The addition of continuous infusion 5-FU to preoperative radiation therapy increases tumor response, leading to increased sphincter preservation in locally advanced rectal cancer

Adenocarcinoma involving the urinary bladder

A man in his 70s previously diagnosed with an adenocarcinoma of the prostate, received external beam radiation therapy (EBRT) and brachytherapy 11 years ago. Ten years later, he developed urinary symptoms and a cystoscopy identified a bladder neck tumour. A transurethral resection of a bladder tumour was performed, and pathology revealed a high-grade adenocarcinoma consistent with a colorectal primary. A colonoscopy was unremarkable, and imaging studies showed tumour involving the bladder and prostate. Tumour markers and a CARIS genomic prevalence score also favoured a colorectal cancer primary.The patient refused surgery and underwent chemoradiation with a combination of EBRT and brachytherapy with concurrent capecitabine. Imaging studies obtained 6 months after reirradiation revealed an enlarged left-sided mesorectal lymph node concerning for disease recurrence. The lymph node was treated with Stereotactic Body Radiation Therapy and his post-treatment imaging revealed a response to treatment with no other evidence of disease.

The Auxiliary Effects of Low-Molecular-Weight Fucoidan in Locally Advanced Rectal Cancer Patients Receiving Neoadjuvant Concurrent Chemoradiotherapy Before Surgery: A Double-Blind, Randomized, Placebo-Controlled Study

Patients with cancer use low-molecular-weight fucoidan (LMF) as a supplement to therapy. However, most studies of LMF are in vitro or conducted using animals. Concurrent chemoradiotherapy (CCRT) is the gold standard for locally advanced rectal cancer (LARC). This study investigated the quality of life (QoL) and clinical outcomes of patients with LARC taking LMF as a supplement to neoadjuvant CCRT. This was a double-blind, randomized, placebo-controlled study. The sample comprised 87 patients, of whom 44 were included in a fucoidan group and 43 were included in a placebo group. We compared their QoL scores and clinical outcomes before treatment, and at 1 month, 2 months, and 3 months posttreatment. Pretreatment and posttreatment gut microbiota differences were also compared. Although enhanced physical well-being (PWB) at 2 months and 3 months posttreatment in the fucoidan group were observed (both P < .0125), the improvements of the Functional Assessment of Cancer Therapy for Patients with Colorectal Cancer (FACT-C) were nonsignificant (all P > .0125). Skin rash and itching and fatigue were less common in the fucoidan group (both P < .05). Posttreatment, the genus Parabacteroides was significantly more common in the gut microbiota of the fucoidan group. LMF administration improved the QoL, skin rash and itching, fatigue, and gut microbiota composition of the patients with LARC receiving CCRT.Clinical Trial Registration: NCT04342949.

Screening of MicroRNA Related to Irradiation Response and the Regulation Mechanism of miRNA-96-5p in Rectal Cancer Cells

Neoadjuvant chemoradiotherapy has been widely used in the treatment of locally advanced rectal cancer due to the excellent advantages of irradiation in cancer therapy. Unfortunately, not every patient can benefit from this treatment, therefore, it is of great significance to explore biomarkers that can predict irradiation sensitivity. In this study, we screened microRNAs (miRNAs) which were positively correlated with irradiation resistance and found that miRNA-552 and miRNA-183 families were positively correlated with the irradiation resistance of rectal cancer, and found that high expression of miRNA-96-5p enhanced the irradiation resistance of rectal cancer cells through direct regulation of the GPC3 gene and abnormal activation of the canonical Wnt signal transduction pathway. Based on the radioreactivity results of patient-derived xenograft models, this is the first screening report for radio-resistant biomarkers in rectal cancer. Our results suggest that miRNA-96-5p expression is an important factor affecting the radiation response of colorectal cancer cells.

Relation between body composition and severe diarrhea in patients treated with preoperative chemoradiation with capecitabine for rectal cancer: a single-centre cohort study

Background

Chemoradiation with capecitabine followed by surgery is standard care for locally advanced rectal cancer (LARC). Severe diarrhea is considered a dose-limiting toxicity of adding capecitabine to radiation therapy. The aim of this study was to describe the risk factors and the impact of body composition on severe diarrhea in patients with LARC during preoperative chemoradiation with capecitabine.

Methods

A single centre retrospective cohort study was conducted in a tertiary referral centre. All patients treated with preoperative chemoradiation with capecitabine for LARC from 2009 to 2015 were included. Patients with locally recurrent rectal cancer who received chemoradiation for the first time were included as well. Logistic regression analyses were performed to identify risk factors for severe diarrhea.

Results

A total of 746 patients were included. Median age was 64 years (interquartile range 57–71) and 477 patients (64%) were male. All patients received a radiation dosage of 25 × 2 Gy during a period of five weeks with either concomitant capecitabine administered on radiation days or continuously during radiotherapy. In this cohort 70 patients (9%) developed severe diarrhea. In multivariable logistic regression analyses female sex (OR: 4.42, 95% CI 2.54–7.91) and age ≥ 65 (OR: 3.25, 95% CI 1.85–5.87) were the only risk factors for severe diarrhea.

Conclusions

Female patients and patients aged sixty-five or older had an increased risk of developing severe diarrhea during preoperative chemoradiation therapy with capecitabine. No relation was found between body composition and severe diarrhea.

Extraperitoneal colostomy after laparoscopic abdominoperineal resection using a cannula for tunnel creation through a trocar port

BACKGROUND

Extraperitoneal colostomy (EPC) after laparoscopic abdominoperineal resection (APR) remains a challenge for surgeons. This study aims to summarize our laparoscopic EPC method and assess its effects versus a transperitoneal colostomy (TPC) for patients with rectal tumors.

METHODS

A total of 133 patients with rectal cancer treated with laparoscopic APR between May 2009 and May 2020 were retrospectively reviewed. The clinical data, including demographics, comorbidities, tumor stage, colostomy duration, and complications were compared between the EPC group and the TPC group.

RESULTS

The EPC group included 83 patients whose extraperitoneal tunnels were created using a cannula through a trocar port, and the TPC group included 50 patients whose stomata were formed traditionally. There were no differences in colostomy time [(23.1 ± 6) min vs. (21.4 ± 4) min, P = 0.078], number of parastomal dermatitis patients (5 vs. 2, P = 0.916), or number of stomal stenoses (1 vs. 1, P = 0.715) between the EPC and TPC groups. No cases of parastomal hernia developed in the EPC group, whereas 4 patients were diagnosed with a parastomal hernia; the difference between the two groups was statistically significant (P = 0.036).

CONCLUSIONS

Laparoscopic EPC have a lower incidence of parastomal hernia than TPC. It is easy and inexpensive to create an extraperitoneal tunnel using a cannula through a trocar port.

Adding Adjuvants to Fluoropyrimidine-based Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: An Option Worthy of Serious Consideration

The application of fluoropyrimidine-based neoadjuvant chemoradiotherapy (Fu-nCRT) of locally advanced rectal cancer (LARC) has become a common therapeutic regimen. In order to improve the efficacy and enable more patients to benefit from this treatment, an accumulation of studies have been carried out on the auxiliary use of other drugs with Fu-nCRT. However, due to specific challenges and the potential opportunities that coexist in this field, a more reasonable approach to the mode of treatment remains to be explored. In this review, we have summarized the results of the studies on the combination of Fu-nCRT with cytotoxic drugs, anti-tumor angiogenesis, and anti-EGFR agents, as well as the status of the application of immune checkpoint inhibitors in the neoadjuvant therapy of LARC patients.

Retrospective study of the functional and oncological outcomes of conformal sphincter preservation operation in the treatment of very low rectal cancer

BACKGROUND

Conformal sphincter preservation operation (CSPO) is a new surgical procedure for very low rectal cancers (within 4-5 cm from the anal verge). CSPO preserves more of the dentate line and distal rectal wall and also avoids injuring nerves in the intersphincteric space, resulting in satisfactory anal function after resection. The aim of this study was to analyze the short-term surgical results and long-term oncological and functional outcomes of CSPO.

METHODS

Consecutive patients with very low rectal cancer, who had CSPO between January 2011 and October 2018 at Changhai Hospital, Shanghai were included. Patient demographics, clinicopathological features, oncological outcomes and anal function were analyzed.

