotoxic agents (molecularly targeted peptides) or can act as carriers (guiding missile) of chemotherapeutic agents and radionuclides by specifically targeting cancer cells. More than 60 natural and synthetic cationic peptides are approved in the USA and other major markets for the treatment of cancer and other diseases. Compared to traditional cancer treatments, peptides exhibit anticancer activity with high specificity and the ability to rapidly kill target cancer cells. ACP's target and kill cancer cells via different mechanisms, including membrane disruption, pore formation, induction of apoptosis, necrosis, autophagy, and regulation of the immune system. Modified peptides have been developed as carriers for drugs, vaccines, and peptide-drug conjugates, which have been evaluated in various phases of clinical trials for the treatment of different types of solid and leukemia cancer.

CONCLUSIONS

This review highlights the potential of ACPs as a promising therapeutic option for cancer treatment, particularly through the use of peptide vaccines and peptide-drug conjugates. Despite the limitations of peptides, such as poor metabolic stability and low bioavailability, modified peptides show promise in addressing these challenges. Various mechanism of action of anticancer peptides. Modes of action against cancer cells including: inducing apoptosis by cytochrome c release, direct cell membrane lysis (necrosis), inhibiting angiogenesis, inducing autophagy-mediated cell death and immune cell regulation.

Oncologic outcomes of watch-and-wait strategy or surgery for low to intermediate rectal cancer in clinical complete remission after adjuvant chemotherapy: a systematic review and meta-analysis

BACKGROUND

A watch-and-wait (WW) strategy or surgery for low to intermediate rectal cancer that has reached clinical complete remission (cCR) after neoadjuvant chemotherapy (nCRT) or total neoadjuvant therapy (TNT) has been widely used in the clinic, but both treatment strategies are controversial.

OBJECTIVE

The aim of this study was to compare the oncologic outcomes of a watch-and-wait strategy or a surgical approach to treat rectal cancer in complete remission and to report the evidence-based clinical advantages of the two treatment strategies.

METHODS

Seven national and international databases were searched for clinical trials comparing the watch-and-wait strategy with surgical treatment for oncological outcomes in patients with rectal cancer in clinical complete remission.

RESULTS

In terms of oncological outcomes, there was no significant difference between the watch-and-wait strategy and surgical treatment in terms of overall survival (OS) (HR = 0.92, 95% CI (0.52, 1.64), P = 0.777), and subgroup analysis showed no significant difference in 5-year disease-free survival (5-year DFS) between WW and both local excision (LE) and radical surgery (RS) (HR = 1.76, 95% CI (0.97, 3.19), P = 0.279; HR = 1.98, 95% CI (0.95, 4.13), P = 0.164), in distant metastasis rate (RR = 1.12, 95% CI (0.73, 1.72), P = 0.593), mortality rate (RR = 1.62, 95% CI (0.93, 2.84), P = 0.09), and organ preservation rate (RR = 1.05, 95% CI (0.94, 1.17), P = 0.394) which were not statistically significant and on the outcome indicators of local recurrence rate (RR = 2.09, 95% CI (1.44, 3.03), P < 0.001) and stoma rate (RR = 0.35, 95% CI (0.20, 0.61), P < 0.001). There were significant differences between the WW group and the surgical treatment group.

CONCLUSION

There were no differences in OS, 5-year DFS, distant metastasis, and mortality between the WW strategy group and the surgical treatment group. The WW strategy did not increase the risk of local recurrence compared with local resection but may be at greater risk of local recurrence compared with radical surgery, and the WW group was significantly better than the surgical group in terms of stoma rate; the WW strategy was evidently superior in preserving organ integrity compared to radical excision. Consequently, for patients who exhibit a profound inclination towards organ preservation and the evasion of stoma formation in the scenario of clinically complete remission of rectal cancer, the WW strategy can be contemplated as a pragmatic alternative to surgical interventions. It is, however, paramount to emphasize that the deployment of such a strategy should be meticulously undertaken within the ambit of a multidisciplinary team's management and within specialized centers dedicated to rectal cancer management.

Predicting the risk of distant metastasis in patients with locally advanced rectal cancer using model based on pre-treatment T2WI-based radiomic features plus postoperative pathological stage

Objective

To assess the prognostic value of a model based on pre-treatment T2WI-based radiomic features and postoperative pathological staging in patients with locally advanced rectal cancer who have undergone neoadjuvant chemoradiotherapy.

Methods

Radiomic features were derived from T2WI, and a radiomic signature (RS) was established and validated for the prediction of distant metastases (DM). Subsequently, we designed and validated a nomogram model that combined the radiomic signature and postoperative pathological staging for enhanced DM prediction. Performance measures such as the concordance index (C-index) and area under the curve (AUC) were computed to assess the predictive accuracy of the models.

Results

A total of 260 patients participated in this study, of whom 197 (75.8%) were male, and the mean age was 57.2 years with a standard deviation of 11.2 years. 15 radiomic features were selected to define the radiomic signature. Patients with a high-risk radiomic signature demonstrated significantly shorter distant metastasis-free survival (DMFS) in both the development and validation cohorts. A nomogram, incorporating the radiomic signature, pathological T stage, and N stage, achieved an area under the curve (AUC) value of 0.72 (95% CI, 0.60-0.83) in the development cohort and 0.83 (95% CI, 0.73-0.92) in the validation cohort.

Conclusion

A radiomic signature derived from T2WI-based radiomic features can effectively distinguish patients with varying risks of DM. Furthermore, a nomogram integrating the radiomic signature and postoperative pathological stage proves to be a robust predictor of DMFS.

Deep learning of endoscopic features for the assessment of neoadjuvant therapy response in locally advanced rectal cancer

BACKGROUND

For locally advanced rectal cancer (LARC), accurate response evaluation is necessary to select complete responders after neoadjuvant therapy (NAT) for a watch-and-wait (W&W) strategy. Algorithms based on deep learning have shown great value in medical image analyses. Here we used deep learning algorithms of endoscopic images for the assessment of NAT response in LARC.

METHOD

214 LARC patients were retrospectively included in the study. After NAT, these patients underwent total mesorectal excision (TME) surgery. Among them, 51 (23.8%) of the patients achieved a pathological complete response (pCR). 160 patients from Shanghai Changzheng Hospital were regarded as primary dataset, and the other 54 patients from Zhejiang Cancer Hospital were regarded as validation dataset. ResNet-18 and DenseNet-121 were applied to train the models based on endoscopic images after NAT. Deep learning models were valid in the validation dataset and compared to manual method.

RESULTS

The performances were comparable in AUC between deep learning models and manual method. For mean metrics, sensitivity (0.750 vs. 0.417) and AUC (0.716 vs. 0.601) in ResNet-18 deep learning model were higher than those in the manual method. The deep learning models were able to identify the endoscopic features associated with NAT response by the heatmaps. A diagnostic flow diagram which integrated the deep learning model to assist the clinicians in making decisions for W&W strategy was constructed.

CONCLUSIONS

We created deep learning models using endoscopic features for assessment of NAT in LARC. The deep learning models achieved modest accuracies and performed comparably to manual method.

Current Approaches to Neoadjuvant Immunotherapy in Resectable Non-small Cell Lung Cancer

PURPOSE OF REVIEW

For decades, early-stage resectable non-small cell lung cancer (NSCLC), while potentially curable, has been marred by unacceptably high recurrence rates.

RECENT FINDINGS

Anti-PD(L)1 immune checkpoint blockade (ICB) has revolutionized the treatment of advanced NSCLC, and with recent approvals in the peri-operative space, is now poised to transform the systemic treatment paradigm for localized and locally-advanced NSCLC. In this review, we focus on neoadjuvant ICB in resectable NSCLC, highlighting the pre-clinical rationale for neoadjuvant ICB, early clinical trials, randomized phase 3 trial data, and future directions for resectable NSCLC.

Examined lymph node numbers influence prognosis in rectal cancer treated with neoadjuvant therapy

Background

The number of lymph nodes examined (LNe) is often insufficient in patients with rectal cancer (RC) treated with neoadjuvant therapy; however, its prognostic value remains controversial. Thus, we retrospectively explored whether LNe had an influence on staging and prognosis and investigated whether there was a cut-off value for better prognosis in patients with RC treated with neoadjuvant therapy.

Methods

Data were collected from seven prospective hospital databases in China from July 2002 to May 2018. Binary logistic regression models were used to predict lymph node metastasis. The cut-off value for LNe was determined using X-tile 3.6.1. Survival outcomes and risk factors were analyzed using the log-rank test and Cox regression model.

Results

A total of 482 patients were included, of whom 459 had complete overall survival (OS) information. Using the percentile method, the total number of lymph nodes examined (TLNe) was 14-16 (40th-60th percentile), and the proportion of patients with lymph node metastasis reached a maximum of 48.1%. Cox multivariate analysis showed that the odds ratio (OR) remained the highest when TLNe was 14-16 (OR = 3.379, P = 0.003). The 3-year and 5-year OS were 85.4% and 77.8%, respectively. Negative lymph nodes examined (NLNe) of ≤6 was an independent risk factor for 3-year and 5-year OS (3-year OS 71.1% vs. 85.9%, P = 0.004; 5-year OS 66.3% vs. 74.3%, P = 0.035). Subgroup analysis for patients with ypN + showed that higher 3-year and 5-year OS were achieved when the TLNe was >10, 78.8% vs. 54.0% (P = 0.005), and 60.8% vs. 36.0% (P = 0.012), respectively. Patients with ypN0M0 had a higher 5-year OS when the TLNe was >19 (P = 0.055).

