Multidisciplinary treatment of patients with rectal cancer: Development during the past decades and plans for the future

Postoperative morbidity following Hartmann's procedure in comparison to anterior resection and abdominoperineal resection for rectal cancer-a population-based study

AIM

There is ongoing controversy regarding the extent to which Hartmann's procedure (HP) should be used in rectal cancer treatment. This study was designed to investigate 30-day postoperative morbidity and mortality following HP, anterior resection (AR) and abdominoperineal resection (APR) for rectal cancer using a national registry.

METHODS

All patients operated for rectal cancer, tumour height 5-15 cm, between the years 2010 and 2017, were identified through the Swedish colorectal cancer registry.

RESULTS

A total of 8476 patients were included: 1210 (14%) undergoing HP, 5406 (64%) AR and 1860 (22%) APR. HP was associated with an increased risk of intra-abdominal infection (OR 1.7, CI 1.26-2.28, P = 0.0004) compared to AR and APR, while APR was related to an increased risk of overall complications (OR 1.18, CI 1.01-1.40, P = 0.040). No significant difference was observed in the rate of reoperations and readmissions between HP, AR and APR, and type of surgical procedure was not a risk factor for 30-day mortality. Findings from a subgroup analysis of patients with a tumour 5-7 cm from the anal verge revealed that HP was not associated with increased risk for complications or 30-day mortality.

CONCLUSIONS

For patients where AR is not appropriate HP is a valid alternative with a favourable outcome. APR was associated with the highest overall 30-day complication rate.

Recent advances in rectal cancer treatment - are we on the right track?

Background

Staging and treatment of rectal cancer have evolved over several decades with considerably fewer locoregional recurrences but no marked improved survival since systemic recurrence risks remain virtually unchanged. This development will briefly be summarised followed by a thorough discussion of two recent developments.

Methods

A systematic approach towards the literature is aimed at focusing on organ preservation and the delivery of all non-surgical treatments prior to surgery or total neoadjuvant treatment (TNT).

Results

Organ preservation, that is to defer surgery if the tumour happens to disappear completely after any pre-treatment given to locally advanced tumours to decrease recurrence risks has increased in popularity and is, if not universally, widely accepted. To give neo-adjuvant treatment to intentionally obtain a clinically complete remission to avoid surgery is practised in some environments but is mostly still experimental. TNT, that is to provide both radiotherapy and chemotherapy aimed at killing microscopic disease in the pelvis or elsewhere has been subject to several trials. Collectively, they show that the chance of achieving a complete response, pathologically or clinically, has approximately doubled, increasing the chance for organ preservation, and the risk of distant metastasis has decreased at least in some trials. The best schedule remains to be established.

Conclusions

To obtain substantial progress and also improve survival, the systemic treatments need to be improved even if preoperative delivery is more effective and better tolerated than postoperative. The locoregional treatment may be further optimised through better risk prediction.

Determinants of Pre-Surgical Treatment in Primary Rectal Cancer: A Population-Based Study

When preoperative radiotherapy (RT) is best used in rectal cancer is subject to discussions and guidelines differ. To understand the selection mechanisms, we analysed treatment decisions in all patients diagnosed between 2010-2020 in two Swedish regions (Uppsala with a RT department and Dalarna without). Information on staging and treatment (direct surgery, short-course RT, or combinations of RT/chemotherapy) in the Swedish Colorectal Cancer Registry were used. Staging magnetic resonance imaging (MRI) permitted a division into risk groups, according to national guidelines. Logistic regression explored associations between baseline characteristics and treatment, while Cohen's kappa tested congruence between clinical and pathologic stages. A total of 1150 patients without synchronous metastases were analysed. Patients from Dalarna were older, had less advanced tumours and were pre-treated less often (52% vs. 63%, p < 0.001). All MRI characteristics (T-/N-stage, MRF, EMVI) and tumour levels were important for treatment choice. Age affected if chemotherapy was added. The correlation between clinical and pathological T-stage was fair/moderate and poor for N-stage. The MRI-based risk grouping influenced treatment choice the most. Since the risk grouping was modified to diminish the pre-treated proportion, fewer patients were irradiated with time. MRI staging is far from optimal. A stronger wish to decrease irradiation may explain why fewer patients from Dalarna were irradiated, but inequality in health care cannot be ruled out.

