Nodal downstaging as a treatment goal for node-positive pancreatic cancer

The differential effect of neoadjuvant chemotherapy and chemoradiation on nodal downstaging in pancreatic adenocarcinoma

BACKGROUND/OBJECTIVES

Neoadjuvant chemotherapy (NCT) and chemoradiotherapy (NCRT) enhance resectability in patients with pancreatic adenocarcinoma (PDAC). This study compares the effect of NCT and NCRT on lymph nodal downstaging and survival.

METHODS

The 2004-2016 National Cancer Database Pancreas Participant User File was used to identify patients who underwent surgery for PDAC. Fisher's exact, Wilcoxon rank-sum, multivariate logistic regression, and log-rank were used. Downstaging was defined as clinically node-positive patients who demonstrated node-negativity on pathology.

RESULTS

Of 42,545 patients meeting criteria, 3311 received NCT and 1511 received NCRT. After surgery for clinically node-positive disease, 23.3% of NCT patients and 41.3% of NCRT patients demonstrated nodal downstaging. Younger age and lower tumor grade independently predicted downstaging. Downstaging after neoadjuvant therapy was associated with improved survival versus no nodal treatment response (29.8 vs. 22.8 months, p < 0.001). Downstaging by NCT was associated with improved overall survival versus downstaging by NCRT (37.5 vs. 26.6 months, p = 0.001). No survival difference existed between those with no nodal response after NCT or NCRT (p = 0.101).

CONCLUSIONS

Although nodal downstaging is more likely post-NCRT, survival is superior in those downstaged post-NCT. Overall survival is determined by the systemic burden of disease. Post-therapy histologic analysis may be less prognostic post-NCRT.

Is There a Role for Neoadjuvant Systemic Therapy for cT4bM0 Colon Cancer? A Propensity Score-Matched Analysis of the National Cancer Database

BACKGROUND

Nonmetastatic T4b colon cancer has been traditionally treated with upfront surgery, often requiring technically challenging multiorgan resection. Neoadjuvant chemotherapy can potentially downsize these tumors and improve their resectability.

OBJECTIVE

This study aimed to explore trends and outcomes of neoadjuvant chemotherapy use compared to upfront surgery in patients with nonmetastatic T4b colon cancer. This study also sought to determine factors associated with increased neoadjuvant chemotherapy use and with overall survival.

DESIGN

Retrospective cohort study.

SETTINGS

Conducted using the National Cancer Database.

PATIENTS

Patients with nonmetastatic T4b colon cancer who underwent colectomy (2006-2016) were included in the study. Patients receiving neoadjuvant chemotherapy were propensity-matched (1:2) to those who underwent upfront surgery in either clinically node-negative or node-positive disease.

MAIN OUTCOME MEASURES

Postoperative outcomes (length of stay, 30-d readmission, 30/90-d mortality), oncologic resection adequacy (R0 rate, number of resected/positive nodes), and overall survival were the main outcome measures.

RESULTS

Neoadjuvant chemotherapy was used in 7.7% of the patients. Neoadjuvant chemotherapy use increased over the study period from 4% to 16% in the entire cohort, from 3% to 21% in patients with clinically node-positive disease, and from 6% to 12% in patients with clinically node-negative disease. Factors associated with increased use of neoadjuvant chemotherapy included younger age (OR 0.97; 95% CI, 0.96-0.98; p < 0.001), male sex (OR 1.35; 95% CI, 1.11-1.64; p = 0.002), recent diagnosis year (OR 1.16; 95% CI, 1.12-1.20; p < 0.001), academic centers (OR 2.65; 95% CI, 2.19-3.22; p < 0.001), clinically node-positive (OR 1.23; 95% CI, 1.01-1.49; p = 0.037), and tumor located in the sigmoid colon (OR 2.44; 95% CI, 1.97-3.02; p < 0.001). Patients who received neoadjuvant chemotherapy had significantly higher R0 resection compared with upfront surgery (87% vs 77%; p < 0.001). On multivariable analysis, neoadjuvant chemotherapy was associated with higher overall survival (HR 0.76; 95% CI, 0.64-0.91; p = 0.002). On propensity-matched analyses, neoadjuvant chemotherapy was associated with a higher 5-year overall survival compared to upfront surgery in patients with clinically node-positive disease (57% vs 43%; p = 0.003) but not in patients with clinically node-negative disease (61% vs 56%; p = 0.090).

