Outcomes of neoadjuvant chemoradiotherapy followed by total mesorectal excision surgery for locally advanced rectal cancer: a single-institution experience

Identification of patients with locally advanced rectal cancer eligible for neoadjuvant chemotherapy alone: Results of a retrospective study

BACKGROUND AND OBJECTIVES

Neoadjuvant chemotherapy (nCT) appears in a few clinical studies as an alternative to neoadjuvant chemoradiation (nCRT) in selected patients with locally advanced rectal cancer (LARC). We aimed to compare the clinical outcomes of nCT with or without nCRT in patients with LARC and to identify patients who may be suitable for nCT alone.

MATERIALS AND METHODS

A total of 155 patients with LARC who received neoadjuvant treatment (NT) were retrospectively analysed from January 2016 to June 2021. The patients were divided into two groups: nCRT (n = 101) and nCT (n = 54). More patients with locally advanced disease (cT4, cN+ and magnetic resonance imaging-detected mesorectal fascia [mrMRF] positive [+]) were found in the nCRT group. Patients in the nCRT group received a dose of 50 Gy/25 Fx irradiation with concurrent capecitabine, and the median number of nCT cycles was two. In the nCT group, the median number of cycles was four.

RESULTS

The median follow-up duration was 30 months. The pathologic complete response (pCR) rate in the nCRT group was significantly higher than that in the nCT group (17.5% vs. 5.6%, p = 0.047). A significant difference was observed in the locoregional recurrence rate (LRR); 6.9% in the nCRT group and 16.7% in the nCT group (p = 0.011). Among patients with initial mrMRF (+) status, the LRR in the nCRT group was significantly lower than that in the nCT group (6.1% vs. 20%, p = 0.007), but not in patients with initial mrMRF negative (-) (10.5% in each group, p = 0.647). Compared with the nCT group, a lower LRR was observed in patients in the nCRT group with initial mrMRF (+) converted to mrMRF (-) after NT (5.3% vs. 23%, p = 0.009). No significant difference was observed between the two groups regarding acute toxicity and overall and progression-free survivals. Multivariate analysis showed that nCRT and ypN stage were independent prognostic factors for the development of LRR.

CONCLUSION

Patients with initial mrMRF (-) may be suitable for nCT alone. However, patients with initial mrMRF (+) converted to mrMRF (-) after nCT are still at high risk of LRR, and radiotherapy is recommended. Prospective studies are required to confirm these findings.

Analysis of Survival in Complete Pathological Response after Long-Course Chemoradiotherapy in Patients with Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy prior to surgery is the standard treatment for locally advanced rectal cancer. This consists in the patient's complete pathological response being achieved with no residual tumor presence in the resected specimen, which results in survival improvement.

METHODS

This retrospective study aimed to examine the rate of complete pathological response in patients with advanced rectal cancer treated with neoadjuvant long-course chemoradiotherapy and to examine the survival differences between the different tumor regression grade (TRG) scores.

RESULTS

A total of 154 patients were operated prior to long-course chemoradiotherapy with a total of 50 Gy plus FOLFOX protocol. Complete pathologic response was achieved in 29 (18.8%) patients. There was no statistical difference for the different pathologic responses according to gender, type of surgery, and number of harvested lymph nodes. Mean survival for all the groups was 37.2 months. Survival within a different TRG score exhibited statistical significance (p = 0.006). Overall, the survival rate during the follow-up period was of 81.8%.

CONCLUSIONS

The complete pathological response rate in this study was of 18.8%. High tumor regression grade scores (TRG0 and TRG1) had a survival rate of over 90% during follow-up. Multivariate analysis identified perineural invasion and tumor regression grade as independent factors that affect survival.

Survival landscape of different tumor regression grades and pathologic complete response in rectal cancer after neoadjuvant therapy based on reconstructed individual patient data

BACKGROUND

Neoadjuvant therapy can lead to different tumor regression grades (TRG) in rectal cancer after neoadjuvant therapy. The purposes of this study are to investigate the relationships among TRG, pathologic complete response (pCR) and long-term survival, on the basis of reconstructed individual patient data (IPD).

METHODS

The PubMed, Embase, Ovid and Cochrane CENTRAL databases were searched. The primary endpoint was to evaluate the survival landscape of different TRGs after neoadjuvant therapy and the secondary endpoint was to evaluate the associations between pCR and survival. IPD were reconstructed with Kaplan-Meier curves.

RESULTS

The 10-year overall survival (OS) and 5-year disease-free survival (DFS) were clearly higher in the pCR group than in the non-pCR (npCR) group (80.5% vs. 48.3, 90.1% vs. 69.8%). Furthermore, the OS and DFS increased with improvement in tumor regression after neoadjuvant therapy. According to the IPD, the pCR group had longer OS (HR = 0.240, 95% CI = 0.177-0.325, p < 0.001) and DFS (HR = 0.274, 95% CI = 0.205-0.367, p < 0.001) than the npCR group. Better tumor regression was associated with better survival outcomes (p < 0.005). Direct calculation of published HR values yielded similar results.

CONCLUSIONS

Our results indicate a positive relationship between better tumor regressions and improved survival benefits among the npCR group and patients with rectal cancer achieving pCR had much longer OS and DFS than patients achieving npCR, presenting a survival landscape of different TRGs and pCR in rectal cancer after neoadjuvant therapy.

