Evolving Treatment Options and Future Directions for Locally Advanced Rectal Cancer

Construction and Evaluation of Nomogram for Hematological Indicators to Predict Pathological Response after Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

OBJECTIVE

A retrospective study was conducted by developing prediction models to evaluate the association between hematological indexes, their changes during neoadjuvant chemoradiotherapy (NCRT), and tumor pathological response in patients with locally advanced rectal cancer.

METHODS

The clinical data of 202 patients who received NCRT and radical surgery in Sichuan Cancer Hospital were retrospectively analyzed. Univariate and logistic multivariate regression analyses were used to identify hematological indexes with predictive significance. The independent risk factors were imported into the R software, and a nomogram prediction model was developed. The bootstrap method and ROC curve were used to evaluate the discriminative degree of the model.

RESULTS

Univariate analysis demonstrated age, tumor diameter, preoperative T, distance from tumor to the anal verge, CEA before NCRT, preoperative CEA, lymphocyte changes, platelet changes, and pathology of rectal cancer after NCRT were associated. Multivariate analysis demonstrated that age, tumor distance from the anus, preoperative CEA, lymphocyte changes, and platelet changes were independent risk factors. The independent risk factors were imported into the R software to construct a nomogram model. The area under the ROC was 0.76, and the slope of the calibration curve of the nomogram was close to 1.

CONCLUSION

A low preoperative CEA level, a young age, a high tumor from the anal verge, the maintenance of circulating lymphocyte level, and a decreased platelet level after NCRT are important factors for favorable outcomes after NCRT. Developing a nomogram prediction model with good discrimination and consistency can provide some guidance for predicting pathological responses after NCRT.

Overexpression of MLF1IP promotes colorectal cancer cell proliferation through BRCA1/AKT/p27 signaling pathway

BACKGROUND AND OBJECTIVE

MLF1IP has been correlated with the progression and prognosis of a few tumors. However, the role of MLF1IP in colorectal cancer remains unclear. Here, we examined the expression and function of MLF1IP in colorectal cancer and investigated possible molecular mechanisms.

METHODS

MLF1IP expressions in colorectal cancer tissues and cell lines were detected by quantitative real-time PCR, western blotting, and immunohistochemistry. In vitro and in vivo assays were performed to explore the function and underlying molecular mechanisms of MLF1IP in colorectal cancer.

RESULTS

The expression levels of MLF1IP were significantly up-regulated in colorectal cancer tissues and CRC cell lines (P < 0.05). High expression of MLF1IP was significantly associated with TNM stage, T classification, lymph node involvement, distant metastasis, and poor patient survival (all P < 0.05). Overexpressing MLF1IP promoted while silencing MLF1IP inhibited, the proliferation and clonogenicity of colorectal cancer cells and tumorigenicity in NOD/SCID mice (P < 0.05). In addition, we demonstrated that the pro-proliferative effect of MLF1IP on colorectal cancer cells was associated with mediating the G1-to-S phase transition. MLF1IP knockdown enhanced BRCA1 activity concomitantly with p-AKT downregulation and p27 upregulation, while overexpression of MLF1IP has the opposite effect. Moreover, upregulation of BRCA1 can partially abolish the proliferative activity of MLF1IP.

CONCLUSIONS

These findings suggest that MLF1IP may promote proliferation and tumorigenicity of colorectal cancer cells via BRCA1/AKT/p27 signaling axis, and thereby provides potential targets for colorectal cancer therapy.

Apparent diffusion coefficient for the prediction of tumor response to neoadjuvant chemo-radiotherapy in locally advanced rectal cancer

Background

Patients with locally advanced rectal cancer generally have different response rates to preoperative neoadjuvant chemo-radiotherapy. This study investigated the value of the apparent diffusion coefficient (ADC) as a predictor to forecast the response to neoadjuvant chemo-radiotherapy in patients with locally advanced rectal cancer.

Methods

Ninety-one locally advanced rectal cancer patients who underwent neoadjuvant chemo-radiotherapy between 2015 and 2018 were enrolled. Diffusion-weighted magnetic resonance imaging was performed before treatment and within 4 weeks after the completion of neoadjuvant chemo-radiotherapy. Mean ADC values of regions of interest were evaluated by two radiologists. The tumor response was evaluated according to RESCIST 1.1. The cut-off value for the mean ADC and increasing percentage (ΔADC%) after neoadjuvant chemo-radiotherapy was calculated using the receiver operating characteristic curve. The response rate of pre-ADC and ΔADC% above/below the cut-off values was determined using the chi-square test, respectively. Primary tumor progression-free survival (PFS) was analyzed using the Kaplan–Meier method, based on the pre-ADC and ΔADC% cut-off values.