LIMITATIONS

Retrospective design.

CONCLUSION

Neoadjuvant chemotherapy use for nonmetastatic T4b has increased significantly on the national level, more so in patients with clinically node-positive disease. Patients with node-positive disease treated with neoadjuvant chemotherapy had higher overall survival compared to those who underwent upfront surgery. See Video Abstract at http://links.lww.com/DCR/C228 .

EXISTE LUGAR PARA LA TERAPIA SISTMICA NEOADYUVANTE PARA EL CNCER DE COLON CTBM UN ANLISIS EMPAREJADO DE PUNTAJE DE PROPENSIN DE LA BASE DE DATOS NACIONAL DEL CNCER

ANTECEDENTES:El cáncer de colon T4b no metastásico se ha tratado tradicionalmente con cirugía inicial, que frecuentemente requiere de una resección multiorgánica técnicamente desafiante. La quimioterapia neoadyuvante puede potencialmente reducir el tamaño y mejorar la resecabilidad de esos tumores.OBJETIVO:Explorar las tendencias y los resultados del uso de quimioterapia neoadyuvante en pacientes con cáncer de colon T4b no metastásico, en comparación con la cirugía inicial. Determinar los factores asociados con el aumento del uso de quimioterapia neoadyuvante y con la supervivencia general.DISEÑO:Estudio de cohorte retrospectivo.AJUSTES:Utilizando de la Base de Datos Nacional del Cáncer.PACIENTES:Pacientes con cáncer de colon T4b no metastásico sometidos a colectomía (2006-2016). Los pacientes que recibieron quimioterapia neoadyuvante fueron emparejados por propensión (1:2) con aquellos sometidos a cirugía inicial, ya sea en enfermedad clínica con ganglios negativos o ganglios positivos.PRINCIPALES MEDIDAS DE RESULTADO:Resultados posoperatorios (duración de la hospitalización, reingreso a los 30 días, mortalidad a los 30/90 días), adecuación de la resección oncológica (tasa R0, número de ganglios resecados/positivos) y supervivencia general.RESULTADOS:La quimioterapia neoadyuvante se utilizó en el 7,7% de los pacientes. El uso de quimioterapia neoadyuvante aumentó durante el período de estudio del 4% al 16% en toda la cohorte; del 3% al 21% en pacientes con enfermedad clínica y ganglios positivos; y del 6% al 12% en pacientes con enfermedad clínica y ganglios negativos. Los factores asociados con un mayor uso de quimioterapia neoadyuvante incluyeron, edad más joven (OR 0,97, IC del 95 %: 0,96-0,98, p < 0,001), sexo masculino (OR 1,35, IC del 95 %: 1,11-1,64, p = 0,002), año de diagnóstico mas reciente (OR 1,16, 95% IC: 1,12-1,20, p < 0,001), centros académicos (OR 2,65, 95% IC: 2,19-3,22, p < 0,001), enfermedad clínica con ganglios positivos (OR 1,23, 95% IC: 1,01-1,49, p = 0,037), y tumor localizado en colon sigmoide (OR 2,44, 95% IC: 1,97-3,02, p < 0,001). Los pacientes que recibieron quimioterapia neoadyuvante tuvieron una resección R0 significativamente mayor en comparación con la cirugía inicial (87 % frente a 77 %, p < 0,001). En análisis multivariable, la quimioterapia neoadyuvante se asoció con una mayor supervivencia global (HR 0,76, IC del 95%: 0,64-0,91, p = 0,002). En los análisis de propensión pareada, la quimioterapia neoadyuvante se asoció con una mayor supervivencia general a los 5 años en comparación con la cirugía inicial en pacientes con enfermedad clínica con ganglios positivos (57% frente a 43%, p = 0,003), pero no en pacientes con enfermedad clínica y ganglios negativos (61% vs 56%, p = 0,090).LIMITACIONES:Diseño retrospectivo.CONCLUSIÓN:El uso de quimioterapia neoadyuvante para T4b no metastásico ha aumentado significativamente a nivel nacional, más aún en pacientes con enfermedad clínica y ganglios positivos. Los pacientes con enfermedad y ganglios positivos tratados con quimioterapia neoadyuvante tuvieron una mayor supervivencia general en comparación con la cirugía inicial. Consulte Video Resumen en http://links.lww.com/DCR/C228 . (Traducción-Dr. Fidel Ruiz Healy ).

