Rectal cancer radiotherapy

The effect of adjuvant chemoradiotherapy on survival after R0 resection for stage III-N2 nonsmall cell lung cancer: A meta-analysis

BACKGROUND

Adjuvant chemotherapy is still the standard treatment for stage III-N2 nonsmall cell lung cancer after R0 resection, and it is still controversial whether conventional adjuvant radiotherapy is needed. We used meta-analysis to try to answer whether adjuvant postoperative chemoradiotherapy (POCRT) can bring survival benefits to patients with stage III-N2 nonsmall cell lung cancer after R0 resection.

METHODS

Up to June 25, 2021, the databases of PubMed, Embase, Cochrane Library, CNKI, and Wanfang were searched, and clinical studies on POCRT for stage III-N2 nonsmall cell lung cancer were included. RevMan5.4 software was used for meta-analysis.

RESULTS

A total of 8959 patients were included in 5 randomized controlled trials and 17 retrospective studies. The results of the meta-analysis showed that POCRT could improve 3 and 5 years overall survival (OS) rate (OR = 1.52, 95%CI: 1.05-2.20; OR = 1.30, 95%CI: 1.16-1.46), 3 and 5 years disease-free survival (DFS) rate (OR = 1.34, 95%CI: 1.01-1.76; OR = 1.74, 95%CI: 1.43-2.12), and 5-year locoregional recurrence-free survival (LRFS) rate (OR = 2.69, 95%CI: 1.76-4.11) in patients with stage III-N2 nonsmall cell lung cancer compared with adjuvant postoperative chemotherapy (POCT) alone. But could not improve 5-year distant metastasis-free survival (DMFS) rate (OR = 1.14, 95%CI: 0.52-2.52). The results of subgroup analysis showed that postoperative sequential chemoradiotherapy could improve the 3 and 5 years OS rate (OR = 2.06, 95%CI: 1.22-3.46; OR = 1.39, 95%CI: 1.21-1.59). Three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) can improve the 3 and 5 years OS rate (OR = 1.80, 95%CI: 1.09-2.99; OR = 1.31, 95%CI: 1.04-1.66). In addition, POCRT could improve the 3-year OS rate (OR = 1.88, 95%CI: 1.21-2.92) in patients with N2 single-station lymph node metastasis compared with POCT alone.

CONCLUSION

Compared with POCT alone, adjuvant POCRT can significantly improve the overall survival rate of patients with NSCLC after R0 resection of stage III-N2, especially in patients with N2 single-station lymph node metastasis. Accurate radiotherapy techniques such as 3DCRT or IMRT are recommended, and postoperative sequential chemoradiotherapy is the best treatment mode.

Total Mesorectal Excision vs. Transanal Endoscopic Microsurgery Followed by Radiotherapy for T2N0M0 Distal Rectal Cancer: A Multicenter Randomized Trial

Introduction

Transanal endoscopic microsurgery (TEM) is an organ-preserving treatment alternative for patients with early rectal cancer. However, TEM alone is associated with greater risk of local recurrence and inferior survival in comparison with total meso-rectal excision (TME). As an important adjuvant therapy, radiotherapy can effectively reduce the local recurrence rate of rectal cancer. This study aimed to investigate whether TEM followed by radiotherapy can be a valid alternative to TME in T2N0M0 distal rectal cancer treatment.

Methods

We plan to recruit 168 participants meeting established inclusion criteria. Following informed consent, participants will randomly receive treatment protocols of TEM followed by radiotherapy (a total dose of 45–50.4 Gy given in 25–28 factions) or TME. Depending on post-operative pathology, the participants will receive either long-term follow-up or further treatment. The primary endpoint of this trial is 3-year local recurrence rate. The secondary end points include 3-year disease-free survival rate, 3-year overall survival rate, 3-year mortality rate, post-operative quality of life, post-operative safety index, intraoperative evaluation index and post-operative short-term evaluation index.

Discussion

This trial is the first prospective randomized trial to investigate the rectum preserving treatment by using transanal local excision followed by radiotherapy.

Clinical trial registration

The trial was prospectively registered at ClinicalTrials.gov NCT04098471 on September 20, 2019.

Urinary adverse effects of pelvic radiotherapy

Objective

Radiation is an integral part of the treatment of many pelvic tumors. The cellular death induced by radiotherapy (RT) benefits cancer control but can also result in adverse effects (AEs) on the organ being treated or those adjacent to it. RT for cancers of the pelvis (bladder, prostate, rectum, uterus or cervix) can result in AEs in the urinary tract. While the acute urinary AEs of pelvic RT are well described, late AEs are less well characterized. The burden of treatment for late AEs may be large given the prevalence of tumors in the pelvis and the high utilization of RT to treat them.