RESULTS

A total of 102 patients (67 men) with a mean age of 56.9 ± 10.8 years were included. The median distance of the tumor from the anal verge was 3 (IQR, 3-4) cm. Thirty-five patients received neoadjuvant chemoradiation (nCRT). The median distal resection margin (DRM) was 0.5 (IQR, 0.3-0.8) cm. One patient had a positive DRM. All circumferential margins were negative. There was no perioperative mortality. The postoperative complication rate was 19.6%. The median duration of follow-up was 28 (IQR, 12-45.5) months. The local recurrence rate was 2% and distant metastasis rate was 10.8%. The 3-year overall survival and disease-free survival rates were 100% and 83.9%, respectively. The mean Wexner incontinence and low anterior resection syndrome scores 12 months after ileostomy reversal were 5.9 ± 4.3, and 29.2 ± 6.9, respectively.

CONCLUSIONS

For patients with very low rectal cancers, fecal continence can be preserved with CSPO without compromising oncological results.

Analysis of influencing factors of no/low response to preoperative concurrent chemoradiotherapy in locally advanced rectal cancer

The aim of this study is to investigate the influencing factors associated with no/low response to preoperative concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer (LARC) patients. A total of 79 patients were included in this prospective study. Fifteen factors that might affect the resistance to CCRT were included in this logistic regression analysis, these factors include the general clinical data of patients, the expression status of tumor stem cell marker CD44v6 and the volumetric imaging parameters of primary tumor lesions. We found that the no/low response status to preoperative CCRT was positively correlated with the real tumor volume (RTV), the total surface area of tumor (TSA), and CD44v6 expression, whereas negatively correlated with the tumor compactness (TC). According to the results of logistic regression analysis, two formulas that could predict whether or not no/low response to preoperative CCRT were established. The Area Under Curve (AUC) of the two formulas and those significant measurement data (RTV, TC, TSA) were 0.900, 0.858, 0.771, 0.754, 0.859, the sensitivity were 95.8%, 79.17%, 62.50%, 95.83%, 62.5%, the specificity were 70.9%, 74.55%, 83.64%,47.27%, 96.36%, the positive predictive values were 58.96%, 57.58%, 62.51%,44.23%, 88.23%, the negative predictive values were 97.48%, 89.13%, 83.64%, 96.29%, and 85.48%, respectively.

Baseline and early 3D-CUBE volume reconstruction of locally advanced rectal cancer to predict tumor response after neoadjuvant chemotherapy

PURPOSE

To explore whether volumetric measurements of 3D-CUBE sequences based on baseline and early treatment time can predict neoadjuvent chemotherapy (NCT) efficacy of locally advanced rectal cancer (LARC).

MATERIAL AND METHOD

73 patients with LARC were enrolled from February 2014 to January 2018. All patients underwent MRIs during the baseline period before NCT (BL-NCT) and the first month of NCT (FM-NCT), and tumor volume (TV) was measured using 3D-CUBE, and tumor volume reduction (TVR) and tumor volume reduction rate (TVRR) were calculated. In addition, tumor invasion depth, tumor maximal length, range of tumor involvement in the circumference of intestinal lumen and distance from inferior part of tumor to the anal verge were measured using baseline high-spatial-resolution T2-weighted MRIs. All patients were categorized into sensitive and insensitive groups based on post-surgical pathology after completion of the full courses of NCT. The receiver operating characteristic (ROC) curve was used to analyze the value of different MRI parameters in predicting efficacy of NCT.

RESULTS

Statistically significant differences in TV of BL-NCT, TVR and TVRR from BL-NCT to FM-NCT were detected between sensitive and insensitive groups (P < 0.05, respectively). The areas under the curves (AUC) of ROC of TVR and TVRR in predicting efficacy of NCT (0.890 [95% CI, 0.795∼0.951], 0.839 [95% CI, 0.735∼0.915]) were significantly better than that of TV (0.660 [95% CI, 0.540∼0.767]) (P < 0.05, respectively).

CONCLUSION

Reconstruction of 3D-CUBE volume in the first month of NCT is necessary, and both TVR and TVRR can be used as early predictors of NCT efficacy.

Additional Chemotherapy with 5-FU plus Leucovorin between Preoperative Chemoradiotherapy and Surgery Improved Treatment Outcomes in Patients with Advanced Rectal Cancer

Purpose: The aim of the preliminary study was to evaluate the efficacy and safety of 4-week chemotherapy with 5-Fluorouracil and leucovorin (LV5FU2) during the resting periods between preoperative CRT and surgery in patients with LARC. Materials and Methods: Standard preoperative CRT was delivered to the entire pelvis at a total dose of 5040 Gy of radiation with concurrent 5-FU or capecitabine for 6 weeks. Twenty-three patients received additional preoperative chemotherapy with two cycles of 5-FU and LV (LV 200 mg/m2 and 5-FU bolus 400 mg/m2 on day 1, and 5-FU infusion 2400 mg/m2 for 46 hrs, every 2 weeks) after preoperative CRT. Surgery was performed at 2-4 weeks following the completion of preoperative chemotherapy. Results: Between May 2013 and January 2015, 23 patients underwent preoperative CRT, with additional chemotherapy and surgery, and 23 patients completed the scheduled treatment. The median follow-up duration was 42.0 months. The tumor down-staging rate was observed in 65.2%, and pathologic complete remission (pCR) was noted in 5 patients (21.7%). T and N down-staging were observed in 16 (69.6%) and 14 (60.9%) patients, respectively. The four-year disease-free survival (DFS) rate was 73.9% and the four-year overall survival (OS) rate was 90.9% in patients who received additional chemotherapy. The four-year DFS rate was 100% in the tumor down-staging group vs. 25.0% in the non-down staging group treated with additional chemotherapy (P <0.001). There was also a significant difference of the four-year OS rate 100% in the tumor down-staging group compared with 71.4% in the non-down staging group (P = 0.031). Conclusions: This preliminary study showed that additional preoperative chemotherapy with LV5FU2 was well tolerable and had an improvement in the downstaging rate and survival. Randomized controlled trial of this strategy is encouraged for definitive conclusions.

Matched case-control analysis comparing oncologic outcomes between preoperative and postoperative chemoradiotherapy for rectal cancer

PURPOSE

To investigate patterns of recurrence and oncologic outcomes after recurrence between preoperative and postoperative chemoradiotherapy (CRT).

METHODS

Records of patients with stage II or III locally advanced rectal cancer seen between January 2000 and December 2010 were analyzed. The outcomes for patients undergoing preoperative CRT followed by radical resection (n = 466) were compared with outcomes of patients matched for sex, age, and stage who had surgery and then postoperative CRT (n = 466). Recurrence rates and sites, treatment of recurrence, and oncologic outcomes after recurrence were investigated. The rate of sphincter preservation and permanent stoma formation were also evaluated.

RESULTS

Recurrence occurred in 124 and 140 patients in the pre- and postoperative CRT groups, respectively. The local and systemic recurrence rates were 3.6% and 20.8%, respectively, in the preoperative CRT group and 3.0% and 25.3%, respectively, in the postoperative CRT group (P = 0.245). Time to recurrence was longer in the postoperative CRT group (19 months vs. 24.2 months, P = 0.029). The overall rates of sphincter preservation (sphincter preservation operation and postoperative permanent stoma formation) did not significantly different between the two groups (P = 0.381). The 5-year overall survival rate after recurrence did not differ between the two groups (25.6% vs. 18.6%, P = 0.051).

CONCLUSION

Preoperative and postoperative CRT are both safe and suitable treatment methods for rectal cancer, so the choice can be tailored to the patient's situation.

Effect of Neoadjuvant Chemoradiotherapy with Capecitabine versus Fluorouracil for Locally Advanced Rectal Cancer: A Meta-Analysis

A meta-analysis was carried out to compare the efficacy and safety of capecitabine plus radiation with 5-fluorouracil (5-FU) plus radiotherapy (RT) as neoadjuvant treatment in locally advanced rectal cancer (LARC). We searched the Cochrane database, Ovid, Medline, Embase, ISI databases, and Chinese Biomedical Literature Database between January 1998 and October 2014. Trials of capecitabine compared with 5-FU plus RT as neoadjuvant treatment for LARC were considered for inclusion. RevMan software was used to analyze these data. Nine trials were included in this meta-analysis, which covered a total of 3141 patients. The meta-analysis showed that capecitabine group had statistically significant better pCR rates (OR, 1.34; 95% CI, 1.10-1.64; P = 0.003), T downstaging rates (OR, 1.58; 95% CI, 1.22-2.06; P = 0.0007), N downstaging rates (OR, 2.06; 95% CI, 1.34-3.16; P = 0.001), less distant metastasis (OR, 0.63; 95% CI, 0.44-0.88; P = 0.007), and lowered leucocytes (OR, 0.25; 95% CI, 0.11-0.54; P = 0.0005), but with higher incidence of hand-foot syndrome (HFS) (OR, 4.43; 95% CI, 1.59-12.33; P = 0.004). Capecitabine was more efficient than 5-FU in terms of tumor response in neoadjuvant treatment for patients with LARC and favourably low toxicity with the exception of HFS.