Preoperative downstaging of pancreatic cancer is associated with improved survival after multi-agent chemotherapy, but not after radiation

BACKGROUND

Downstaging has been associated with improved survival for many cancers. However, the implications of downstaging are unclear for pancreatic cancer in an era of effective neoadjuvant systemic chemotherapy.

METHODS

NCDB retrospective cohort study of resected pancreatic carcinoma treated with neoadjuvant therapy.

RESULTS

The study included 73,985 patients: 66,589 with no neoadjuvant therapy, 2,102 neoadjuvant radiation therapy (N-RT), 3,195 neoadjuvant multiagent chemotherapy (N-MAC) and 2.099 with both neoadjuvant radiation and multiagent chemotherapy. There was increased use of N-MAC over the period of this study. Patients selected for treatment with N-MAC had longer survival from surgery on univariate (23.1 vs. 18.7 months, p = < 0.01) and multivariate analyses HR 0.81 (0.76-0.87, p < 0.001) compared to those selected with N-RT. Downstaging was similar in N-RT and N-MAC groups (25.1 vs. 24.1%, p = 0.43). Downstaging following N-MAC was associated with a survival benefit, HR 0.85 (0.74-0.98). However, downstaging following N-RT was not associated with a survival advantage, HR 1.12 (0.99-0.99).

CONCLUSION

Clinicians have rapidly adopted N-MAC for treatment of pancreatic cancer. Although the rates of downstaging are similar between treatment groups, response translates into increased survival only with N-MAC and not with N-RT.

Analysis of Risk Factors for Distant Metastasis of Pancreatic Ductal Adenocarcinoma without Regional Lymph Node Metastasis and a Nomogram Prediction Model for Survival

Background

Negative regional lymph nodes do not indicate a lack of distant metastasis. A considerable number of patients with negative regional lymph node pancreatic cancer will skip the step of regional lymph node metastasis and directly develop distant metastasis.

Methods

We retrospectively analyzed the clinicopathological characteristics of patients with negative regional lymph node pancreatic cancer and distant metastasis in the Surveillance, Epidemiology, and End Results database from 2010 to 2015. Multivariate logistic analysis and Cox analysis were used to determine the independent risk factors that promoted distant metastasis and the 1-, 2-, and 3-year cancer-specific survival in this subgroup.

Results

Sex, age, pathological grade, surgery, radiotherapy, race, tumor location, and tumor size were significantly correlated with distant metastasis (P < 0.05). Among these factors, pathological grade II and above, tumor site other than the pancreatic head, and tumor size >40 mm were independent risk factors for distant metastasis; age ≥60 years, tumor size ≤21 mm, surgery, and radiation were protective factors against distant metastasis. Age, pathological grade, surgery, chemotherapy, and metastasis site were identified as predictors of survival. Among them, age ≥40 years, pathological grade II and above, and multiple distant metastasis were considered independent risk factors for cancer-specific survival. Surgery and chemotherapy were considered protective factors for cancer-specific survival. The prediction performance of the nomogram was significantly better than that of the traditional American Joint Committee on Cancer tumor, node, metastasis staging system. We also established an online dynamic nomogram calculator, which can predict the survival rate of patients at different follow-up time points.

Conclusion

Pathological grade, tumor location, and tumor size were independent risk factors for distant metastasis in pancreatic ductal adenocarcinoma with negative regional lymph nodes. Older age, smaller tumor size, surgery, and radiotherapy were protective factors against distant metastasis. A new nomogram that was constructed could effectively predict cancer-specific survival in pancreatic ductal adenocarcinoma with negative regional lymph nodes and distant metastasis. Furthermore, an online dynamic nomogram calculator was established.

