The timing of surgery after preoperative short-course S-1 chemoradiotherapy with delayed surgery for T3 lower rectal cancer

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.

Short-course radiotherapy with immediate or delayed surgery in rectal cancer: A meta-analysis

BACKGROUND

The safety and efficacy of preoperative short-course radiotherapy had been verified in rectal cancer. However, the timing of surgery after radiation had not been well defined. Thus, we performed this meta-analysis to compare the interval time of surgery after short-course radiotherapy in rectal cancer: immediate surgery (<4 weeks) vs delayed surgery (>4 weeks).

METHODS

We searched the PubMed, EMBASE, MEDLINE, and Cochrane Library database. The primary endpoints were survival rates and pathological outcomes, and the second endpoints included sphincter preservation rate, R0 resection rate and postoperative complications. RevMan 5.3 was used to calculate pooled risk ratio (RRs) and 95% confidence interval (CIs).

RESULTS

In total, 5 eligible studies including 1244 participants were identified. The delayed surgery group had a markedly higher pathological complete response rate [RR = 15.71, 95% CI (2.10, 117.30), P = 0.007] and downstaging rate [RR = 2.63, 95% CI (1.77, 3.90), P < 0.00001], a higher proportion of patients with adjuvant pathologic stage 0 + I disease [RR = 1.49, 95% CI (1.23, 1.81), P < 0.0001] and a lower incidence of postoperative complications [RR = 0.81, 95% CI (0.70, 0.95), P = 0.008] than did the immediate surgery group, but the survival rate, sphincter preservation rate and R0 resection rate were similar between the two groups.

CONCLUSION

Based on better pathologic outcomes and fewer postoperative complications, we recommended short-course radiotherapy with delayed surgery for more than 4 weeks.

Upfront Systemic Chemotherapy and Short-Course Radiotherapy with Delayed Surgery for Locally Advanced Rectal Cancer with Distant Metastases: Outcomes, Compliance, and Favorable Prognostic Factors

PURPOSE/OBJECTIVE(S)

Optimal treatment for locally advanced rectal cancer (LARC) with distant metastasis remains elusive. We aimed to evaluate upfront systemic chemotherapy and short-course radiotherapy (RT) followed by delayed surgery for such patients, and to identify favorable prognostic factors.

MATERIALS/METHODS

We retrospectively reviewed 50 LARC patients (cT4 or cT3, <2 mm from the mesorectal fascia) with synchronous metastatic disease. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival, treatment-related toxicity, and compliance. We considered P values <0.05 significant.

RESULTS

At 22 months median follow-up, the median PFS time was 16 months and the 2-year PFS rate was 34.8%. Thirty-five patients who received radical surgery for primary and metastatic tumors were designated the curable group. Six patients with clinical complete response (ypCR) of metastases who underwent radical surgery for only the primary tumor were classified as potentially curable. Nine patients who received no radical surgery (3 received palliative surgery) were deemed the palliative group. The ypCR rate among surgery patients was 13.6%. PFS rates for the curable or potentially curable groups were significantly longer than that of the palliative group (P<0.001). On multivariate analysis, solitary organ metastasis and R0 status were independent prognostic factors for PFS.

CONCLUSIONS

These findings demonstrated that a strong possibility that upfront chemotherapy and short-course RT with delayed surgery are an effective alternative treatment for LARC with potentially resectable distant metastasis, owing to achievement of pathologic down-staging, R0 resection, and favorable compliance and toxicity, despite the long treatment duration.

Comparison of the pathological response of the mesorectal positive nodes between short-course chemoradiotherapy with delayed surgery and long-course chemoradiotherapy in patients with rectal cancer

BACKGROUND

The aim of this study was to compare the pathological response of mesorectal positive nodes between short-course chemoradiotherapy with delayed surgery (SCRT-delay) and long-course chemoradiotherapy (LC-CRT) in patients with rectal cancer.

METHOD

The resected primary tumor specimens following the two different approaches were assessed utilizing the tumor regression grade (TRG 0-4), and each positive lymph node was assessed according to the lymph node regression grade (LRG 1-3), with TRG 4 and LRG 3 indicating total regression. The lymph node sizes were measured to elucidate any correlation with LRG scores.