Efficacy and safety of different radiotherapy doses in neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer: A retrospective study

Background

This study aims to compare the efficacy and safety of neoadjuvant chemoradiotherapy (nCRT) with different radiotherapy doses (45Gy and 50.4Gy) in patients with locally advanced rectal cancer (LARC).

Methods

Herein, 120 patients with LARC were retrospectively enrolled between January 2016 and June 2021. All patients underwent two courses of induction chemotherapy (XELOX), chemoradiotherapy, and total mesorectum excision (TME). A total of 72 patients received a radiotherapy dose of 50.4 Gy, while 48 patients received a dose of 45 Gy. Surgery was then performed within 5-12 weeks following nCRT.

Results

There was no statistically significant difference between the baseline characteristics of the two groups. The rate of good pathological response in the 50.4Gy group was 59.72% (43/72), while in the 45Gy group achieved 64.58% (31/48) (P>0.05). The disease control rate (DCR) in the 50.4Gy group was 88.89% (64/72), compared to 89.58% (43/48) in the 45Gy group (P>0.05). The incidence of adverse reactions for radioactive proctitis, myelosuppression, and intestinal obstruction or perforation differed significantly between the two groups (P<0.05). The anal retention rate in the 50.4Gy group was significantly higher in contrast to the 45Gy group (P<0.05).

Conclusions

Patients receiving a radiotherapy dose of 50.4Gy have a better anal retention rate but also a higher incidence of adverse events such as radioactive proctitis, myelosuppression, and intestinal obstruction or perforation, and a comparable prognosis to patients treated with a radiotherapy dose of 45Gy.

The efficacy and safety of different radiotherapy doses in neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Background

This study aimed to evaluate efficacy and adverse effects of different radiotherapy (RT) doses in neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Methods

Fifty-nine patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy in hospital between January 2015 and May 2017 were enrolled in retrospective analysis. The patients were divided into the 56-Gy group and the 50-Gy group. The concurrent chemotherapy regimen was based on capecitabine. All patients received one cycle of oxaliplatin combined with capecitabine induction chemotherapy. All patients completed neoadjuvant chemoradiotherapy and received radical surgery.

Results

Of the patients in this study, 29 patients and 30 patients received a radiation dose of 56- and 50-Gy, respectively. All clinical characteristics were matched between the two groups. All patients received surgery 6 to 8 weeks after completing RT. The therapeutical effective rate in the 56-Gy group was 93.10% (27/29), compared with 66.67% in the 50-Gy group (20/30); the difference between the two groups was statistically significant (χ²=6.36, P=0.01). The pathological complete remission (pCR) rate in the 56-Gy group (37.93%, 11/29) was statistically significantly higher than that in the 50-Gy group (13.33%, 4/30) (χ²=4.71, P=0.030). The anal preservation rate in the 56-Gy group (65.5%, 19/29) was statistically significantly higher than that in the 50-Gy group (33.33%, 10/30) (χ²=6.11, P=0.01). The 56-Gy group had a local recurrence rate of 0% (0/29) and a distant metastasis rate of 10.34% (3/29), while the 50-Gy group had a local recurrence rate of 6.67% (2/30) and a distant metastasis rate of 16.67% (5/30); no significant difference existed between the two groups (χ²=2.00, 0.50, P=0.16, 0.48). The incidence of adverse reactions (gastrointestinal reactions, bone marrow suppression, and perianal skin reactions) in the 56-Gy group was not significantly different from that in the 50-Gy group (P>0.05).

Conclusions

Increasing the radiation dose can significantly improve the anal preservation and pCR rates of patients with locally advanced rectal cancer, thus improving their life quality. Moreover, it does not increase the rates of recurrence or adverse reactions. Our findings have certain clinical significance, but further prospective study is needed.

Rectal washout does not increase the complication risk after anterior resection for rectal cancer

Background

To reduce local recurrence risk, rectal washout (RW) is integrated in the total mesorectal excision (TME) technique when performing anterior resection (AR) for rectal cancer. Although RW is considered a safe practice, data on the complication risk are scarce. Our aim was to examine the association between RW and 30-day postoperative complications after AR for rectal cancer.