Establishment of a multi-parameters MRI model for predicting small lymph nodes metastases (<10 mm) in patients with resected pancreatic ductal adenocarcinoma

PURPOSE

To evaluate the potential role of MR findings and DWI parameters in predicting small regional lymph nodes metastases (with short-axis diameter < 10 mm) in pancreatic ductal adenocarcinomas (PDACs).

METHODS

A total of 127 patients, 82 in training group and 45 in testing group, with histopathologically diagnosed PDACs who underwent pancreatectomy were retrospectively analyzed. PDACs were divided into two groups of positive and negative lymph node metastases (LNM) based on the pathological results. Pancreatic cancer characteristics, short axis of largest lymph node, and DWI parameters of PDACs were evaluated.

RESULTS

Univariate and multivariate analyses showed that extrapancreatic distance of tumor invasion, short-axis diameter of the largest lymph node, and mean diffusivity of tumor were independently associated with small LNM in patients with PDACs. The combining MRI diagnostic model yielded AUCs of 0.836 and 0.873, and accuracies of 81.7% and 80% in the training and testing groups. The AUC of the MRI model for predicting LNM was higher than that of subjective MRI diagnosis in the training group (rater 1, P = 0.01; rater 2, 0.008) and in a testing group (rater 1, P = 0.036; rater 2, 0.024). Comparing the subjective diagnosis, the error rate of the MRI model was decreased. The defined LNM-positive group by the MRI model showed significantly inferior overall survival compared to the negative group (P = 0.006).

CONCLUSIONS

The MRI model showed excellent performance for individualized and noninvasive prediction of small regional LNM in PDACs. It may be used to identify PDACs with small LNM and contribute to determining an appropriate treatment strategy for PDACs.

Bayesian Approach to Understand the Association Between Treatment Down-staging and Survival for Patients With Pancreatic Adenocarcinoma

OBJECTIVE

To evaluate the association between staging concordance, treatment sequencing, and response to neoadjuvant therapy (NAT) on the survival of patients with pancreatic ductal adenocarcinoma (PDAC).

SUMMARY OF BACKGROUND DATA

NAT is increasingly utilized in the management of patients with PDAC, but it is unclear whether its benefit is contingent on tumor down-staging.

METHODS

This was a cohort study of stage I-III PDAC patients in the National Cancer Database (2006-2015) treated with upfront resection or NAT followed by surgery. We determined staging concordance using patients' clinical and pathological staging data. For NAT patients, we used Bayesian analysis to ascertain staging concordance accounting for down-staging.

RESULTS

Among 16,597 patients treated at 979 hospitals, 13,982 had an upfront resection and 2,615 NAT followed by surgery. Overall survival (OS) at 5-years ranged from 26.0% (95% CI 24.9%-27.1%) among cT1-2N0 patients to 18.6% (17.9%-19.2%) among cT1-3N+ ones. Patients with cT3-4 or cN+ tumors had improved OS after NAT compared to upfront surgery (all p< 0.001), while there was no difference among patients with cT1-2N0 (P = 0.16) disease. Relative to accurately staged cT1-2-3N+ or cT4 patients treated with upfront surgery, NAT was associated with a lower risk of death [HR 0.46 (0.37-0.57) for N+; HR 0.56 (0.40-0.77) for T4 disease], even among those without tumor down-staging [HR 0.81 (0.73-0.90) for N+; HR 0.48 (0.39-0.60) for T4].

CONCLUSIONS

NAT is associated with improved survival for PDAC, particularly for patients with more advanced disease and regardless of down-staging. Consideration should be given to recommending NAT for all PDAC patients.

AJCC 8th edition pathologic nodal staging of resected pancreatic adenocarcinoma predicts survival regardless of treatment sequencing

OBJECTIVE

The primary aim was to compare overall survival (OS) between neoadjuvant therapy (NT) and surgery-first (SF) patients with pancreatic adenocarcinoma (PDAC) by nodal stage using the American Joint Commission on Cancer 8th Edition (AJCC8).

BACKGROUND

Rates of nodal positivity are consistently lower following NT versus SF sequencing. It's unclear whether post-NT nodal stage (ypNx) has similar survival compared to SF (pNx) using AJCC8.

