Tumor response after long interval comparing 5x5Gy radiation therapy with chemoradiation therapy in rectal cancer patients

New Opportunities for Minimizing Toxicity in Rectal Cancer Management

Advances in multimodal management of locally advanced rectal cancer (LARC), consisting of preoperative chemotherapy and/or radiotherapy followed by surgery with or without adjuvant chemotherapy, have improved local disease control and patient survival but are associated with significant risk for acute and long-term morbidity. Recently published trials, evaluating treatment dose intensification via the addition of preoperative induction or consolidation chemotherapy (total neoadjuvant therapy [TNT]), have demonstrated improved tumor response rates while maintaining acceptable toxicity. In addition, TNT has led to an increased number of patients achieving a clinical complete response and thus eligible to pursue a nonoperative, organ-preserving, watch and wait approach, thereby avoiding toxicities associated with surgery, such as bowel dysfunction and stoma-related complications. Ongoing trials using immune checkpoint inhibitors in patients with mismatch repair-deficient tumors suggest that this subgroup of patients with LARC could potentially be treated with immunotherapy alone, sparing them the toxicity associated with preoperative treatment and surgery. However, the majority of rectal cancers are mismatch repair-proficient and less responsive to immune checkpoint inhibitors and require multimodal management. The synergy noted in preclinical studies between immunotherapy and radiotherapy on immunogenic tumor cell death has led to the design of ongoing clinical trials that explore the benefit of combining radiotherapy, chemotherapy, and immunotherapy (mainly of immune checkpoint inhibitors) and aim to increase the number of patients eligible for organ preservation.

Organ Preservation in Rectal Cancer: An Overview of the Dutch Perspective and Recent Developments

Although current guidelines on rectal cancer treatment often recommend rectal resection with or without neoadjuvant (chemo)radiotherapy, there is growing interest in organ-preserving treatment approaches among patients and clinicians in the Netherlands. Currently, multiple ongoing studies are investigating the value of different non-operative treatment modalities to improve tumour response rates and increase the chance of successful organ preservation. Papillon contact X-ray brachytherapy is a promising treatment modality to improve the chance of organ preservation, which seems especially relevant for elderly and frail patients unable or refusing to undergo total mesorectal excision surgery. The elderly and frail patient with rectal cancer poses a significant challenge and warrants a thorough multidisciplinary approach to provide the most optimal organ-preserving treatment. In this overview, an insight into the Dutch perspectives and developments within the field of organ preservation and the set-up of a Papillon facility to complete the spectrum of organ-preserving treatment options in a tertiary referral centre for rectal cancer treatment has been provided.

Clinical benefits of oral capecitabine over intravenous 5-fluorouracyl regimen in case of neoadjuvant chemoradiotherapy followed by surgery for locally advanced rectal cancer

Background: During the last decade, one of the most important treatment options for locally advanced, potencially resectable rectal tumours was neoadjuvant chemoradiotherapy (CRT) followed by surgery. Methods: Effects of the neoadjuvant treatment on surgical outcomes were retrospectively analysed in 185 patients with stage T2-T4 and N0-2, resectable rectal tumour among two patient groups defined by radiosensitizer agents. Group 1 (n = 94) involved radiotherapy (RT) with 50.4 Gy total dose (25 × 1.8 Gy + 3 × 1.8 Gy tumour bed boost), and intravenous 5-fluorouracil (5-FU) (350 mg/m²) with leucovorin (20 mg/m²) on the 1-5 and 21-25 days, while Group 2 (n = 91) RT and orally administrated capecitabine (daily 2 × 825 mg/m²) on RT days. Surgery was carried out after 8-10 weeks. Side effects, perioperative complications, type of surgery, number of removed regional lymph nodes, resection margins and tumour regression grade (TRG) were analysed. Results: More favourable side effects were observed in Group 2. Despite the same rate of diarrhoea (Group 1 vs. Group 2: 54.3% vs. 56.0%), Grade 2-3 diarrhoea ratio was lower (p = 0.0352) after capecitabine (Group 2). Weight loss occurred in 17.0% and 2.2% (p = 0.00067), while nausea and vomiting was described in 38.3% and 15.4% (p = 0.00045) with 5-FU treatment and capecitabine respectively. Anaemia was observed in 33.0% and 22.0% (p = 0.0941). Complete tumour regression occurred in 25.3% after oral- and 13.8% after intravenous treatment (p = 0.049). Ratio of sphincter preservation was higher with laparoscopy than open surgery (72.3% vs. 39.7%) (p = 0.00001). Conclusion: The study confirms advantages of neoadjuvant chemoradiotherapy with oral capecitabine for rectal tumours, such as more favourable side effect profile and overall clinical outcome, with increased rate of complete tumour regression.