Methods

Patients from the Swedish Colorectal Cancer Registry who underwent AR between 2007 and 2013 were analysed using multivariable methods.

Results

A total of 4821 patients were included (4317 RW, 504 no RW). The RW group had lower rates of overall complications (1578/4317 (37%) vs. 208/504 (41%), p = 0.039), surgical complications (879/4317 (20%) vs. 140/504 (28%), p < 0.001) and 30-day mortality (50/4317 (1.2%) vs. 12/504 (2.4%), p = 0.020). In multivariable analysis, RW was a risk factor neither for overall complications (OR 0.73, 95% CI 0.60–0.90, p = 0.002) nor for surgical complications (OR 0.62, 95% CI 0.50–0.78, p < 0.001).

Conclusions

RW is a safe technique that does not increase the 30-day postoperative complication risk after AR with TME technique for rectal cancer.

Accuracy of high-resolution rectal magnetic resonance imaging re-staging with histopathology in locally advanced rectal cancer after neoadjuvant chemoradiotherapy

BACKGROUND/OBJECTIVE

Re-staging of locally advanced rectal cancer (LARC) following neoadjuvant chemoradiotherapy (NCRT) is a crucial step in surgical decision-making. Currently, MRI is the imaging of choice for evaluation of LARCs, however, the diagnostic accuracy of this modality is inconsistent. In this study, we evaluated the diagnostic accuracy of MRI in LARC and analyzed the factors that influenced the accuracy.

METHODS

The records of 133 patients diagnosed with LARC who were operated on during 2011-2018 were retrospectively reviewed. All patients received NCRT followed by re-staging based on high-resolution rectal MRI. The MRI results were analyzed for their yT and yN accuracy and anal sphincter involvement and compared with the related histopathological studies after definitive surgery.

RESULTS

Re-staging MRIs gave overall accuracy in both the yT stage and yN evaluation of 85% (K 0.45 and 0.21, respectively). The MRI tended to overstaging for tumor invasion and understaging for lymph node involvement (sign test p-values = 0.017 and 0.022, respectively.) The highest accuracy of the yT stage was yT4b (93%, K 0.71). The study found that larger tumors (>3 cm) were associated with significantly higher accuracy in the yT readings while lack of lymphovascular invasion was associated with higher accuracy in the yN readings. The negative predictive value for anal sphincter involvement was 100%.

CONCLUSION

MRI has limited accuracy in post-NCRT re-staging in LARC, tending to give overstaged yT readings and understaged yN readings. An MRI exclusion of sphincteric involvement is highly reliable.

Postoperative complications in relation to overall treatment time in patients with rectal cancer receiving neoadjuvant radiotherapy

Background

The optimal timing of surgery for rectal cancer after radiotherapy (RT) is disputed. The Stockholm III trial concluded that it was oncologically safe to delay surgery for 4–8 weeks after short-course RT (SRT), with fewer postoperative complications compared with SRT with surgery within a week. Other studies have indicated that an even shorter interval between RT and surgery (0–3 days) might be beneficial. The aim of this study was to identify the optimal interval to surgery after RT.

Methods

Patients were analysed as treated, in terms of overall treatment time (OTT), the interval from the start of RT until the day of surgery. Patients receiving SRT (5 × 5 Gy) were categorized according to OTT: 7 days (group A), 8–13 days (group B), 5–7 weeks (group C) and 8–13 weeks (group D). Patients receiving long-course RT (25 × 2 Gy) were grouped into those with an OTT of 9–11 weeks (group E) or 12–14 weeks (group F). Outcomes assessed were postoperative complications and early mortality.

Results

A total of 810 patients were analysed (group A, 100; group B, 247; group C, 192; group D, 160; group E, 52; group F, 59). Baseline patient characteristics were similar. There were significantly more overall complications in group B than in groups C and D. Adjusted odds ratios, with B as the reference group, were: 0·72 (95 per cent c.i. 0·40 to 1·32; P = 0·289), 0·50 (0·30 to 0·84; P = 0·009) and 0·39 (0·23 to 0·65; P &lt; 0·001) for groups A, C and D respectively. Early mortality was similar in all groups. There were no significant differences between long-course RT groups.

Conclusion

These results suggest that surgery should optimally be delayed for 4–12 weeks (OTT 5–13 weeks) after SRT.