Conclusion

The TLNe and NLNe influenced the staging accuracy and demonstrated prognostic value in patients with RC treated with neoadjuvant therapy.

Improved Survival After Adjuvant Therapy in Locally Advanced Rectal Cancer Patients With Pathologic Complete Response

BACKGROUND

The benefit of adjuvant therapy is unclear in patients with rectal cancer achieving a pathologic complete response after neoadjuvant chemoradiotherapy and total mesorectal excision.

OBJECTIVE

This study aimed to assess the benefit of adjuvant chemotherapy on survival among rectal cancer patients with a pathologic complete response after neoadjuvant chemoradiation.

DESIGN

Retrospective cohort study.

SETTING

National Cancer Database (2004-2017).

PATIENTS

Patients with clinical stage 2 or 3 rectal adenocarcinoma who underwent neoadjuvant chemoradiation (50-50.4 Gy in 25-28 fractions) followed by total mesorectal excision with a pathologic complete response were included.

INTERVENTION

Adjuvant chemotherapy.

MAIN OUTCOME MEASURES

Overall survival.

RESULTS

There were 20,518 patients and 2221 (11%) had a pathologic complete response after neoadjuvant chemoradiation. Of 2221 patients, 1441 (65%) did not receive adjuvant therapy and 780 (35%) did. Patients who received adjuvant therapy were more likely to be younger (median 58 vs 62 y), have private insurance (61% vs 49%), and have node-positive disease (57% vs 48%) (all p < 0.05). There were no differences in sex, race, Charlson-Deyo score, clinical T-stage, tumor size and differentiation, adequate lymphadenectomy (12 or more), or sphincter preservation between groups (all p > 0.05). Overall survival at 5, 10, and 14 years was significantly longer in the adjuvant group (93%, 85%, 83%, respectively) compared to patients who did not receive adjuvant therapy (87%, 67%, 51%, respectively) ( p < 0.001). In a subgroup analysis, adjuvant therapy was associated with improved survival in patients with clinical stage 2 and 3 rectal cancer ( p < 0.001). After adjusting for patient and tumor characteristics, omission of adjuvant chemotherapy was associated with significantly worse survival (HR 1.53, 95% 1.08-2.16).

LIMITATIONS

Selection bias, unknown perioperative morbidity, chemotherapy regimen, recurrence status, and other unidentified factors limiting survival analysis.

CONCLUSIONS

In patients with clinical stage 2 or 3 rectal cancer, adjuvant chemotherapy was associated with improved overall survival in patients achieving a pathological complete response after neoadjuvant chemoradiotherapy. See Video Abstract at http://links.lww.com/DCR/C139 .

SOBREVIDA MEJORADA DESPUS DE LA TERAPIA ADYUVANTE EN PACIENTES CON CNCER DE RECTO LOCALMENTE AVANZADO CON RESPUESTA PATOLGICA COMPLETA

ANTECEDENTES:En los pacientes con cáncer de recto que logran una respuesta patológica completa después de la quimiorradioterapia neoadyuvante y la escisión total del mesorrecto, el beneficio de la terapia adyuvante no está claro.OBJETIVO:Evaluar el beneficio de la quimioterapia adyuvante en la sobrevida de los pacientes con cáncer de recto con una respuesta patológica completa después de la quimiorradioterapia neoadyuvante.DISEÑO:Estudio de cohorte retrospectivo.ESCENARIO:Base de Datos Nacional de Cáncer (2004-2017).PACIENTES:Pacientes con adenocarcinoma rectal en estadio clínico 2 ó 3 que se sometieron a quimiorradiación neoadyuvante (50-50,4 Gy en 25-28 fracciones) seguida de escisión mesorrectal total con una respuesta patológica completa.INTERVENCIÓN:Quimioterapia adyuvante.PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida global.RESULTADOS:Hubo 20.518 pacientes y 2.221 (11%) tuvieron una respuesta patológica completa después de la quimiorradiación neoadyuvante. Entre estos 2221 pacientes, 1441 (65%) no recibieron terapia adyuvante y 780 (35%) sí. Los pacientes que recibieron terapia adyuvante tenían más probabilidades de ser más jóvenes (mediana de 58 frente a 62 años), tener un seguro privado (61% frente a 49%) y tener enfermedad con linfonodos positivos (57% frente a 48 %) (todos p < 0,05). No hubo diferencias en género, raza, puntuación de Charlson-Deyo, estadio T clínico, tamaño y diferenciación del tumor, linfadenectomía adecuada (≥12) o preservación del esfínter entre los grupos (todos p > 0,05). La sobrevida general a los 5, 10 y 14 años fue significativamente mayor en el grupo adyuvante (93%, 85%, 83%, respectivamente) en comparación con los pacientes que no recibieron terapia adyuvante (87%, 67%, 51% respectivamente) ( p < 0,001). En un análisis de subgrupos, la terapia adyuvante se asoció con una mejor sobrevida general en pacientes con cáncer de recto en estadio clínico 2 y 3 ( p < 0,001). Después de ajustar por las características del paciente y del tumor, la omisión de la quimioterapia adyuvante se asoció con una sobrevida global significativamente peor (HR 1,53, IC del 95%, 1,08-2,16).LIMITACIONES:Sesgo de selección; morbilidad perioperatoria desconocida, régimen de quimioterapia, estado de recurrencia y otros factores no identificados que limitan el análisis de sobrevida.CONCLUSIONES:En pacientes con cáncer de recto en estadio clínico 2 ó 3, la quimioterapia adyuvante se asoció con una mejor sobrevida general en pacientes que lograron una respuesta patológica completa después de la quimiorradioterapia neoadyuvante. Consulte Video Resumen en http://links.lww.com/DCR/C139 . (Traducción-Dr. Felipe Bellolio ).

Circumferential Resection Margin as Predictor of Nonclinical Complete Response in Nonoperative Management of Rectal Cancer

BACKGROUND

Short-course radiation therapy and consolidation chemotherapy with nonoperative intent has emerged as a novel treatment paradigm for patients with rectal cancer, but there are no data on the predictors of clinical complete response.

OBJECTIVE

Evaluate the predictors of clinical complete response and survival.

DESIGN

Retrospective cohort.

SETTINGS

National Cancer Institute-designated cancer center.

PATIENTS

Patients with stage I to III rectal adenocarcinoma treated between January 2018 and May 2019 (n = 86).

INTERVENTIONS

Short-course radiation therapy followed by consolidation chemotherapy.

MAIN OUTCOME MEASURES

Logistic regression was performed to assess for predictors of clinical complete response. The end points included local regrowth-free survival, regional control, distant metastasis-free survival, and overall survival.

RESULTS

A positive (+) circumferential resection margin by MRI at diagnosis was a significant predictor of nonclinical complete response (OR: 4.1, p = 0.009) when adjusting for CEA level and primary tumor size. Compared to patients with a negative (-) pathologic circumferential resection margin, patients with a positive (+) pathologic circumferential resection margin had inferior local regrowth-free survival (29% vs 87%, p < 0.001), regional control (57% vs 94%, p < 0.001), distant metastasis-free survival (43% vs 95%, p < 0.001), and overall survival (86% vs 95%, p < 0.001) at 2 years. However, the (+) and (-) circumferential resection margin by MRI subgroups in patients who had a clinical complete response both had similar regional control, distant metastasis-free survival, and overall survival of more than 90% at 2 years.

LIMITATIONS

Retrospective design, modest sample size, short follow-up, and the heterogeneity of treatments.

CONCLUSIONS

Circumferential resection margin involvement by MRI at diagnosis is a strong predictor of nonclinical complete response. However, patients who achieve a clinical complete response after short-course radiation therapy and consolidation chemotherapy with nonoperative intent have excellent clinical outcomes regardless of the initial circumferential resection margin status. See Video Abstract at http://links.lww.com/DCR/C190 .

