Impact of Time Interval Between Chemoradiation and Surgery on Pathological Complete Response and Survival in Rectal Cancer

Exploring treatment outcomes in Stage II-III rectal cancer patients undergoing neoadjuvant therapy at a tertiary care center in Pakistan: a comprehensive analysis of pathological outcomes

BACKGROUND

Rectal cancer treatment has transformed in recent years, with neoadjuvant treatment (NT) and total neoadjuvant treatment (TNT) aiming to enhance pathological responses. This pioneering study in our country delves into rectal cancer management, offering crucial insights by examining pathological outcomes in patients treated with the NT and TNT approach, shaping the evolving landscape.

METHODS

In this retrospective-cohort study spanning January 2017 to December 2022 at a tertiary care hospital in Pakistan, ethical approval was obtained to examine outcomes of two treatments. Patients were divided into TNT (chemoradiation and pre-surgery 5 FU-based chemotherapy) and NT (chemoradiation, surgery, and subsequent 5 FU-based chemotherapy). The primary end-point was response rates-no response, pathological complete response (pCR), near complete response (near CR), and partial response (PR). The Chi-Square Test for Independence assessed the association between treatment response and type (TNT or NT). Data analysis used STATA MP 64; significance was set at p < 0.05 for all two-tailed tests.

RESULTS

We analyzed 77 patients, 60 underwent standard neoadjuvant chemoradiation, and 17 followed the total neoadjuvant approach. Predominantly male, most were > 65 with ECOG 0-1. The TNT group showed higher response rates (76% vs 62%, p = 0.039), with 40.38% achieving pCR. In the overall population, pCR and near-CR were similar (27.2% vs 26%), while PR were 14%. Treatment characteristics correlated significantly with chemotherapy type, concurrent chemoradiation, LVI, PNI, and T, N, M staging (p < 0.05). Median overall survival was not reached, and mean survival was 89.1 months (CI: 95.0 to 83.3). Side effects varied, with notable differences in neuropathy, diarrhea, oral mucositis, and thrombocytopenia between NT and TNT groups.

CONCLUSION

Our study adds to evidence favoring neoadjuvant approaches in managing rectal cancer in pakistan. Demonstrating a favorable pcr rate, ongoing research with extended follow-up is essential, given the dynamic landscape of rectal cancer treatment for improved patient outcomes.

Does a long interval between neoadjuvant chemoradiotherapy and surgery benefit the clinical outcomes of locally advanced rectal cancer? A systematic review and meta analyses

PURPOSE

The study aims to systematically evaluate the clinical efficacy after 8 weeks (long interval, LI) between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer.

METHODS

The PubMed database, EMBASE database, and the Cochrane Library (deadline: September 25, 2021) were searched to select clinical studies that compared two intervals between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer: after 8 weeks (long interval, LI) and within 8 weeks (short interval, SI). The included studies were screened and evaluated according to the inclusion and exclusion criteria, and meta-analysis was performed by RevMan 5.3 software.

RESULTS

Eighteen studies were included, with 9070 cases in the LI group and 14,207 cases in the SI group. The analysis results showed that the pathologic complete response (PCR) rate in the LI group was higher than that in the SI group (P < 0.00001). There was no significant difference in the R0 resection rate (P = 0.85), anal preservation rate (P = 0.89), morbidity rate (P = 0.60), anastomotic leakage rate (P = 0.06), operation time (P = 0.58), local recurrence rate (P = 0.56), distant metastasis rate (P = 0.32), or overall survival (OS) rate (P = 0.17) between the two groups.

CONCLUSION

A longer interval between neoadjuvant chemoradiotherapy and surgery can improve the PCR rate; however, it has no significant impact on the clinical efficacy or long-term prognosis. Due to some limitations in the number and quality of the studies, these findings still need to be further verified by multicenter, large-sample high-quality RCTs in the future.

The time Interval Between the End of Radiotherapy and Surgery Does Not Affect Outcomes in Rectal Cancer

INTRODUCTION

The ideal time interval between the completion of chemoradiotherapy and subsequent surgical resection of advanced stage rectal tumors is highly debated. Our aim is to study the effect of the time interval between the completion of chemoradiotherapy and surgical resection on postoperative and oncologic outcomes in rectal cancer.