Stage distribution utilizing magnetic resonance imaging in an unselected population of primary rectal cancers

BACKGROUND

Pre-operative radiotherapy (RT) or chemo-radiotherapy (CRT) are sometimes recommended prior to rectal cancer surgery, but guideline recommendations vary. The aim was to describe stage distribution and other important characteristics required for the treatment decision of patients with primary rectal cancers utilizing magnetic resonance imaging (MRI) in an unselected population.

PATIENTS AND METHODS

All 796 histopathologically verified rectal adenocarcinomas diagnosed 2010-2015 in two counties in Sweden (population 630,000 in 2015) were identified. Staging with pelvic MRI unless contraindications were present, treatment and pathology followed Swedish guidelines.

RESULTS

Twenty-three % of cases (n = 186) had distant metastases at diagnosis, demonstrating more advanced tumor and nodal stages when compared with non-metastatic patients (p < 0.001), and they more often displayed MRI-identified mucinous features and extramural vascular invasion (EMVI) than non-metastatic tumors (p < 0.001 for both). In non-metastatic patients, 8% displayed clinical stage T1 (cT1), 21% cT2, and 53% cT3; one-third of the latter threatened or involved the mesorectal fascia (MRF+). Almost 20% had stage cT4 (4% cT4a, 14% cT4b) of which 50% were considered "non-resectable". EMVI was seen in 33% of cT3M0 tumors and in 48% of cT4M0 tumors.

CONCLUSIONS

In an unselected population, approximately 80% of primary rectal cancers are referred to as "locally advanced" (stage II-III, or cT3-4 or N+), meaning that they, according to many international guidelines, are recommended neo-adjuvant treatment. This study provides a detailed description of the clinical stages and presence of characteristics identifiable on MRI which are of importance when assessing the needs for RT/CRT, when using different guidelines.

Preoperative radiotherapy or chemoradiotherapy in rectal cancer - Is survival improved? An update of the "Nordic" LARC study in non-resectable cancers

The randomized "Nordic" LARC study compared preoperative long-course radiotherapy alone (RT) or with chemotherapy (CRT) in the most locally advanced/ugly rectal cancers. Despite significantly better local control in the CRT group, no overall survival benefit was seen after 10 years follow-up. The relations between local control and survival are discussed.

Neoadjuvant Therapy in Rectal Cancer Patients With Clinical Stage II to III Across European Countries: Variations and Outcomes

BACKGROUND

Neoadjuvant therapy improves survival of patients with clinical stage II and III rectal cancer in clinical trials. In this study, we investigated the administration of neoadjuvant radiotherapy (neo-RT) and neoadjuvant chemoradiotherapy (neo-CRT) and its association with survival in resected patients in 2 European countries (The Netherlands and Sweden) and at 3 specialist centers.

MATERIALS AND METHODS

Administration of neoadjuvant treatment (all registries) and overall survival after surgery in The Netherlands and Sweden were assessed. Hazard ratios (HRs) were obtained using Cox regression adjusted for potential confounders.

RESULTS

A total of 16,095 rectal cancer patients with clinical stage II and III were eligible for analyses. Large variations in administration of neo-RT and neo-CRT were observed. Elderly patients less often received neo-RT and neo-CRT. Patients with stage III disease received neo-CRT more frequently than neo-RT. Administration of neo-RT versus surgery without neoadjuvant treatment was significantly associated with improved survival in The Netherlands (HR, 0.62; 95% confidence interval [CI], 0.53-0.73) as well as in Sweden (HR, 0.79; 95% CI, 0.69-0.90). Administration of neo-CRT was associated with enhanced survival in The Netherlands (HR, 0.62; 95% CI, 0.50-0.78) but not in Sweden (HR, 0.97; 95% CI, 0.80-1.18). The mortality of patients treated with neo-CRT compared with neo-RT showed inconsistent results in population-based centers.

CONCLUSIONS

Our results support an association of neo-RT with enhanced survival among stage II and III rectal cancer patients. Comparing neo-CRT with neo-RT, larger variations and inconsistent results with respect to survival were observed across centers.