EL MARGEN DE RESECCIN CIRCUNFERENCIAL COMO PREDICTOR NO CLNICO DE RESPUESTA COMPLETA EN EL MANEJO CONSERVADOR DEL CNCER DE RECTO

ANTECEDENTES:La radioterapia de corta duración y la quimioterapia de consolidación en el manejo conservador, han surgido como un nuevo paradigma de tratamiento, para los pacientes con cáncer de recto, lastimosamente no hay datos definitivos sobre los predictores de una respuesta clínica completa.OBJETIVO:Evaluar los predictores de respuesta clínica completa y de la sobrevida.DISEÑO:Estudio retrospectivo de cohortes.AJUSTES:Centro oncológico designado por el NCI.PACIENTES:Adenocarcinomas de recto estadio I-III tratados entre 01/2018 y 05/2019 (n = 86).INTERVENCIONES:Radioterapia de corta duración seguida de quimioterapia de consolidación.PRINCIPALES MEDIDAS DE RESULTADO:Se realizó una regresión logística para evaluar los predictores de respuesta clínica completa. Los criterios de valoración incluyeron la sobrevida libre de recidiva local, el control regional, la sobrevida libre de metástasis a distancia y la sobrevida general.RESULTADOS:Un margen de resección circunferencial positivo (+) evaluado por imagenes de resonancia magnética nuclear en el momento del diagnóstico fue un predictor no clínico muy significativo de respuesta completa (razón de probabilidades/ OR: 4,1, p = 0,009) al ajustar el nivel de antígeno carcinoembrionario y el tamaño del tumor primario. Comparando con los pacientes que presetaban un margen de resección circunferencial patológico negativo (-), los pacientes con un margen de resección circunferencial patológico positivo (+) tuvieron una sobrevida libre de recidiva local (29% frente a 87%, p < 0,001), un control regional (57% frente a 94%, p < 0,001), una sobrevida libre de metástasis a distancia (43% frente a 95%, p < 0,001) y una sobrevida global (86% frente a 95%, p < 0,001) inferior en 2 años de seguimiento. Sin embargo, los subgrupos de margen de resección circunferencial (+) y (-) evaluados por imágenes de resonancia magnética nuclear en pacientes que tuvieron una respuesta clínica completa tuvieron un control regional similar, una sobrevida libre de metástasis a distancia y una sobrevida general >90% en 2 años de seguimiento.LIMITACIONES:Diseño retrospectivo, tamaño modesto de la muestra, seguimiento corto y heterogeneidad de tratamientos.CONCLUSIONES:La afectación del margen de resección circunferencial evaluado por resonancia magnética nuclear al momento del diagnóstico es un fuerte factor predictivo no clínico de respuesta completa. Sin embargo, los pacientes que logran una respuesta clínica completa después de un curso corto de radioterapia y quimioterapia de consolidación como manejo conservador tienen excelentes resultados clínicos independientemente del estado del margen de resección circunferencial inicial. Consulte Video Resumen en http://links.lww.com/DCR/C190 . (Traducción-Dr. Xavier Delgadillo ).

Clinical significance of adjuvant chemotherapy for pathological complete response rectal cancer patients with acellular mucin pools after neoadjuvant chemoradiotherapy

Background

Approximately 15-30% of locally advanced rectal cancer (LARC) patients achieved pathological complete response (pCR) after neoadjuvant chemoradiotherapy (CRT) and total mesorectal excision, but the clinical significance of adjuvant chemotherapy (ACT) for pCR patients remains unclear.

Objectives

To determine whether LARC pCR patients can benefit from the administration of ACT.

Design

Single center retrospective study.

Methods

This study retrospectively included 280 LARC patients who achieved pCR after CRT and surgery from 2011 to 2019. The information of patients was recorded. Main outcome measures included 5-year disease-free survival (DFS) and 5-year overall survival. Subgroup analysis was conducted on whether pCR patients with acellular mucin pools received ACT or not.

Results

A total of 74/280 (26.4%) patients were identified with acellular mucin pools. Disease recurrence occurred in 38/280 (13.6%) patients, and in the subgroup of patients with acellular mucin pools, 15/74 (20.3%) patients developed distant metastases. The existence of acellular mucin pools was associated with worse DFS (79.7% versus 88.8%, P = 0.037). Among pCR patients with acellular mucin pools, 9/25 (36.0%) of non-ACT patients occurred recurrence, and ACT was beneficial for improving DFS (hazard ratio: 0.245; 95% confidence interval: 0.084-0.719; P = 0.010).

Conclusions

The existence of acellular mucin pools may represent a sign of invasive tumor biology, which indicated a negative prognosis. ACT can improve the prognosis of patient with acellular mucin pools, so ACT should be considered for them.

The preoperative geriatric nutritional risk index predicts long-term prognosis in elderly locally advanced rectal cancer patients: a two-center retrospective cohort study

BACKGROUND

The objective is to explore the value of preoperative geriatric nutritional risk index (GNRI) in evaluating long-term prognosis in elderly locally advanced rectal cancer (LARC) patients who accepted neoadjuvant chemoradiotherapy (NCRT) and to compare GNRI with established nutritional markers, including prognostic nutritional index (PNI) and controlling nutritional status (CONUT) score.

METHODS

Preoperative GNRI was retrospectively assessed in 172 LARC patients aged ≥ 60 years who underwent radical resection after NCRT at two centers. Optimal cutoff value of GNRI was determined by X-tile program. The association of GNRI with clinicopathological parameters and nutritional markers was analyzed. The survival ability of markers was evaluated using time-dependent receiver-operating characteristic (ROC) curve analysis. Finally, survival analysis was performed using Kaplan-Meier and Cox regression analysis.

RESULTS

GNRI was highly correlated with nutritional markers. An optimal cutoff value for the GNRI was 96. In the time-dependent ROC curve, GNRI demonstrated a stable predictive ability for both disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that GNRI was the only nutritional marker that independently predicted DFS (HR 2.457, 95% CI 1.066-5.665, P = 0.035) and OS (HR 9.002, 95% CI 3.100-26.146, P < 0.001). As an additional benefit, GNRI was able to stratify survival in subgroups of ypTNM and tumor response.

CONCLUSION

Preoperative GNRI is a promising predictor of long-term survival for elderly LARC patients undergoing NCRT, superior to the established nutritional markers.

Clinical feasibility of the therapeutic strategies total neoadjuvant therapy and "watch and wait" in the treatment of rectal cancer patients with recurrence after clinical complete response

Purpose

In recent years, total neoadjuvant therapy (TNT) has emerged as a new therapeutic strategy against advanced rectal cancer (RC). After administration of TNT, some patients show complete clinical response (cCR) to treatment however, disputes about the effects of TNT and the alternative treatment plans in case of recurrence after cCR still exist.

Methods

A total of 100 patients were included in this paper. CR and non-CR was observed when these patients were administered with TNT at the First Affiliated Hospital of Dalian Medical University, China from May 2015 to June 2021. These patients received different chemotherapeutic regimens, with close monitoring and watch and wait (W&W) strategy being applied by a multidisciplinary team (MDT). According to treatment results, patients were divided into a cCR group and a non-cCR group; according to the recurrence during W&W, they were divided into a recurrence group and a no-local-recurrence group. This study analyzed the factors that may affect the prognosis, and summarized the surgery and treatment after recurrence.

Results

The TNT strategy was effective, and 85% of patients achieved local remission. However, W&W did not affect the survival time of CR patients, nor did it cause new distant metastasis due to local recurrence during the observation period (P > 0.05). However, for patients with positive CRM, we do not recommend W&W as the first choice of treatment (P < 0.05).

Conclusion

(1) Whole-course neoadjuvant therapy was an effective treatment scheme for advanced mid-term rectal cancer. The total local reduction rate of this group of cases was 85.00%, meaning that 25 patients achieved CR. (2) W&W was safe and reliable, and CR patients could receive it as the preferred treatment. (3) CRM was an independent risk factor for local recurrence in CR patients. We do not recommend W&W as the preferred treatment for CR patients with positive CRM.

Cytokeratin 7 Expression and Mismatch Repair Status for Survival Prediction in Patients With Low Rectal Cancer After Neoadjuvant Therapy

BACKGROUND

More than half of the patients with locally advanced low rectal cancer exhibit no or minor response to nCRT. It is important to investigate the predictive and prognostic values of potential biomarkers in patients with locally advanced low rectal cancer receiving nCRT.

MATERIALS AND METHODS

This retrospective study included 162 patients with locally advanced low rectal cancer who underwent nCRT, followed by total mesorectal excision (TME) between 2016 and 2019. Cytokeratin 7 (CK7) expression and mismatch repair (MMR) status were determined by immunohistochemistry (IHC). Categorical variables were compared using the chi-square test. Overall survival (OS) and disease-free survival (DFS) curves were estimated using the Kaplan-Meier and Cox methods.

RESULTS

There were predominance significant differences in distance from anus margin (P < .0001) and circumferential extent of the tumor (P < .0001).CK7 positive expression was detected in 21 of the 162 patients (13%). The univariate and multivariate analysis revealed that patients whose tumors had CK7 positive expression had significantly shorter OS (HR = 3.878, P = .038; HR = 1.677, P = .035) and DFS (HR = 3.055, P = .027;HR = 3.569, P = .038) than those with CK7 negative expression. While patients with CK7 positive expression had a higher proportion of worse TRG compared with CK7 negative patients (P = .001). Patients with deficient mismatch repair (dMMR) just occupied a small proportion (8.6%), but there was still a close connection between the MMR status and recurrence after TME (P = .045). MMR status was an independent risk factor affecting the OS (HR = .307, P < .0001; HR = .123, P < .0001) and DFS (HR = .288, P < .0001; HR = .286, P < .0001) by univariate and multivariate analysis. But no significant difference in the proportion of TRG was observed between patients with dMMR and pMMR (P = .920).

CONCLUSIONS

The result confirms negative prognostic role of CK7-positive and dMMR statuses, which have potential predictive value for neoadjuvant chemoradiotherapy response. This provides opportunity to modify individualized treatment strategies for patients with different CK7 expression levels and dMMR statuses.

Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

Background

For rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Methods

The study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan-Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).

Results

Of 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.

Conclusion

Adjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Prognostic value of final pathological stage in colon adenocarcinoma after neoadjuvant chemotherapy: A propensity score-matched study

Background

Neoadjuvant chemotherapy (NAC) could improve local tumor control of locally advanced colon cancer (LACC), but the prognostic value of yp stage in colon cancer remains unknown. Here, we aimed to ascertain yp stage as an indicator for LACC prognosis after NAC.

