Rationale and design of a prospective, multicenter, phase II clinical trial of safety and efficacy evaluation of long course neoadjuvant chemoradiotherapy plus tislelizumab followed by total mesorectal excision for locally advanced rectal cancer (NCRT-PD1-LARC trial)

BACKGROUND

Long course radiotherapy plus neoadjuvant chemotherapy followed by resection (total mesorectal excision, TME) has accepted widespread recognized in the treatment of locally advanced rectal cancer (LARC). Tislelizumab, an anti-PD1 humanized IgG4 monoclonal antibody, has been demonstrated with clinical activity and is approved for treating recurrent/refractory classical Hodgkin lymphoma and locally advanced/metastatic urothelial carcinoma in China. However, the safety and efficacy of long course (neoadjuvant chemoradiotherapy, NCRT) plus tislelizumab followed by TME for LARC is still uncertain.

METHODS

This NCRT-PD1-LARC trial will be a prospective, multicenter and phase II clinical trial designed to evaluate the safety and efficacy of LARC patients treated with long course NCRT plus tislelizumab followed by TME. This trial will consecutively enroll 50 stage II/III LARC patients (cT3N0M0 and cT1-3N1-2M0) with the tumor distal location ≤ 7 cm from anal verge at 7 centers in China. The enrolled patients will receive long course radiotherapy (50 Gy/25 f, 2 Gy/f, 5 days/week) and three 21-day cycles capecitabine (1000 mg/m2, bid, po, day1-14) plus three 21-day cycles tislelizumab (200 mg, iv.gtt, day8), followed by TME 6-8 weeks after the end of radiotherapy. The primary efficacy endpoint will be the pathological complete response (pCR) rate, which is defined as absence of viable tumor cells in the primary tumor and lymph nodes.

DISCUSSION

To our knowledge, this trial is the first multicenter clinical trial in China to assess the safety and efficacy of NCRT plus anti-PD1 therapy followed by TME to treat patients with LARC. NCRT followed by TME was recognized as the most recommended treatment against LARC while could not be completely satisfied in clinic. This study expects to provide a solid basis and encouraging outcomes for this promising combination of radiotherapy, chemotherapy and immunotherapy in LARC.

TRIAL REGISTRATION

Name of the registry: ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT04911517. Date of registration: 23 May 2021. URL of trial registry record: https://www.

CLINICALTRIALS

gov/ct2/show/NCT04911517?id=BFH-NCRTPD&draw=2&rank=1 .

The clinical relevance of indeterminate lung nodules in patients with locally recurrent rectal cancer

AIM

To evaluate the clinical relevance of indeterminate lung nodules (ILN) in patients with locally recurrent rectal cancer (LRRC) treated in a tertiary referral centre.

METHODS

All patients with LRRC diagnosed between 2000 and 2017 were retrospectively reviewed. Reports of staging chest CT-scans were evaluated for ILN. Patients with distant metastases including lung metastases at time of LRRC diagnosis were excluded. Overall (OS), progression-free survival (PFS) and the cumulative incidence of lung metastases were compared between patients with and without ILN.

RESULTS

In total 556 patients with LRRC were treated during the study period. In the 243 patients eligible for analysis, 68 (28%) had ILN at LRRC diagnosis. Median OS was 37 months for both the patients with and without ILN (p = 0.37). Median PFS was 14 months for the patients with ILN and 16 months for patients without ILN (p = 0.80). After correction for potential confounding, ILN present at LRRC diagnosis was not associated with impaired OS or PFS (adjusted hazards ratio [95% confidence interval]: 0.81 [0.54-1.22] and 1.09 [0.75-1.59]). The 5-year cumulative incidence of lung metastases was 31% in patients with ILN and 28% in patients without ILN (p = 0.19).

CONCLUSION

Our study shows that ILN are present in roughly a quarter of patients with LRRC. No differences in OS, PFS, or the cumulative incidence of lung metastases were found between patients with and without ILN at LRRC diagnosis. These results suggest that ILN are of little to no clinical relevance in patients with LRRC.

What Is the Utility of Restaging Imaging for Patients With Clinical Stage II/III Rectal Cancer After Completion of Neoadjuvant Chemoradiation and Prior to Proctectomy?

BACKGROUND

In the United States, patients with clinical stage II or III rectal cancer typically receive neoadjuvant chemoradiation therapy (chemo/XRT) over a 5-6 week period followed by a 6-10 week break prior to proctectomy. In the current study, we evaluate the utilization of restaging studies performed and detection of disease progression during this window.