On a prolonged interval between rectal cancer (chemo)radiotherapy and surgery

Preoperative radiotherapy (RT) or chemoradiotherapy (CRT) is often required before rectal cancer surgery to obtain low local recurrence rates or, in locally advanced tumours, to radically remove the tumour. RT/CRT in tumours responding completely can allow an organ-preserving strategy. The time from the end of the RT/CRT to surgery or to the decision not to operate has been prolonged during recent years. After a brief review of the literature, the relevance of the time interval to surgery is discussed depending upon the indication for RT/CRT. In intermediate rectal cancers, where the aim is to decrease local recurrence rates without any need for down-sizing/-staging, short-course RT with immediate surgery is appropriate. In elderly patients at risk for surgical complications, surgery could be delayed 5-8 weeks. If CRT is used, surgery should be performed when the acute radiation reaction has subsided or after 5-6 weeks. In locally advanced tumours, where CRT is indicated, the optimal delay is 6-8 weeks. In patients not tolerating CRT, short-course RT with a 6-8-week delay is an alternative. If organ preservation is a goal, a first evaluation should preferably be carried out after about 6 weeks, with planned surgery for week 8 if the response is inadequate. In case the response is good, a new evaluation should be carried out after about 12 weeks, with a decision to start a 'watch-and-wait' programme or operate. Chemotherapy in the waiting period is an interesting option, and has been the subject of recent trials with promising results.

Risk of second primary cancer in patients treated with radiotherapy for rectal cancer

BACKGROUND

Many patients with rectal cancer receive radiotherapy (RT) to reduce the risk of local recurrence. Radiation may give rise to adverse effects, including second primary cancers. In view of the divergent results of previous studies, the present study evaluated the risk of second primary cancer following RT in all randomized RT rectal cancer trials conducted in Sweden and in the Swedish ColoRectal Cancer Registry (SCRCR).

METHODS

Patients included in five randomized trials and the SCRCR were linked to the Swedish Cancer Registry. Cox regression models estimated the hazard ratio (HR) of second primary cancer among patients who received RT compared with those who did not.

RESULTS

A total of 13 457 patients were included in this study; 7024 (52·2 per cent) received RT and 6433 (47·8 per cent) had surgery alone. Overall, no increased risk of second primary cancer was observed with RT (HR 1·03; 95 per cent c.i. 0·92 to 1·15), independently of follow-up time and location within or outside of the irradiated volume. In the randomized trials, with longer follow-up (maximum 31 years), a slight increase was observed outside of (HR 1·33, 1·01 to 1·74) but not within (HR 1·11, 0·73 to 1·67) the irradiated volume. Irradiated men had a lower risk of prostate cancer than those treated with surgery alone (HR 0·68, 0·51 to 0·91).

CONCLUSION

Overall, there was no increased risk of second primary cancer following RT for rectal cancer within or outside of the irradiated volume up to 20 years of follow-up. Men with rectal cancer who received RT had a reduced risk of prostate cancer.

A Review of Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Neoadjuvant chemoradiotherapy has become the standard treatment for locally advanced rectal cancer. Neoadjuvant chemoradiotherapy not only can reduce tumor size and recurrence, but also increase the tumor resection rate and anus retention rate with very slight side effect. Comparing with preoperative chemotherapy, preoperative chemoradiotherapy can further reduce the local recurrence rate and downstage. Middle and low rectal cancers can benefit more from neoadjuvant chemradiotherapy than high rectal cancer. It needs to refine the selection of appropriate patients and irradiation modes for neoadjuvant chemoradiotherapy. Different therapeutic reactions to neoadjuvant chemoradiotherapy affect the type of surgical techniques, hence calling for the need of much attention. Furthermore, many problems such as accurate staging before surgery, selection of suitable neoadjuvant chemoradiotherapy method, and sensitivity prediction to preoperative radiotherapy need to be well settled.

Time trends, improvements and national auditing of rectal cancer management over an 18-year period

AIM

The main aims were to explore time trends in the management and outcome of patients with rectal cancer in a national cohort and to evaluate the possible impact of national auditing on overall outcomes. A secondary aim was to provide population-based data for appraisal of external validity in selected patient series.

METHOD

Data from the Swedish ColoRectal Cancer Registry with virtually complete national coverage were utilized in this cohort study on 29 925 patients with rectal cancer diagnosed between 1995 and 2012. Of eligible patients, nine were excluded.