Methods

The data of patients diagnosed with colon adenocarcinoma between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results database. After 1:2 propensity score matching, cancer-specific survival (CSS) and overall survival (OS) were compared between the NAC and Non-NAC groups of different stage classifications. The correlation between clinical and pathological factors and CSS was identified.

Results

A total of 49, 149, and 81 matched pairs of stage 0-I, II, and III patients, respectively, were generated for analysis. For stage 0-I (p = 0.011) and III (p = 0.015), only CSS in the NAC groups were inferior. Receiving NAC was an independent prognostic risk factor for patients with stage 0-I (hazard ratio, 7.70; 95% confidence interval, 1.820-32.5; p = 0.006) and stage III (hazard ratio, 1.73; 95% confidence interval, 1.11-2.68; p = 0.015).

Conclusions

The CSS was poorer among LACC patients who underwent NAC than among those who did not. The yp stage of colon cancer after NAC has distinctive significance, which may contribute to predicting the prognosis and guiding the treatment of LACC patients after NAC.

Predictive value of a serum tumor biomarkers scoring system for clinical stage II/III rectal cancer with neoadjuvant chemoradiotherapy

BACKGROUND

Multiple classes of molecular biomarkers have been studied as potential predictors for rectal cancer (RC) response. Carcinoembryonic antigen (CEA) is the most widely used blood-based marker of RC and has proven to be an effective predictive marker. Cancer antigen 19-9 (CA19-9) is another tumor biomarker used for RC diagnosis and postoperative monitoring, as well as monitoring of the therapeutic effect. Using a panel of tumor markers for RC outcome prediction is a practical approach.

AIM

To assess the predictive effect of pre-neoadjuvant chemoradiotherapy (NCRT) CEA and CA19-9 levels on the prognosis of stage II/III RC patients.

METHODS

CEA and CA19-9 levels were evaluated 1 wk before NCRT. According to the receiver operating characteristic curve analysis, the optimal cut-off point of CEA and CA19-9 levels for the prognosis were 3.55 and 19.01, respectively. The novel serum tumor biomarker (NSTB) scores were as follows: score 0: Pre-NCRT CEA < 3.55 and CA19-9 < 19.01; score 2: Pre-NCRT CEA > 3.55 and CA19-9 > 19.01; score 1: Other situations. Pathological information was recorded according to histopathological reports after the operation.

RESULTS

In the univariate analysis, pre-NCRT CEA < 3.55 [P = 0.025 for overall survival (OS), P = 0.019 for disease-free survival (DFS)], pre-NCRT CA19-9 < 19.01 (P = 0.014 for OS, P = 0.009 for DFS), a lower NSTB score (0-1 vs 2, P = 0.009 for OS, P = 0.005 for DFS) could predict a better prognosis. However, in the multivariate analysis, only a lower NSTB score (0-1 vs 2; for OS, HR = 0.485, 95%CI: 0.251-0.940, P = 0.032; for DFS, HR = 0.453, 95%CI: 0.234-0.877, P = 0.019) and higher pathological grade, node and metastasis stage (0-I vs II-III; for OS, HR = 0.363, 95%CI: 0.158-0.837, P = 0.017; for DFS, HR = 0.342, 95%CI: 0.149-0.786, P = 0.012) were independent predictive factors.

CONCLUSION

The combination of post-NCRT CEA and CA19-9 was a predictive factor for clinical stage II/III RC patients receiving NCRT, and the combined index had a stronger predictive effect.

Adjuvant chemotherapy after neoadjuvant chemoradiation and proctectomy improves survival irrespective of pathologic response in rectal adenocarcinoma: a population-based cohort study

BACKGROUND

This study sought to determine whether adjuvant chemotherapy (AC) compared to no AC (noAC) after neoadjuvant chemoradiation (CRT) and resection for rectal adenocarcinoma prolongs survival. Current guidelines from expert groups are conflicting, and data to support administering AC to patients who received neoadjuvant CRT are lacking.

METHODS

A total of 19,867 patients met inclusion/exclusion criteria. Mean age was 58.6 ± 12.0 years, and 12,396 (62.4%) were males. Complete response (CR) was documented in 3801 (19.1%) patients and 8167 (41.1%) received AC. The cohort was stratified into pathological complete (pCR, N = 3801) and incomplete (pIR, N = 16,066) subgroups, and pIR further subcategorized into ypN0 (N = 10,191) and ypN + (N = 5875) subgroups. After propensity score matching, AC was associated with improved OS in the pCR subgroups (mean 139.1 ± 1.9 vs. 134.0 ± 2.2 months; p < 0.001), in pIR ypN0 subgroup (141.6 ± 1.5 vs. 129.9 ± 1.2 months, p < 0.001), and in pIR ypN + subgroup (155.9 ± 5.4 vs. 126.5 ± 7.6 months; p < 0.001).

RESULTS

AC was associated with improved OS in patients who received neoadjuvant CRT followed by proctectomy for clinical stages II and III rectal adenocarcinoma. This effect persisted irrespective of pathological response status.

CONCLUSIONS

AC following neoadjuvant CRT and surgery is associated with improved OS in patients with rectal adenocarcinoma. These findings warrant adoption of AC after neoadjuvant CRT and surgery for clinical stage II and III rectal adenocarcinoma.

Poorly differentiated cluster grade-a vital predictor for lymph node metastasis and oncological outcomes in patients with T1 colorectal cancer: a retrospective study

Background

T1 colorectal cancers have a low lymph node metastasis rate and good prognosis. Thus, endoscopic resection is an attractive choice. This study aimed to describe the value of poorly differentiated cluster grade in identifying endoscopically curable T1 colorectal cancers.

Methods

We included 183 T1 colorectal cancer patients who underwent curative resection. Univariate and multivariate logistic regressions were used to identify lymph node metastasis predictors. The Akaike information criterion was used to determine whether poorly differentiated cluster grade was the best predictor. Backward regression was used to screen the variables. Survival analyses were conducted to determine the prognostic predictive power of poorly differentiated cluster grade. Correlations among predictors and concordance between our pathologists were also investigated.

Results

Poorly differentiated cluster grade was an independent predictor for lymph node metastasis (adjusted odds ratio [OR]_{G 3} = 0.001; 95% confidence interval [95% CI]_{G 3} =  < 0.001, 0.139) in T1 colorectal cancer patients; moreover, it had the best predictive value (AIC = 61.626) among all indicators. It was also screened for inclusion in the predictive model. Accordingly, a high poorly differentiated cluster grade independently indicated shorter overall survival (hazard ratio [HR]_{G 2} = 4.315; 95% CI_{G 2} = 1.506, 12.568; HR_{G 3} = 5.049; 95% CI_{G 3} = 1.326, 19.222) and disease-free survival (HR_{G 3} = 6.621; 95% CI_{G 3} = 1.472, 29.786).

Conclusions

Poorly differentiated cluster grade is a vital reference to manage T1 colorectal cancer. It could serve as an indicator to screen endoscopically curable T1 colorectal cancers.

ctDNA for Risk of Recurrence Assessment in Patients Treated with Neoadjuvant Treatment: A Systematic Review and Meta-analysis

BACKGROUND

We wanted to investigate the association between circulating tumor DNA (ctDNA) detection at baseline, during and after neoadjuvant treatment, after surgery, and recurrence, in patients with nonmetastatic cancer.

PATIENTS AND METHODS

In this systematic review and meta-analysis, we included studies that investigated patients undergoing neoadjuvant treatment for nonmetastatic cancer and provided recurrence indices stratified for ctDNA status at the following timepoints: baseline, during treatment, posttreatment, and postsurgery. Study quality was reported with the Newcastle-Ottawa scale, REMARK checklist, and GRADE approach. PubMed, Embase, Cochrane Library, and Web of Science were our data sources (inception to 3 June 2021). The main outcome was risk of recurrence.

RESULTS

We identified ten studies including 727 patients with rectal, breast, gastric, and bladder cancer. All studies reported posttreatment ctDNA analysis, while seven, four, and six reported baseline, during treatment, and postsurgery ctDNA analysis, respectively. ctDNA detection was associated to recurrence across all timepoints [baseline: risk ratio (RR) 2.86, 95% confidence interval (CI) 1.33-6.14, during treatment: RR 3.81, 95% CI 2.09-6.92, posttreatment: RR 4.29, 95% CI 2.79-6.60, postsurgery: RR 8.03, 95% CI 3.16-20.43]. Heterogeneity was low to moderate.

CONCLUSIONS

This meta-analysis of observational studies found that ctDNA detection in patients undergoing neoadjuvant treatment for nonmetastatic cancer was associated with recurrence. A stronger association was evident in posttreatment and postsurgery timepoints. However, some studies reported low negative predictive value (NPV) of pathological complete response, showing that ctDNA-detection-guided escalation and de-escalation studies following neoadjuvant treatment regimens are needed before its role as a treatment guidance can be affirmed.

Oncologic benefit of adjuvant chemotherapy for locally advanced rectal cancer after neoadjuvant chemoradiotherapy and curative surgery with selective lateral pelvic lymph node dissection: An international retrospective cohort study

INTRODUCTION

Intensive local treatment comprising total mesorectal excision (TME) with selective lateral pelvic lymph node dissection (LPND) after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) has received attention among clinicians treating rectal cancer. It remains unclear whether adjuvant chemotherapy (ACT) after intensive local treatment is beneficial for these patients. We evaluated the oncologic benefit of ACT for patients with LARC who received intensive local treatment.

