A decision analysis model predicts the optimal treatment pathway for patients with colorectal cancer and resectable synchronous liver metastases

Effect of treatment sequence on survival in stage IV rectal cancer with synchronous and potentially resectable liver metastases

BACKGROUND AND OBJECTIVES

The optimal treatment sequence in stage IV rectal cancer (RC) with synchronous liver metastases (SLM) remains undefined. Here, we compared outcomes between patients treated with the bowel-first approach (BFA) or the liver-first approach (LFA).

METHODS

Consecutive patients diagnosed with stage IV RC with SLM and who underwent complete resection were included. Both groups were matched using propensity scores. Differences in postoperative outcome, local control, and long-term survival were studied. In addition, a decision analysis (DA) model was built using TreeAge Pro to define the approach that results in the highest treatment completion rate.

RESULTS

During a 12-year period, 52 patients were identified, 21 and 31 of whom underwent the BFA and the LFA, respectively. Twenty-eight patients were matched; patients treated with the BFA experienced a longer median OS (50.0 vs 33.0 months; P = .40) and higher 5-year OS (42.9% vs 28.6%). The DA defined the BFA to be superior when the failure threshold (ie, no R0 resection, treatment discontinuation regardless of cause) for colectomy is less than 28.6%.

CONCLUSIONS

In stage IV rectal cancer with SLM, either the BFA or the LFA result in similar long-term outcomes. Treatment should be tailored according to clinicopathological variables.

Radiologic and pathologic response to neoadjuvant chemotherapy predicts survival in patients undergoing the liver-first approach for synchronous colorectal liver metastases

PURPOSE

To investigate the short- and long-term outcomes of liver first approach (LFA) in patients with synchronous colorectal liver metastases (CRLM), evaluating the predictive factors of survival.

METHODS

Sixty-two out of 301 patients presenting with synchronous CRLM underwent LFA between 2007 and 2016. All patients underwent neoadjuvant chemotherapy. After neoadjuvant treatment patients were re-evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST). Liver resection was scheduled after 4-6 weeks. Changes in non-tumoral parenchyma and the tumor response according to the Tumor Regression Grade score (TRG) were assessed on surgical specimens. Primary tumor resection was scheduled 4-8 weeks following hepatectomy.

RESULTS

Five patients out of 62 (8.1%) showed "Progressive Disease" at re-evaluation after neoadjuvant chemotherapy, 22 (35.5%) showed "Stable Disease" and 35 (56.5%) "Partial Response"; of these latter, 29 (82%) showed histopathologic downstaging. The 5-year survival (OS) rate was 55%, while the 5-year disease-free survival (DFS) rate was 16%. RECIST criteria, T-stage, N-stage and TRG were independently associated with OS. Bilobar presentation of disease, RECIST criteria, R1 margin and TRG were independently associated with DFS. Patients with response to neoadjuvant chemotherapy had better survival than those with stable or progressive disease (radiological response 5-y OS: 65% vs. 50%; 5-y DFS: 20% vs. 10%; pathological response 5-y OS: 75% vs. 56%; 5-y DFS: 45% vs. 11%).

CONCLUSIONS

LFA is an oncologically safe strategy. Selection is a critical point, and the best results in terms of OS and DFS are observed in patients having radiological and pathological response to neoadjuvant chemotherapy.

Defining optimum treatment of patients with pancreatic adenocarcinoma using regret-based decision curve analysis

OBJECTIVE

To use regret decision theory methodology to assess three treatment strategies in pancreatic adenocarcinoma.

BACKGROUND

Pancreatic adenocarcinoma is uniformly fatal without operative intervention. Resection can prolong survival in some patients; however, it is associated with significant morbidity and mortality. Regret theory serves as a novel framework linking both rationality and intuition to determine the optimal course for physicians facing difficult decisions related to treatment.

