Prognostic value of the ratio of pretreatment carcinoembryonic antigen to tumor volume in rectal cancer

Background

As a commonly used biomarker in rectal cancer (RC), the prognostic value of carcinoembryonic antigen (CEA) remains underexplored. This study aims to evaluate the prognostic value of pretreatment CEA/tumor volume in RC.

Methods

This retrospective study included patients who underwent pretreatment magnetic resonance imaging (MRI) with histologically confirmed primary rectal adenocarcinoma from November 2012 to April 2018. Patients were divided into high-risk and low-risk groups according to the median values of CEA/Diapath (CEA to pathological diameter), CEA/DiaMRI (CEA to MRI tumor diameter), and CEA/VolMRI (CEA to MRI tumor volume). Cox regression analysis was utilized to determine the prognostic value of CEA, CEA/Diapath, CEA/DiaMRI, and CEA/VolMRI. Stepwise regression was used to establish nomograms for predicting disease-free survival (DFS) and overall survival (OS). Predictive performance was estimated by using the concordance index (C-index) and area under curve receiver operating characteristic (AUC).

Results

A total of 343 patients [median age 58.99 years, 206 (60.06%) males] were included. After adjusting for patient-related and tumor-related factors, CEA/VolMRI was superior to CEA, CEA/Diapath, and CEA/DiaMRI in distinguishing high-risk from low-risk patients in terms of DFS [hazard ratio (HR) =1.83; P=0.010] and OS (HR =1.67; P=0.048). Subanalysis revealed that CEA/VolMRI stratified high death risk in CEA-negative individuals (HR =2.50; P=0.038), and also stratified low recurrence risk in CEA-positive individuals (HR =2.06; P=0.024). In the subanalysis of stage II or III cases, the highest HRs and the smallest P values were observed in distinguishing high-risk from low-risk patients according to CEA/VolMRI in terms of DFS (HR =2.44; P=0.046 or HR =2.41; P=0.001) and OS (HR =1.96; P=0.130 or HR =2.22; P=0.008). The nomograms incorporating CEA/VolMRI showed good performance, with a C-index of 0.72 [95% confidence interval (CI): 0.68-0.79] for DFS and 0.73 (95% CI: 0.68-0.80) for OS.

Conclusions

Higher CEA/VolMRI was associated with worse DFS and OS. CEA/VolMRI was superior to CEA, CEA/Diapath, and CEA/DiaMRI in predicting DFS and OS. Pretreatment CEA/VolMRI may facilitate risk stratification and treatment decision-making.

Research progress of PD-1/PD-L1 immunotherapy in gastrointestinal tumors

Gastrointestinal tumor (GIT) is a common malignant tumor of the digestive system, which seriously threatens people's health and life. With the deepening of the study on the mechanism of tumor immune escape, programmed death receptor ligand 1 (PD-L1) has been proved to interact with the tumor microenvironment to mediate tumor immune escape. PD-L1 inhibitor is a hot spot in tumor immunotherapy in recent years, which can restore the activity of T cells, enhance the body's ability of immune response, and ultimately enable the immune system to effectively identify and kill gastric cancer cells, then achieve long-term tumor remission in patients with GITs. At present, variety of PD-L1 inhibitors such as pembrolizumab, nivolumab and avelumab have been approved for the market, and they have achieved good results in clinical studies on the GIT. This paper reviews the progress of PD-1/PD-L1 immunotherapy in GITs which include gastric cancer, colon cancer and rectal cancer.

Local staging of rectal cancer using fused high resolution diffusion weighted imaging and modified MR rectography

Rectal cancer (RC) is a common malignant tumor with high mortality. MR imaging plays an important role in treatment decision making of RC. Unfortunately, the contents (gas and feces) in the rectum often induce artifacts and thus negatively affect the depicting and staging of RC. We developed a new protocol for MR rectography using oral administration of iso-osmotic mannitol to distend lumen after bowel cleansing preparation. Fused MR rectography and high resolution diffusion weighted imaging (DWI) is then performed to facilitate detection and staging of RC. Our present technique can eliminate the effect of gas and feces on image quality, especially on DWI, and can achieve satisfactory bowel distention, lesion depicture and visualization of surgical planes. Fused high resolution DWI and MR rectography can be a promising technique to improve the accuracy of RC local staging.