METHODS

Patients who underwent neoadjuvant chemoradiotherapy for resected locally advanced rectal tumors between 2004 and 2015 were included in this analysis. The time interval was calculated from the date of radiation completion to date of surgery. Patients were split into 2 groups based on the time interval (<8 weeks and >8 weeks). Postoperative outcomes (anastomotic leak, pathologic complete response (pCR), and readmission) and survival were assessed with multivariable logistic regression and Cox regression models while adjusting for relevant confounders.

RESULTS

200 patients (62% male) underwent resection with a median time interval of 8 weeks from completion of radiotherapy. On multivariable logistic regression, there was no significant increase in odds between time interval to surgery and anastomotic leak (aOR = .8 [.27-2.7], P = .8), pCR (aOR = 1.2[.58-2.6] P = .6), or readmission (aOR = 1.02, 95% CI:0.49-2.24, P = .9). Time interval to surgery was not an independent prognostic factor for overall (HR = 1.04 CI = .4-2.65, P = .9) and disease-free survival (HR = 1.2 CI = .5-2.9, P = .6).

CONCLUSION

The time interval between neoadjuvant radiotherapy completion and surgical resection does not affect anastomotic leak rate, achievement of pCR, or overall and disease-free survival in patients with rectal cancer. Extended periods of time to surgical resection are relatively safe.

Temporal determinants of tumour response to neoadjuvant rectal radiotherapy

Introduction

In locally advanced rectal cancer, longer delay to surgery after neoadjuvant radiotherapy increases the likelihood of histopathological tumour response. Chronomodulated radiotherapy in rectal cancer has recently been reported as a factor increasing tumour response to neoadjuvant treatment in patients having earlier surgery, with patients receiving a larger proportion of afternoon treatments showing improved response. This paper aims to replicate this work by exploring the impact of these two temporal factors, independently and in combination, on histopathological tumour response in rectal cancer patients.

Methods

A retrospective review of all patients with rectal adenocarcinoma who received long course (≥24 fractions) neoadjuvant radiotherapy with or without chemotherapy at a tertiary referral centre was conducted. Delay to surgery and radiotherapy treatment time were correlated to clinicopathologic characteristics with a particular focus on tumour regression grade. A review of the literature and meta-analysis were also conducted to ascertain the impact of time to surgery from preoperative radiotherapy on tumour regression.

Results

From a cohort of 367 patients, 197 patients met the inclusion criteria. Complete pathologic response (AJCC regression grade 0) was seen in 46 (23%) patients with a further 44 patients (22%) having at most small groups of residual cells (AJCC regression grade 1). Median time to surgery was 63 days, and no statistically significant difference was seen in tumour regression between patients having early or late surgery. There was a non-significant trend towards a larger proportion of morning treatments in patients with grade 0 or 1 regression (p = 0.077). There was no difference in tumour regression when composite groups of the two temporal variables were analysed. Visualisation of data from 39 reviewed papers (describing 27379 patients) demonstrated a plateau of response to neoadjuvant radiotherapy after approximately 60 days, and a meta-analysis found improved complete pathologic response in patients having later surgery.

Conclusions

There was no observed benefit of chronomodulated radiotherapy in our cohort of rectal cancer patients. Review of the literature and meta-analysis confirms the benefit of delayed surgery, with a plateau in complete response rates at approximately 60-days between completion of radiotherapy and surgery. In our cohort, time to surgery for the majority of our patients lay along this plateau and this may be a more dominant factor in determining response to neoadjuvant therapy, obscuring any effects of chronomodulation on tumour response. We would recommend surgery be performed between 8 and 11 weeks after completion of neoadjuvant radiotherapy in patients with locally advanced rectal cancer.

Optimal timing of surgery for bronchial sleeve resection after neoadjuvant chemoradiotherapy

INTRODUCTION

Sleeve resection is an established oncological operative treatment for centrally located tumors with reduced complications compared to pneumonectomy. In cases of neoadjuvant chemoradiotherapy, the optimal timing of surgery for bronchial anastomotic healing has not been adequately explored.

MATERIALS AND METHODS

Between 2006 and 2017, 584 tracheobronchial sleeve resections were retrospectively analyzed. We selected all patients (n = 88) after sleeve lobectomy or sleeve bilobectomy for lung cancer with fully completed neoadjuvant chemoradiotherapy. Bronchial healing was assessed by bronchoscopy on the 7th postoperative day using our earlier published classification from grades 1 to 5.