RESULTS

During the study period, overall, relative and disease-free survival increased. Postoperative mortality after 30 and 90 days decreased to 1.7% and 2.9%. The 5-year local recurrence rate dropped to 5.0%. Resection margins improved, as did peri-operative blood loss despite more multivisceral resections being performed. Fewer patients underwent palliative resection and the proportion of non-operated patients increased. The proportions of temporary and permanent stoma formation increased. Preoperative radiotherapy and chemoradiotherapy became more common as did multidisciplinary team conferences. Variability in rectal cancer management between healthcare regions diminished over time when new aspects of patient care were audited.

CONCLUSION

There have been substantial changes over time in the management of patients with rectal cancer, reflected in improved outcome. Much indirect evidence indicates that auditing matters, but without a control group it is not possible to draw firm conclusions regarding the possible impact of a quality control registry on faster shifts in time trends, decreased variability and improvements. Registry data were made available for reference.

Current considerations in colorectal cancer surgery

Colorectal cancer is one of the most common cancers in the world. The last decades improvement in survival in all stages of the disease has been achieved. Many factors contributes to this improvement; earlier diagnosis, better pre-operative staging, neoadjuvant radiochemotherapy, better surgical method and approach, introduction of pre- and post-operative multidisciplinary team conferences and adjuvant chemotherapy. Currently, new modalities are developing; robotics and organ preserving through wait-and-watch will give colorectal surgeons even more treatment options. This article highlights important aspects of colorectal cancer management now and in the future.

Microsatellite instability and mutations in BRAF and KRAS are significant predictors of disseminated disease in colon cancer

BACKGROUND

Molecular alterations are well studied in colon cancer, however there is still need for an improved understanding of their prognostic impact. This study aims to characterize colon cancer with regard to KRAS, BRAF, and PIK3CA mutations, microsatellite instability (MSI), and average DNA copy number, in connection with tumour dissemination and recurrence in patients with colon cancer.

METHODS

Disease stage II-IV colon cancer patients (n = 121) were selected. KRAS, BRAF, and PIK3CA mutation status was assessed by pyrosequencing and MSI was determined by analysis of mononucleotide repeat markers. Genome-wide average DNA copy number and allelic imbalance was evaluated by SNP array analysis.

RESULTS

Patients with mutated KRAS were more likely to experience disease dissemination (OR 2.75; 95% CI 1.28-6.04), whereas the opposite was observed for patients with BRAF mutation (OR 0.34; 95% 0.14-0.81) or MSI (OR 0.24; 95% 0.09-0.64). Also in the subset of patients with stage II-III disease, both MSI (OR 0.29; 95% 0.10-0.86) and BRAF mutation (OR 0.32; 95% 0.16-0.91) were related to lower risk of distant recurrence. However, average DNA copy number and PIK3CA mutations were not associated with disease dissemination.

CONCLUSIONS

The present study revealed that tumour dissemination is less likely to occur in colon cancer patients with MSI and BRAF mutation, whereas the presence of a KRAS mutation increases the likelihood of disseminated disease.

The localisation of cancer in the sigmoid, rectum or rectosigmoid junction using endoscopy or radiology-What is the most accurate method?

INTRODUCTION

There is a difference in approach between colon and rectal cancer.

AIM

EVALUATE THE METHODS OF LOCALISATION: endoscopy and radiology.

MATERIALS AND METHODS

Patients with cancer in the sigmoid or rectum diagnosed with endoscopy, were included. Patients underwent additional radiological examinations. The resection specimen served as the gold standard. A tumour surrounded by serosa was considered a sigmoid cancer, surrounded by perirectal fat, than it was rectal cancer. If the frontal edge of the tumour showed serosa and the dorsal plane perirectal fat than the tumour was located in the "rectosigmoid".

RESULTS

A total of 182 cancers were diagnosed. Of the 128 cancers with gold standard, endoscopy had the correct localisation in 112 (87.5%), and radiology in 114 (90.5%) cases. Concordance between both techniques was present in 80%. In 28 cases there was discordance. Radiology located 10 sigmoidal cancers wrongly in the rectum. One rectal cancer was placed in the sigmoid. In 16 cases the endoscopic localisation wrongly was the sigmoid. Sensitivity and specificity for endoscopy in sigmoidal cancer is 100% and 77% respectively, for rectal cancer 77% and 100%. Sensitivity of radiology for cancer in the sigmoid and rectum are 80% and 98% respectively. Specificity for both cancers is 98% and 80% respectively.