Preoperative chemoradiotherapy for clinically diagnosed T3N0 rectal cancer

PURPOSE

This retrospective study compared the recurrence-free survival (RFS) and local recurrence rates of patients who received preoperative chemoradiotherapy (PCRT) for cT3N0 vs. those who did not.

METHODS

We analyzed the records of 593 patients with transrectal ultrasound (TUS) or magnetic resonance image (MRI)-staged cT3N0 mid and low locally advanced rectal cancer, including 255 who received PCRT and 338 who did not. The RFS and cumulative local recurrence rates were compared in the two groups. We also investigated the rates of pathologic complete response (pCR) and mesorectal lymph node (LN) involvement in the PCRT group.

RESULTS

The overall pCR rate was 13.3 %. Of the 338 non-PCRT patients, 125 (37.0 %) had pathologically positive mesorectal LNs. Sphincter-preserving surgery was performed in 431 (72.7 %) of the 593 patients, with similar rates in the two groups. However, the sphincter preservation rate in patients with low rectal cancer was higher among those who received PCRT than among those who did not (64.8 vs. 47 %, P = 0.002). The 5-year RFS (76.4 vs. 75.5 %, P = 0.92) and local recurrence (3.9 vs. 3.0 %, P = 0.97) rates were similar in the PCRT and non-PCRT groups.

CONCLUSION

Although PCRT did not improve the RFS or local recurrence rates, it increased the chance of sphincter preservation in patients with low rectal cancer. The advantages of PCRT for patients with cT3N0 should be re-evaluated considering the limitation of pretreatment staging, oncologic benefits, and improved sphincter preservation.

Preoperative Chemoradiation in Locally Advanced Rectal Cancer: Efficacy and Safety

Background

Preoperative chemoradiation (CRT) is considered the standard of care in the management of stage II/III rectal cancer. The aim of this retrospective study was to assess the efficacy and safety of preoperative CRT in our patient cohort with locally advanced rectal adenocarcinoma.

Methods

Forty patients with cT3-4N0-2M0 adenocarcinoma of the lower (n = 26) and mid/upper (n = 14) rectum were enrolled in this study between 2001 and 2012. Radiotherapy (RT) was given to the pelvis. The median prescribed dose was 45 Gy (daily dose, 1.8 - 2.0 Gy). All patients received chemotherapy concurrently with RT and underwent surgery 6 - 8 weeks after CRT. Low anterior resection (LAR) was achieved in 21 patients. Total mesorectal excision (TME) was performed in 24 patients.

Results

Tumor downstaging (expressed as TN downstaging) was observed in 15 patients (38%); a pathological complete response (pCR) was pathologically confirmed in six of them. In nine out of the 26 (23%) patients with low lying tumors, sphincter preservation (SP) was possible. SP was also possible in all but one patient (13%) who achieved a pCR. In three out of 15 patients (8%) with preoperative sphincter infiltration, SP was achieved. With a median follow-up of 58 months, the 4-year local control (LC), distant metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) rates were 89.7%, 86.9%, 79.5% and 81.2%, respectively. The pretreatment tumor size was predictive of response to preoperative CRT. The response to preoperative CRT did show a significant impact on DFS and on OS. TME resulted in a statistically significant increased DFS rate. No grade 3/4 acute toxicity was reported. Three patients developed grade 3 late side effects.

Conclusion

Preoperative CRT demonstrates encouraging rates of disease control and facilitates complete resection and SP in advanced rectal cancer with acceptable late toxicity.

The accuracy of MRI, endorectal ultrasonography, and computed tomography in predicting the response of locally advanced rectal cancer after preoperative therapy: A metaanalysis

BACKGROUND

To perform a metaanalysis to determine and compare the diagnostic performance of MRI, endorectal ultrasonography (ERUS), and computed tomography (CT) in predicting the response of locally advanced rectal cancer after preoperative therapy.

METHODS

All previously published articles on the role of MRI, CT, and/or ERUS in predicting the response of rectal cancer to preoperative therapy were collected. We divided the objective in 3 parts: the accuracy to assess (i) complete response, (ii) to detect T4 tumors with invasion to the circumferential resection margin (CRM), and (iii) to predict the presence of lymph node metastasis. The pooled estimates of, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated using a bivariate mixed effect analysis.

RESULTS

Forty-six studies comprising 2,224 patients were included. (i) The pooled accuracy to assess complete tumor response were (a) 75% for MRI, (b) 82% for ERUS, (c) and 83% for CT. (ii) Pooled accuracy to detect T4 tumors with invasion to the CRM were (a) 88% and (b) 94% for ERUS. (iii) Pooled accuracy to predict the presence of lymph node metastasis was (a) 72% for MRI, (b) 72% for ERUS, (c) and 65% for CT.

CONCLUSION

MRI, CT, and ERUS cannot be used to predict complete response of locally advanced rectal cancer after CRT. In addition, the positive predictive value for these imaging techniques is low for the assessment of tumor invasion in the CRM. The accuracy of the modalities to predict the presence of metastatic lymph node disease is also low.

Neoadjuvant therapy for gastric cancer: current evidence and future directions

Although surgical resection remains the only potentially curative treatment for gastric cancer (GC), poor long-term outcomes with resection alone compel a multimodality approach to this disease. Multimodality strategies vary widely; while adjuvant approaches are typically favored in Asia and the United States (USA), a growing body of evidence supports neoadjuvant and/or perioperative strategies in locally advanced tumors. Neoadjuvant approaches are particularly attractive given the morbidity associated with surgical management of GC and the substantial risk of omission of adjuvant therapy. The specific advantages of chemoradiotherapy (CRT) compared to chemotherapy have not been well defined, particularly in the preoperative setting and trials aimed at determining the optimal elements and sequencing of therapy are underway. Future studies will also define the role of targeted and biologic therapies.

How can we determine the best neoadjuvant chemoradiotherapy regimen for rectal cancer?

SUMMARY 

The current management of patients with clinically defined ‘locally advanced rectal cancer’ often involves fluoropyrimidine-based preoperative chemoradiotherapy (CRT) followed by total mesorectal excision. The focus remains primarily on reducing local recurrence, and improving survival, with organ preservation an increasing target. The best neoadjuvant CRT is the most effective regimen, balanced against the tolerability and late functional consequences, which should be selected for the individual according to their individual risk of local and distant recurrence. Hence, what makes the best neoadjuvant treatment depends on the activity and toxicity of the particular schedule, the aims of treatment, the individual disease characteristics and the individual patient pharmacogenomics. Current research efforts focus on enhancing the efficacy of CRT by integrating additional cytotoxics and biologically targeted agents.

Sphincter preservation in distal CT2N0 rectal cancer after preoperative chemoradiotherapy

BACKGROUND

Preoperative chemoradiotherapy is usually not indicated for cT2N0 rectal cancer. Abdominoperineal resection is the standard treatment for distal rectal tumors. The aim of the study was to evaluate the actual sphincter-preservation rate in patients with distal cT2N0 rectal cancer given neoadjuvant chemoradiotherapy.

METHODS

Data were retrospectively collected for all patients who were diagnosed with distal cT2N0 rectal cancer at a tertiary medical center in 2000-2008 and received chemoradiotherapy followed by surgery (5-7 weeks later).

RESULTS

Thirty-three patients (22 male) of median age 65 years (range, 32-88) were identified. Tumor distance from the anal verge ranged from 0 to 5 cm. R0 resection with sphincter preservation was accomplished in 22 patients (66%), with a 22% pathological complete response rate. Median follow-up time was 62 months (range 7-120). There were no local failures. Crude disease-free and overall survival were 82% and 86%, respectively. Factors associated with sphincter preservation were tumor location (OR=0.58, p=0.02, 95% CI=0.37-0.91) and pathological downstaging (OR=7.8, p=0.02, 95% CI=1.35-45.85). Chemoradiotherapy was well tolerated.

CONCLUSION

High rates of sphincter preservation can be achieved after preoperative chemoradiotherapy for distal cT2N0 rectal cancer, with tolerable toxicity, without compromising oncological outcome.

Can a biomarker-based scoring system predict pathologic complete response after preoperative chemoradiotherapy for rectal cancer?

BACKGROUND

Numerous molecular markers have been investigated as potential predictors of tumor responses to preoperative chemoradiotherapy (preCRT) for rectal cancer.

OBJECTIVE

To develop a system in which biomarkers are used to predict the likelihood of a pathologic complete response (pCR) to preCRT.

