Adjuvant Chemotherapy Improves Survival Following Resection of Locally Advanced Rectal Cancer with Pathologic Complete Response

Significant Pathologic Response Following Neoadjuvant Therapy and Curative Resection in Patients With Rectal Cancer: Surgical and Oncological Outcomes From a Retrospective Cohort Study

AIM

This study evaluated surgical complication rates, recurrence-free survival, overall survival (OS), and stoma status of patients with rectal cancer after significant pathologic response following neoadjuvant treatment and curative resection. Pathologic complete response (pCR) and near-pCR patients constitute patients in our study.

METHODS

Included was a retrospective cohort study of patients with rectal cancer who were diagnosed between July 2011 and September 2022 and who underwent neoadjuvant therapy and surgical resection.

RESULTS

Of 696 patients with rectal cancer, 149 (21.4%) cases achieved significant pathologic response. During the 64 (70.5) months of follow-up, recurrence occurred in 16.1% of patients and distant metastases account for the majority of them. Age (p = 0.014) and receiving adjuvant chemotherapy (p = 0.016) were significantly related to the occurrence of recurrence. The five-year recurrence-free survival (RFS) and OS rates were obtained at 83% and 87%, respectively. Although age and surgical technique were significant factors in univariate Cox regression analysis, none of the candidate variables were significant prognostic factors for RFS in the multiple models. The risk of surgical complications remained in these patients. The most frequent complication attributed to infection (20.8%). Despite the 24.8% presence of permanent stoma at primary surgery, more than 50% of our patients lived without stoma at the last follow-up.

CONCLUSION

Our recurrence rate was about 16%, and it was related to age and adjuvant chemotherapy. These patients achieved over 80% rates of five-year RFS and OS. No significant prognostic factors were found on RFS in the multivariable model. As a matter of course, the risk of surgical complications and permanent stoma has still remained in these patients.

Impact of adjuvant chemotherapy on survival after pathological complete response in rectal cancer: a meta-analysis of 31,558 patients

BACKGROUND

Locally advanced rectal cancer (LARC) typically involves neoadjuvant chemoradiotherapy (nCRT) followed by surgery (total mesorectal excision, TME). While achieving a complete pathological response (pCR) is a strong indicator of a positive prognosis, the specific benefits of adjuvant chemotherapy after pCR remain unclear. To address this knowledge gap, we conducted a systematic review and meta-analysis to assess the potential advantages of adjuvant therapy in patients who achieve pCR.

METHODS

In this study, we searched Medline, Embase, and Web of Science databases for relevant research. We focused on binary outcomes, analyzing them using odds ratios (ORs) with 95% confidence intervals (CIs). To account for potential variability between studies, all endpoints were analyzed with DerSimonian and Laird random-effects models. We assessed heterogeneity using the I2 statistic and employed the R statistical software (version 4.2.3) for all analyses.

RESULTS

Thirty-four studies, comprising 31,558 patients, were included. The outcomes demonstrated a significant difference favoring the AC group in terms of overall survival (OS) (HR 0.75; 95% CI 0.60-0.94; p = 0.015; I2 = 0%), and OS in 5 years (OR 1.65; 95% CI 1.21-2.24; p = 0.001; I2 = 39%). There was no significant difference between the groups for disease-free survival (DFS) (HR 0.94; 95% CI 0.76-1.17; p = 0.61; I2 = 17%), DFS in 5 years (OR 1.19; 95% CI 0.82-1.74; p = 0.36; I2 = 43%), recurrence-free survival (RFS) (HR 1.10; 95% CI 0.87-1.40; p = 0.39; I2 = 0%), and relapse-free survival (OR 1.08; 95% CI 0.78-1.51; p = 0.62; I2 = 0%).

CONCLUSION

This systematic review and meta-analysis found a significant difference in favor of the ACT group in terms of survival after pCR. Therefore, the administration of this treatment as adjuvant therapy should be encouraged in clinical practice.

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.

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 ).

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.

Association of distance traveled on receipt of surgery in patients with locally advanced rectal cancer

PURPOSE

Studies have shown patients residing in rural settings have worse cancer-related outcomes than those in urban settings. Specifically, rural patients with colorectal cancer have lower rates of screening and longer time to treatment. However, physical distance traveled has not been as well studied. This study sought to determine disparities in receipt of surgery in patients by distance traveled for care.

METHODS

A retrospective cohort study of patients with AJCC stage II/III rectal adenocarcinoma was identified within the National Cancer Database (2004-2017). Primary outcome was correlation of distance traveled to receipt of surgery. Multi-variable logistic regression was used to adjust for confounding factors.