Predictors of Definitive Treatment Interruptions of Long-Course Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

Introduction To identify predictors of definitive treatment interruptions (DTI) of the neoadjuvant long-course radiotherapy (LCRT) in locally advanced rectal cancer (LARC), and to determine their impact on clinical outcomes. Methods Patients with stage II-III LARC treated between 2009-2018 were retrospectively analyzed (n=101, median FU 49.5 months). Logistic regression models evaluated the impact of relevant clinical variables on grade 3 or greater (G3+) acute toxicity, definitive treatment interruption (DTI), pCR, and definitive ostomy (dOST) rates. The secondary outcomes were LRC, MFS, PFS, CSS, and OS. Results The incidences of grade 3 and 4 toxicities were 25.3%, and 1.1%, respectively. The most common G3+ toxicities were peri-anal dermatitis (14.7%) and diarrhea (7.4%), which were more frequent in females (p=0.040) and tumors close to the anal verge (p=0.019). In this study, 11 patients (10.9%) developed DTI, which was associated with these G3+ events (p<0.001). Resection occurred after 7.1 weeks (median, IQR:6.1-8.9). Downstaging occurred in 57.4% (17.8% pCR), 88% achieved negative margins and the dOST rate was 56.4%. The five-year LRC, MFS, PFS, CSS and OS were: 94.4%, 78.9%, 74.7%, 85.2% and 81.6%, respectively. DTI events did not impact any outcome. The factors associated with loco-regional failure were close/positive margins (p<0.001) and stage ypIII (p=0.002). Conclusions: Tumors close to the anal verge and female sex were associated with increased G3+ toxicity, which was predictive of DTI. The resultant partial/complete omission of the planned boost, however, dose did not increase the chance of LR. Further studies to clarify the benefit and optimal timing to deliver the boost are warranted, especially for positive margins.

The immune microenvironment landscape shows treatment-specific differences in rectal cancer patients

Neoadjuvant therapy is the cornerstone of modern rectal cancer treatment. Insights into the biology of tumor responses are essential for the successful implementation of organ-preserving strategies, as different treatments may lead to specific tumor responses. In this study, we aim to explore treatment-specific responses of the tumor microenvironment. Patients with locally advanced adenocarcinoma of the rectum who had received neo-adjuvant chemotherapy (CT), neo-adjuvant radiochemotherapy (RCT), neo-adjuvant radiotherapy with a long-interval (LRT) or short-interval (SRT) or no neoadjuvant therapy (NT) as control were included. Multiplex-immunofluorescence was performed to determine the presence of cytotoxic T-cells (T-cyt; CD3+CD8+), regulatory T-cells (T-reg; CD3+FOXP3+), T-helper cells (T-helper; CD3+CD8-FOXP3-), B cells (CD20+), dendritic cells (CD11c+) and tumor cells (panCK+). A total of 80 rectal cancer patients were included. Treatment groups were matched for gender, tumor location, response to therapy, and TNM stage. The pattern of response (shrinkage vs. fragmentation) was, however, different between treatment groups. Our analyses reveal that RCT-treated patients exhibited lower stromal T-helper, T-reg, and T-cyt cells compared to other treatment regimens. In conclusion, we demonstrated treatment-specific differences in the immune microenvironment landscape of rectal cancer patients. Understanding the underlying mechanisms of this landscape after a specific therapy will benefit future treatment decisions.

