Population-based study of effectiveness of neoadjuvant radiotherapy on survival in US rectal cancer patients according to age

Effect of adjuvant chemotherapy on the oncological outcome of rectal cancer patients with pathological complete response

BACKGROUND

Locally advanced rectal cancer is typically treated using a combination of neoadjuvant chemoradiotherapy and total mesorectal resection. While achieving pathological complete response following neoadjuvant chemoradiotherapy has been recognized as a positive prognostic factor in oncology, the necessity of adjuvant chemotherapy for locally advanced rectal cancer patients with pathological complete response after surgery remains uncertain. The objective of this meta-analysis was to examine the impact of adjuvant chemotherapy on the oncological outcomes of rectal cancer patients who attain pathological complete response after neoadjuvant chemoradiotherapy.

METHODS

This meta-analysis followed the guidelines outlined in the preferred reporting items for systematic review and meta-analysis (PRISMA). The Web of Science, PubMed, and Cochrane Library databases were systematically searched to identify relevant literature.

RESULTS

A total of 34 retrospective studies, including 9 studies from the NCBD database, involving 31,558 patients with pathological complete response rectal cancer, were included in the meta-analysis. The included studies were published between 2008 and 2023. The pooled analysis demonstrated that adjuvant chemotherapy significantly improved overall survival (HR = 0.803, 95% CI 0.678-0.952, P = 0.011), and no heterogeneity was observed (I2 = 0%). Locally advanced rectal cancer patients with pathological complete response who underwent adjuvant chemotherapy exhibited a higher 5-year overall survival rate compared to those who did not receive adjuvant chemotherapy (OR = 1.605, 95% CI 1.183-2.177, P = 0.002). However, the analysis also revealed that postoperative ACT did not lead to improvements in disease-free survival and recurrence-free survival within the same patient population. Subgroup analysis indicated that pathological complete response patients with clinical stage T3/T4, lymph node positivity, and younger than 70 years of age may benefit from adjuvant chemotherapy in terms of overall survival.

CONCLUSIONS

The findings of this meta-analysis suggest that adjuvant chemotherapy has a beneficial effect on improving overall survival among rectal cancer patients with pathological complete response. However, no such association was observed in terms of disease-free survival and recurrence-free survival.

Prognostic Factors of Rectal Cancer in Southern Iran

BACKGROUND

Rectal cancer accounts for one-third of all colorectal cancer (CRC) cases. Due to physiological and anatomical differences, some researchers consider rectal cancer as a separate organ malignancy during the recent decades. However, limited studies have been conducted in this regard in Iran. Therefore, the aim of this study is to determine survival of rectal cancer and its^, affecting factors in Fars province, southern Iran.

METHODS

In this cohort study, we used the data of 387 patients with rectal cancer gathered by the Colorectal Research Center of Shiraz University of Medical Sciences between 2007 and 2015. The impact of 35 explanatory factors including demographic information, medical history, pathologic data, and imaging findings was evaluated using Cox regression analysis.

RESULTS

Out of all patients, 111 ones (29%) died. The median follow-up period was 36 months. The patients' mean age at diagnosis was 56.72 ± 13.89 years. Their 5-year survival was 65% (95% CI: 58-69%). The results of multiple Cox regression analysis showed that sex (male/female; HR = 1.73, 95% CI: 1.15-2.67), vascular invasion (yes/no; HR = 2.40, 95% CI: 1.45-3.99), and lymph node ratio (> 0.2 vs ≤ 0.2; HR = 2.19, 95% CI: 1.41-3.40) were significantly correlated to survival.

CONCLUSION

Various geographical parts of Iran show different rates regarding rectal cancer survival. A better 5-year survival rate was detected by this study for the patients with rectal cancer in Fars province, southern Iran, compared to many parts of the country. Moreover, gender, vascular invasion, and nodal status played an important role in survival of rectal cancer.

Prognostic Factors Affecting Short- and Long-Term Recurrence-Free Survival of Patients with Rectal Cancer using Cure Models: A Cohort Study

Background:

Understanding the prognostic factors affecting the recurrence-free survival (RFS) of patients with rectal cancer (RC) is the mainstay of care. The present study aimed to identify factors affecting both short- and long-term RFS of patients with RC using semiparametric mixture cure models.

Methods:

The data were obtained from the database of the Colorectal Research Center of Shiraz University of Medical Sciences, Shiraz, Iran, which was collected during 2007-2017. To determine the factors affecting recurrence, cure models were applied to short-term and long-term RFS of patients with RC separately. The cure rate was calculated using the smcure package in R 3.5.1 (2018-07-02) software. P<0.05 was considered statistically significant.

Results:

Out of the 376 eligible patients with RC, 75.8% of men and 74.5% of women were long-term survivors. The mean age of the patients was 57.0±13.8 years. Lymph node ratio (LNR)≤0.2 increased the probability of short-term RFS. The prominent factors affecting long-term RFS were body mass index (BMI)<25 kg/m² (OR=1.98, P=0.047), tumor-node-metastasis (TNM) stage (OR=6.48, P<0.001), abdominal pain (OR=2.15, P=0.007), and computed tomography (CT) scan detected pelvic lymph nodes (OR=3.40, P=0.01). Over a 9-year follow-up period, the empirical and estimated values of cure rates were 75.3% and 83.9%, respectively.