RESULTS

65,234 patients were included in the analysis. 94.6% resided in urban-metro areas while 2.2% resided in rural areas. Patients were predominantly non-Hispanic White (NHW) (75.2%) with an overall median age at diagnosis of 61 (IQR 52-71). Overall, 82.6% of patients received surgery. NHW patients were more likely to receive surgery than non-Hispanic Black patients (OR 0.67; 95% CI 0.61-0.73, p < 0.001), as were patients who were privately insured (OR 1.90, 95% CI 1.67-2.15, p < 0.001) or had Medicare (OR 1.68, 95% CI 1.47-1.92, p < 0.001) compared to uninsured patients. Patients traveling distances in the 4th quartile (median 47.9 miles) were more likely to receive surgery than those traveling the shortest distances (1st quartile: median 2.5 miles) (OR 1.37, 95% CI 1.24-1.50, p < 0.001).

CONCLUSION

Patients traveling farther distances were more likely to receive surgery than those traveling shorter distances. Shorter distance traveled does not appear to be associated with higher rates of surgical resection in patients with stage II/III rectal cancer.

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.

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.

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.

The "Immunoscore" in rectal cancer: could we search quality beyond quantity of life?

Because of the function and anatomical environment of the rectum, therapeutic strategies for local advanced rectal cancer (LARC) must deal with two challenging stressors that are a high-risk of local and distal recurrences and a high-risk of poor quality of life (QoL). Over the last three decades, advances in screening tests, therapies, and combined-modality treatment options and strategies have improved the prognosis of patients with LARC. However, owing to the heterogeneous nature of LARC and genetic status, the patient may not respond to a specific therapy and may be at increased risk of side-effects without the life-prolonging benefit. Indeed, each therapy can cause its own side-effects, which may worsen by a combination of treatments resulting in long-term poor QoL. In LARC, QoL has become even more essential with the increasing incidence of rectal cancer in young individuals. Herein, we analyzed the value of the Immunoscore-Biopsy (performed on tumor biopsy at diagnosis) in predicting outcomes, alone or in association with clinical and imaging data, for each therapy used in LARC.

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.

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.

Pretreatment MR-based radiomics nomogram as potential imaging biomarker for individualized assessment of perineural invasion status in rectal cancer

PURPOSE

To investigate whether pretreatment magnetic resonance (MR)-based radiomics nomogram can individualize prediction of perineural invasion (PNI) status in rectal cancer (RC).

MATERIAL AND METHODS

A total of 122 RC patients with pathologically confirmed were classified as training cohort (n = 87) and test cohort (n = 35). 180 radiomics features were extracted from all lesions based on oblique axial T₂WI TSE images. The dimensionality reduction and feature selection in training cohort were realized by the maximum relevance minimum redundancy (mRMR) algorithm and the least absolute shrinkage and selection operator (LASSO) regression model. A predictive model combining radiomics features and clinical risk factors (pathological N stage, pathological LVI status) was established by multivariate logistic regression analysis. The performance of the model was assessed based on its receiver operating characteristic (ROC) curve, nomogram, and calibration.

RESULTS

The developed radiomics nomogram that integrated the radiomics signature and clinical risk factors could provide discrimination in the training and test cohorts. The accuracy and the area under the curve (AUC) for assessing PNI status were 0.82, 0.86, respectively, in the training cohort, while they were 0.71 and 0.85 in the test cohort. The goodness-of-fit of the nomogram was evaluated using the Hosmer-Lemeshow test (p = 0.52 in training cohort and p = 0.24 in test cohort). Decision curve analysis (DCA) showed that the radiomics nomogram was clinically useful.

CONCLUSION

The developed radiomics nomogram might be helpful in the individualized assessment PNI status in patients with RC. This stratification of RC patients according to their PNI status may provide the basis for individualized adjuvant therapy, especially for stage II patients.

Pathological complete response after neoadjuvant therapy for pancreatic ductal adenocarcinoma does not equal cure

BACKGROUND

There is a scarcity of data about patients with pancreatic ductal adenocarcinoma (PDAC) who received neoadjuvant therapy before radical resection and achieved a pathological complete response (pCR). The aim of this study was to describe the recurrence and survival in this subset of patients.

METHODS

The Embase, Web of Science and PubMed databases were systematically searched for eligible studies published between January 2000 and August 2020. Clinicopathological data of individual patients with pCR after neoadjuvant therapy for PDAC were extracted, pooled and analysed.

RESULTS

A total of 87 patients were subject to analysis. The majority of patients were female (61.5%) with a median age of 64 (range 43-75) years. Among reported, 41.9% of patients received gemcitabine-based neoadjuvant chemotherapy, 33.7% received FOLFIRINOX (5-fluorouracil, oxaliplatin, irinotecan and leucovorin)-based regimen and 24.4% received fluoropyrimidine drugs-based regimen. Preoperative radiation was administered to 78.8% of the patients. Twenty-nine (33.3%) patients developed disease recurrence during a median follow-up period of 22.4 (range 2-194) months. The median, 1-, 3- and 5-year overall survival rates were 105 months, 93.6%, 70.3% and 70.3%, respectively.