Short course radiotherapy and delayed surgery for locally advanced rectal cancer in frail patients: is it a valid option?

OBJECTIVE

The endpoint of the present study was to evaluate the outcomes of short-course radiotherapy (SCRT) and SCRT with delayed surgery (SCRT-DS) on a selected subgroup of frail patients with locally advanced middle/low rectal adenocarcinoma.

METHODS

From January 2008 to December 2018, a total of 128 frail patients with locally advanced middle-low rectal adenocarcinoma underwent SCRT and subsequent restaging for eventual delayed surgery. Rates of complete pathological response, down-staging, disease free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

128 patients completed 5 × 5 Gy pelvic radiotherapy. 69 of these were unfit for surgery; 59 underwent surgery 8 weeks (average time: 61 days) after radiotherapy. Downstaging of T occurred in 64% and down-staging of N in 50%. The median overall survival (OS) of SCRT alone was 19.5 months. The 1-year, 2-year, 3-year and 5-year OS was 48%, 22%, 14% and 0% respectively. In the surgical group, the median disease-free survival (DFS) and median OS were, respectively, 67 months (95% CI 49.8-83.1 months) and 72.1 months (95% CI 57.5-86.7 months). The 1, 2, 3, 5-year OS was 88%, 75%, 51%, 46%, respectively. Post-operative morbidity was 22%, mortality was 3.4%.

CONCLUSIONS

Frail patients with advanced rectal cancer are often "unfit" for long-term neoadjuvant chemoradiation. A SCRT may be considered a valid option for this group of patients. Once radiotherapy is completed, patients can be re-evaluated for surgery. If feasible, SCRT and delayed surgery is the best option for frail patients.

Late gastrointestinal toxicity after radiotherapy for rectal cancer: a systematic review

PURPOSE

Although the multimodal cancer treatment techniques have greatly improved over the years, irradiation-induced late gastrointestinal toxicity remains a great concern as it may highly affect the quality of life of a patient. The aim of this study was to define the prevalence of late gastrointestinal toxicities.

METHODS

Electronic databases of Cochrane Library, Embase, Web of Science, CENTRAL and PubMed were searched until September 2019. We used the following keywords: radiotherapy, radiation therapy, irradiation, rectal cancer, gastrointestinal toxicity, adverse effects, late effects, pelvic radiation and pelvic radiation disease.

RESULTS

Nine studies were included into this review out of 4785 that were preidentified as potentially relevant. Overall prevalence of severe (Grade 3 or higher) late irradiation-induced gastrointestinal toxicities was up to 19%. Most frequent toxicities of any grade were reported to be diarrhoea (up to 35%), faecal incontinence (22%), incontinence to gas (71%), rectal bleeding (9%), rectal pain (13%) and obstruction (7.4%). Preoperative treatment approaches and more advance radiotherapy techniques such as intensity-modulated and image-guided radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) turn out to result in lower late gastrointestinal toxicity rates.

CONCLUSION

After great improvements in rectal cancer treatment, late gastrointestinal toxicity after radiotherapy is experienced less frequent and less severe; however, it remains a great concern associated with worse quality of life.

Radiation therapy for rectal cancer

Radiotherapy (RT) has remained an important pillar in the multi-modality management of rectal cancer. Adjuvant RT with concurrent chemotherapy (chemo-RT) was once the standard of care for locally advanced rectal cancer, but with time, that has now changed and neoadjuvant chemo-RT followed by total mesorectal excision (TME) surgery is the new standard. Alternatively, neoadjuvant RT alone remains an option and clinicians are tasked to choose between the two. In an era of personalised oncological management, it is unsurprising that the treatment for rectal cancer is following suit and upcoming trials are studying ways to improve outcomes and minimise toxicity for patients while tailoring treatments specific to each patient's tumour. We review the evolution of the role of RT in rectal cancer and look forward to what the future holds.

MAP17 (PDZK1IP1) and pH2AX are potential predictive biomarkers for rectal cancer treatment efficacy

Rectal cancer represents approximately 10% of cancers worldwide. Preoperative chemoradiotherapy increases complete pathologic response and local control, although it offers a poor advantage in survivorship and sphincter saving compared with that of radiotherapy alone. After preoperative chemoradiotherapy, approximately 20% of patients with rectal cancer achieve a pathologic complete response to the removed surgical specimen; this response may be related to a better prognosis and an improvement in disease-free survival. However, better biomarkers to predict response and new targets are needed to stratify patients and obtain better response rates.

MAP17 (PDZK1IP1) is a small, 17 kDa non-glycosylated membrane protein located in the plasma membrane and Golgi apparatus and is overexpressed in a wide variety of human carcinomas. MAP17 has been proposed as a predictive biomarker for reactive oxygen species, ROS, inducing treatments in cervical tumors or laryngeal carcinoma. Due to the increase in ROS, MAP17 is also associated with the marker of DNA damage, phosphoH2AX (pH2AX). In the present manuscript, we examined the values of MAP17 and pH2AX as surrogate biomarkers of the response in rectal tumors. MAP17 expression after preoperative chemoradiotherapy is able to predict the response to chemoradiotherapy, similar to the increase in pH2AX. Furthermore, we explored whether we can identify molecular targeted therapies that could help improve the response of these tumors to radiotherapy. In this sense, we found that the inhibition of DNA damage with olaparib increased the response to radio- and chemotherapy, specifically in tumors with high levels of pH2AX and MAP17.