MATERIALS AND METHODS

This international multicentre retrospective cohort study included 737 patients treated in Japan and Korea between 2010 and 2017. The effectiveness of ACT on recurrence-free survival (RFS) was evaluated using univariable and multivariable Cox proportional hazards models, with subgroup analyses to identify subpopulations potentially benefiting from ACT.

RESULTS

The median follow-up was 49 months; the 5-year RFS and local recurrence rates for the entire cohort were 72.1% and 4.9%, respectively; 514 patients (69.7%) received adjuvant chemotherapy, without an oncologic benefit (hazard ratio, 1.14; 95% confidence interval [CI]: 0.79-1.68) demonstrated in the multivariable Cox regression analysis. In subgroup analyses, the distributions of the 95% CI in patients aged ≥70 years and those with ypStage 0 tended to place a disproportionate emphasis that favoured the non-ACT treatment strategy.

CONCLUSION

Despite achieving good local control with intensive local treatment strategy, the effectiveness of ACT for the LARC patients with CRT followed by TME with selective LPND was not proved. Elderly patients and those with ypStage0 may not receive benefit from ACT after CRT and TME ± LPND.

Comprehensive Analysis of miRNA-Mediated Regulatory Network and Identification of Prognosis Biomarkers in Rectal Cancer

Rectal cancer is a malignant tumor with poor prognosis. Identification of prognostic biomarkers is needed to improve overall survival of rectal cancer patients. Here, we firstly identified miR-20a-5p significantly classifying high-risk group and low-risk group of rectal cancer patients. We also found that several known miRNAs miR-142-5p, miR-486-5p, miR-490-3p and miR-133a-3p played important roles in rectal cancer. Secondly, we constructed and analyzed a rectal cancer-related miRNA-mRNA network. A rectal cancer-related functional module was identified from the miRNA-mRNA network. Survival analysis demonstrated great prognosis capacity of the module to distinguish rectal cancer patients. Thirdly, a rectal cancer-related miRNA-lncRNA network was constructed, which followed power law distribution. Hub miRNAs and lncRNAs of the network were suggested to show significant prognosis ability and be enriched in cancer-related pathways. Fourthly, we constructed a rectal cancer-related ceRNA network and detected several typical lncRNA-miRNA-mRNA crosstalk, such as HAND2-AS1, HAND2 and miR-20a-5p crosstalk and MBNL1-AS1, miR-429 and LONRF2 crosstalk, which were validated to function in improving overall survival of rectal cancer patients. Finally, we identified the regulatory feedback that was constituted by transcriptional factors and lncRNAs, including MEIS1, MEIS2 and multiple lncRNAs. We also demonstrated that these lncRNAs were high related to immune cell infiltration. All these results can help us to uncover the molecular mechanism and provide new light on miRNA-mediated gene crosstalks in rectal cancer.

Does a long interval between neoadjuvant chemoradiotherapy and surgery benefit the clinical outcomes of locally advanced rectal cancer? A systematic review and meta analyses

PURPOSE

The study aims to systematically evaluate the clinical efficacy after 8 weeks (long interval, LI) between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer.

METHODS

The PubMed database, EMBASE database, and the Cochrane Library (deadline: September 25, 2021) were searched to select clinical studies that compared two intervals between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer: after 8 weeks (long interval, LI) and within 8 weeks (short interval, SI). The included studies were screened and evaluated according to the inclusion and exclusion criteria, and meta-analysis was performed by RevMan 5.3 software.

RESULTS

Eighteen studies were included, with 9070 cases in the LI group and 14,207 cases in the SI group. The analysis results showed that the pathologic complete response (PCR) rate in the LI group was higher than that in the SI group (P < 0.00001). There was no significant difference in the R0 resection rate (P = 0.85), anal preservation rate (P = 0.89), morbidity rate (P = 0.60), anastomotic leakage rate (P = 0.06), operation time (P = 0.58), local recurrence rate (P = 0.56), distant metastasis rate (P = 0.32), or overall survival (OS) rate (P = 0.17) between the two groups.

CONCLUSION

A longer interval between neoadjuvant chemoradiotherapy and surgery can improve the PCR rate; however, it has no significant impact on the clinical efficacy or long-term prognosis. Due to some limitations in the number and quality of the studies, these findings still need to be further verified by multicenter, large-sample high-quality RCTs in the future.

Evaluation of the learning curve for conformal sphincter preservation operation in the treatment of ultralow rectal cancer

Background

To investigate the learning curve of conformal sphincter preservation operation (CSPO) in the treatment of ultralow rectal cancer and to further explore the influencing factors of operation time.

Methods

From August 2011 to April 2020, 108 consecutive patients with ultralow rectal cancer underwent CSPO by the same surgeon in the Department of Colorectal Surgery of Changhai Hospital. The moving average and cumulative sum control chart (CUSUM) curve were used to analyze the learning curve. The preoperative clinical baseline data, postoperative pathological data, postoperative complications, and survival data were compared before and after the completion of learning curve. The influencing factors of CSPO operation time were analyzed by univariate and multivariate analysis.

Results

According to the results of moving average and CUSUM method, CSPO learning curve was divided into learning period (1–45 cases) and learning completion period (46–108 cases). There was no significant difference in preoperative clinical baseline data, postoperative pathological data, postoperative complications, and survival data between the two stages. Compared with the learning period, the operation time (P < 0.05), blood loss (P < 0.05), postoperative flatus and defecation time (P < 0.05), liquid diet time (P < 0.05), and postoperative hospital stay (P < 0.05) in the learning completion period were significantly reduced, and the difference was statistically significant. Univariate and multivariate analysis showed that distance of tumor from anal verge (≥ 4cm vs. < 4cm, P = 0.039) and T stage (T3 vs. T1-2, P = 0.022) was independent risk factors for prolonging the operation time of CSPO.

Conclusions

For surgeons with laparoscopic surgery experience, about 45 cases of CSPO are needed to cross the learning curve. At the initial stage of CSPO, beginners are recommended to select patients with ultralow rectal cancer whose distance of tumor from anal verge is less than 4 cm and tumor stage is less than T3 for practice, which can enable beginners to reduce the operation time, accumulate experience, build self-confidence, and shorten the learning curve on the premise of safety.

The Utility of ADC First-Order Histogram Features for the Prediction of Metachronous Metastases in Rectal Cancer: A Preliminary Study

Simple Summary

Metachronous metastases are the main factors affecting survival in rectal cancer, and 15–25% of patients will develop them at a 5-year follow-up. Early identification of patients with higher risk of developing distant metachronous metastases would help to improve therapeutic protocols and could allow for a more accurate, personalized management. Apparent diffusion coefficient (ADC) represents an MRI quantitative biomarker, which can assess the diffusion characteristics of tissues, depending on the microscopic mobility of water, showing information related to tissue cellularity. First-order histogram-based features statistics describe the frequency distribution of intensity values within a region of interest, revealing microstructural alterations. In our study, we demonstrated that whole-tumor ADC first-order features may provide useful information for the assessment of rectal cancer prognosis, regarding the occurrence of metachronous metastases.

Abstract

This study aims the ability of first-order histogram-based features, derived from ADC maps, to predict the occurrence of metachronous metastases (MM) in rectal cancer. A total of 52 patients with pathologically confirmed rectal adenocarcinoma were retrospectively enrolled and divided into two groups: patients who developed metachronous metastases (n = 15) and patients without metachronous metastases (n = 37). We extracted 17 first-order (FO) histogram-based features from the pretreatment ADC maps. Student’s t-test and Mann–Whitney U test were used for the association between each FO feature and presence of MM. Statistically significant features were combined into a model, using the binary regression logistic method. The receiver operating curve analysis was used to determine the diagnostic performance of the individual parameters and combined model. There were significant differences in ADC 90th percentile, interquartile range, entropy, uniformity, variance, mean absolute deviation, and robust mean absolute deviation in patients with MM, as compared to those without MM (p values between 0.002–0.01). The best diagnostic was achieved by the 90th percentile and uniformity, yielding an AUC of 0.74 [95% CI: 0.60–0.8]). The combined model reached an AUC of 0.8 [95% CI: 0.66–0.90]. Our observations point out that ADC first-order features may be useful for predicting metachronous metastases in rectal cancer.

Impact of pathological response after neoadjuvant chemotherapy on adjuvant therapy decisions and patient outcomes in gastrointestinal cancers

BACKGROUND

Neoadjuvant chemotherapy (NAC) is frequently used in gastrointestinal cancers (GIC), and pathological, radiological, and tumor marker responses are assessed during and after NAC.

AIM

To evaluate the relationship between pathologic, radiologic, tumor marker responses and recurrence-free survival (RFS), overall survival (OS), adjuvant chemotherapy (AC) decisions, and the impact of changing to a different AC regimen after poor response to NAC.

