Oncologic outcome after preoperative chemoradiotherapy in patients with pathologic T0 (ypT0) rectal cancer

Predicting disease-free survival in locally advanced rectal cancer using a prognostic model based on pretreatment b-value threshold map and postoperative pathologic features

PURPOSE

Disease-free survival (DFS) after neoadjuvant chemoradiotherapy (nCRT) is an important factor in affecting the quality of life and determining the subsequent treatment procedures for patients with locally advanced rectal cancer (LARC). This study aimed to develop a novel prognostic model for predicting the DFS in patients with LARC following nCRT and to verify its effectiveness.

MATERIALS AND METHODS

Patients with LARC who underwent magnetic resonance imaging (MRI) and nCRT at our institution between November 2017 and March 2022 were enrolled in this retrospective study. Clinicopathologic data and MRI indicators of all patients were collected and evaluated. All patients were divided into DFS and non-DFS groups according to the presence or absence of local recurrence or distant metastasis. The differences in the b-value threshold (bthreshold) and apparent diffusion coefficient (ADC) values between the DFS and non-DFS groups were compared. The Cox analyses were used to determine the risk factors in predicting the DFS. A merged model was established based on the risk factors, and a nomogram was constructed. The predictive performances of the merged model were validated using the receiver-operating characteristic (ROC) and decision curve analysis (DCA).

RESULTS

Of the 524 patients enrolled, 132 who underwent surgical resection post-nCRT were included in the final analysis. The post-neoadjuvant therapy pathological N stage, extramural venous invasion (EMVI), and bthreshold were independent factors in predicting the DFS. The C-index of the model was 0.688. The area under the curve (AUC) of the nomogram in predicting the 1-, 3-, and 5-year survival rates of patients was 0.731, 0.723, and 0.779, respectively. The DCA demonstrated that the merged model had a greater advantage than either the "all" or the "none" scheme when the threshold probability was between 0.1 and 0.65.

CONCLUSION

A merged model based on the bthreshold value and clinicopathological features showed the potential to predict the prognosis of patients with LARC after nCRT and surgery.

Local tumor regrowth after clinical complete response following neoadjuvant therapy for rectal cancer: what happens when organ preservation falls short

Organ preservation strategies, especially watch and wait, after neoadjuvant treatment in locally advanced rectal cancer, have become topics that generate significant interest, for both patients and clinicians. The obvious advantage of these strategies is the avoidance of surgery with its associated risks and functional consequences. Over time, it has become evident that these strategies offer acceptable safety in oncological terms and, in most patients, allows preservation of the rectum without harming patients in terms of distant metastasis or survival. However, there is a small group of patients in whom the tumor returns after an initially diagnosed clinical complete response; patients with local tumor regrowth. The main threat in these patients is not simply local disease, which can be successfully managed in most cases, but the possible effects it may have on distant metastases. The pathophysiology of the phenomenon of local tumor regrowth is not well known and, therefore, strategies to minimize possible impact on survival are not well defined. Our aim is to review key issues in this subgroup that pose a substantial threat to the safety and viability of organ-preserving and watch-and-wait strategies. We also explore possible pathophysiologic explanations and future directions and perspectives that may improve both local and systemic disease control.

Patient Survival With ypT0N+ Following Neoadjuvant Therapy in Rectal Cancer

BACKGROUND

After neoadjuvant therapy, pathologic analysis of rectal cancer resected specimens may show a complete response in the primary tissue cancer with residual tumor in the lymph nodes (ypT0N+).

OBJECTIVES

The aim of this study was to describe the 5-year overall survival and factors associated with survival of ypT0N+ patients with rectal cancer who had neoadjuvant therapy followed by surgery and to compare these patients' survival with patients in other pathologic categories.

DESIGN

We conducted a retrospective analysis.

SETTINGS

We used the National Cancer Database.

PATIENTS

We identified patients with rectal adenocarcinoma who underwent total neoadjuvant therapy or neoadjuvant chemoradiation followed by surgery between 2006 and 2016. Besides ypT0N+, 5 pathologic categories were identified: ypT0N0, ypT1-2N0, ypT3-4N0, ypT1-2N+, and ypT3-4N+.