DESIGN & SETTING

This is a retrospective analysis of tumor specimens collected prior to preCRT from 81 patients who underwent curative resection for primary rectal adenocarcinoma between June 2008 and February 2012.

MAIN OUTCOME MEASURES

Using tissue microarrays and immunohistochemistry, expression levels of twelve candidate biomarkers (p53, p21, Bcl2, Bax, EGFR, Cox-2, MLH-1, MSH-2, Ku70, VEGF, TS, Ki-67) were evaluated in paraffin-embedded tumor samples collected before preCRT. The correlation between biomarker expression levels and the pathologic response to preCRT was assessed based on histopathological staging (pTNM) and tumor regression grade (TRG).

RESULTS

Expression levels of 4 biomarkers (p53, VEGF, p21, Ki67) correlated with pCR. Patients showing low expression of p53 and/or high expression of VEGF, p21, and Ki67 exhibited a significantly greater pCR rate. A scoring system devised so that one point was given for each biomarker whose expression level correlated with pCR (score range: 0-4) showed that 1 of 26 patients with scores of 0 to 1 achieved pCR, whereas 26 of 55 patients with scores of 2 to 4 achieved pCR (3.8% vs. 47.3%, p < 0.001). For prediction of pCR, the scoring system showed 96.3% sensitivity, 46.3% specificity, a 47.3% positive predictive value, and a 96.2% negative predictive value.

LIMITATIONS

Immunohistochemistry has limitations related to reproducibility and the ability to provide quantitative information. In addition, this study lacks test and validation sets.

CONCLUSIONS

Expression levels of 4 biomarkers correlated with pCR after preCRT for rectal cancer. A scoring system based on levels of biomarker expression showed good sensitivity and negative predictive value for pCR.

Five fractions of radiation therapy followed by 4 cycles of FOLFOX chemotherapy as preoperative treatment for rectal cancer

BACKGROUND

Preoperative radiation therapy with 5-fluorouracil chemotherapy is a standard of care for cT3-4 rectal cancer. Studies incorporating additional cytotoxic agents demonstrate increased morbidity with little benefit. We evaluate a template that: (1) includes the benefits of preoperative radiation therapy on local response/control; (2) provides preoperative multidrug chemotherapy; and (3) avoids the morbidity of concurrent radiation therapy and multidrug chemotherapy.

METHODS AND MATERIALS

Patients with cT3-4, any N, any M rectal cancer were eligible. Patients were confirmed to be candidates for pelvic surgery, provided response was sufficient. Preoperative treatment was 5 fractions radiation therapy (25 Gy to involved mesorectum, 20 Gy to elective nodes), followed by 4 cycles of FOLFOX [5-fluorouracil, oxaliplatin, leucovorin]. Extirpative surgery was performed 4 to 9 weeks after preoperative chemotherapy. Postoperative chemotherapy was at the discretion of the medical oncologist. The principal objectives were to achieve T stage downstaging (ypT < cT) and preoperative grade 3+ gastrointestinal morbidity equal to or better than that of historical controls.

RESULTS

76 evaluable cases included 7 cT4 and 69 cT3; 59 (78%) cN+, and 7 cM1. Grade 3 preoperative GI morbidity occurred in 7 cases (9%) (no grade 4 or 5). Sphincter-preserving surgery was performed on 57 (75%) patients. At surgery, 53 patients (70%) had ypT0-2 residual disease, including 21 (28%) ypT0 and 19 (25%) ypT0N0 (complete response); 24 (32%) were ypN+. At 30 months, local control for all evaluable cases and freedom from disease for M0 evaluable cases were, respectively, 95% (95% confidence interval [CI]: 89%-100%) and 87% (95% CI: 76%-98%). Cases were subanalyzed by whether disease met requirements for the recently activated PROSPECT trial for intermediate-risk rectal cancer. Thirty-eight patients met PROSPECT eligibility and achieved 16 ypT0 (42%), 15 ypT0N0 (39%), and 33 ypT0-2 (87%).

CONCLUSION

This regimen achieved response and morbidity rates that compare favorably with those of conventionally fractionated radiation therapy and concurrent chemotherapy.

Current issues in locally advanced colorectal cancer treated by preoperative chemoradiotherapy

In patients with locally advanced rectal cancer, preoperative chemoradiotherapy has proven to significantly improve local control and cause lower treatment-related toxicity compared with postoperative adjuvant treatment. Preoperative chemoradiotherapy followed by total mesorectal excision or tumor specific mesorectal excision has evolved as the standard treatment for locally advanced rectal cancer. The paradigm shift from postoperative to preoperative therapy has raised a series of concerns however that have practical clinical implications. These include the method used to predict patients who will show good response, sphincter preservation, the application of conservative management such as local excision or “wait-and-watch” in patients obtaining a good response following preoperative chemoradiotherapy, and the role of adjuvant chemotherapy. This review addresses these current issues in patients with locally advanced rectal cancer treated by preoperative chemoradiotherapy.

A Predictive Genetic Signature for Response to Fluoropyrimidine-Based Neoadjuvant Chemoradiation in Clinical Stage II and III Rectal Cancer

PURPOSE

Pre-operative chemoradiation (CRT) is currently the standard of care for patients with clinical stage II and III rectal cancer but only about 45% of patients achieve tumor downstaging and <20% of patients achieve a pathologic complete response. Better methods to stratify patients according to potential neoadjuvant treatment response are needed. We used microarray analysis to identify a genetic signature that correlates with a pathological complete response (pCR) to neoadjuvant CRT. We performed a gene network analysis to identify potential signaling pathways involved in determining response to neoadjuvant treatment.

PATIENTS AND METHODS

We identified 31 T3-4 N0-1 rectal cancer patients who were treated with neoadjuvant fluorouracil-based CRT. Eight patients were identified to have achieved a pCR to treatment while 23 patients did not. mRNA expression was analyzed using cDNA microarrays. The correlation between mRNA expression and pCR from pre-treatment tumor biopsies was determined. Gene network analysis was performed for the genes represented by the predictive signature.

RESULTS

A genetic signature represented by expression levels of the three genes EHBP1, STAT1, and GAPDH was found to correlate with a pCR to neoadjuvant treatment. The difference in expression levels between patients who achieved a pCR and those who did not was greatest for EHBP1. Gene network analysis showed that the three genes can be connected by the gene ubiquitin C (UBC).

CONCLUSION

This study identifies a 3-gene signature expressed in pre-treatment tumor biopsies that correlates with a pCR to neoadjuvant CRT in patients with clinical stage II and III rectal cancer. These three genes can be connected by the gene UBC, suggesting that ubiquitination is a molecular mechanism involved in determining response to treatment. Validating this genetic signature in a larger number of patients is proposed.

Sphincter-sparing surgery for adenocarcinoma of the distal 3 cm of the true rectum: results after neoadjuvant therapy and minimally invasive radical surgery or local excision

BACKGROUND

Ideal treatment of rectal cancer includes controlling the cancer; minimizing trauma, morbidity, and mortality; and avoiding a colostomy with preservation of adequate function. These goals become more challenging the further distal in the rectum the cancer is located. We sought to determine whether minimally invasive sphincter-preservation surgery (SPS) can accomplish good cancer control, maintaining sphincter function with minimal morbidity and mortality in rectal cancers of the distal 3 cm after receiving neoadjuvant chemoradiotherapy.

METHODS

We retrospectively reviewed a prospectively maintained rectal cancer database of a single colorectal surgeon to identify all patients with cancers of the distal 3 cm undergoing SPS via a laparoscopic total mesorectal excision or transanal endoscopic microsurgery (TEM). All patients received neoadjuvant chemoradiotherapy. Patient data, including demographics, initial tumor characteristics, staging, radiation dose, perioperative morbidity and mortality, and local recurrence (LR) and survival, were analyzed.