CONCLUSIONS

The endoscopist and the radiologist should not be too overconfident with localisation of the tumour in cases of high rectal or low sigmoidal cancer.

An umbrella protocol for standardized data collection (SDC) in rectal cancer: a prospective uniform naming and procedure convention to support personalized medicine

Predictive models allow treating physicians to deliver tailored treatment moving from prescription by consensus to prescription by numbers. The main features of an umbrella protocol for standardizing data and procedures to create a consistent dataset useful to obtain a trustful analysis for a Decision Support System for rectal cancer are reported.

Optimal Time Intervals between Pre-Operative Radiotherapy or Chemoradiotherapy and Surgery in Rectal Cancer?

BACKGROUND

In rectal cancer therapy, radiotherapy or chemoradiotherapy (RT/CRT) is extensively used pre-operatively to (i) decrease local recurrence risks, (ii) allow radical surgery in non-resectable tumors, and (iii) increase the chances of sphincter-saving surgery or (iv) organ-preservation. There is a growing interest among clinicians and scientists to prolong the interval from the RT/CRT to surgery to achieve maximal tumor regression and to diminish complications during surgery.

METHODS

The pros and cons of delaying surgery depending upon the aim of the pre-operative RT/CRT are critically evaluated.

RESULTS

Depending upon the clinical situation, the need for a time interval prior to surgery to allow tumor regression varies. In the first and most common situation (i), no regression is needed and any delay beyond what is needed for the acute radiation reaction in surrounding tissues to wash out can potentially only be deleterious. After short-course RT (5Gyx5) with immediate surgery, the ideal time between the last radiation fraction is 2-5 days, since a slightly longer interval appears to increase surgical complications. A delay beyond 4 weeks appears safe; it results in tumor regression including pathologic complete responses, but is not yet fully evaluated concerning oncologic outcome. Surgical complications do not appear to be influenced by the CRT-surgery interval within reasonable limits (about 4-12 weeks), but this has not been sufficiently explored. Maximum tumor regression may not be seen in rectal adenocarcinomas until after several months; thus, a longer than usual delay may be of benefit in well responding tumors if limited or no surgery is planned, as in (iii) or (iv), otherwise not.

CONCLUSION

A longer time interval after CRT is undoubtedly of benefit in some clinical situations but may be counterproductive in most situations. After short-course RT, long-term results from the clinical trials are not yet available to routinely recommend an interval longer than 2-5 days, unless the tumor is non-resectable at diagnosis.

Are PREDIST criteria better than PERCIST criteria as a PET predictor of preoperative treatment response in rectal cancer?

Fluorine-18-fluorodeoxyglucose PET/CT is an accurate tool for predicting the response to preoperative chemoradiotherapy in locally advanced rectal cancer patients. The need for standardization has contributed to the development of various criteria for harmonizing PET response. The novel proposed set of criteria called PET Residual Disease in Solid Tumor (PREDIST) seems to better distinguish between responder and nonresponder patients to chemoradiotherapy compared with the PET Response Criteria in Solid Tumors criteria.

MRI-based treatment of rectal cancer: is prognostication of the recurrence risk solid enough to render radiation redundant?

BACKGROUND

Most current guidelines recommend neoadjuvant short course radiotherapy (sRT) or radio-chemotherapy (nRCT) for rectal cancer stage II and III. After the introduction of total mesorectal excision (TME) and magnetic resonance imaging (MRI), this proceeding has been questioned and omission of neoadjuvant treatment according to preoperative MRI-criteria has been propagated. Aim of the present paper is to review the state of evidence regarding MRI-based treatment decision depending on the predicted width of the circumferential resection margin (CRM).

METHODS

A comprehensive survey of the literature was performed using the search terms "rectal cancer", "radiotherapy", "radio-chemotherapy", "MRI-based therapy", "circumferential resection margin". Data from lately published observational studies were compared to results from randomized trials and outcome analyses of the Norwegian national cancer registry.