Conclusion:

The results showed that factors affecting short-term RFS might be different from long-term RFS. A lower BMI was related to a poorer prognosis in patients with RC. Early diagnosis leads to a lower TNM stage and could increase the probability of long-term RFS.

How to improve clinical research in a department of radiation oncology

INTRODUCTION

Radiation therapy is a core modality for cancer treatment. Around 40% of cancer cures include the use of radiotherapy, either as a single strategy or combined with other treatments. In the past decade, substantial technical advances and novel insights into radiobiological properties have considerably improved patients' outcomes. This study overviewed the landscape of clinical research at our radiotherapy department.

METHODS

We surveyed our institutional database of clinical trials to collect information for completed or ongoing radiation therapy clinical trials, from 2005 to December 2017 at the Lucien Neuwirth cancer institute.

RESULTS

A total of 31 clinical trials were undertaken during the study period, of which 4 studies (12.9%) were industry-sponsored and 3 studies (9.7%) were launched by our radiotherapy unit. The vast majority of clinical trials (83.9%) were dedicated to unique organ localization, especially urological cancer (prostate or bladder) (42%). We also observed a shift towards more phase II trials during the study period as well as a special focus on elderly population. Over the last decade, the number of included patients increased by a 5.3 fold input, with 135 inclusions before 2011 and 720 inclusions after 2011.

DISCUSSION

This study provided an observational and comprehensive analysis of radiotherapy research. From a monocentric point-of-view, these results reflected the on-going progress of worldwide radiotherapy research. Based on a 13-years' experience, this study aimed at highlighting essential cues to ensure efficient and perennial research.

Cardiovascular diseases in survivors of childhood cancer

Over the past few decades, the diagnosis and management of children with various malignancies have improved tremendously. As a result, there are an increasing number of children who are long-term cancer survivors. With improved survival, however, has come an increased risk of treatment-related cardiovascular complications that can appear decades after treatment. These problems are serious enough that all caregivers of childhood cancer survivors, including oncologists, cardiologists, and other health care personnel, must pay close attention to the short- and long-term effects of chemotherapy and radiotherapy on these children. This review discusses the effects of treatment-related cardiovascular complications from anthracyclines and radiotherapy and the methods for preventing, screening, and treating these complications.

Pleotropic role of RNA binding protein CELF2 in autophagy induction

We previously reported that ionizing radiation (IR) mediates cell death through the induction of CUGBP elav-like family member 2 (CELF2), a tumor suppressor. CELF2 is an RNA binding protein that modulates mRNA stability and translation. Since IR induces autophagy, we hypothesized that CELF2 regulates autophagy-mediated colorectal cancer (CRC) cell death. For clinical relevance, we determined CELF2 levels in The Cancer Genome Atlas (TCGA). Role of CELF2 in radiation response was carried out in CRC cell lines by immunoblotting, immunofluorescence, autophagic vacuole analyses, RNA stability assay, quantitative polymerase chain reaction and electron microscopy. In vivo studies were performed in a xenograft tumor model. TCGA analyses demonstrated that compared to normal tissue, CELF2 is expressed at significantly lower levels in CRC, and is associated with better overall 5-year survival in patients receiving radiation. Mechanistically, CELF2 increased levels of critical components of the autophagy cascade including Beclin-1, ATG5, and ATG12 by modulating mRNA stability. CELF2 also increased autophagic flux in CRC. IR significantly induced autophagy in CRC which correlates with increased levels of CELF2 and autophagy associated proteins. Silencing CELF2 with siRNA, mitigated IR induced autophagy. Moreover, knockdown of CELF2 in vivo conferred tumor resistance to IR. These studies elucidate an unrecognized role for CELF2 in inducing autophagy and potentiating the effects of radiotherapy in CRC.

Comparative survival analysis of preoperative and postoperative radiotherapy in stage II-III rectal cancer on the basis of long-term population data

This study compared long-term population-based survival outcomes of preoperative and postoperative radiotherapy (RT) approaches in rectal cancer. Patients with stage II-III rectal cancer between 1998 and 2013 were identified using the Surveillance, Epidemiology, and End Results database. Overall survival (OS) and disease-specific survival (DSS) rates were estimated in propensity-matched study population according to the use of RT. Among the 28,320 eligible patients, a total of 18,400 patients were identified from propensity score matching process balancing the distribution of prognostic covariates. The 10-year OS and DSS rates were higher in patients with preoperative RT than the postoperative group (51.6% vs. 49.8% with P < 0.001, and 65.4% vs. 64.8% with P = 0.037, respectively). However, in multivariate analysis, selection of combined RT sequence did not affect the survival (hazard ratio [HR] 1.04 and 95% confidence interval [CI] 0.98−1.10 for OS; HR 0.97 and 95% CI 0.90−1.05 for DSS). Regarding hazard rate functions of cancer-specific mortality, the overall time-course risks after preoperative and postoperative RT were comparable. This study provides additional insight into the long-term prognostic implications of the two RT strategies, suggesting that the sequence of RT does not lead to differential survival in stage II-III rectal cancer.