RESULTS

A total of 161 patients (108 men) underwent SPS via 3 techniques: transanal abdominal transanal proctosigmoidectomy (TATA, n = 106), TEM (n = 49), or ultralow anterior resection (LAR, n = 6). Average age was 62 years (range 22-90 years). The mean levels in rectum from the anorectal ring were as follows: TATA, 1.3 cm (range -1.0 to 3.0 cm), TEM, 1.5 cm (range -0.5 to -3.0 cm), and LAR, 2.9 cm (range 2.5-3.0 cm) (p > 0.05). Preoperative T stage was as follows: T3, n = 108 (TATA 83, TEM 20, LAR 5), T2, n = 48 (TATA 22, TEM 25, LAR 1), T1, n = 3 (TATA 1, TEM 2), and T4, n = 2 (both TEM). All patients received concomitant 5-fluorouracil-based chemotherapy and radiotherapy (mean, 5300 cGy; range 3,000-7,295 cGy). The mean estimated blood loss was 376 ml (range 10-3,600 ml). There were no mortalities. Morbidity rates were as follows: LAR, 0; TATA, 13.2%; and TEM, 32 % (wound disruption: major, 10%; minor, 16%). Pathologic staging was as follows: ypCR: uT2, 34%, and uT3, 19%. Overall LR was 3.7%. By procedure, the follow-up, LR, and KM5YAS, respectively, were: TATA, 37.9 months, 3 and 95%; TEM, 36.3 months, 6 and 88%; and LAR, 63.1 months, 0 and 75% (p > 0.05).

CONCLUSIONS

This study demonstrates positive oncologic outcomes, low LR rates, and high KM5YS after minimally invasive SPS. A colostomy-free lifestyle and cancer control make the minimally invasive surgical approach an excellent treatment option for complex distal rectal cancers.

Tumor scatter after neoadjuvant therapy for rectal cancer: are we dealing with an invisible margin?

BACKGROUND

After the impressive response of rectal cancers to neoadjuvant therapy, it seems reasonable to ask: can we can excise the small ulcer locally or avoid a radical resection if there is no gross residual tumor? Does gross response reflect what happens to tumor cells microscopically after radiation?

OBJECTIVE

The aim of this study was to identify microscopic tumor cell response to radiation.

DESIGN

This study is a retrospective review of a prospectively collected database.

SETTING

This investigation was conducted at a single tertiary medical center.

PATIENTS

Patients were selected who had elective radical resection for rectal cancer after preoperative chemotherapy and radiation performed by 2 colorectal surgeons between 2006 and 2011.

MAIN OUTCOME MEASURES

The primary outcome measured was tumor presence after radiation therapy

RESULTS

Of the 75 patients, 20 patients were complete responders and 55 had residual cancer. Of these patients, 28 had no tumor cells seen outside the gross ulcer, and 27 (49.1%) had tumor outside the visible ulcer or microscopic tumor present with no overlying ulcer. Of these tumors, 81.5% were skewed away from the ulcer center. The mean distance of distal scatter was 1.0 cm from the visible ulcer edge to a maximum of 3 cm; 3 patients had tumor cells more than 2 cm distal to the visible ulcer edge. Tumor scatter outside the ulcer was not associated with poor prognostic factors, such as nodal and distant disease, perineural invasion, or mucin; however, it was associated with lymphovascular invasion (χ2 = 4.12, p = 0.038)

LIMITATIONS

There was limited access to clinical information gathered outside our institution.

CONCLUSIONS

Our study suggests that 1) after radiation, the gross ulcer cannot be used to determine the sole area of potential residual tumor, 2) cancer cells may be found up to 3 cm distally from the gross ulcer, so the traditional 2-cm margin may not be adequate, and 3) local excision of the ulcer or no excision after apparent complete response appears to be insufficient treatment for rectal cancer.

Neoadjuvant oral vs. infusional chemoradiotherapy on locally advanced rectal cancer: Prognostic factors

AIM

To evaluate the prognostic factors and impact on survival of neoadjuvant oral and infusional chemoradiotherapy in patients with locally advanced rectal cancer.

BACKGROUND

There is still no definitive consensus about the prognostic factors and the impact of neoadjuvant chemoradiotherapy on survival. Some studies have pointed to an improvement in overall survival (OS) and progression-free survival (PFS) in patients with tumor downstaging (TD) and nodal downstaging (ND).

MATERIALS AND METHODS

A set of 159 patients with LARC were treated preoperatively. Group A - 112 patients underwent concomitant oral chemoradiotherapy: capecitabine or UFT + folinic acid. Group B - 47 patients submitted to concomitant chemoradiation with 5-FU in continuous infusion. 63.6% of patients were submitted to adjuvant chemotherapy.

RESULTS

GROUP A

pathologic complete response (pCR) - 18.7%; TD - 55.1%; ND - 76%; loco-regional response - 74.8%. Group B: pCR - 11.4%; TD - 50%; ND - 55.8%; LRR - 54.5%. The loco-regional control was 95.6%. There was no difference in survival between both groups. Those with loco-regional response had better PFS.

CONCLUSIONS

Tumor and nodal downstaging, loco-regional response and a normal CEA level turned out to be important prognostic factors in locally advanced rectal cancer. Nodal downstaging and loco-regional response were higher in Group A. Those with tumor downstaging and loco-regional response from Group A had better OS. Adjuvant chemotherapy had no impact on survival except in those patients with loco-regional response who achieved a higher PFS.

Delayed surgery for rectal cancer patients receiving neoadjuvant chemoradiotherapy: a promising method in its infancy

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) is used to downstage locally advanced rectal cancer before surgery. Accumulating data suggest that tumor response to nCRT is time dependent. A delay between nCRT and surgery may increase the proportion of patients that achieve a favorable response. However, delayed surgery beyond 6-8 weeks may increase the technical difficulty, and the risks of surgical complications and recurrence or metastasis. This article briefly reviews the relevant literature to evaluate the efficiency and safety of delayed surgery.

METHODS

Two non-cohort studies and 10 cohort studies were reviewed. The results were analyzed and the limitations discussed.

RESULTS

Although debatable, the findings of the included studies are promising. Delayed surgery may increase the proportion of favorable tumor response without compromising prognosis. However, most of the studies were retrospective, which introduces bias into the evaluation.

CONCLUSION

Delayed surgery is potentially useful, but this needs to be verified by further well-designed prospective trials.

Comparison of neoadjuvant oral chemotherapy with UFT plus Folinic acid or Capecitabine concomitant with radiotherapy on locally advanced rectal cancer

AIM

To evaluate the differences in treatment response and the impact on survival with both oral agents (UFT and Capecitabine) as neoadjuvant chemotherapy administered concomitantly with radiotherapy.

BACKGROUND

There are still no studies comparing the use of neoadjuvant oral chemotherapy either with UFT plus Folinic acid or Capecitabine concomitant with radiotherapy in locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

A set of 112 patients with LARC were treated preoperatively. GROUP 1 - 61 patients underwent concomitant oral chemotherapy with Capecitabine (825 mg/m(2) twice daily). GROUP 2 - 51 patients submitted to concomitant oral chemotherapy with UFT (300 mg/m(2)/d) + Folinic acid (90 mg/d) and radiotherapy. 57.1% of patients were submitted to adjuvant chemotherapy.

RESULTS

GROUP 1: acute toxicity - 80.3%; pathological complete response (pCR) - 10.5%; tumor downstaging (TD) - 49.1%; nodal downstaging (ND) - 76.5%; loco-regional response (LRR) - 71.9%; toxicity to adjuvant chemotherapy - 75%. GROUP 2: acute toxicity - 80.4%; pCR - 28%; TD - 62%; ND - 75.6%; LRR - 78%; toxicity to adjuvant chemotherapy - 56%. There was no difference in survival nor loco-regional control between the groups.

CONCLUSIONS

Patients treated with neoadjuvant oral UFT + Folinic acid had a higher rate of pathologic complete response than patients treated with Capecitabine concomitant with radiotherapy. There were no differences in downstaging, LRR, toxicity, survival or loco-regional control between both groups. There was a trend to a higher rate of toxicity to adjuvant chemotherapy in the Capecitabine group.

Implementation of HybridArc treatment technique in preoperative radiotherapy of rectal cancer: dose patterns in target lesions and organs at risk as compared to helical Tomotherapy and RapidArc

Purpose

HybridArc is a novel treatment technique blending aperture-enhanced optimized arcs with discrete IMRT-elements, allowing selection of arcs with a set of static IMRT-beams. This study compared this new technique to helical Tomotherapy, and RapidArc, in preoperative radiotherapy of rectal cancer.

Material and methods

Twelve rectal cancer patients treated consecutively with Tomotherapy Hi-Art II system were simulated with HybridArc and RapidArc. Treatment plans were designed to deliver homogeneous dose of 46.0Gy to mesorectum and draining lymph nodes, with a simultaneous-integrated-boost to the primary tumor up to a total dose of 55.2Gy. Planning objectives were 95% of prescribed dose to 95% of PTVs, while minimizing the volume of small bowel receiving more than 15Gy (V15) and the mean bladder dose. Dose gradient towards simultaneous-integrated-boost (GI), calculated by dividing the volume receiving more then 52.4Gy (95% of PTV55.2Gy)to the volume of PTV55.2Gy, was kept below 1.5. Mean beam-on time and amount of MUs were also analyzed.