MAIN OUTCOME MEASURE

The primary outcome measure was 5-year overall survival.

RESULTS

We included 30,751 patients with rectal adenocarcinoma. A total of 342 patients developed ypT0N+, of whom 181 (52.9%) received total neoadjuvant therapy. Among patients who received total neoadjuvant therapy, developing ypT0N+ was associated with a lower 5-year overall survival than ypT0N0 and ypT1-2N0. However, ypT0N+ disease was associated with a higher 5-year overall survival than ypT3-4N+. There were no differences in 5-year overall survival between ypT0N+ and ypT3-4N0 or ypT1-2N+. Similar findings were noticed among patients who received neoadjuvant chemoradiation and adjuvant chemotherapy. For patients with ypT0N+, older age, male gender, and higher number of positive lymph nodes were all associated with a decrease in the overall survival.

LIMITATIONS

Limitations include the retrospective nature of this study, lack of variables describing the chemotherapy and radiation regimens used, and paucity of data on disease-specific survival or recurrence.

CONCLUSIONS

Developing ypT0N+ was associated with a lower 5-year overall survival than ypT0N0 and ypT1-2N0. However, it was associated with a higher 5-year overall survival than ypT3-4N+. See Video Abstract at http://links.lww.com/DCR/B863 .

SOBREVIDA DE LOS PACIENTES CON YPTN DESPUS DE LA TERAPIA NEOADYUVANTE EN EL CNCER DE RECTO

ANTECEDENTES:Después del tratamiento neoadyuvante en el cáncer de recto bajo, el análisis patológico de la pieza operatoria resecada, puede mostrar una respuesta patológica completa del tumor primario pero con tumor residual en los ganglios linfáticos (ypT0N+).OBJETIVOS:Describir la sobrevida general a 5 años y los factores asociados con la sobrevida de los pacientes ypT0N+ con cáncer de recto, que recibieron terapia neoadyuvante seguida de cirugía y comparar la sobrevida de estos pacientes con la de pacientes con otros estadios patológicos.DISEÑO:Realizamos un análisis retrospectivo.AJUSTES:Utilizamos la base de datos nacional del cáncer.PACIENTES:Identificamos pacientes con adenocarcinoma de recto que se sometieron a terapia neoadyuvante total, seguida de cirugía entre 2006 y 2016. Además de ypT0N +, se identificaron 5 categorías patológicas: ypT0N0, ypT1-2N0, ypT3-4N0, ypT1-2N+, e ypT3-4N+.PRINCIPAL MEDIDA DE RESULTADO:La medida de resultado principal fue la supervivencia general a 5 años.RESULTADOS:Se incluyeron 30.751 pacientes con adenocarcinoma de recto. Un total de 342 pacientes desarrollaron ypT0N+, de los cuales 181 (52,9%) recibieron terapia neoadyuvante total. Entre los pacientes que recibieron terapia neoadyuvante total, el desarrollo de ypT0N+ se asoció con una supervivencia general a 5 años más baja que ypT0N0 e ypT1-2N0. Sin embargo, la enfermedad ypT0N+ se asoció con una supervivencia general a 5 años más alta que ypT3-4N+. No hubo diferencias en la supervivencia global a 5 años entre ypT0N+ y ypT3-4N0 o ypT1-2N+. Se observaron hallazgos similares entre los pacientes que recibieron terapia neoadyuvante y quimioterapia adyuvante. Para los pacientes con ypT0N+, la edad avanzada, el sexo masculino y un mayor número de ganglios linfáticos positivos se asociaron con una disminución en la supervivencia general.LIMITACIONES:Las limitaciones incluyen la naturaleza retrospectiva del estudio, la falta de variables que describan los regímenes de quimioterapia y radiación utilizados y la escasez de datos sobre la supervivencia o la recurrencia específicas de la enfermedad.CONCLUSIONES:El desarrollo de ypT0N+ se asoció con una supervivencia general a 5 años más baja que ypT0N0 e ypT1-2N0. Sin embargo, se asoció con una supervivencia global a 5 años más alta que ypT3-4N+. Consulte Video Resumen en http://links.lww.com/DCR/B863 . (Traducción-Dr. Rodrigo Azolas ).