Trends and disparities in the utilization of hypofractionated neoadjuvant radiation therapy for rectal cancer in the United States

Background

Neoadjuvant conventionally fractionated radiotherapy (CFRT) versus hypofractionated radiotherapy (HFRT) for rectal cancer (RC) is among the most controversial and debatable areas of radiotherapeutic management. This is the only known study evaluating the utilization of neoadjuvant HFRT for RC in the United States, and focuses on trends and health disparities.

Methods

The National Cancer Data Base was queried [2004-2015] for newly-diagnosed cT3-T4 N_any or cT_any N1-2 M0 rectal adenocarcinoma undergoing neoadjuvant RT, with or without chemotherapy, followed by resection. Following analysis based on temporal trends, multivariate logistic regression determined factors associated with receipt of HFRT.

Results

Altogether, 29,994 patients met study criteria: 29,724 (99%) were treated with CFRT, and 270 (1%) with HFRT. Temporally, utilization of HFRT rose significantly, from 0.2% in 2004 to 2.0% in 2015, with the steepest slope at most recent time periods. HFRT was more likely administered to older patients, those with more comorbidities, and node-positive disease (P<0.05 for all). There were racial differences, as African-Americans were independently less likely to receive HFRT (P=0.043). The two strongest predictors of HFRT administration (by odds ratio) were time period and therapy at academic centers (P<0.05 for all).

Conclusions

Although HFRT is underutilized in the US, its use is rising and has increased nearly tenfold over the last decade. Disparities in HFRT delivery are emphasized, especially concerning disease-/patient-specific factors, socioeconomic status, and race. These data may serve as a benchmark for future investigation as well as for health disparities in the radiotherapeutic treatment of RC.

Advantages of a multi-state approach in surgical research: how intermediate events and risk factor profile affect the prognosis of a patient with locally advanced rectal cancer

Background

Standard survival analysis fails to give insight into what happens to a patient after a first outcome event (like first relapse of a disease). Multi-state models are a useful tool for analyzing survival data when different treatments and results (intermediate events) can occur. Aim of this study was to implement a multi-state model on data of patients with rectal cancer to illustrate the advantages of multi-state analysis in comparison to standard survival analysis.

Methods

We re-analyzed data from the RCT FOGT-2 study by using a multi-state model. Based on the results we defined a high and low risk reference patient. Using dynamic prediction, we estimated how the survival probability changes as more information about the clinical history of the patient becomes available.

Results

A patient with stage UICC IIIc (vs UICC II) has a higher risk to develop distant metastasis (DM) or both DM and local recurrence (LR) if he/she discontinues chemotherapy within 6 months or between 6 and 12 months, as well as after the completion of 12 months CTx with HR 3.55 (p = 0.026), 5.33 (p = 0.001) and 3.37 (p < 0.001), respectively. He/she also has a higher risk to die after the development of DM (HR 1.72, p = 0.023). Anterior resection vs. abdominoperineal amputation means 63% risk reduction to develop DM or both DM and LR (HR 0.37, p = 0.003) after discontinuation of chemotherapy between 6 and 12 months. After development of LR, a woman has a 4.62 times higher risk to die (p = 0.006). A high risk reference patient has an estimated 43% 5-year survival probability at start of CTx, whereas for a low risk patient this is 79%. After the development of DM 1 year later, the high risk patient has an estimated 5-year survival probability of 11% and the low risk patient one of 21%.

Conclusions

Multi-state models help to gain additional insight into the complex events after start of treatment. Dynamic prediction shows how survival probabilities change by progression of the clinical history.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0476-z) contains supplementary material, which is available to authorized users.