METHODS

A retrospective review of patients with clinical stage II/III rectal cancer was performed. Medical records were analyzed to collect clinicopathologic data and the performance and results of preoperative, early postoperative, and first surveillance CT and/or PET/CT in patients completing long course neoadjuvant chemo/XRT and undergoing proctectomy.

RESULTS

Between 2005 and 2017, 176 patients with clinical stage II or III rectal adenocarcinoma completed neoadjuvant chemo/XRT and underwent proctectomy. Preoperative restaging with CT CAP and/or CT/PET was performed in 72 (40.9%) patients with no detection of disease progression. Of the 104 patients without preoperative restaging, 1 had intraoperative detection of liver metastases and 31 had early postoperative reimaging (within 30 days of proctectomy) of which 2 had detection of new pulmonary metastases. Among 72 patients with no preoperative or early postoperative reimaging, first surveillance imaging was available in 47 and detected new metastases in 8 (17%).

DISCUSSION

In patients with clinical stage II/III rectal cancer who undergo long course neoadjuvant chemo/XRT, perioperative reimaging with CT CAP and/or PET/CT detects new metastases in a small percentage of patients. A multi-institutional, prospective analysis using standardized staging protocols is warranted to better determine the value of preoperative restaging in these patients.

Limited Role for Routine Restaging After Neoadjuvant Therapy in Locally Advanced Rectal Cancer

BACKGROUND

Although many patients with locally advanced rectal cancer undergo restaging imaging after neoadjuvant chemoradiotherapy and before surgery, the benefit of this practice is unclear. The purpose of this study was to examine the impact of reimaging on outcomes.

MATERIALS AND METHODS

We performed a retrospective analysis of consecutive patients with stage 2 and 3 rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy between May 2005 and April 2018. Patient and disease characteristics, imaging, treatment, and oncologic outcomes were compared between those who underwent restaging and those who went directly to surgery. Predictors of outcomes and cost effectiveness of restaging were determined.

RESULTS

Of 224 patients, 146 underwent restaging. Six restaged patients had findings leading to a change in management. There was no difference in freedom from recurrence (P = 0.807) and overall survival (P = 0.684) based on restaging. Pretreatment carcinoembryonic antigen level >3 ng/mL (P = 0.010), clinical T stage 4 (P = 0.016), and pathologic T4 (P = 0.047) and N2 (P = 0.002) disease increased the risk of death, whereas adjuvant chemotherapy decreased the risk of death (P < 0.001) on multivariate analysis. Disease recurrence was lower with pelvic exenteration (P = 0.005) and in females (P = 0.039) and higher with pathologic N2 (P = 0.003) and N3 (P = 0.002) disease. The average cost of reimaging is $40,309 per change in management; however, $45 is saved per patient when downstream surgical costs are considered.

CONCLUSIONS

Imaging restaging after neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer rarely changes treatment and does not improve survival. In a subset of patients at higher risk for worse outcome, reimaging may be beneficial.

Restaging Patients with Rectal Cancer Following Neoadjuvant Chemoradiation: A Systematic Review

BACKGROUND

In the USA, most patients with clinical stage II/III rectal cancer receive neoadjuvant chemoradiation (chemo/XRT) over 5-6 weeks followed by a 6-10-week break before proctectomy. As chemotherapy is delivered at radio-sensitizing doses, there is essentially a 3-month window during which potential systemic disease is untreated. Evidence regarding the utility of restaging patients prior to proctectomy is limited.

METHODS

PubMed, Scopus, Web of Science, and the Cochrane Library were searched for studies evaluating the utility of restaging patients with rectal cancer after completion of long-course chemo/XRT, and reporting associated changes in management. Studies that were non-English, included <50 patients, or examining the diagnostic accuracy of imaging modalities were excluded. Study quality was evaluated using the modified Newcastle Ottawa Scale.

RESULTS

Eight studies were identified including a total of 1251 patients restaged between completion of chemo/XRT and proctectomy. All studies were retrospective. Restaging identified new metastatic disease in 72 (6.0%) patients, with 4 studies reporting specific sites: liver (n = 28), lung (n = 8), adrenal (n = 1), bone (n = 1), and multiple sites (n = 7). Overall progression (distant or local) was detected in 88 (7.0%) patients and resulted in a change in management in 77 (87.5%) of these patients. Tumor-related prognostic characteristics were inconsistently reported among studies, precluding meta-analysis.

CONCLUSIONS

Although restaging between completion of neoadjuvant chemo/XRT and proctectomy detects disease progression in only a small percentage of patients, findings alter the treatment plan in the vast majority of these patients. Multi-institutional collaboration with analysis of well-defined prognostic variables may better identify patients most likely to benefit from restaging.