A Multidisciplinary Approach for the Personalised Non-Operative Management of Elderly and Frail Rectal Cancer Patients Unable to Undergo TME Surgery

Despite it being the optimal curative approach, elderly and frail rectal cancer patients may not be able to undergo a total mesorectal excision. Frequently, no treatment is offered at all and the natural course of the disease is allowed to unfold. These patients are at risk for developing debilitating symptoms that impair quality of life and require palliative treatment. Recent advancements in non-operative treatment modalities have enhanced the toolbox of alternative treatment strategies in patients unable to undergo surgery. Therefore, a proposed strategy is to aim for the maximal non-operative treatment, in an effort to avoid the onset of debilitating symptoms, improve quality of life, and prolong survival. The complexity of treating elderly and frail patients requires a patient-centred approach to personalise treatment. The main challenge is to optimise the balance between local control of disease, patient preferences, and the burden of treatment. A comprehensive geriatric assessment is a crucial element within the multidisciplinary dialogue. Since limited knowledge is available on the optimal non-operative treatment strategy, these patients should be treated by dedicated multidisciplinary rectal cancer experts with special interest in the elderly and frail. The aim of this narrative review was to discuss a multidisciplinary patient-centred treatment approach and provide a practical suggestion of a successfully implemented clinical care pathway.

Pathological response post neoadjuvant therapy for locally advanced rectal cancer is an independent predictor of survival

AIM

Neoadjuvant treatment (NaT) for locally advanced rectal cancer prior to surgery has led to improved outcomes. However, the relationship between pathological response to NaT and survival is not entirely clear. The aim of this study was to assess the degree of pathological response to NaT on survival outcomes.

METHODS

Clinical and pathological data were collected from a prospectively maintained pathology database between 2005 and 2017. The primary outcome was the overall survival based on pathological response categorized as complete, good partial, partial and minimal. Univariate and multivariate analyses were conducted to identify variables predictive of survival. Cox proportional hazard ratios were used for survival.

RESULTS

A total of 596 patients had surgery following NaT for locally advanced rectal cancer. The median follow-up was 4.57 years (interquartile range 2.21-8.15 years). The overall survival for complete pathological response was 75.6% vs. 37.3% for minimal response (P < 0.001). The overall survival at the end of the study in the good partial vs. partial response groups was 58.9% vs. 39% (P < 0.001). On multivariate analysis, the degree of pathological response remains an independent variable for overall and disease-specific survival across all categories.

DISCUSSION

In addition to other pathological variables, the degree of pathological response to NaT is an independent predictor for survival outcomes. Future verification of these findings elsewhere could support NaT response being used for adjuvant therapy decision making.

A Comprehensive Evaluation of Associations Between Routinely Collected Staging Information and The Response to (Chemo)Radiotherapy in Rectal Cancer

Simple Summary

Rectal cancer patients are often treated with radiotherapy, either alone or combined with chemotherapy, prior to surgery to enable radical surgery on a non-resectable tumor or to lower the recurrence risk. For some patients, the tumor disappears completely after preoperative treatment, while others experience little or no benefit. Accurate prediction of therapy response before treatment is of great importance for a personalized treatment approach and intentional organ preservation. We performed a comprehensive evaluation of the predictive capacity of all routinely collected staging information at diagnosis in a population-based, completely staged patient material of 383 patients representing a real-life clinical situation. Size or stage of the rectal tumor were independent predictors of excellent response irrespective of preoperative treatment, with small/early-stage tumors being significantly more likely to reach a complete response. Levels of the tumor marker carcinoembryonic antigen (CEA) above upper normal limit halved the chance of response.