CONCLUSION

Despite the excellent long-term outcomes, a pCR does not equal cure because this cohort of patients still has a significant risk of recurrence.

Management of the positive pathologic circumferential resection margin in rectal cancer: A national cancer database (NCDB) study

BACKGROUND

The circumferential resection margin (CRM) is a primary predictor of local recurrence and survival in rectal cancer, and an important consideration in guiding treatment. CRM is usually predicted preoperatively, so optimal management of an unexpected pathologic positive CRM involvement is debatable. We aimed to investigate the postoperative management of T3N0 rectal cancers with a positive pathologic CRM, and the impact of each strategy on survival.

METHODS

The NCDB was reviewed for pathological T3N0 rectal cancer cases from 2010 to 2015, that received neoadjuvant chemotherapy, had surgical resection with pathological clear margins, but a positive pathologic CRM(disease≤2 mm from radial margin). The main outcomes were the incidence, treatment modalities used, and impact of each modality on survival. Univariate analysis evaluated the demographic and provider characteristics across treatment groups. Kaplan-Meier and Cox regression analysis assessed survival and factors associated with overall survival (OS).

RESULTS

Of 1607 cases with a positive CRM, 65% (1045) received no adjuvant treatment and 35% (n = 562) received adjuvant chemotherapy (AC). After matching, the 1-, 3-, and 5-year OS rates were 98.5%, 88.6% and 76.6% for AC and 96.9%, 84.6% and 68.4% for with no treatment (p = .027). Factors independently associated with improved OS were treatment at an academic/research facility (p = .009), minimally invasive approach (p = .005), well and moderately differentiated tumor (p < .001), absence of perineural invasion (p = .015) and AC administration (p = .047).

CONCLUSION

In T3N0 rectal cancers resected with local clear margins but a positive pathologic CRM, AC improved OS. However, only a third received this option. Further study is needed to investigate the disparities in AC use in these patients with unexpected pathologic results.

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.

Voltage-gated sodium channel Nav1.5 promotes tumor progression and enhances chemosensitivity to 5-fluorouracil in colorectal cancer

Na_v1.5, encoded by SCN5A, has been associated with metastasis in colorectal cancer (CRC). Here, we investigated the mechanism by which Na_v1.5 regulates tumor progression and whether Na_v1.5 influences chemosensitivity to 5-fluorouracil (5-FU) in CRCs. CRC cases were evaluated for Na_v1.5 expression. Elevated Na_v1.5 expression was associated with poor prognosis in CRCs, whereas stage II/III patients with upregulated SCN5A expression could have better survival after receiving 5-FU-based adjuvant chemotherapy. In CRC cells, SCN5A knockdown reduced the proliferation, migration and invasion. According to RNA sequencing, SCN5A knockdown inhibited both the cell cycle and epithelial-mesenchymal transition. In addition, Na_v1.5 stabilized the KRas-calmodulin complex to modulate Ras signaling, promoting Ca²⁺ influx through the Na⁺-Ca²⁺ exchanger and Ca²⁺ release-activated calcium channel. Meanwhile, SCN5A knockdown increased the 50% inhibitory concentration to 5-FU by upregulating 5-FU-stimulated apoptosis in CRCs. In conclusion, Na_v1.5 could progress to proliferation and metastasis through Ca²⁺/calmodulin-dependent Ras signaling in CRC, and it could also enhance 5-FU-stimulated apoptosis. Clinically, patients with stage II/III CRCs with elevated SCN5A expression demonstrated poor prognosis, yet those patients could benefit more from 5-FU-based chemotherapy than patients with lower SCN5A expression.

Association between adjuvant chemotherapy and survival in patients with rectal cancer and pathological complete response after neoadjuvant chemoradiotherapy and resection

Background

For patients with locally advanced rectal cancer (LARC), it is unclear whether neoadjuvant chemoradiotherapy-induced pathologic complete response (pCR) individuals would further benefit from adjuvant chemotherapy (ACT).

Methods

The pCR individuals who received different ACT cycles were paired by propensity score matching. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were calculated by Kaplan–Meier and log-rank test.