Early Systemic Failure After Preoperative Chemoradiotherapy for the Treatment of Patients With Rectal Cancer

Purpose

Distant metastasis can occur early after neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer. This study was conducted to evaluate the clinical characteristics of patients who developed early systemic failure.

Methods

The patients who underwent neoadjuvant CRT for a rectal adenocarcinoma between June 2007 and July 2015 were included in this study. Patients who developed distant metastasis within 6 months after CRT were identified. We compared short- and long-term clinicopathologic outcomes of patients in the early failure (EF) group with those of patients in the control group.

Results

Of 107 patients who underwent neoadjuvant CRT for rectal cancer, 7 developed early systemic failure. The lung was the most common metastatic site. In the EF group, preoperative carcinoembryonic antigen was higher (5 mg/mL vs. 2 mg/mL, P = 0.010), and capecitabine as a sensitizer of CRT was used more frequently (28.6% vs. 3%, P = 0.002). Of the 7 patients in the EF group, only 4 underwent a primary tumor resection (57.1%), in contrast to the 100% resection rate in the control group (P < 0.001). In terms of pathologic outcomes, ypN and TNM stages were more advanced in the EF group (P < 0.001 and P = 0.047, respectively), and numbers of positive and retrieved lymph nodes were much higher (P < 0.001 and P = 0.027, respectively).

Conclusion

Although early distant metastasis after CRT for rectal cancer is very rare, patients who developed early metastasis showed a poor nodal response with a low primary tumor resection rate and poor oncologic outcomes.

Restaging after neoadjuvant chemoradiation in rectal cancers: is histology the key in patient selection?

BACKGROUND

Neoadjuvant chemoradiation is the standard of care for locally advanced rectal cancer. However, there is no clarity regarding the necessity for restaging scans to rule out systemic progression of disease post chemoradiation with existing literature being divided on the need for the same.

METHODS

Data from a prospectively maintained database was retrospectively analysed. All locally advanced rectal cancers (node positive/T4/T3 with threatened or involved CRM) were included. Biopsy proof of adenocarcinoma and CT scan of abdomen and chest were mandatory. Grade of tumor and response to CTRT on restaging magnetic resonance imaging (MRI) were documented.

RESULTS

Out of 119 patients subjected to CTRT, 72 underwent definitive total mesorectal excision while 13 patients progressed locoregionally on restaging MR pelvis and 15 other patients progressed systemically while the rest defaulted. Patients with poorly differentiated (PD) cancers were compared to those with well/moderately differentiated (WMD) tumors. PD tumors had a significantly higher rate of local progression (32.1% vs. 5.6% %, P=0.0011) and systemic progression (35.7% vs. 6.9%, P=0.0008) as compared to WMD tumors. Only one-third (9/28) of PD patients underwent TME while the rest progressed.

CONCLUSIONS

Selecting poorly differentiated tumors alone for restaging CECT abdomen and thorax will be a cost effective strategy as the rate of progression is very high. Also patients with PD tumors need to be consulted about the high probability of progression of disease.

Outcome in patients with resectable locally recurrent rectal cancer after total mesorectal excision with and without previous neoadjuvant radiotherapy for the primary rectal tumor

BACKGROUND

The widespread use of neoadjuvant radiotherapy (nRTx) followed by total mesorectal excision (TME) introduced the problem of treating locally recurrent rectal cancer (LRRC) after nRTx and TME. Few data exist on the outcome of the surgical treatment of this type of LRRC and the influence of nRTx for the primary tumor on the outcome is unclear.

METHODS

All patients receiving multimodality treatment (including intraoperative radiotherapy) for LRRC in our center between 1996 and 2012 were analyzed retrospectively. The outcome of patients with nonmetastasized resectable LRRC who received nRTx and TME for the primary tumor was compared to the outcome of patients who did not receive nRTx for the primary tumor.

RESULTS

During this period, 139 patients underwent surgery for LRRC; 93 of these patients underwent curative surgery for LRRC after TME for the primary tumor. Sixty-five patients did not receive nRTx for the primary tumor, whereas 28 patients received nRTx for the primary tumor. There were no significant differences in the number of incomplete resections or perioperative morbidities. There was no significant difference in 5-year overall survival (28 vs. 43%, p = 0.81), recurrence-free survival (55 vs. 48%, p = 0.5), and disease-free survival (27 vs. 40%, p = 0.59).

CONCLUSIONS

Surgical treatment of carefully selected patients with nonmetastasized resectable LRRC after nRTx and TME for the primary tumor is feasible and can result in sustained local control and overall survival. Patients with resectable LRRC who received nRTx for the primary tumor do not have a poorer outcome than patients who did not.