Abstract

Radiotherapy (RT) or chemoradiotherapy (CRT) are frequently used in rectal cancer, sometimes resulting in complete tumor remission (CR). The predictive capacity of all clinical factors, laboratory values and magnetic resonance imaging parameters performed in routine staging was evaluated to understand what determines an excellent response to RT/CRT. A population-based cohort of 383 patients treated with short-course RT (5 × 5 Gy in one week, scRT), CRT, or scRT with chemotherapy (scRT+CT) and having either had a delay to surgery or been entered into a watch-and-wait program were included. Complete staging according to guidelines was performed and associations between investigated variables and CR rates were analyzed in univariate and multivariate analyses. In total, 17% achieved pathological or clinical CR, more often after scRT+CT and CRT than after scRT (27%, 18% and 8%, respectively, p < 0.001). Factors independently associated with CR included clinical tumor stage, small tumor size (<3 cm), tumor level, and low CEA-value (<3.8 μg/L). Size or stage of the rectal tumor were associated with excellent response in all therapy groups, with small or early stage tumors being significantly more likely to reach CR (p = 0.01 (scRT), p = 0.01 (CRT) and p = 0.02 (scRT+CT). Elevated level of carcinoembryonic antigen (CEA) halved the chance of response. Extramural vascular invasion (EMVI) and mucinous character may indicate less response to RT alone.

Signet ring cell component in pretreatment biopsy predicts pathological response to preoperative chemoradiotherapy in rectal cancer

PURPOSE

Neoadjuvant therapy is routinely used in the management of locally advanced rectal cancer. This study aimed to evaluate the predictive value of pathological parameters in tumor response after treatment.

METHODS

We reviewed the hematoxylin-eosin slides from pretreatment biopsies of 150 rectal cancer patients who received preoperative chemoradiotherapy (PCRT) at Sun Yat-sen University Cancer Center between May 2013 and June 2016. Pathological and clinical parameters were both studied. The tumor response after chemoradiotherapy was evaluated using the tumor regression grade (TRG). Logistic regression was used to evaluate the relevance between these parameters and tumor response.

RESULTS

Complete tumor response (TRG0 and pCR) to PCRT was identified in 40 (26.7%) patients. The pCR rate was 93.33% (14 of 15) in cases with signet ring cell component versus 19.26% (26 of 135) in those without signet ring cell component (p < 0.001). Four cases with signet ring cell component were evaluated as clinical complete response (cCR), all of whom also achieved pCR; in contrast, only 9 of 15 (60%) cCR cases without signet ring cell achieved pCR.

CONCLUSION

Our data suggest that the signet ring cell component in pretreatment biopsies may be a potential predictor of tumor response to PCRT in rectal cancer. This suggests patients with clinical complete response are more suitable for a wait-and-watch approach.

MRI response rate after short-course radiotherapy on rectal cancer in the elderly comorbid patient: results from a retrospective cohort study

Background

The aim of the present study was to evaluate MRI response rate and clinical outcome of short-course radiotherapy (SCRT) on rectal cancer as an alternative to chemoradiotherapy in patients where downstaging is indicated.

Methods

A retrospective analysis was performed of a patient cohort with rectal carcinoma (cT1-4cN0-2 cM0–1) from a large teaching hospital receiving restaging MRI, deferred surgery or no surgery after SCRT between 2011 and 2017. Patients who received chemotherapy during the interval between SCRT and restaging MRI were excluded.

The primary outcome measure was the magnetic resonance tumor regression grade (mrTRG) at restaging MRI after SCRT followed by a long interval. Secondary, pathological tumor stage, complete resection rate and 1-year overall survival were assessed.