RESULTS

Seventy-four patients with ypN-positive rectal cancer had 220 positive lymph nodes following the SCRT-delay, and 48 patients had 141 positive lymph nodes following the LC-CRT. The distribution of LRG 1/2/3 in the two groups was 123/72/25 and 60/31/50 (p < 0.001), respectively, and the distribution of TRG 0/1/2/3/4 in the two groups was 36/19/19/0 and 12/15/20/1 (p = 0.005), respectively. The requirements of total regression of positive lymph nodes were a primary tumor degenerated to TRG 3 with a size less than 6 mm in SCRT-delay (sensitivity, 60.9 %) or a primary tumor degenerated to TRG 2-4 with a size less than 5 mm at TRG 2 (sensitivity, 57.6 %) or 6 mm at TRG 3 and 4 (sensitivity, 84.2 %) in LC-CRT as indicated by the receiver operating characteristic curve analysis.

CONCLUSION

The tumor regression effect of LC-CRT on the primary tumor and positive nodes was more favorable than SCRT-delay, and LC-CRT is able to predict the LRG 3 response with a high sensitivity.

Diffusion-weighted magnetic resonance imaging for prediction of tumor response to neoadjuvant chemoradiotherapy using irinotecan plus S-1 for rectal cancer

The purpose of this study was to investigate the clinical value of diffusion-weighted (DW) magnetic resonance imaging (MRI) as a predictor of tumor response in patients receiving neoadjuvant chemoradiotherapy (NA-CRT) for rectal cancer (RC) through measurement of the apparent diffusion coefficient (ADC) value in each tumor. Neoadjuvant radiotherapy with a total dose of 45 Gy in 25 fractions was performed in all 16 patients with RC, combined with irinotecan and S-1. MRI was performed before and after NA-CRT. Multiple factors were assessed to predict the pathological response to NA-CRT. The pathological response rate was determined in 9 patients (56.3%). Statistical analyses indicated that the ADC value prior to NA-CRT was significantly lower in patients with a better response to NA-CRT (P=0.023). A cut-off value of 0.750×10^-3 mm²/sec obtained by a receiver operating characteristic curve analysis indicated a sensitivity of 77.8% and specificity of 85.7% for pathological responders to NA-CRT. In addition, the patients with lower ADC values exhibited a greater pathological response to NA-CRT (P=0.041). In conclusion, the ADC value of MRI of RC patients treated with NA-CRT followed by surgery may provide valuable information to predict the response to NA-CRT.

Short-course radiotherapy with delayed surgery versus conventional chemoradiotherapy: A comparison of the short- and long-term outcomes in patients with T3 rectal cancer

INTRODUCTION

The aim of this study was to compare the short- and long-term outcomes between short-course radiotherapy with delayed surgery (SRT-delay) and a standard conventional chemoradiotherapy (CRT) regimen.

METHODS

Two collaborating institutions adopted different regimens; the SRT-delay regimen was selected by Meiwa Hospital and the CRT regimen was selected by Hyogo College of Medicine. The inclusion criteria were T3 middle and low rectal cancer patients treated with radical surgery after preoperative therapy. The median follow-up period was 44 months (range, 12-85).

RESULTS

From 2007 to 2013, 104 patients were treated using the SRT-delay regimen and 61 patients were treated using the CRT regimen. The pretreatment characteristics of the 2 groups were not significantly different. The sphincter-preserving rate (93.3%, 85.2%), T downstaging (37.5%, 37.7%), ypN(-) (74.0%, 67.2%), postoperative complications and the bowel, and urinary and sexual functioning of the SRT-delay regimen were noninferior to those of the CRT regimen. The 3-year local recurrence-free survival, recurrence-free survival, and overall survival in the SRT-delay and CRT groups were 90.6% and 90.6% (P = .764), 83.8% and 78.3% (P = .687) and 96.0% and 92.8% (P = .833), respectively.

CONCLUSION

The SRT-delay regimen was noninferior in terms of the downstaging effect, and oncologic and functional outcomes compared with the CRT regimen for T3 middle and low rectal cancer.