METHODS

We used the Cox proportional hazards model to predict survival of patients with pancreatic adenocarcinoma and generated a decision model using regret-based decision curve analysis, which integrates both the patient's prognosis and the physician's preferences expressed in terms of regret associated with a certain action. A physician's treatment preferences are indicated by a threshold probability, which is the probability of death/survival at which the physician is uncertain whether or not to perform surgery. The analysis modeled 3 possible choices: perform surgery on all patients; never perform surgery; and act according to the prediction model.

RESULTS

The records of 156 consecutive patients with pancreatic adenocarcinoma were retrospectively evaluated by a single surgeon at a tertiary referral center. Significant independent predictors of overall survival included preoperative stage [P = 0.005; 95% confidence interval (CI), 1.19-2.27], vitality (P < 0.001; 95% CI, 0.96-0.98), daily physical function (P < 0.001; 95% CI, 0.97-0.99), and pathological stage (P < 0.001; 95% CI, 3.06-16.05). Compared with the "always aggressive" or "always passive" surgical treatment strategies, the survival model was associated with the least amount of regret for a wide range of threshold probabilities.

CONCLUSIONS

Regret-based decision curve analysis provides a novel perspective for making treatment-related decisions by incorporating the decision maker's preferences expressed as his or her estimates of benefits and harms associated with the treatment considered.

A systematic review of a liver-first approach in patients with colorectal cancer and synchronous colorectal liver metastases

BACKGROUND

Since the liver metastases rather than the colorectal cancer itself is the main determinant of patient's survival, the 'Liver-First Approach (LFA)' with upfront chemotherapy followed by a hepatic resection of colorectal liver metastases (CLM) and finally a colorectal cancer resection was proposed. The aim of this review was to analyse the evidence for LFA in patients with colorectal cancer and synchronous CLM.

METHODS

A literature search of databases (MEDLINE and EMBASE) to identify published studies of LFA in patients with colorectal cancer and synchronous CLM was undertaken focussing on the peri-operative regimens of LFA and survival outcomes.

RESULTS

Three observational studies and one retrospective cohort study were included for review. A total of 121 patients with colorectal cancer and synchronous CLM were selected for LFA. Pre-operative chemotherapy was used in 99% of patients. One hundred and twelve of the initial 121 patients (93%) underwent a hepatic resection of CLM. In total, 60% had a major liver resection and the R0 resection rate was 93%. Post-operative morbidity and mortality after the hepatic resection were 20% and 1%, respectively. Ultimately, 89 of the initial 121 (74%) patients underwent a colorectal cancer resection. Post-operative morbidity and mortality after a colorectal resection were 50% and 6%, respectively. The median overall survival was 40 months (range 19-50) with a recurrence rate of 52%.

CONCLUSIONS

Current evidence suggests that LFA is safe and feasible in selected patients with colorectal cancer and synchronous CLM. Future studies are required to further define patient selection criteria for LFA and the exact role of LFA in the management of synchronous CLM.

Rectal cancer staging: focus on the prognostic significance of the findings described by high-resolution magnetic resonance imaging

High-resolution (HR) magnetic resonance imaging (MRI) has become an indispensable tool for multidisciplinary teams (MDTs) addressing rectal cancer. It provides anatomic information for surgical planning and allows patients to be stratified into different groups according to the risk of local and distant recurrence. One of the objectives of the MDT is the preoperative identification of high-risk patients who will benefit from neoadjuvant treatment. For this reason, the correct evaluation of the circumferential resection margin (CRM), the depth of tumor spread beyond the muscularis propria, extramural vascular invasion and nodal status is of the utmost importance. Low rectal tumors represent a special challenge for the MDT, because decisions seek a balance between oncologic safety, in the pursuit of free resection margins, and the patient's quality of life, in order to preserve sphincter function. At present, the exchange of information between the different specialties involved in dealing with patients with rectal cancer can rank the contribution of colleagues, auditing their work and incorporating knowledge that will lead to a better understanding of the pathology. Thus, beyond the anatomic description of the images, the radiologist's role in the MDT makes it necessary to know the prognostic value of the findings that we describe, in terms of recurrence and survival, because these findings affect decision making and, therefore, the patients' life. In this review, the usefulness of HR MRI in the initial staging of rectal cancer and in the evaluation of neoadjuvant treatment, with a focus on the prognostic value of the findings, is described as well as the contribution of HR MRI in assessing patients with suspected or confirmed recurrence of rectal cancer.