Results

The cut-off value of mean pre-ADC and ΔADC% was 0.94 × 10^–3 mm²/s (80.36% sensitivity, 74.29% specificity) and 26.0% (73.21% sensitivity, 77.14% specificity), respectively. Lower mean pre-ADC values were related to a better response rate (83.3% vs 29.7%, P < 0.001) and PFS (26.12 vs 17.70 months, P = 0.004). ΔADC% above the cut-off value was also related to a better response rate (83.7% vs 35.7%, P < 0.001) and PFS (26.93 vs 15.65 months, P = 0.034).

Conclusions

The mean ADC pre-treatment value and ΔADC% were potential predictors for the tumor response in locally advanced rectal cancer patients treated with neoadjuvant chemo-radiotherapy.

Efficacy and safety of intraoperative radiotherapy in rectal cancer: A systematic review and meta-analysis

BACKGROUND

In recent years, intraoperative radiotherapy (IORT) has been increasingly used for the treatment of rectal cancer. However, the efficacy and safety of IORT for the treatment of rectal cancer are still controversial.

AIM

To evaluate the value of IORT for patients with rectal cancer.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science databases, and conference abstracts and included randomized controlled trials and observational studies on IORT vs non-IORT for rectal cancer. Dichotomous variables were evaluated by odds ratio (OR) and 95% confidence interval (CI), hazard ratio (HR) and 95%CI was used as a summary statistic of survival outcomes. Statistical analyses were performed using Stata V.15.0 and Review Manager 5.3 software.

RESULTS

In this study, 3 randomized controlled studies and 12 observational studies were included with a total of 1460 patients, who are mainly residents of Europe, the United States, and Asia. Our results did not show significant differences in 5-year overall survival (HR = 0.80, 95%CI = 0.60-1.06; P = 0.126); 5-year disease-free survival (HR = 0.94, 95%CI = 0.73-1.22; P = 0.650); abscess (OR = 1.10, 95%CI = 0.67-1.80; P = 0.713), fistulae (OR = 0.79, 95%CI = 0.33-1.89; P = 0.600); wound complication (OR = 1.21, 95%CI = 0.62-2.36; P = 0.575); anastomotic leakage (OR = 1.09, 95%CI = 0.59-2.02; P = 0.775); and neurogenic bladder dysfunction (OR = 0.69, 95%CI = 0.31-1.55; P = 0.369). However, the meta-analysis of 5-year local control was significantly different (OR = 3.07, 95%CI = 1.66-5.66; P = 0.000).

CONCLUSION

The advantage of IORT is mainly reflected in 5-year local control, but it is not statistically significant for 5-year overall survival, 5-year disease-free survival, and complications.

Impact of Nutritional Indices on the Survival Outcomes of Patients with Colorectal Cancer

Background

The effect of preoperative nutritional status on the survival of patients with colorectal cancer is still unknown. The purpose of our study was to examine the impact of the prognostic nutritional index (PNI), prealbumin (PAB) and the albumin to globulin ratio (AGR) on survival outcomes in patients with colon and rectal cancer.

Methods

Between January 2012 and December 2013, 361 patients with colorectal cancer who underwent curative surgery in the survey and various clinical and haematological parameters were recorded. The optimal cut-off values of the PNI, PAB and AGR were determined by MedCalc software, and Cox regression analysis was performed to investigate the effect of the PNI, PAB and AGR on the overall survival (OS) of patients with colon and rectal cancer.

Results

In patients with colon and rectal cancer, a high PNI, PAB, and AGR correlate with higher survival times. Receiver operating characteristic (ROC) curve analysis showed that at most time points, the PNI has a higher area under the curve (AUC) in predicting colon and rectal cancer OS. Multivariate Cox regression analysis showed that of the PNI, PAB and AGR, only the PNI was an independent risk factor for OS in patients with colon and rectal cancer. Patients with a high PNI were predicted to have higher OS (hazard ratio [HR]: 0.479; 95% confidence interval [CI]: 0.233–0.985; P = 0.045) in colon cancer and higher OS (HR: 0.225; 95% CI: 0.111–0.454; P < 0.001) in rectal cancer compared with patients with a low PNI.

Conclusion

Preoperative PNI, PAB and AGR may be predictors of OS in patients with colon and rectal cancer after radical surgery, especially the PNI, which has a good ability to predict OS in both tumours.