METHODS

This is a single-institution retrospective cohort study with routine consideration of NT. Patients undergoing PDAC resection from 2010 to 2018 were analyzed and OS compared by nodal stage using AJCC8.

RESULTS

Of 450 total patients, 24% were treated with SF and 76% NT. SF patients had potentially resectable disease in 97% of the cases, whereas NT patients had more advanced clinical stages at diagnosis: borderline resectable 34%, locally advanced 5%. NT patients had higher rates of node-negativity (52.4% vs 22.7%) and lower rates of pathologic N2 disease (19.1% vs 43.6%) vs. SF (p < 0.001). For each pathologic nodal stage, SF and NT groups had similar 5-year OS [pN0/ypN0 52.7% vs. 53.6%, p = 0.723], [pN1/ypN1 37.0% vs. 36.7%, p = 0.872], and [pN2/ypN2 16.6% vs. 21.0%, p = 0.508].

CONCLUSIONS

AJCC8 stratifies outcomes for each post-NT nodal stage similar to SF counterparts. Despite presenting with more advanced clinical stage, NT patients had lower rates of nodal metastases yet comparable OS when stratified by final nodal status. These data provide both hope for patients with obvious radiographic nodal disease at presentation and further support for considering NT sequencing for most patients diagnosed with localized PDAC.

Prognostic factors in patients with locally advanced or borderline resectable pancreatic ductal adenocarcinoma: chemotherapy vs. chemoradiotherapy

PURPOSE

To identify common and unique pre-treatment prognostic factors in patients with borderline resectable (BR) or locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC), treated with chemotherapy (CTx) or concurrent chemoradiotherapy (CRT).

METHODS

We enrolled 215 patients with BR/LA PDAC, who were treated with either CTx (n = 82) or CRT (n = 133) as a first-line treatment between 2013 and 2016. Clinical data and CT imaging findings for predicting overall survival (OS) and progression-free survival (PFS) were analyzed using Cox regression analysis.

RESULTS

Carbohydrate antigen (CA) 19-9 > 1000 U/mL (hazard ratio [HR] 1.91; p = 0.001) and non-homogeneous enhancement (HR 1.95; p < 0.001) were associated with shorter OS in all study populations. There was no significant difference in median OS (15.3 vs 16.8 months, p = 0.297) and PFS (10.0 vs 11.7 months, p = 0.321) between the CTx and CRT groups. Non-homogeneous enhancement (HR 2.04; p = 0.006) and presence of positive lymph node on CT (HR 2.38; p = 0.036) were associated with poor OS in the CTx group, while CA 19-9 > 1000 U/mL (HR 2.38; p = 0.001) and non-homogeneous enhancement (HR 1.73; p = 0.006) were independent predictors for poor OS in the CRT group.

CONCLUSION

Enhancement pattern on CT was a common prognostic factor for patients with PDAC treated with either CTx or CRT. Presence of positive lymph nodes on CT was a poor prognostic factor for the CTx group only, whereas CA 19-9 > 1000 U/mL was a poor prognostic factor for the CRT group only.

Preoperative Therapy Regimen Influences the Incidence and Implication of Nodal Downstaging in Patients with Gastric Cancer

Purpose

Nodal downstaging after preoperative therapy for gastric cancer has been shown to impart excellent prognosis, but this has not been validated in a national cohort. The role of neoadjuvant chemoradiation (NACR) in nodal downstaging remains unclear when compared with that of neoadjuvant chemotherapy alone (NAC). Furthermore, it is unknown whether the prognostic implications of nodal downstaging differ by preoperative regimen.

Materials and Methods

Using the National Cancer Database, overall survival (OS) duration was compared among natural N0 (cN0/ypN0), downstaged N0 (cN+/ypN0), and node-positive (ypN+) gastric cancer patients treated with NACR or NAC. Factors associated with nodal downstaging were examined in a propensity score-matched cohort of cN+ patients, matched 1:1 by receipt of NACR or NAC.