RESULTS

The median interval to surgery was 50 days (interquartile range 46-53, mean 50.03 ± 3.72). Mean anastomotic grade was 2.05 ± 1.03 and in 29.5% of the patients a critical anastomosis (grade ≥3) was documented. Anastomotic healing showed optimal results (bronchoscopic grade mean value: 1.5 ± 0.70) between the 6th and 8th postchemoradiotherapy week (P = .001). All patients operated before (bronchoscopic grade mean value: 2.3 ± 1.02) or after the above period (bronchoscopic grade mean value: 2.5 ± 1.15) had an increased ratio of anastomotic healing complications.

CONCLUSION

It is safer to perform sleeve-resections for non-small cell lung cancer after neoadjuvant trimodal treatment between the 6th and 8th week of completion of chemoradiotherapy.

Dose-time fractionation schedules of preoperative radiotherapy and timing to surgery for rectal cancer

Chemoradiotherapy (CRT) is extensively used prior to surgery for rectal cancer to provide significantly better local control, but the radiotherapy (RT), as the other component of CRT, has been subject to less interest than the drug component in recent years. With considerable developments in RT, the use of advanced techniques, such as intensity-modulated radiotherapy (IMRT) in rectal cancer, is garnering more attention nowadays. The radiation dose can be better conformed to the target volumes with possibilities for synchronous integrated boost without increased complications in normal tissue. Hopefully, both local recurrence and toxicities can be further reduced. Although those seem to be of interest, many issues remain unresolved. There is no international consensus regarding the radiation schedule for preoperative RT for rectal cancer. Moreover, an enormous disparity exists regarding the RT delivery. With the advent of IMRT, variations will likely increase. Moreover, time to surgery is also quite variable, as it depends upon the indication for RT/CRT in the clinical practices. In this review, we discuss the options and problems related to both the dose-time fractionation schedule and time to surgery; furthermore, it addresses the research questions that need answering in the future.

Gastrointestinal Malignancies and the COVID-19 Pandemic: Evidence-Based Triage to Surgery

BACKGROUND

The COVID-19 pandemic has led to widespread cancelation of electively scheduled surgeries, including for colorectal, pancreatic, and gastric cancer. The American College of Surgeons and the Society of Surgical Oncology have released guidelines for triage of these procedures. We seek to synthesize available evidence on delayed resection and oncologic outcomes, while also providing a critical assessment of the released guidelines.

METHODS

A systematic review was conducted to identify literature between 2005 and 2020 investigating the impact of time to surgery on oncologic outcomes in colorectal, pancreatic, and gastric cancer.

RESULTS

For colorectal cancer, 1066 abstracts were screened and 43 papers were included. In primarily resected colon cancer, delay over 30 to 40 days is associated with lower survival. In rectal cancer, time to surgery over 7 to 8 weeks following neoadjuvant therapy is associated with decreased survival. Three hundred ninety-four abstracts were screened for pancreatic cancer and nine studies were included. Two studies demonstrate increased unexpected progression with delayed surgery over 30 days. Out of 633 abstracts screened for gastric cancer, six studies were included. No identified study demonstrated worse survival with increased time to surgery.

CONCLUSION

Moderate evidence suggests that delayed resection of colorectal cancer worsens survival; the impact of time to surgery on gastric and pancreatic cancer outcomes is uncertain. Early resection of gastrointestinal malignancies provides the best chance for curative therapy. During the COVID-19 pandemic, prioritization of procedures should account for available evidence on time to surgery and oncologic outcomes.

Meta-analysis of the effect of extending the interval after long-course chemoradiotherapy before surgery in locally advanced rectal cancer

BACKGROUND

The current standard of care in locally advanced rectal cancer (LARC) is neoadjuvant long-course chemoradiotherapy (nCRT) followed by total mesorectal excision (TME). Surgery is conventionally performed approximately 6-8 weeks after nCRT. This study aimed to determine the effect on outcomes of extending this interval.

METHODS

A systematic search was performed for studies reporting oncological results that compared the classical interval (less than 8 weeks) from the end of nCRT to TME with a minimum 8-week interval in patients with LARC. The primary endpoint was the rate of pathological complete response (pCR). Secondary endpoints were recurrence-free survival, local recurrence and distant metastasis rates, R0 resection rates, completeness of TME, margin positivity, sphincter preservation, stoma formation, anastomotic leak and other complications. A meta-analysis was performed using the Mantel-Haenszel method.