RESULTS

Only one observational study using MRI-based treatment according to the anticipated CRM provided 5 year local recurrence data, however only for 65 patients. The second study did not yet evaluate recurrence rates. Two randomized trials comparing sRT to primary TME showed significantly worse outcome for non-irradiated patients. Data from the Norwegian rectal cancer registry demonstrate that TME alone is associated with higher LRR than achievable with preoperative RT.

CONCLUSIONS

Current evidence does not support the omission of neoadjuvant treatment for stage II-III rectal cancer on the basis of an MRI-predicted negative CRM. Randomized studies are warranted to clarify whether and for which subgroups TME alone is safe in terms of local recurrences.

Short-course radiotherapy followed by neo-adjuvant chemotherapy in locally advanced rectal cancer--the RAPIDO trial

BACKGROUND

Current standard for most of the locally advanced rectal cancers is preoperative chemoradiotherapy, and, variably per institution, postoperative adjuvant chemotherapy. Short-course preoperative radiation with delayed surgery has been shown to induce tumour down-staging in both randomized and observational studies. The concept of neo-adjuvant chemotherapy has been proven successful in gastric cancer, hepatic metastases from colorectal cancer and is currently tested in primary colon cancer.

METHODS AND DESIGN

Patients with rectal cancer with high risk features for local or systemic failure on magnetic resonance imaging are randomized to either a standard arm or an experimental arm. The standard arm consists of chemoradiation (1.8 Gy x 25 or 2 Gy x 25 with capecitabine) preoperatively, followed by selective postoperative adjuvant chemotherapy. Postoperative chemotherapy is optional and may be omitted by participating institutions. The experimental arm includes short-course radiotherapy (5 Gy x 5) followed by full-dose chemotherapy (capecitabine and oxaliplatin) in 6 cycles before surgery. In the experimental arm, no postoperative chemotherapy is prescribed. Surgery is performed according to TME principles in both study arms. The hypothesis is that short-course radiotherapy with neo-adjuvant chemotherapy increases disease-free and overall survival without compromising local control. Primary end-point is disease-free survival at 3 years. Secondary endpoints include overall survival, local control, toxicity profile, and treatment completion rate, rate of pathological complete response and microscopically radical resection, and quality of life.

DISCUSSION

Following the advances in rectal cancer management, increased focus on survival rather than only on local control is now justified. In an experimental arm, short-course radiotherapy is combined with full-dose chemotherapy preoperatively, an alternative that offers advantages compared to concomitant chemoradiotherapy with or without postoperative chemotherapy. In a multi-centre setting this regimen is compared to current standard with the aim of improving survival for patients with locally advanced rectal cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01558921.

Rectal cancer : when is the local recurrence risk low enough to refrain from the aim to prevent it?

Recently, preliminary results of the OCUM study (optimized surgery and MRI-based multimodal therapy of rectal cancer) were published and raised concern in the scientific community. In this observational study, the circumferential resection margin status assessed in preoperative MRI (mrCRM) was used to decide for either total mesorectal excision (TME) alone or neoadjuvant radiochemotherapy (nRCT). In contrast to current guidelines, neither T3 stage (with negative CRM) nor clinically positive lymph nodes were an indication for nRCT. Pathologically node-positive patients received chemotherapy (ChT). Overall, 230 patients were included, of whom 96 CRM-positive patients received nRCT. The CRM was accurately predicted in MRI, the rate of mesorectal plane resection was high. Recurrence rates have not yet been reported, but an impressive rate of down-staging for both T and N stage after nRCT was observed, while acute side effects were minimal. Nonetheless, the authors conclude that a substantial number of patients could be "spared severe radiation toxicity" and propagate their concept for prospectively replacing current guidelines. This is based on the hypothesis that CRM is a valid surrogate parameter for the risk of local recurrence and in case of a negative CRM, nRCT becomes dispensable. Moreover, it is assumed that lymph node status is no more relevant. Both assumptions are a contradiction to recent data from randomized studies as specified below. As 5-year locoregional recurrence rate (LRR) of only of 5-8% and < 5% in low risk rectal cancer can be achieved by the addition of RT, the noninferiority of surgery alone can not be presumed unless the expected 5-year LRR is ≤ 5-8%, whereas any excess of this range renders the study design inacceptable. Unless a publication explicitly specifies 5-year LRR, results are not exploitable for clinical decisions.