Pathologic stage of ypT0N+ rectal cancers following neo-adjuvant treatment: clinical interpretation of an orphan status

Approximately 20% of locally advanced rectal cancers treated with neoadjuvant therapy achieve a pathologic complete response, but approximately 10% of them present residual nodal metastases (ypT0N+). We aimed this research to compare the survival rates of ypT0/ypTisN+ and stage 3a rectal cancer patients. A large multicenter study recently investigated ypT0/ypTis rectal cancers treated between 2005 and 2015 in Italy and Spain. ypT0/ypTisN+ were selected and compared with stage 3a rectal cancers treated at the same institutions with upfront surgery (ySICO group). Additionally, the SEER database was searched for patients with stage 3a rectal cancers treated with surgery in the same years. Overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) were analyzed using Kaplan-Meier curves and random survival forest analysis (RSF). The ySICO study population consisted of 19 ypT0/2ypTisN+ (mean follow-up 41.8 months) and 72 Stage 3a patients (mean follow-up 56.9 months). These subgroups were comparable, but stage 3a patients were treated more frequently with adjuvant therapy (90.5% vs 61.9%, p 0.0001). No significant differences were reported between the ySICO subgroups for the OS, DFS, and DSS curves. When the 1213 SEER patients were added to Stage 3a, the RFS model failed to differentiate OS between groups that presented identical survival. Root analysis showed that adjuvant therapy was the only variable differentiating OS and DSS in the ySICO population. These findings suggest that ypT0/ypTisN+ and stage 3a rectal cancers could be ranked together based on their similar outcomes and pathologic assessment, and they stress the importance of adjuvant therapy in patients presenting with residual nodal metastases.

Prognostic factors in patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy and radical resection of rectal cancer

BACKGROUND

There are only a few studies on the prognosis of patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy (NCRT) and radical resection of rectal cancer. The aim of the study was to identify prognostic factors with regard to oncological outcome in ypT0 patients after NCRT and radical resection.

METHODS

All ypT0 patients with rectal cancer after NCRT and radical resection between January 2010 and June 2019 were included. Cox univariate and multivariate regression analyses were used to determine the prognostic factors of these patients.

RESULTS

Seventy-six patients with ypT0 rectal cancer were included. In nine patients (11.8%), lymph node metastasis was identified. Age, gender, elevated carcinoembryonic antigen (CEA) and ypN+ were risk factors associated with a worse 5-year disease-free survival (DFS) rate in univariate analysis (P = 0.08, 0.14, 0.007 and 0.003, respectively). In multivariate analysis, ypN+ and elevated CEA before NCRT were independent risk factors for worse 5-year DFS (P = 0.005 and 0.021, respectively). Elevated CEA before NCRT, post-operative chemotherapy and ypN+ were risk factors associated with worse overall survival in univariate analysis (P = 0.14, 0.002 and 0.17, respectively). However, in multivariate analysis, none of these three factors were independent risk factors for worse overall survival (P = 0.20, 0.34 and 0.06, respectively).

CONCLUSION

ypN+ and elevated CEA before NCRT were found to be independent risk factors for an unfavourable DFS in ypT0 patients with complete response of the tumour after neoadjuvant chemoradiotherapy for rectal cancer.

Local excision in mid-to-low rectal cancer patients who revealed clinically total or near-total regression after preoperative chemoradiotherapy; a proposed trial

BACKGROUND

Preoperative chemoradiotherapy (pre-CRT) followed by total mesorectal excision (TME) is currently a standard therapy for locally advanced mid-to-low rectal cancer. Less aggressive, organ-preserving option such as local excision (LE) or watchful wait can alternatively be used for patients who respond well to pre-CRT. High-resolution rectal magnetic resonance imaging (MRI) is one of the most useful methods to assess pre-CRT response, and the MERCURY group has shown that the MR tumor regression grade (mrTRG) correlated with the pathologic TRG. The aim of this study is to compare postoperative complication and oncologic outcomes between LE and TME in mid-to-low rectal cancer patients whose tumors are mrTRG grade 1 (radiological complete remission) or 2 (predominant fibrosis; near-complete remission) after pre-CRT.