METHODS AND RESULTS

Medical records of GIC patients treated with NAC at Mount Sinai between 1/2012 and 12/2018 were reviewed. One hundred fifty-six patients (58.3% male, mean age 63 years) were identified. Primary tumor sites were: 43 (27.7%) pancreas, 62 (39.7%) gastroesophageal, and 51 (32.7%) colorectal. After NAC, 31 (19.9%) patients had favorable pathologic response (FPR; defined as College of American Pathologists [CAP] score 0-1). Of 107 patients with radiological data, 59 (55.1%) had an objective response, and of 113 patients with tumor marker data, 61 (54.0%) had a ≥50% reduction post NAC. FPR, but not radiographic or serological responses, was associated with improved RFS (HR 0.28; 95% CI 0.11-0.72) and OS (HR 0.13; 95% CI 0.2-0.94). Changing to a different AC regimen from initial NAC, among all patients and specifically among those with unfavorable pathological response (UPR; defined as CAP score 2-3) after NAC, was not associated with improved RFS or OS.

CONCLUSIONS

GIC patients with FPR after NAC experienced significant improvements in RFS and OS. Patients with UPR did not benefit from changing AC. Prospective studies to better understand the role of pathological response in AC decisions and outcomes in GIC patients are needed.

Biomarkers in Locally Advanced Rectal Cancer: A Review

Locally advanced rectal cancers (LARC) are the subject of a rapidly evolving treatment paradigm. The critical timepoints where management decisions are required during the care of the LARC patient are: prior to the institution of any treatment, post neoadjuvant therapy and post-surgery. This article reviews the clinical, imaging, blood-based, tissue-based, and molecular biomarkers that can assist clinicians at these timepoints in the patient's management, in prognosticating for their LARC patients or in predicting responses to therapy in the multi-modality neoadjuvant treatment era.

A meta-analysis of the watch-and-wait strategy versus total mesorectal excision for rectal cancer exhibiting complete clinical response after neoadjuvant chemoradiotherapy

Background

Some clinical researchers have reported that patients with cCR (clinical complete response) status after neoadjuvant chemoradiotherapy (nCRT) could adopt the watch-and-wait (W&W) strategy. Compared with total mesorectal excision (TME) surgery, the W&W strategy could achieve a similar overall survival. Could the W&W strategy replace TME surgery as the main treatment option for the cCR patients? By using the meta-analysis method, we evaluated the safety and efficacy of the W&W strategy and TME surgery for rectal cancer exhibiting cCR after nCRT.

Methods

We evaluated two treatment strategies for rectal cancer with cCR after nCRT up to July 2021 by searching the Cochrane Library, PubMed, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Clinical data for primary outcomes (local recurrence, cancer-related death and distant metastasis), and secondary outcomes (disease-free survival (DFS) and overall survival (OS)) were collected to evaluate the efficacy and safety in the two groups.

Results

We included nine studies with 818 patients in the meta-analysis, and there were five moderate-quality studies and four high-quality studies. A total of 339 patients were in the W&W group and 479 patients were in the TME group. The local recurrence rate in the W&W group was greater than that in the TME group in the fixed-effects model (OR 8.54, 95% CI 3.52 to 20.71, P < 0.001). The results of other outcomes were similar in the two groups.

Conclusion

The local recurrence rate of the W&W group was greater than that in the TME group, but other results were similar in the two groups. With the help of physical examination and salvage therapy, the W&W strategy could achieve similar treatment effects with the TME approach.

Trial registration

Protocol registration number: CRD42021244032.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02415-y.

Comparison of guidelines on rectal cancer: exception proves the rule?

The standard of care for early or locally advanced rectal cancer is promoted by multiple clinical practice guidelines globally, but the considerable differences between the guidelines may cause confusion. We compared the latest updated clinical practice guidelines from five professional societies/authorities: National Comprehensive Cancer Network, American Society of Colorectal Surgeons, European Society of Medical Oncology, Chinese National Health Commission, and Chinese Society of Clinical Oncology. Key evidence is discussed for a better understanding of some seemingly contradictory recommendations.

Evaluating the benefit of adjuvant chemotherapy in patients with ypT0–1 rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND

Adjuvant chemotherapy (ACTx) is recommended in rectal cancer patients after preoperative chemoradiotherapy (PCRT), but its efficacy in patients in the early post-surgical stage who have a favorable prognosis is controversial.

AIM

To evaluate the long-term survival benefit of ACTx in patients with ypT0–1 rectal cancer after PCRT and surgical resection.

METHODS

We identified rectal cancer patients who underwent PCRT followed by surgical resection at the Asan Medical Center from 2005 to 2014. Patients with ypT0–1 disease and those who received ACTx were included. The 5-year overall survival (OS) and 5-year recurrence-free survival (RFS) were analyzed according to the status of the ACTx.

RESULTS

Of 520 included patients, 413 received ACTx (ACTx group) and 107 did not (no ACTx group). No significant difference was observed in 5-year RFS (ACTx group, 87.9% vs no ACTx group, 91.4%, P = 0.457) and 5-year OS (ACTx group, 90.5% vs no ACTx group, 86.2%, P = 0.304) between the groups. cT stage was associated with RFS and OS in multivariate analysis [hazard ratio (HR): 2.57, 95% confidence interval (CI): 1.07–6.16, P = 0.04 and HR: 2.27, 95%CI: 1.09–4.74, P = 0.03, respectively]. Furthermore, ypN stage was associated with RFS and OS (HR: 4.74, 95%CI: 2.39–9.42, P < 0.00 and HR: 4.33, 95%CI: 2.20–8.53, P < 0.00, respectively), but only in the radical resection group.

CONCLUSION

Oncological outcomes of patients with ypT0–1 rectal cancer who received ACTx after PCRT showed no improvement, regardless of the radicality of resection. Further trials are needed to evaluate the efficacy of ACTx in these group of patients.

Pretreatment Neutrophil-to-Lymphocyte Ratio Associated with Tumor Recurrence and Survival in Patients Achieving a Pathological Complete Response Following Neoadjuvant Chemoradiotherapy for Rectal Cancer

Simple Summary

Patients with locally advanced rectal cancer who achieve a pathological complete response to neoadjuvant chemoradiotherapy have been associated with excellent long-term prognosis. However, approximately 9% to 12% of patients with a pathological complete response have been reported to experience tumor recurrence and thereby experience poor outcomes. Identifying predictors of recurrence in patients with a pathological complete response is crucial for precise medicine. The neutrophil-to-lymphocyte ratio is a widely available biomarker of systemic inflammation and affects colorectal prognosis. The study aimed to assess the association between neutrophil-to-lymphocyte ratio and oncological outcomes in rectal cancer patients exhibiting a pCR. We found that a pretreatment high neutrophil-to-lymphocyte ratio (≥3.2) was an independent predictor of reduced overall survival and disease-free survival in patients with locally advanced rectal cancer who achieved a pathological complete response to neoadjuvant chemoradiotherapy. Our findings demonstrate that the neutrophil-to-lymphocyte ratio helps identify patients with a pathological complete response who are at high risk of tumor relapse and might facilitate patient selection for precise medicine.

Abstract

The clinical influence of the neutrophil-to-lymphocyte ratio (NLR) in predicting outcomes in patients with locally advanced rectal cancer (LARC) who achieve a pathological complete response (pCR) to neoadjuvant chemoradiotherapy (NACRT) has seldom been investigated. We retrospectively recruited 102 patients with LARC who achieved a pCR to NACRT and the association of NLR status with survival and tumor recurrence in the patients was analyzed. Thirteen patients (12.7%) developed tumor recurrence. A high NLR (≥3.2) was significantly associated with tumor recurrence (p = 0.039). The 5-year OS rates in patients with a low NLR and patients with a high NLR were 95.1% and 77.7%, respectively (p = 0.014); the 5-year DFS rates in patients with low NLR and patients with a high NLR were 90.6% and 71.3%, respectively (p = 0.031). The Cox proportional hazards model indicated that an NLR of ≥3.2 was an independent poor prognostic factor for DFS (hazard ratio [HR] = 3.12, 95% confidence interval [CI] = 1.06–9.46, p = 0.048) and OS (HR = 6.96, 95% CI = 1.53–35.51, p = 0.013). A pretreatment high NLR (≥3.2) was a promising predictor of reduced OS and DFS in patients with LARC who achieved a pCR to NACRT.

Can Elevated Pretreatment Serum Carcinoembryonic Antigen Levels Serve as a Potential Biomarker Guiding Adjuvant Chemotherapy in Rectal Cancer Patients With ypTis-3N0 After Neoadjuvant Radiotherapy and Surgery?

Survival benefit of adjuvant chemotherapy (ACT) remained controversial in patients with stage II/III rectal cancer (RC) who received neoadjuvant therapy and surgery. This study aimed to investigate the guiding role of elevated pretreatment serum carcinoembryonic antigen (CEA) levels for receiving ACT in yield pathological Tis-3N0 (ypTis-3N0) RC patients after neoadjuvant radiotherapy and surgery. Between 2004 and 2015, 10,973 RC patients with ypTis-3N0 who received neoadjuvant radiotherapy and radical surgery were retrospectively analyzed using the Surveillance, Epidemiology, and End Results (SEER) database. Compared with CEA-normal group, elevated-CEA patients had worse 5-year CSS rate (90.1 vs 83.5%). The 5-year CSS rates were 86.3 and 87.4% for ypTis-3N0M0 patients with or without ACT, respectively. Patients receiving ACT had a comparable 5-year CSS rate compared to those who did not regardless of CEA levels in ypTis-3N0M0 RC patients (CEA elevation group: 76.4 vs. 83.5%, P = 0.305; CEA normal group: 90.0 vs. 90.1%, P = 0.943). Intriguingly, ypT3N0M0 RC patients with elevated CEA levels may benefit from ACT (5-year CSS: 69.1 vs. 82.9%, P = 0.045), while those with normal CEA levels did not (5-year CSS: 89.3 vs. 89.3%, P = 0.885). Multivariate Cox analysis demonstrated that ACT tended to be a protective factor in elevated-CEA ypT3N0M0 RC patients (HR = 0.633, 95% CI = 0.344–1.164, P = 0.141), while ACT was not associated with improved CSS in normal-CEA ypT3N0M0 RC patients (HR = 1.035, 95% CI = 0.487–2.202, P = 0.928). Elevated pretreatment serum CEA levels may serve as a promising biomarker guiding ACT in rectal cancer patients with ypT3N0M0.