Results

Of 7,426 patients (natural N0 [n=1,858, 25.4%], downstaged N0 [n=1,813, 24.4%], node-positive [n=3,755, 50.4%]), 58.2% received NACR, and 41.9% received NAC. The median OS durations of downstaged N0 (5.1 years) and natural N0 (5.6 years) patients were similar to one another and longer than that of node-positive patients (2.1 years) (P<0.001). In the matched cohort of cN+ patients, more recent diagnosis (2010–2015 vs. 2004–2009) (odds ratio [OR], 2.57; P<0.001) and NACR (OR, 2.02; P<0.001) were independently associated with nodal downstaging. The 5-year OS rate of downstaged N0 patients was significantly lower after NACR (46.4%) than after NAC (57.7%) (P=0.003).

Conclusions

Downstaged N0 patients have the same prognosis as natural N0 patients. Nodal downstaging occurred more frequently after NACR; however, the survival benefit of nodal downstaging after NACR may be less than that when such is achieved by NAC.

Accuracy of various criteria for lymph node staging in ductal adenocarcinoma of the pancreatic head by computed tomography and magnetic resonance imaging

BACKGROUND

Lymph node staging of ductal adenocarcinoma of the pancreatic head (PDAC) by cross-sectional imaging is limited. The aim of this study was to determine the diagnostic accuracy of expanded criteria in nodal staging in PDAC patients.

METHODS

Sixty-six patients with histologically confirmed PDAC that underwent primary surgery were included in this retrospective IRB-approved study. Cross-sectional imaging studies (CT and/or MRI) were evaluated by a radiologist blinded to histopathology. Number and size of lymph nodes were measured (short-axis diameter) and characterized in terms of expanded morphological criteria of border contour (spiculated, lobulated, and indistinct) and texture (homogeneous or inhomogeneous). Sensitivities and specificities were calculated with histopathology as a reference standard.

RESULTS

Forty-eight of 66 patients (80%) had histologically confirmed lymph node metastases (pN+). Sensitivity, specificity, and Youden's Index for the criterion "size" were 44.2%, 82.4%, and 0.27; for "inhomogeneous signal intensity" 25.6%, 94.1%, and 0.20; and for "border contour" 62.7%, 52.9%, and 0.16, respectively. There was a significant association between the number of visible lymph nodes on preoperative CT and lymph node involvement (pN+, p = 0.031).

CONCLUSION

Lymph node staging in PDAC is mainly limited due to low sensitivity for detection of metastatic disease. Using expanded morphological criteria instead of size did not improve regional nodal staging due to sensitivity remaining low. Combining specific criteria yields improved sensitivity with specificity and PPV remaining high.

Long-term outcomes by response to neoadjuvant chemotherapy or chemoradiation in patients with resected pancreatic adenocarcinoma

Background

Response of pancreatic adenocarcinoma to neoadjuvant chemotherapy (nCT) or chemoradiotherapy (nCRT) may be associated with prognosis, but long-term outcomes based on response to neoadjuvant therapy have not been well evaluated to date.

Methods

The National Cancer Database was queried for patients with pancreatic adenocarcinoma receiving nCT/nCRT. To evaluate response to nCT/nCRT, comparisons were made from cT and cN stage to the respective post-neoadjuvant therapy ypT and ypN stages. Based on these comparisons, patients were classified as responders, progressors, or non-responders. Statistical analyses included estimation of survival using Kaplan-Meier analysis, as well as multivariable Cox proportional hazards modeling.

Results

Of 2,028 patients, 30% had a response, 32% progressed, and 38% had no response; 1% of patients experienced pathologic complete response (pCR). Responders were more likely to have received multi-agent chemotherapy (P=0.0001) as well as radiotherapy (RT) (P=0.02) in the neoadjuvant setting. Response to nCT/nCRT was also associated with a higher R0 resection rate (P=0.02). At a median follow-up of 49 months, median overall survival (OS) was higher in responders than non-responders or progressors (29.9 vs. 24.3 vs. 22.2 months, P<0.001). The mean OS for patients experiencing pCR was 55.5 months. On multivariable analysis, treatment response was independently associated with OS (P=0.02).

Conclusions

Response to nCT/nCRT independently predicts long-term outcomes following resection of pancreatic adenocarcinoma; higher rates of treatment response were observed for patients receiving neoadjuvant RT as well as neoadjuvant multi-agent chemotherapy. These results may have implications on strategies to improve response rates.