METHODS

A prospective, double-arm, randomized, open-labeled, single center, clinical trial will be conducted in patients with mid-to-low rectal cancer whose tumors are mrTRG 1/2 after pre-CRT at the Asan Medical Center, Seoul, Korea, after approval from the Institution Review Board. Patient medical records will be de-identified using a serial number to protect personal information. Inclusion criteria will include rectal adenocarcinoma with an inferior border < 8 cm from the anal verge, mrTRG 1/2, age > 20, and provision of informed consent. Postoperative complications will be assessed by Clavien-Dindo Classification Grade. Oncologic and functional outcomes will be collected and risk factors related to these outcomes will be investigated.

DISCUSSION

We believed that the rate of postoperative complication of LE will be comparable to that of TME in mid-to-low advanced rectal cancer patients with a favorable response after pre-CRT.

TRIAL REGISTRATION

KCT0002579 ( https://cris.nih.go.kr ) Dec-2017.

Long-term outcomes in patients with ypT0 rectal cancer after neoadjuvant chemoradiotherapy and curative resection

Objective

For patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy (NCRT), significant pathological response of the primary tumor has been proposed to identify candidates for organ preservation. However, this does not address metastatic lymph nodes in the mesorectum. The aim of this study was to assess the incidence of lymph node metastases in ypT0 patients treated with NCRT and curative resection and to explore risk factors associated with survival.

Methods

This was a retrospective study of patients with ypT0 rectal cancer after NCRT and curative resection at a tertiary care center in China from 2005 to 2014.

Results

A total of 60 (18.6%) patients who underwent surgery after NCRT and achieved ypT0 were enrolled in this study; one patient was excluded owing to lack of follow-up. Of these 59 patients, lymph node metastases were found in the mesorectum (ypT0N+) in eight (13.6%) patients. After a median follow-up of 52 months, 5-year recurrence-free survival (82.7% vs. 62.5%, P=0.014) and overall survival (OS) (90.9% vs. 70.0%, P=0.032) were much higher in ypN0 than ypN+ patients. Multivariate analyses showed that ypN+ status (P=0.009) and perioperative blood transfusion (BT) (P=0.001) were significantly independent risk factors associated with recurrence; however, no factor was correlated with 5-year OS.

Conclusions

Patients with ypT0N0 rectal cancer can achieve excellent long-term outcomes; however, positive lymph nodes or tumor deposits can still be found in 13.6% of ypT0 patients. Nodal positivity in the mesorectum and perioperative BT are independent risk factors for recurrence.

Long-term outcomes in ypT0 rectal cancers: An international multi-centric investigation on behalf of Italian Society of Surgical Oncology Young Board (YSICO)

AIM

To investigate the outcome and pattern of survivals of rectal cancer patients presenting a complete or nearly complete tumor response after neo-adjuvant treatment.

METHODS

Young surgeons <40 years old affiliated to the Italian Society of Surgical Oncology (YSICO) from 13 referral centers for colorectal cancer treatment, were invited to participate a retrospective study. Records from patients treated from 2005 to 2015 with a pathological diagnosis of ypT0/ypTis were retrieved and pooled in a common data-base for statistical purposes. All clinical and pathological variables were reviewed. Univariate and multivariate analyses were conducted with the end-point of survivals.

RESULTS

Two hundreds and sixty-one patients were analyzed including 237 ypT0 and 24 ypTis. Nodal positive patients were 8.7%. More than sixty-six percent of the patients did not perform adjuvant chemotherapy, with a statistical difference comparing N0 versus N+ patients (66.8% vs 40.9%, p 0.02). Mean follow-up was of 47.6 months. Twenty-two relapses were observed, 91.6% at a distant site. The mean time to recurrence was of 35.3 months. On univariate analysis, the use of adjuvant chemotherapy correlated with better OS exclusively in ypT0N + patients and not in ypT0N0. Univariate and multivariate analyses documented nodal positivity as the only prognostic factor correlated with a worse OS.