Current evidence regarding the role of adjuvant chemotherapy in rectal cancer patients with pathologic complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

PURPOSE

The aim of this meta-analysis was to investigate the role of adjuvant chemotherapy (AC) in rectal cancer patients with pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) and curative resection.

METHODS

This study was completed in accordance to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The electronic scholar databases (Medline, Web of Science, Scopus) were screened for eligible articles. The level of evidence (LoE) was assessed using the GRADE methodology.

RESULTS

Overall, 23 non-randomized studies and 17,406 patients were included in the present meta-analysis. Pooled comparisons confirmed that AC improved overall survival (HR: 0.68, p=0.0003), but not disease-free (p=0.22) and recurrence-free survival (p=0.39). However, the LoE for all outcomes was characterized as "very low," due to the absence of RCTs.

CONCLUSIONS

Considering the study limitations and the lack of randomized studies, further high-quality RCTs are required to confirm the findings of our study.

Deep learning radiomics-based prediction of distant metastasis in patients with locally advanced rectal cancer after neoadjuvant chemoradiotherapy: A multicentre study

BACKGROUND

Accurate predictions of distant metastasis (DM) in locally advanced rectal cancer (LARC) patients receiving neoadjuvant chemoradiotherapy (nCRT) are helpful in developing appropriate treatment plans. This study aimed to perform DM prediction through deep learning radiomics.

METHODS

We retrospectively sampled 235 patients receiving nCRT with the minimum 36 months' postoperative follow-up from three hospitals. Through transfer learning, a deep learning radiomic signature (DLRS) based on multiparametric magnetic resonance imaging (MRI) was constructed. A nomogram was established integrating deep MRI information and clinicopathologic factors for better prediction. Harrell's concordance index (C-index) and time-dependent receiver operating characteristic (ROC) were used as performance metrics. Furthermore, the risk of DM in patients with different response to nCRT was evaluated with the nomogram.

FINDINGS

DLRS performed well in DM prediction, with a C-index of 0·747 and an area under curve (AUC) at three years of 0·894 in the validation cohort. The performance of nomogram was better, with a C-index of 0·775. In addition, the nomogram could stratify patients with different responses to nCRT into high- and low-risk groups of DM (P < 0·05).

INTERPRETATION

MRI-based deep learning radiomics had potential in predicting the DM of LARC patients receiving nCRT and could help evaluate the risk of DM in patients who have different responses to nCRT.

FUNDING

The funding bodies that contributed to this study are listed in the Acknowledgements section.

Nomogram to Predict Distant Metastasis Probability for Pathological Complete Response Rectal Cancer Patients After Neoadjuvant Chemoradiotherapy

Purpose

This study aimed to predict the risks of distant metastasis (DM) of locally advanced rectal cancer (LARC) patients with pathological complete response (pCR) after neoadjuvant chemoradiotherapy (NACRT) and total mesorectal excision (TME), and to find the association between adjuvant chemotherapy (ACT) and their survival outcomes.

Methods and Materials

A total of 242 patients with LARC achieving pCR after NACRT were enrolled in this retrospective study. We developed a nomogram model using logistic regression analyses for predicting risk of DM. The model performance was evaluated by the concordance index and calibration curve. Survival was determined using Kaplan–Meier survival curve.

Results

Age, pre-operative CEA, pre-treatment CEA and distance of tumor to anal verge were identified as significantly associated variables that could be enrolled in the model to predict the risk of DM for pCR patients. The nomogram we created had a bootstrapped-concordance index of 0.731 (95% CI = 0.627 to 0.834) and was well calibrated. The high risk group was more likely to develop DM than low risk group (total score) (95% CI = 1.439 to 6.493, P = 0.0036). The 1-year, 3-year, and 5-year distant metastasis-free survival (DMFS) for the low and high risk groups (total score ≤ 90 vs > 90) was 97.8%, 94.2%, 94.2% and 91.3%, 83.4%, 81.8%, respectively (P = 0.0036). DM occurred within 1 and 2 years after TME surgery was 33.3% and 55.6% for the low risk group, and 47.3% and 84.2% for the high risk group. The value of ACT was assessed among the whole cohort, patients with cT_3-4, with cN₊ or with either DM risk group, but no significant difference was observed concerning DMFS whether ACT was given or not (all P > 0.05). Active treatment after DM was more beneficial than palliative treatment (P < 0.001).

Conclusion

The nomogram model, including age, pre-operative CEA, pre-treatment CEA and distance to anal verge, predicted the probability of DM among LARC patients achieving pCR after NACRT. The effects of ACT were not seen in different subgroups, while closer clinical follow-up may have greater contribution to pCR patients in the first 2 years, especially for patients with relatively higher risk to develop DM. It is suggested that timely active treatment can bring survival benefit for pCR patients developing DM after NACRT.

Associations between clinical characteristics and tumor response to neoadjuvant chemoradiotherapy in rectal cancer

Following standard neoadjuvant chemoradiotherapy and total mesorectal excision, some patients with locally advanced rectal cancer achieve good response (pathological T0-2N0), while others show nonresponse (pathological T3-4N0 or node-positive). To date, the clinicopathological predictors of good response and the necessity of adjuvant chemotherapy treatment (ACT) in good responders remain unclear. In this retrospective study, clinicopathological characteristics were surveyed to investigate the correlation with good response; furthermore, a propensity score matching (PSM) model was designed to balance the confounding factors between good responders treated with ACT or observation. A total of 2255 patients were enrolled, including 1069 good responders and 1186 nonresponders. The results of the survival analysis showed a good response predicted a better 3-year prognosis (p < 0.001). The logistic regression analysis showed less advanced T and N stages (T3 vs. T4; N0 vs. N1-2), more neoadjuvant chemotherapy (nCT) cycles (≥4 vs. 1-3), and delayed surgery (≥8 weeks vs. <8 weeks) were independent predictors of a good response (p < 0.05). Especially, patients treated with both more nCT cycles and a delay in surgery included the greatest number of good responders (p < 0.001). For good responders, after PSM (1:3), 235 observation cases were matched to 705 ACT cases. As compared with observation, ACT had no greater impact on prognosis analysis (p > 0.05). In conclusion, more cycles of nCT and a delay in surgery predicted a better response, and the delivery of ACT might be omitted in good responders.

Downstaged ypT0-2N0 rectal cancer after neoadjuvant chemoradiation therapy may not need adjuvant chemotherapy: a retrospective cohort study

PURPOSE

Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer.

METHODS

Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes.

RESULTS

One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033).

CONCLUSION

Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.

Clinical efficacy of laparoscopic modified Parks operation on the ultra-low rectal cancer

OBJECTIVES

To investigate the clinical efficacy of laparoscopic modified Parks operation on the patients with ultra-low rectal cancer.

METHODS

According to the preoperative stage and intraoperative anastomotic position, 98 patients with ultra-low rectal cancer above T2 stage underwent laparoscopic Dixon operation, modified Parks operation and Miles operation, respectively. All patients were divided into 3 groups: a Dixon operation group (n=39), a modified Parks operation group (n=43) and a Miles operation group (n=16). The clinical data and postoperative follow-up results were collected, compared, and analyzed to evaluate the clinical efficacy of laparoscopic modified Parks operation.

RESULTS

The patients were more obese, the distance between tumor and anal margin was closer, and the operation time was longer in the modified Parks operation group than those in the Dixon operation group (all P<0.05). However, the results of bleeding volume, the number of lymph nodes and the postoperative complications in the modified park operation group were similar than those in the Dixon operation group (all P>0.05). In addition, the exhaust and defecation time and the hospitalization time were shorter, and the total cost of hospitalization was lower in the modified Parks operation group than those in the Dixon operation group (all P<0.05). Although the anal function in the modified Parks operation group was poor in the early postoperative period, it reached the same level as that in the Dixon operation group from 6 months after the treatments with the regular anal function exercise (P>0.05). There were no significant differences in tumor size, body shape, distance between tumor and anal margin, operation time, bleeding volume, number of lymph nodes detected, postoperative exhaust and defecation time between the Miles operation group and the modified Parks operation group, but the hospitalization time was shorter, the incidence of complications and the total cost of hospitalization were lower in the modified Parks operation group (all P<0.05).

CONCLUSIONS

Laparoscopic modified Parks operation is a safe, economical and effective anus preservation operation, which can not only save the anus for some patients who had to perform Miles operation, but also recover better and faster after operation. Although the early anal function of patients performed with the modified operation is poor, it can gradually recover to the same level as the patients performed with the Dixon operation.