Multi-modality treatment of colorectal liver metastases

Liver metastases synchronously or metachronously occur in approximately 50% of colorectal cancer patients. Multimodality comprehensive treatment is the best therapeutic strategy for these patients. However, the optimal pattern of multimodality therapy is still controversial, and it raises several significant concerns. Liver resection is the most important treatment for colorectal liver metastases. The definition of resectability has shifted to focus on the completion of R0 resection and normal liver function maintenance. The role of neoadjuvant and adjuvant chemotherapy still needs to be clarified. The management of either progression or complete remission during neoadjuvant chemotherapy is challenging. The optimal sequencing of surgery and chemotherapy in synchronous colorectal liver metastases patients is still unclear. Conversional chemotherapy, portal vein embolization, two-stage resection, and tumor ablation are effective approaches to improve resectability for initially unresectable patients. Several technical issues and concerns related to these methods need to be further explored. For patients with definitely unresectable liver disease, the necessity of resecting the primary tumor is still debatable, and evaluating and predicting the efficacy of targeted therapy deserve further investigation. This review discusses different patterns and important concerns of multidisciplinary treatment of colorectal liver metastases.

Adverse features on rectal MRI identify a high-risk group that may benefit from more intensive preoperative staging and treatment

BACKGROUND

Magnetic resonance imaging (MRI) is highly accurate in local staging of rectal cancer. It can identify features known to be associated with increased risk of metastatic disease. We evaluated the incidence of synchronous metastatic disease on fludeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) and contrast-enhanced multiple-row detector computed tomography (ceMDCT) in MRI-stratified high- and low-risk rectal cancers. The aim was to determine the incidence of synchronous metastatic disease according to MRI risk features.

METHODS

A total of 236 patients with rectal cancer were recruited to a study evaluating FDG-PET/CT. All patients underwent MRI staging and were stratified into high and low risk (high risk: extramural venous invasion, extramural spread of >5 mm or T4, involved circumferential resection margin or intersphincteric plane involved for low rectal tumors). Confirmed metastases were those identified on FDG-PET/CT and ceMDCT.

RESULTS

Imaging data were available for 230 (97.5%) of 236 patients. Incidence of confirmed distant metastases was significantly greater in the MRI high-risk group, with 28 (20.7%) of 135 (95% confidence interval [CI] 14.8-28.3), versus the low-risk group, with 4 (4.2%) of 95 (95% CI 1.7-10.3) (odds ratio 6.0, 95% CI 2.0-17.6, P<0.001).

CONCLUSIONS

Adverse features found on rectal MRI identify patients at increased risk of synchronous metastatic disease. This group may benefit from additional preoperative investigation for synchronous metastases such as FDG-PET/CT or liver MRI and from alternative neoadjuvant chemotherapy regimens including induction chemotherapy.

Culture and characterization of thymic epithelium from autoimmune NZB and NZB/W mice

Autoimmune NZB and NZB/W mice display early abnormalities in thymus histology, T cell development, and mature T cell function. Abnormalities in the subcapsular/medullary thymic epithelium (TE) can also be inferred from the early disappearance of thymulin from NZB. It has also been reported that NZB thymic epithelial cells do not grow in culture conditions that support the growth of these cells from other strains of mice. In order to study the contribution of TE to the abnormal T cell development and function in NZB and NZB/W mice, we have devised a culture system which supports the growth of TE cells from these mice. The method involves the use of culture vessels coated with extracellular matrix produced by a rat thymic epithelial cell line. TEA3A1, and selective low-calcium, low-serum medium. In addition TEA3A1 cells have been used as an antigen to generate monoclonal antibodies specific for subcapsular/medullary TE. These antibodies, as well as others already available, have been used to show that the culture conditions described here select for cells displaying subcapsular/medullary TE markers, whereas markers for cortical TE and macrophages are absent.