CONCLUSION

Recurrences were mostly diagnosed at a distant site and within the third year of follow-up. Nodal positivity was the only variable independently correlated with a worse OS. Univariate analysis documented a benefit for the use of adjuvant chemotherapy treatment exclusively in ypT0N + rectal cancers.

Long-Term Outcome of Rectal Cancer With Clinically (EUS/MRI) Metastatic Mesorectal Lymph Nodes Treated by Neoadjuvant Chemoradiation: Role of Organ Preservation Strategies in Relation to Pathologic Response

BACKGROUND

Organ preservation strategies are under investigation for patients with locally advanced rectal cancer (LARC) who achieve a complete pathologic response in the primary tumor (ypT0) after neoadjuvant chemoradiation therapy (CRT). This study explored the value of this approach for cN+ patients.

METHODS

Data were retrieved from our institutional prospective rectal cancer database. Tumors with mesorectal lymph nodes larger than 5 mm shown on endorectal ultrasonography, pelvic magnetic resonance imaging, or both were staged as cN+.

RESULTS

The study population comprised 226 patients (142 men and 84 women; median age, 64 years) with LARC who underwent CRT followed by surgery including total mesorectal excision (TME) (n = 179) and full-thickness local excision (LE) (n = 47) between 1996 and 2013. At staging, 123 patients (54.4 %) were cN+. In 65 cases (28.7 %), ypCR was observed. Metastatic mesorectal lymph nodes (ypN+) were detected in 41.6 % of the cN+ patients and in 2.8 % of the cN0 patients (P < 0.01). Among the cN+ patients, 16 % of the ypT0 cases were ypN+ compared with 51.8 % of the no-ypT0 cases (P < 0.01). Among the cN+ patients who underwent TME, the 5-year disease-specific survival (DSS) and disease-free survival (DFS) rates were respectively 100 and 91.6 % for the ypT0 patients compared with 71.2 and 58.0 % for the no-ypT0 patients (P = 0.01). Among the ypN+ patients, the 5-year DSS and DFS rates were both 100 % for the ypT0 cases compared with 59.1 and 43.3 % for the no-ypT0 patients. Among the cN+ and ypT0 patients, the 5-year DSS and DFS were respectively 100 and 85.7 % for the TME patients compared with 100 and 91.6 % for the LE patients. In the multivariate analysis, ypT0 was the only independent prognostic factor.

CONCLUSIONS

Protocols aimed at organ preservation in LARC that achieve ypT0 after CRT can be offered also to cN+ patients.

Lymph node status as a prognostic indicator after preoperative neoadjuvant chemoradiotherapy of rectal cancer

AIM

The primary aim of this study was to examine lymph node status after neoadjuvant chemoradiotherapy (CRT) using a novel scoring system describing the pathological lymph node regression grade. The proposed scoring system was based on the percentage of fibrosis and the presence of residual tumour amount. The secondary aim of the study was to assess the oncological impact of this scoring system.

METHOD

The project was a retrospective cohort study over a 10-year period. Two hundred and two patients with rectal cancer who had received CRT followed by curative surgery were included. A histopathologist prospectively scored each specimen and the impact of the scoring system on survival and recurrence was analysed.

RESULTS

One hundred and ninety patients completed long-course preoperative CRT and formed the basis of the study. Overall, 40 recurrences (local and distant) were observed over a median follow-up of 36 months. The lymph node regression score was a significant predictor of tumour recurrence (hazard ratio 1.273, 95% CI 1.048-1.548; P = 0.015). The overall mortality rate was 21%, and a lower lymph node regression score was correlated with an improved survival curve (P = 0.01).

CONCLUSION

The results demonstrate that lymph node response to neoadjuvant CRT based on a nodal regression scoring system is related to recurrence.