College of American Pathologists Tumor Regression Grading System for Long-Term Outcome in Patients with Locally Advanced Rectal Cancer

BACKGROUND

The National Comprehensive Cancer Network's Rectal Cancer Guideline Panel recommends American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) system to evaluate pathologic response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer (LARC). Yet, the clinical significance of the AJCC/CAP TRG system has not been fully defined.

MATERIALS AND METHODS

This was a multicenter, retrospectively recruited, and prospectively maintained cohort study. Patients with LARC from one institution formed the discovery set, and cases from external independent institutions formed a validation set to verify the findings from discovery set. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were assessed by Kaplan-Meier analysis, log-rank test, and Cox regression model.

RESULTS

The discovery set (940 cases) found, and the validation set (2,156 cases) further confirmed, that inferior AJCC/CAP TRG categories were closely /ccorrelated with unfavorable survival (OS, DFS, LRFS, and DMFS) and higher risk of disease progression (death, accumulative relapse, local recurrence, and distant metastasis) (all p < .05). Significantly, pairwise comparison revealed that any two of four TRG categories had the distinguished survival and risk of disease progression. After propensity score matching, AJCC/CAP TRG0 category (pathological complete response) patients treated with or without adjuvant chemotherapy displayed similar survival of OS, DFS, LRFS, and DMFS (all p > .05). For AJCC/CAP TRG1-3 cases, adjuvant chemotherapy treatment significantly improved 3-year OS (90.2% vs. 84.6%, p < .001). Multivariate analysis demonstrated the AJCC/CAP TRG system was an independent prognostic surrogate.

CONCLUSION

AJCC/CAP TRG system, an accurate prognostic surrogate, appears ideal for further strategizing adjuvant chemotherapy for LARC.

IMPLICATIONS FOR PRACTICE

The National Comprehensive Cancer Network recommends the American Joint Committee of Cancer and College of American Pathologists (AJCC/CAP) tumor regression grading (TRG) four-category system to evaluate the pathologic response to neoadjuvant treatment for patients with locally advanced rectal cancer; however, the clinical significance of the AJCC/CAP TRG system has not yet been clearly addressed. This study found, for the first time, that any two of four AJCC/CAP TRG categories had the distinguished long-term survival outcome. Importantly, adjuvant chemotherapy may improve the 3-year overall survival for AJCC/CAP TRG1-3 category patients but not for AJCC/CAP TRG0 category patients. Thus, AJCC/CAP TRG system, an accurate surrogate of long-term survival outcome, is useful in guiding adjuvant chemotherapy management for rectal cancer.

Survival Advantage With Adjuvant Chemotherapy for Locoregionally Advanced Rectal Cancer: A Veterans Health Administration Analysis

BACKGROUND

Adjuvant chemotherapy (AC) after chemoradiation (CRT) and surgery for locoregionally advanced rectal cancer (LARC) is a standard of care in the United States. This study examined the role, optimal regimen, and duration of AC using data from the largest integrated health system in the United States.

PATIENTS AND METHODS

Using the Veterans Affairs Central Cancer Registry, patients with stage II-III rectal cancer diagnosed in 2001 through 2011 who received neoadjuvant CRT and surgery with or without AC were identified. Kaplan-Meier analysis, log-rank tests, and propensity score (PS) adjustment analysis were used to assess survival.

RESULTS

A total of 866 patients were identified; 417 received AC and 449 did not (observation [OBS] group). Median follow-up was 109 months. Median disease-specific survival (DSS) was not reached. Six-year DSS was 73.7%; 79.5% for the AC group versus 68.0% for the OBS group. PS-matched analysis for DSS favored AC (P=.0002). Median overall survival (OS) was 90.8 months. Six-year OS was 56.7%; 64.3% for AC versus 49.6% for OBS. In PS-matched analysis, median OS was 117.4 months for AC and 74.3 months for OBS (P<.0001). A DSS advantage was seen when comparing ≥4 months with <4 months of AC (P=.023). No difference in DSS or OS was seen with single-agent versus multiagent AC.

CONCLUSIONS

In this population of patients with LARC treated with neoadjuvant CRT and surgery, OS and DSS were improved among those treated with AC versus OBS. DSS benefits were seen with ≥4 months of AC. No additional benefit was observed with multiagent therapy. In the absence of phase III data, these findings support the use of AC for LARC.

Omission of Adjuvant Chemotherapy in Rectal Cancer Patients with Pathologic Complete Response: a National Analysis

BACKGROUND

An increasing number of patients achieve a pathologic complete response (pCR) after neoadjuvant chemoradiation for locally advanced rectal cancer. Consensus guidelines continue to recommend oncologic resection followed by adjuvant chemotherapy in these patients. We hypothesize that there is significant variability in compliance with this recommendation.

METHODS

The National Cancer Database was queried from 2006 to 2015 for patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiation followed by oncologic resection with a pCR (ypT0N0). Hierarchical logistic regression models were used to generate risk and reliability-adjusted rates of adjuvant chemotherapy utilization in patients with pCR at each hospital.

RESULTS

In total, 2421 pCR patients were identified. Five-year overall survival was improved in pCR patients who received adjuvant chemotherapy compared with those who did not (92 vs. 85%, p < 0.01). Multivariate analysis indicated that improvement in overall survival remained associated with adjuvant chemotherapy (HR 0.60, 95% CI 0.44-0.82, p < 0.01). The mean adjuvant chemotherapy utilization rate among hospitals was 32%. There was an upward trend in use over the past decade, but two-thirds still do not receive the recommended therapy. High chemotherapy utilizer hospitals were more likely to be academic centers (54.9 vs. 45.9%, p < 0.01) when compared with low chemotherapy utilizers.

CONCLUSION

Adjuvant chemotherapy is associated with improved survival in rectal cancer patients with pCR following neoadjuvant chemoradiation and oncologic resection. However, utilization among centers in the USA was only 32% with significant variability across centers. National efforts are needed to standardize treatment patterns according to national guidelines.

Overall Survival Benefit in Rectal Cancer After Neoadjuvant Radiotherapy and Adjuvant Chemotherapy: A Propensity-Matched Population-Based Study

Background

It is well known that neoadjuvant radiotherapy could reduce local recurrence followed by surgical resection. However, evidence about oncologic efficacy of radiotherapy and survival benefit of adjuvant chemotherapy after neoadjuvant radiotherapy is still lacking.

Methods

This retrospective propensity score-matched cohort study identified patients with pathologically confirmed rectal cancer and receiving surgery with curative intent from the Surveillance, Epidemiology, and End Results database from 2004 through 2014. Overall survival was compared using the stratified log-rank test. Multivariate Cox regression analysis was used for identifying risk factor and developing prediction nomogram.

Results

A total of 22,008 (11,004 for each group) propensity-matched patients were identified. In the context of receiving adjuvant chemotherapy after surgical resection, there was no significant difference in terms of overall survival between surgery alone group and neoadjuvant radiotherapy and surgery group, whether for stage I (log-rank test p = 0.467), stage II (log-rank test p = 0.310), or stage III (p = 0.994). In case of receiving a prior combination therapy of neoadjuvant radiotherapy and surgery, the following adjuvant chemotherapy could significantly improve overall survival for patients with stage I (log-rank test p <0.001), stage II (log-rank test p = 0.038), and stage III (log-rank test p = 0.014). Nomogram integrating clinicopathologic factors was developed to predict survival benefit associated with neoadjuvant radiotherapy. Calibration and ROC curves validated promising performance for the nomogram.

Conclusion

Patients with rectal cancer underwent neoadjuvant radiotherapy yield acceptable outcomes and are more likely to benefit from adjuvant chemotherapy in terms of overall survival. These data would be evidential for advocating consistency in guideline adherence to the use of adjuvant chemotherapy after neoadjuvant radiotherapy.

Pathologic complete response is associated with decreased morbidity following rectal cancer resection

BACKGROUND

There are conflicting data regarding the relationship between pathologic complete response (pCR) and post-operative complications following rectal cancer resection. The objective of this study was to compare the rates of morbidity among pCR patients and non-pCR patients and to identify factors that predict pCR morbidity in a large national database.

METHODS

This is a retrospective study using American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) targeted proctectomy data (2016-18). Patients with neoadjuvant chemoradiation therapy followed by proctectomy were included, and divided into pCR and non-pCR groups according to final stage. The groups were compared with Student's t-test, Chi-squared or Fisher's exact test. Multivariate logistic regression models were constructed to estimate the association between pCR status and post-operative morbidity while adjusting for key covariates.

RESULTS

244 pCR and 1656 non-pCR patients were included. pCR patients had higher body mass index (28.1 ± 6.2 vs. 29.1 ± 5.9 kg/m²; p = 0.01) and lower pre-operative stage (T stage, p = 0.03; N stage, p < 0.001). The groups were equivalent with respect to surgical approach, type of surgery, and operative time (p > 0.05). Post-operative complications in pCR patients were less frequent than in non-pCR patients (23.0% vs. 29.3%; p = 0.04). This association was robust to adjustment for confounders in logistic regression, as patients with pCR had decreased odds of post-operative morbidity (OR 0.66, CI [0.43, 0.96], p = 0.04).

CONCLUSION

pCR is associated with fewer post-operative complications compared to non-pCR, suggesting that pCR is not a marker of severe pelvic fibrosis. This difference may be due to underlying tumor biology, and associated increased technical challenges resecting larger, non-responsive tumors.