Results

PTV swere adequately covered by all plans. Significant advantage was found for Tomotherapy in sparing small bowel (V15 = 112.7cm³SD73.4cm³) compared to RapidArc (133.4cm³SD75.3cm³) and HybridArc (143.7cm³SD74.4cm³) (p < 0.01). The mean bladder dose was better with RapidArc (20.6GySD2.2Gy) compared to HybridArc (24.2Gy SD4.3Gy) and Tomotherapy (23.0GySD4.7Gy) (p < 0.01). The mean beam-on time was significantly lower (p < 0.01) for HybridArc (2.7min SD0.8) and RapidArc (2.5min SD0.5) compared to Tomotherapy (11.0min SD0.7). The total amount of MUs was significantly (p < 0.01) lower for RapidArc (547SD44)compared to HybridArc (949 SD153).

Conclusions

HybridArc is a feasible solution for preoperative RT with a simultaneous-integrated-boost in rectal cancer patients. It achieved similar PTV coverage with significant lower beam-on time, but less efficient in sparing small bowel and bladder compared to Tomotherapy and RapidArc. The added value of HybridArc is that the treatment modality can be implemented on every LINAC equipped with Dynamic-Conform-Arc and IMRT treatment techniques, while maintaining the same QA-schemes.

A single-centre experience of chemoradiotherapy for rectal cancer: is there potential for nonoperative management?

AIM

The aim of the study was to assess the outcome of patients who received chemoradiotherapy (CRT) for locally advanced rectal cancer, specifically those with complete clinical response (CCR) and who were then managed nonoperatively with a 'Watch and Wait' follow-up protocol.

METHOD

A retrospective study was carried out of patients undergoing preoperative CRT for rectal cancer, conducted in a district general hospital managing rectal cancer through the multidisciplinary team process.

RESULTS

Forty-nine patients received preoperative CRT over a 5-year period (2004-2009). Twelve (24%) were considered potentially to have had a complete response on MRI. Of these, six subsequently had clinical evidence of residual disease, leading to surgery (mean time to surgery, 24 weeks; range, 12-36 weeks). The remaining six had CCR, avoiding surgery (mean follow up, 26 months; range, 12-45 months), with all six patients disease free to date. A further six patients had complete pathological response (CPR) following surgery after comprehensive histopathological assessment of the specimen.

CONCLUSION

In this consecutive series of patients with locally advanced rectal cancer treated with CRT, 12% demonstrated a CCR and have been actively managed conservatively, thereby avoiding surgery. With further improvements in diagnostic assessment of response to CRT, this figure may rise.

Induction chemotherapy with capecitabine and oxaliplatin followed by chemoradiotherapy before total mesorectal excision in patients with locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiation in patients with locally advanced rectal cancer has no impact on overall survival (OS) and distant recurrences. The aim of the study was to evaluate local downstaging, toxicity and long-term outcome in patients with locally advanced rectal cancer after induction therapy with capecitabine and oxaliplatin (CAPEOX) followed by radiotherapy concomitant with capecitabine [chemoradiotherapy (CRT)] before total mesorectal excision (TME).

PATIENTS AND METHODS

Patients with T4 tumors, all T3N+ tumors or T3 tumors involving or with a distance ≤1 mm to the mesorectal fascia were included. Patients were planned for two cycles of CAPEOX followed by radiotherapy concomitant with capecitabine. TME was carried out 6 weeks after the completion of CRT.

RESULTS

Of 84 consecutively admitted patients starting induction CAPEOX, 77 patients underwent surgery. R0 resection was seen in 94% and T downstaging in 69%. In the intention-to-treat group, pathological complete response was seen in 23%. Five-year disease-free survival (DFS) and OS were 63% [95% confidence interval (CI), 52.2% to 73.7%] and 67% (95% CI, 56.1% to 77.3%), respectively. Grade 3/4 toxicity was seen in 18%, and four deaths occurred within 2 months of therapy.

CONCLUSION

Induction chemotherapy before CRT and surgery showed a high local control rate and promising long-term outcome as OS and DFS.

Complete pathologic response after combined modality treatment for rectal cancer and long-term survival: a meta-analysis

BACKGROUND

Complete pathologic response (CPR) after neoadjuvant chemoradiotherapy (combined modality treatment, CMT) for rectal cancer seems associated with improved survival compared to partial or no response (NPR). However, previous reports have been limited by small sample size and single-institution design.

METHODS

A systematic literature review was conducted to detect studies comparing long-term results of patients with CPR and NPR after CMT for rectal cancer. Variables were pooled only if evaluated by 3 or more studies. Study end points included rates of CPR, local recurrence (LR), distant recurrence (DR), 5-year overall survival (OS), and disease-free survival (DFS).

RESULTS

Twelve studies (1,913 patients) with rectal cancer treated with CMT were included. CPR was observed in 300 patients (15.6%). CPR and NPR patient groups were similar with respect to age, sex, tumor size, distance of tumor from the anus, and stage of disease before treatment. Median follow-up ranged from 23 to 46 months. CPR patients had lower rates of LR [0.7% vs. 2.6%; odds ratio (OR) 0.45, 95% confidence interval (CI) 0.22-0.90, P = 0.03], DR (5.3% vs. 24.1%; OR 0.15, 95% CI 0.07-0.31, P = 0.0001), and simultaneous LR + DR (0.7% vs. 4.8%; OR 0.32, 95% CI 0.13-0.79, P = 0.01). OS was 92.9% for CPR versus 73.4% for NPR (OR 3.6, 95% CI 1.84-7.22, P = 0.002), and DFS was 86.9% versus 63.9% (OR 3.53, 95% CI 1.62-7.72, P = 0.002).

CONCLUSIONS

CPR after CMT for rectal cancer is associated with improved local and distal control as well as better OS and DFS.

Sorafenib sensitizes human colorectal carcinoma to radiation via suppression of NF-κB expression in vitro and in vivo

Over-expression of transcription factor nuclear factor-κB (NF-κB) in the residual tumor after the treatment is often observed at the later period of cancer radiotherapy, results in tumor radioresistance and poor treatment outcome. In this study, we combined sorafenib, a multikinase inhibitor, with ionizing radiation to evaluate the therapeutic effect, and to elucidate the possible mechanism responsible for the radiosensitization of sorafenib on a human HT29/tk-luc colorectal carcinoma in vitro and in vivo. Clonogenic survival and cell cycle analysis were used to evaluate the cytotoxicity of sorafenib in vitro. The combination effect and the role of NF-κB in therapeutic efficacy with respects in apoptosis and tumor cell invasion were studied with HT29/tk-luc tumor-bearing animal model. The expression of NF-κB and its downstream-related proteins were assayed with electrophoretic mobility shift assay (EMSA) and Western blot. Sorafenib combined with radiation shows the synergistic cytotoxicity on HT29/tk-luc cells and increased tumor cell apoptosis. Both EMSA and Western blot show that the NF-κB activity induced by radiation is significantly suppressed by sorafenib. Combination of sorafenib and radiation shows the maximum tumor growth inhibition as compared to that of sorafenib alone or radiation alone in vivo (P<0.001). In conclusion, the effect of sorafenib combined with radiation for the treatment of human colorectal carcinoma is synergistic. The mechanism of synergism is through the inhibition of radiation-induced NF-κB expression and its regulated downstream gene products.

Methylenetetrahydrofolate reductase genetic polymorphisms and toxicity to 5-FU-based chemoradiation in rectal cancer

BACKGROUND

There is a large degree of variation in tumour response and host toxicities associated with neoadjuvant chemoradiation for rectal cancer patients. We performed a complimentary pharmacogenetic study to investigate germline polymorphisms of genes involved in 5-fluorouracil (5-FU) and irinotecan pathways and their potential association with clinical outcomes and toxicities from neoadjuvant chemoradiation in patients with rectal cancer treated in a prospective genotype-directed study.

METHODS

The germline DNA of 131 patients was genotyped for 10 variants in TYMS, MTHFR, DPYD, UGT1A1, ABCC1 and SLCO1B1 genes. Ninety-six patients were treated with 5-FU/radiotherapy (RT) and 35 received 5-FU/RT/irinotecan. Relationships between genetic variants and adverse events, tumour response, overall and disease-free survivals were assessed.

RESULTS

MTHFR 1298A>C and MTHFR diplotypes (for 677C>T and 1298A>C) were associated with chemoradiation-related toxicity when 5-FU was used alone. MTHFR haplotypes (677C-1298C) and diplotypes (CA-TA and TA-TA) showed, respectively, a protective and a negative effect on the incidence of severe diarrhoea or mucositis. No association was observed between genetic markers and drug response.