Results

In total, 1041 pCR individuals were identified from 5567 LARC cases. Specifically, 303 pCR cases had no ACT treatment, and 738 pCR patients received fluoropyrimidine-based ACT (median, 4 cycles) treatment. After 1:3 propensity score matching, 297 cases without ACT treatment were matched to 712 cases who received ACT treatment. Kaplan–Meier analysis showed that pCR individuals treated with or without ACT had the similar 3-year outcome (OS, DFS, LRFS and DMFS) (all P > 0.05). Moreover, the pCR patients received different ACT cycle(s) (0 vs. 1–4 cycles, 0 vs. ≥5 cycles) had comparable 3-year OS, DFS, LRFS and DMFS (all P > 0.05). In stratified analysis, ACT treatment did not improve 3-year survival (OS, DFS, LRFS and DMFS) for the baseline high-risk (cT3–4/cN1–2) subgroup patients (all P > 0.05).

Conclusion

ACT, which did not improve survival, is unnecessary to neoadjuvant treatment-induced pCR LARC patients.

Trial registration

2019ZSLYEC-136 (24-6-2019).

Prognostic Significance of Neoadjuvant Rectal Score and Indication for Postoperative Adjuvant Therapy in Rectal Cancer Patients After Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

Neoadjuvant chemoradiotherapy (CRT) is a standard treatment for patients with clinical Stage II/III rectal cancer. However, the benefit of postoperative adjuvant chemotherapy for patients after neoadjuvant CRT is uncertain. Recently, neoadjuvant rectal (NAR) score was suggested as an independent prognostic factor for patients with rectal cancer after neoadjuvant CRT. The aim of this study was to examine the prognostic significance of NAR score in rectal cancer patients who underwent neoadjuvant CRT followed by surgery, and to investigate which patients may benefit from postoperative adjuvant therapy.

PATIENTS AND METHODS

A total of 72 patients who underwent neoadjuvant CRT followed by R0 resection for clinical stage II /III rectal cancer were evaluated. The correlation between NAR score, various clinicopathological factors and disease recurrence were evaluated.

RESULTS

Disease recurrence was significantly more often observed in patients with incomplete neoadjuvant CRT, tumor regression grade (TRG) 3-4, and high NAR score. Multivariate analysis revealed that NAR score was an independent predictor of disease recurrence.

CONCLUSION

NAR score may be one of the predictive markers for disease recurrence in patients who underwent neoadjuvant CRT followed by surgery for rectal cancer. Patients with a low NAR score may benefit form postoperative adjuvant chemotherapy.

Locally advanced rectal cancer: The past, present, and future

From a series of clinical trials in the last several decades, current treatment paradigms for locally advanced rectal cancer include: (1) preoperative long-course radiotherapy (RT) combined with radiosensitizing chemotherapy; (2) preoperative short-course RT alone followed by adjuvant postoperative chemotherapy; and (3) total neoadjuvant therapy with induction chemotherapy followed by chemoradiotherapy. Other strategies under active investigation in both institutional and cooperative trials include neoadjuvant chemotherapy alone without RT in select patients, total neoadjuvant therapy, watchful waiting after a clinical complete response as an alternative to surgical resection, and the use of different chemotherapeutic and targeted agents. The focus of this review is on established and novel therapeutic strategies for locally advanced rectal cancer.

Adjuvant chemotherapy for rectal cancer with complete pathological response (pCR) may not be necessary: a pooled analysis of 5491 patients

Background

It is recommended postoperative adjuvant chemotherapy for all rectal cancers undergoing neo-chemoradiotherapy regardless of the final yield pathology. However, the role of adjuvant chemotherapy in pathological complete response (pCR) remains controversial. We aimed to identify the necessarily of adjuvant chemotherapy in pCR.

Methods

Consecutive patients with pCR in Fudan University Shanghai Cancer Center (FUSCC) were enrolled. Meanwhile, a pooled analysis of individual patient with pCR was performed from PubMed and Embase databases for validation.

Results

A total of 171 patients form FUSCC were identified to achieve pCR with up to almost 10 years follow-up. Among them, those receiving adjuvant chemotherapy had no survival benefits compared to those without adjuvant chemotherapy (log-rank test = 0.17, P = 0.676). The 5y-DFS rates for patients in chemo group and no-chemo group was 87.5 and 88.8%, respectively, showing no significant difference (p = 0.854). No matter chemotherapy regimens, T stage, EMVI and CRM status varied, the results remained consistent. Meantime, the COX model did not demonstrate adjuvant chemotherapy as the independent risk factor for OS and DFS. Additionally, among 18 systemic recurrences in all, the rate of relapse surged rapidly on the 12 months and rose up to peak in the 36th months. In order to validate these results, nine controlled trials involving 5491 patients with pCR were included in this pooled-analysis. For both 5-year overall survival and disease-free survival, the pooling data did not produce a statistically significant effect in cases of adjuvant chemotherapy performed (RR = 0.79 and RR = 0.95, respectively, all p > 0.05).

Conclusion

This study suggested that rectal cancer patients with pCR did not benefit from adjuvant chemotherapy and we recommended that achievement of pCR require more prolonged close follow care in case of distant metastasis.