Results

A total of 47 patients (M:F = 27:20, median age 80 (range 53–88) years), were included. In 33 patients MRI was performed for response assessment 10 weeks after SCRT. A moderate or good response (mrTRG≤3) was observed in 24 of 33 patients (73%). While most patients (85%; n = 28) showed cT3 or cT4 stage on baseline MRI, a ypT3 or ypT4 stage was found in only 20 patients (61%) after SCRT (p <  0.01). A complete radiologic response (mrTRG 1) was seen in 4 patients (12%). Clinical N+ stage was diagnosed in n = 23 (70%) before SCRT compared to n = 8 (30%) post-treatment (p = 0.03).

After SCRT, 39 patients underwent deferred surgery (after a median of 14 weeks after start of SCRT) and a resection with complete margins was achieved in 35 (90%) patients. One-year overall survival after surgery was 82%. Complete pathological response was found in 2 patients (5%).

Conclusions

The use of SCRT followed by a long interval to restaging showed a moderate to good response in 73% and therefore can be considered as an alternative to chemoradiotherapy in elderly comorbid patients.

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.

Is preoperative chemoradiation in rectal cancer patients modulated by ACE inhibitors? Results from the Dutch Cancer Registry

BACKGROUND AND PURPOSE

The aim of this study was to assess the effect of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) on tumor response to preoperative chemoradiation for rectal cancer.

MATERIALS AND METHODS

Data on patients who received chemoradiation prior to surgery for rectal cancer between 2010 and 2015 were retrieved from linkage between the PHARMO Database Network, Dutch Pathology Registry and Netherlands Cancer Registry. Pathological complete response rates (pCR) were compared between patients who did or did not use ACEIs/ARBs during treatment. Multivariable analysis was performed using logistic regression.

RESULTS

Out of 345 patients, 92 patients (26.7%) used ACEIs/ARBs during treatment. Median age was 65 years (range 30-85). Older and male patients were more likely to use ACEIs/ARBs. pCR (ypT0N0) was observed in 17.4% of patients using ACEIs/ARBs compared to 14.6% of patients who did not use ACEIs/ARBs (p = 0.595). A good response (ypT0-1N0) was observed in 21.7% of ACEIs/ARBs patients vs. 19.4% of patients who did not use ACEIs/ARBs (p = 0.724). Multivariable analysis, taking into account background variables and co-medication, showed increased pCR in patients using beta-blockers (odds ratio 2.3, 95% confidence interval 1.0-5.4).

CONCLUSION

In this retrospective cohort, the use of ACEIs/ARBs was not associated with tumor response to preoperative chemoradiation in rectal cancer patients. Thereby, the suggested potentiating effect of ACEIS/ARBs could not be confirmed in our study. Further research could be directed to investigate a possible benefit of beta-blockers or other anti-hypertensive drugs.

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.

An overview of 25 years of incidence, treatment and outcome of colorectal cancer patients

Regarding the continuous changes in the diagnostic process and treatment of colorectal cancer (CRC), it is important to evaluate long-term trends which are relevant in giving direction for further research and innovations in cancer patient care. The aim of this study was to analyze developments in incidence, treatment and survival for patients diagnosed with CRC in the Netherlands. For this population-based retrospective cohort study, all patients diagnosed with CRC between 1989 and 2014 in the Netherlands were identified using data of the nationwide population-based Netherlands Cancer Registry (n = 267,765), with follow-up until January 1, 2016. Analyses were performed for trends in incidence, mortality, stage distribution, treatment and relative survival measured from the time of diagnosis. The incidence of both colon and rectal cancer has risen. The use of postoperative chemotherapy for Stage III colon cancer increased (14-60%), as well as the use of preoperative (chemo)radiotherapy for rectal cancer (2-66%). The administration of systemic therapy and metastasectomy increased for Stage IV disease patients. The 5-year relative survival increased significantly from 53 to 62% for colon cancer and from 51 to 65% for rectal cancer. Ongoing advancements in treatment, and also improvement in other factors in the care of CRC patients-such as diagnostics, dedicated surgery and pre- and postoperative care-lead to a continuous improvement in the relative survival of CRC patients. The increasing incidence of CRC favors the implementation of the screening program, of which the effects should be monitored closely.