Review

For prostate cancer, grade 1 and 2 urinary AEs following external beam radiation therapy (EBRT) are reported to occur in 20-43% and 7-19%, respectively, with a follow up of 10 years. Three-year cumulative risk for grade ≥2 urinary AEs is 28-30%. Following brachytherapy (BT), rates of urinary AEs at 5 years are reported to be 36%, 24%, 6.2% and 0.1% for Radiation Therapy Oncology Group (RTOG) grade 1, 2, 3, and 4, respectively. For bladder cancer, with a median follow-up of 5 years, 7-12% of patients who receive RT experience urinary AEs of grade 3 or more. For cervical cancer, there remains a 0.25% per year risk of severe AEs for at least 25 years following RT, and ureteral stricture is a well-described AE. For endometrial cancer, severe urinary AEs are rare, but at 13 years of follow up, patients report a significantly worse quality of life with respect to urinary function. In rectal cancer, preoperative RT has a lower risk of AEs than postoperative RT, and few urinary AEs are reported in the literature.

Conclusions

Urinary AEs can manifest long after RT, and there is a paucity of studies describing rates of these long-term AEs. It is important that the possible complications of RT are recognized by providers and properly communicated to patients so that they are able to make informed decisions about their cancer treatment.

Morphology and prognostic value of tumor budding in rectal cancer after neoadjuvant radiotherapy

Tumor budding is an acknowledged prognostic marker in colorectal cancer. This study was conducted to investigate the morphology and prognostic significance of budding in rectal cancer after neoadjuvant radiotherapy. Surgical specimens from 96 consecutive patients who underwent neoadjuvant radiotherapy and curative resection were retrieved to assess budding and other clinicopathologic factors. The morphology and prognostic significance of postirradiation tumor budding were closely associated with tumor regression grade. In the tumor regression grade 1 group, tumor budding presented as "false budding" and did not have a significant association with prognosis. In the tumor regression grade 2 and 3 groups, budding was observed surrounded by radiation-induced fibrosis and large populations of infiltrating inflammatory cells, and budding intensity was significantly associated with histologic differentiation, ypN stage, and lymphovascular invasion (P < .05). Moreover, the low-grade budding subgroup showed a significantly higher rate of 5-year disease-free survival than the high-grade budding subgroup (87.5% versus 55.6%, P < .0001). Multivariate analysis showed that pretreatment serum carcinoembyronic antigen, tumor regression grade, and tumor budding were the major independent factors affecting long-term disease-free survival. In conclusion, postirradiation budding has distinct morphology and prognostic significance in rectal cancer after neoadjuvant radiotherapy.

Long-term urinary adverse effects of pelvic radiotherapy

OBJECTIVE

Radiation for tumors arising in the pelvis has been utilized for over a 100 years. Adverse effects (AEs) of radiotherapy (RT) continue to accumulate with time and are reported to show decades after treatment. The benefit of RT for pelvic tumors is well described as is their acute AEs. Late AEs are less well described. The burden of treatment for the late AEs is large given the high utilization of RT.

REVIEW

For prostate cancer, 37% of patients will receive radiation during the first 6 months after diagnosis. Low-and high-grade AEs are reported to occur in 20-43 and 5-13%, respectively, with a median follow-up of ~60 months. For bladder cancer, the grade 2 and grade 3 late AEs occur in 18-27 and 6-17% with a median follow-up of 29-76 months. For cervical cancer, the risk of low-grade AEs following radiation can be as high as 28%. High-grade AEs occur in about 8% at 3 years and 14.4% at 20 years or ~0.34% per year. Radiation AEs appear to be less common or at least less well studied after radiation for rectal and endometrial cancers.

CONCLUSION

Properly delineating the rate of long-term AEs after pelvic RT is instrumental to counseling patients about their options for cancer treatment. Further studies are needed that are powered to specifically evaluate long-term AEs.

Magnetic resonance imaging in locoregional staging of rectal adenocarcinoma

A comprehensive overview of the current status of magnetic resonance imaging (MRI) in the locoregional assessment and management of rectal adenocarcinoma is presented. Staging systems for rectal cancer and treatment strategies in its management are discussed to give the reader the context that shapes MRI acquisition techniques and interpretation. Findings on MRI are detailed and their accuracy reviewed based on currently available evidence. Optimization of MRI acquisition and relevant pelvic anatomy are reviewed. A detailed description of our approach in interpreting MRI for locoregional staging of rectal cancer is given and future directions are also introduced.