RESULTS

Twenty-six publications, including four RCTs, with 25 445 patients were identified. A minimum 8-week interval was associated with increased odds of pCR (odds ratio (OR) 1·41, 95 per cent c.i. 1·30 to 1·52; P < 0·001) and tumour downstaging (OR 1·18, 1·05 to 1·32; P = 0·004). R0 resection rates, TME completeness, lymph node yield, sphincter preservation, stoma formation and complication rates were similar between the two groups. The increased rate of pCR translated to reduced distant metastasis (OR 0·71, 0·54 to 0·93; P = 0·01) and overall recurrence (OR 0·76, 0·58 to 0·98; P = 0·04), but not local recurrence (OR 0·83, 0·49 to 1·42; P = 0·50).

CONCLUSION

A minimum 8-week interval from the end of nCRT to TME increases pCR and downstaging rates, and improves recurrence-free survival without compromising surgical morbidity.

Cross-Sectional Study on MRI Restaging After Chemoradiotherapy and Interval to Surgery in Rectal Cancer: Influence on Short- and Long-Term Outcomes

Background

The time interval between CRT and surgery in rectal cancer patients is still the subject of debate. The aim of this study was to first evaluate the nationwide use of restaging magnetic resonance imaging (MRI) and its impact on timing of surgery, and, second, to evaluate the impact of timing of surgery after chemoradiotherapy (CRT) on short- and long-term outcomes.

Methods

Patients were selected from a collaborative rectal cancer research project including 71 Dutch centres, and were subdivided into two groups according to time interval from the start of preoperative CRT to surgery (< 14 and ≥ 14 weeks).

Results

From 2095 registered patients, 475 patients received preoperative CRT. MRI restaging was performed in 79.4% of patients, with a median CRT–MRI interval of 10 weeks (interquartile range [IQR] 8–11) and a median MRI–surgery interval of 4 weeks (IQR 2–5). The CRT–surgery interval groups consisted of 224 (< 14 weeks) and 251 patients (≥ 14 weeks), and the long-interval group included a higher proportion of cT4 stage and multivisceral resection patients. Pathological complete response rate (n = 34 [15.2%] vs. n = 47 [18.7%], p = 0.305) and CRM involvement (9.7% vs. 15.9%, p = 0.145) did not significantly differ. Thirty-day surgical complications were similar (20.1% vs. 23.1%, p = 0.943), however no significant differences were found for local and distant recurrence rates, disease-free survival, and overall survival.

Conclusions

These real-life data, reflecting routine daily practice in The Netherlands, showed substantial variability in the use and timing of restaging MRI after preoperative CRT for rectal cancer, as well as time interval to surgery. Surgery before or after 14 weeks from the start of CRT resulted in similar short- and long-term outcomes.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-07097-7) contains supplementary material, which is available to authorized users.

Optimal Interval to Surgery After Neoadjuvant Chemoradiotherapy in Rectal Cancer: A Systematic Review and Meta-analysis

This study aimed to evaluate the influence of a waiting interval of ≥ 8 weeks between the end of preoperative neoadjuvant chemoradiotherapy (nCRT) and surgery on the outcomes of patients with locally advanced rectal cancer. We conducted a comprehensive literature review of retrospective and prospective studies from PubMed, Embase, and Cochrane Library databases to investigate the length of the preoperative nCRT-surgery waiting interval and outcomes in patients with locally advanced rectal cancer. The primary outcome measure was pathologic complete response (pCR) rate. Secondary outcome measures included overall survival, disease-free survival, operative time, and the incidence of local recurrence, postoperative complications, anastomotic leakage, and sphincter-preserving surgery. Standardized mean differences and risk ratios were calculated. Thirteen studies involving 19,652 patients were included. The meta-analysis demonstrated that pCR was significantly increased in patients with locally advanced rectal cancer and a waiting interval of ≥ 8 weeks between preoperative nCRT and surgery compared to a waiting interval of < 8 weeks, or a waiting interval of > 8 weeks compared to ≤ 8 weeks (risk ratio = 1.25; 95% confidence interval, 1.16-1.35; P < .0001). There were no significant differences in overall survival, disease-free survival, operative time, or incidence of local recurrence, postoperative complications, or sphincter-preserving surgery. This study revealed that performing surgery after a waiting interval of ≥ 8 weeks after the end of preoperative nCRT is safe and efficacious for patients with locally advanced rectal cancer, significantly improving pCR without increasing operative time or incidence of postoperative complications, compared to a waiting interval of ≤ 8 weeks.