CONCLUSION

MTHFR polymorphisms can potentially predict toxicity in patients treated with 5-FU as a single chemotherapeutic drug.

Bowel exposure in rectal cancer IMRT using prone, supine, or a belly board

PURPOSE

To investigate bowel exposure using prone, supine, or two different belly boards for rectal cancer intensity modulated RT plans using a full bladder protocol.

METHODS AND MATERIALS

For 11 volunteers four MR scans were acquired, on a flat table in prone, supine, and on two different belly boards (IT-V Medizintechnik GmbH® (BB1) and CIVCO® (BB2)), using a full bladder protocol. On each scan a 25×2 Gy IMRT plan was calculated.

RESULTS

BB2 led to an average bowel area volume reduction of 20-30% at any dose level compared to prone. BB1 showed a smaller dose reduction effect, while no differences between prone and supine were found. Differences between BB2 and prone, supine or BB1 were significant up to a level of respectively, 45, 35, and 30 Gy. The reducing effect varied among individuals, except for the 50 Gy region, where no effect was found. An increase in bladder volume of 100 cc led to a significant bowel area V15 reduction of 16% independent of scan type.

CONCLUSIONS

In the low and intermediate dose region a belly board still attributes to a significant bowel dose reduction when using IMRT and a full bladder protocol. A larger bladder volume resulted in a significant decreased bowel area dose.

Can we increase the chance of sphincter saving surgery in rectal cancer with neoadjuvant treatments: lessons from a systematic review of recent randomized trials

PURPOSE

A common hypothesis is that neo-adjuvant treatment in rectal cancer, is able to increase sphincter saving surgery. This review studies data relevant to this question.

STUDY SELECTION

A total of 17 randomized trials were analysed.

RESULTS

Since 1976, the rate of sphincter saving surgery increased from 20% to 75%. In none of the 17 trials it was possible to demonstrate a significant benefit of the neo-adjuvant regimens on the rate of sphincter saving surgery. There was a reduction in the risk of 5-year local recurrence partly due to these neo-adjuvant treatments. These neo-adjuvant regimens had no significant impact on the overall 5-year survival.

CONCLUSIONS

None of the neo-adjuvant treatments tested was able to demonstrate an increase in the rate of sphincter saving surgery. The improvement in conservative surgery is mainly due to technical changes in surgery. Organ preservation after complete clinical response appears as an interesting hypothesis to test.

Thymidylate synthase genotype-directed neoadjuvant chemoradiation for patients with rectal adenocarcinoma

PURPOSE

Downstaging (DS) of rectal cancers is achieved in approximately 45% of patients with neoadjuvant fluorouracil (FU) -based chemoradiotherapy (CRT). Polymorphisms in the thymidylate synthase gene (TYMS) had previously defined two risk groups associated with disparate tumor DS rates (60% v 22%). We conducted a prospective single-institution phase II study using TYMS genotyping to direct neoadjuvant CRT for patients with rectal cancer.

PATIENTS AND METHODS

Patients with T3/T4, N0-2, M0-1 rectal adenocarcinoma were evaluated for germline TYMS genotyping. Patients with TYMS *2/*2, *2/*3, or *2/*4 (good risk) were treated with standard chemoradiotherapy using infusional FU at 225 mg/m²/d. Patients with TYMS *3/*3 or *3/*4 (poor risk) were treated with FU/RT plus weekly intravenous irinotecan at 50 mg/m². The primary end point was pathologic DS. Secondary end points included complete tumor response (ypT0), toxicity, recurrence rates, and overall survival.

RESULTS

Overall, 135 patients were enrolled, of whom 27.4% (37 of 135) were considered poor risk. The prespecified statistical goals were achieved, with DS and ypT0 rates reaching 64.4% and 20% for good-risk and 64.5% and 42% for poor-risk patients, respectively.

CONCLUSION

To our knowledge, this is the first study to prospectively use TYMS genotyping to direct neoadjuvant CRT in patients with rectal cancer. High rates of DS and ypT0 were achieved among both risk groups when personalized treatment was based on TYMS genotype. These results are encouraging, and further evaluation of this genotype-based strategy using a randomized study design for locally advanced rectal cancer is warranted.

18Fluoro-deoxy-glucose positron emission tomography in assessing tumor response to preoperative chemoradiation therapy for locally advanced rectal cancer

BACKGROUND

This study aims to evaluate the efficacy of (18)F-FDG PET in assessing tumor response after preoperative chemoradiation therapy (CRT) for rectal cancer.

METHODS

Maximum standardized uptake value (SUV) was measured for 37 patients who underwent (18)F-FDG PET before and 4 weeks after completion of preoperative CRT. Pre-SUV, post-SUV, the difference between pre- and post-SUV (ΔSUV), and reduction rate (RR) were correlated with tumor response.

RESULTS

A lower mean post-SUV and a higher mean RR were shown in good tumor response (T-downstaging(+) and tumor regression grade 1, 2). Considering pathologic complete response (pCR), the mean post-SUV and the mean RR were significantly different between pCR (+) patients (N = 13) and pCR (-) patients (N = 24) (2.7 vs. 4.8, P < 0.001, 73.9% vs. 58.7%, P = 0.009). With a 3.35 cut-off value for the post-SUV by receiver operating characteristic analysis, 84.6% sensitivity, 79.2% specificity, and 81.2% overall accuracy were obtained for discriminating between pCR (+) and pCR (-) (area under the curve = 0.885, P < 0.001).

CONCLUSIONS

(18)F-FDG PET is potentially useful as a method for assessing tumor response after preoperative CRT for rectal cancer. Post-SUV and RR were significantly associated with pathological treatment response, especially in pCR.

The impact of preoperative chemoradiotherapy on advanced low rectal cancer

BACKGROUND

Preoperative chemoradiotherapy (CCRT) followed by radical resection is an option for advanced low rectal cancer. This study was aimed to clarify the impact of CCRT on patients' outcome.

PATIENTS AND METHODS

One hundred thirty-six patients with rectal cancer (<10  cm from anal verge) were enrolled prospectively between July 2000 and December 2004. The preoperative clinical stage was T3, T4, or node-positive disease. Sixty-nine and 67 patients underwent surgery with and without preoperative CCRT, respectively. The regimen of pre-op CCRT was a radiation dosage of 45  Gy in 20 fractions and oral tegafur-uracil (UFUR) and leucovorin.

RESULTS

There was no statistical difference in the preserved anorectal function between two groups after 5 years of follow-up (62.3% vs. 47.8%; P = 0.125). The 5-year overall survival and disease-free survival (DFS) percentage were 88.4% and 76.8% for patients with preoperative CCRT, and 65.7% and 58.2% for patients without CCRT, respectively. Patients with preoperative CCRT had a higher overall survival rate and DFS (P = 0.001 and 0.015).

CONCLUSIONS

In patients with advanced low rectal cancer, preoperative CCRT followed by radical surgery significantly improved overall survival and DFS compared with surgery alone. The effect of sphincter preservation with preoperative CCRT is questionable.

Thymidylate synthase gene polymorphism affects the response to preoperative 5-fluorouracil chemoradiation therapy in patients with rectal cancer

PURPOSE

This study aims to correlate thymidylate synthase (TS) gene polymorphisms with the tumor response to preoperative 5-fluorouracil (5-FU)-based chemoradiation therapy (CRT) in patients with rectal cancer.

METHODS AND MATERIALS

Forty-four patients with rectal cancer treated with 5-FU-based preoperative CRT were prospectively enrolled in this study. Thymidylate synthase expression and TS gene polymorphisms were evaluated in tumor obtained before preoperative CRT and were correlated with the pathologic response, as assessed by histopathologic staging (pTNM) and tumor regression grade.

RESULTS

Patients exhibited 2R/3R and 3R/3R tandem repeat polymorphisms in the TS gene. With regard to TS expression in these genotypes, 2R/3RC and 3RC/3RC were defined as the low-expression group and 2R/3RG, 3RC/3RG, and 3RG/3RG as the high-expression group. There was no significant correlation between TS expression and tumor response. There was no significant difference in the tumor response between patients homozygous for 3R/3R and patients heterozygous for 2R/3R. However, 13 of 14 patients in the low-expression group with a G>C single-nucleotide polymorphism (SNP) (2R/3RC [n = 5] or 3RC/3RC [n = 9]) exhibited a significantly greater tumor downstaging rate, as compared with only 12 of 30 patients in the high-expression group without the SNP (2R/3RG [n = 10], 3RC/3RG [n = 9], or 3RG/3RG [n = 11]) (p = 0.001). The nodal downstaging rate was also significantly greater in this low-expression group, as compared with the high-expression group (12 of 14 vs. 14 of 30, p = 0.014). However, there was no significant difference in the tumor regression grade between these groups.

CONCLUSIONS

This study suggests that SNPs within the TS enhancer region affect the tumor response to preoperative 5-FU-based CRT in rectal cancer.

Nuclear factor κ-light chain-enhancer of activated B cells is activated by radiotherapy and is prognostic for overall survival in patients with rectal cancer treated with preoperative fluorouracil-based chemoradiotheraphy

PURPOSE

Rectal cancer is often clinically resistant to radiotherapy (RT) and identifying molecular markers to define the biologic basis for this phenomenon would be valuable. The nuclear factor κ-light chain-enhancer of activated B cells (NF-κB) is a potential anti-apoptotic transcription factor that has been associated with resistance to RT in model systems. The present study was designed to evaluate NF-κB activation in patients with rectal cancer undergoing chemoradiotherapy to determine whether NF-κB activity correlates with the outcome in rectal cancer patients.

METHODS AND MATERIALS

A total of 22 patients underwent biopsy at multiple points in a prospective study and the data from another 50 were analyzed retrospectively. The pretreatment tumor tissue was analyzed for multiple NF-κB subunits by immunohistochemistry. Serial tumor biopsy cores were analyzed for NF-κB-regulated gene expression using reverse transcriptase polymerase chain reaction and for NF-κB subunit nuclear localization using immunohistochemistry.

RESULTS

Several NF-κB target genes (Bcl-2, cellular inhibitor of apoptosis protein [cIAP]2, interleukin-8, and tumor necrosis factor receptor-associated-1) were significantly upregulated by a single fraction of RT at 24 h, demonstrating for the first time that NF-κB is activated by RT in human rectal tumors. The baseline NF-κB p50 nuclear expression did not correlate with the pathologic response to RT. However, an increasing baseline p50 level was prognostic for overall survival (hazard ratio, 2.15; p = .040).

CONCLUSION

NF-κB nuclear expression at baseline in rectal cancer was prognostic for overall survival but not predictive of the response to RT. Larger patient numbers are needed to assess the effect of NF-κB target gene upregulation on the response to RT. Our results suggest that NF-κB might play an important role in tumor metastasis but not to the resistance to chemoradiotherapy.

Impact of neoadjuvant chemoradiation on pathologic response and survival of patients with locally advanced rectal cancer

BACKGROUND

The impact of neoadjuvant chemotherapy (CT) and radiotherapy (RT) on overall survival (OS) has been controversial. Some studies have pointed to an improvement in OS and disease-free survival (DFS) in patients with pathologic complete response (pCR).

AIM

To evaluate the therapeutic response and impact on survival of preoperative RT, alone or combined with CT, in patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

A set of 132 patients with LARC were treated preoperatively. GROUP 1: RT alone, 19 patients. GROUP 2: RT and concomitant oral CT (Capecitabine or UFT + leucovorin), 68 patients. GROUP 3: RT and concomitant CT with 5-FU in continuous infusion, 45 patients. 58.2% of patients were submitted to adjuvant CT.

RESULTS

GROUP 1: no pCR, tumoral downstaging was 26.7%. GROUP 2: pCR in 16.9%; tumoral downstaging was 47.7%. GROUP 3: pCR in 11.9%; tumor downstaging was 52.4%. The loco-regional control (LRC) was 95%. The 5-year OS (p = 0.038) and DFS (p = 0.05) were significantly superior in patients treated with CT + RT. Patients with pCR had a significant increase on DFS (p = 0.019). Patients cT3-4 that had a tumoral downstaging to ypT0-2, showed an increase on DFS, OS and LRC.

CONCLUSIONS

CT combined with RT has increased tumoral response and survival rate. Nodal downstaging and pCR were higher in the GROUP 2. The 5-year OS and DFS were significantly superior in CT + RT arms. Patients with pathologic response showed a better DFS. Adjuvant CT had no impact on LRC, DFS nor on OS.

Preoperative chemoradiation and extended pelvic lymphadenectomy for rectal cancer: Two distinct principles

Extended pelvic lymphadenectomy (EPL) with total mesorectal excision (TME) has been reported to provide oncological benefit in lower rectal cancer in Japan. In Western countries EPL is not widely accepted because of frequent morbidity but instead preoperative chemoradiation (CRT) followed by TME has been established as a standard treatment for decreasing local recurrence. Recently, several studies have focused on the comparison between these two distinct therapeutic approaches in Western countries and Japan. A study comparing Dutch trial data and Japanese data revealed that EPL and RT are almost equivalent in decreasing local recurrence in lower rectal cancer as compared with TME alone. Considering that almost 45% survival can be achieved by EPL even in the presence of metastatic lateral lymph nodes (LLNs), EPL performed by experienced surgeons definitely contributes to decrease local recurrence. On the other hand, a randomized controlled trial in Japan that compared EPL with conventional TME following preoperative RT revealed that EPL is associated with a higher frequency of sexual and urinary dysfunction without oncological benefits in the presence of preoperative RT. On this point, preoperative CRT followed by conventional TME without EPL would be a better therapeutic approach in patients without evident metastatic LLNs. For future treatment, it would be desirable to have a narrower indication for EPL using full advantage of recent improvement in image diagnosis. Although objective comparison of these two principles between Japan and the West is difficult due to differences in patient groups, further studies would lead to the next great step towards future improvement in treating lower rectal cancer.

Laparoscopic transanal abdominal transanal resection with sphincter preservation for rectal cancer in the distal 3 cm of the rectum after neoadjuvant therapy

BACKGROUND

This study reports the short- and long-term results for a prospective rectal cancer management program using laparoscopic radical transanal abdominal transanal proctosigmoidectomy with coloanal anastomosis (TATA) after neoadjuvant therapy.

METHODS

A prospective database included 102 rectal cancer patients treated with laparoscopic TATA from 1998 to 2008. Patients with distant metastasis at presentation, patients with a tumor more than 3 cm from the anorectal ring, and patients not undergoing neoadjuvant therapy were excluded, leaving 79 patients (54 men and 25 women) with a mean age of 59.2 years (range, 22-85 years) for this study. 13 patients completed neoadjuvant therapy before the original evaluation, and they are excluded from the report of initial clinical assessment. Before treatment, 50 patients were staged as T3 and 16 patients as T2. The mean level in the rectum superior to the anorectal ring was 1.2 cm (range, -0.5 to 3 cm). In terms of fixity, 31 of the tumors were mobile, 27 were tethered, and 8 showed early fixation. Ulceration was absent in 8 cases, minimal in 12 cases, superficial in 7 cases, moderate in 22 cases, and deep in 17 cases. The mean pretreatment tumor size tumor was 4.8 cm (range, 1.5-12 cm). The median external beam radiation was 5,400 cGy (range, 3,000-8,040 cGy), and 77 patients underwent chemotherapy.

RESULTS

The mean follow-up period was 34.2 months (range, 1.9-113.9 months). There were no perioperative mortalities. The conversion rate was 2.5%, and the mean largest incision length was 4.3 cm (range, 1.2-21 cm). For 84% of the patients, the incision was less than 6.0 cm, and 46% of the patients had no abdominal incision for delivery of the specimen. The mean estimated blood loss was 367 ml (range, 75-2,200 ml). All the patients had a temporary diverting stoma. The major morbidity rate was 11%, and the minor morbidity rate was 19%. The major complications included four full-thickness rectal prolapses with repair, one ischemic neorectum with successful reanastomosis, two bowel obstructions, and two failed anastomoses requiring stoma. The ypT stages included 22 complete responses, 12 cases of ypT1, 22 cases of ypT2, 23 cases of ypT3; 65 cases of ypN0, and 14 cases of ypN + (T3 = 7, T2 = 4, T1 = 3). The local recurrence rate was 2.5% (2/79), and the distant metastases rate was 10.1% (8/79). The KM5YAS rate was 97%. Overall, 90% of the patients lived without a stoma. Neorectal loss was due to positive margins or recurrence and was followed by abdominoperineal resection in three cases and ischemia in two cases. The condition of two patients was not reversed due to comorbidities, and one patient had a stoma secondary to bowel obstruction.

CONCLUSION

The study results indicate excellent local recurrence (2.7%) and 5-year survival rates without the need for permanent colostomy in patients with cancers in the distal one-third of the rectum. Laparoscopic total mesorectal excision (TME) with the TATA approach is safe and can be performed laparoscopically. Multi-institutional studies are required to establish the reproducibility of this promising approach.