Preoperative radiotherapy and local excision of rectal cancer: Long-term results of a randomised study.

BACKGROUND AND PURPOSE: It is uncertain whether local control is acceptable after preoperative radiotherapy and local excision (LE). An optimal preoperative dose/fractionation schedule has not yet been established. MATERIAL AND METHODS: In a phase III study, patients with cT1-2N0M0 or borderline cT2/T3N0M0 < 4 cm rectal adenocarcinomas were randomised to receive either 5 × 5 Gy plus 1 × 4 Gy boost or chemoradiation: 50.4 Gy in 28 fractions plus 3 × 1.8 Gy boost and 5-fluorouracil with leucovorin bolus. LE was performed 6-8 weeks later. Patients with ypT0-1R0 disease were observed. Completion total mesorectal excision (CTME) was recommended for poor responders, i.e. ypT1R1/ypT2-3. RESULTS: Of 61 randomised patients, 10 were excluded leaving 51 for analysis; 29 in the short-course group and 22 in the chemoradiation group. YpT0-1R0 was observed in 66% of patients in the short-course group and in 86% in the chemoradiation group, p = 0.11. CTME was performed only in 46% of patients with ypT1R1/ypT2-3. The median follow-up was 8.7 years. Local recurrence incidences and overall survival at 10 years were respectively for the short-course group vs. the chemoradiation group 35% vs. 5%, p = 0.036 and 47% vs. 86%, p = 0.009. In total, local recurrence at 10 years was 79% for ypT1R1/T2-3 without CTME. CONCLUSIONS: This trial suggests that in the LE setting, both local recurrence and survival are worse after short-course radiotherapy than after chemoradiation. Because of the risk of bias, a confirmatory study is desirable. Lack of CTME is associated with an unacceptably high local recurrence rate.

Methyl-CpG binding column-based identification of nine genes hypermethylated in colorectal cancer.

DNA methylation is an epigenetic event that plays a role in gene expression regulation. Alterations in DNA methylation contribute to cancer development and progression. The aim of this study was to identify gene promoters aberrantly methylated in colorectal tumor tissue in comparison to normal colonic mucosa. Analyses were performed on two pooled DNA samples: from normal and cancerous tissue obtained from CRC patients. DNA was fractionated according to methylation degree with the use of affinity column containing methyl-CpG binding domain. To identify novel hypermethylated gene promoters, methylated DNA from normal and from cancerous tissues were analyzed with the use of promoter microarrays. We identified nine novel genes hypermethylated in colorectal cancer. The frequency of their promoter methylation was assessed in the larger group of patients (n = 77): KCNK12 (methylated in 41% of CRC patients), GPR101 (40%), CDH2 (45%), BARX1 (56%), CNTFR (22%), SYT6 (64%), SMO (21%), EPHA5 (43%), and GSPT2 (21%). The results of gene expression level analysis suggest the role of promoter methylation in downregulation of six out of nine genes examined. We did not find correlation between gene methylation and age, gender, tumor grade or stage. Importantly, in stage IV CRC methylation of GPR101 correlated with longer time to progression (P = 0.0042; HR = 2.5468; 95% CI 1.5391-10.0708).

Modeling oncogenic signaling in colon tumors by multidirectional analyses of microarray data directed for maximization of analytical reliability.

BACKGROUND: Clinical progression of colorectal cancers (CRC) may occur in parallel with distinctive signaling alterations. We designed multidirectional analyses integrating microarray-based data with biostatistics and bioinformatics to elucidate the signaling and metabolic alterations underlying CRC development in the adenoma-carcinoma sequence. METHODOLOGY/PRINCIPAL FINDINGS: Studies were performed on normal mucosa, adenoma, and carcinoma samples obtained during surgery or colonoscopy. Collections of cryostat sections prepared from the tissue samples were evaluated by a pathologist to control the relative cell type content. The measurements were done using Affymetrix GeneChip HG-U133plus2, and probe set data was generated using two normalization algorithms: MAS5.0 and GCRMA with least-variant set (LVS). The data was evaluated using pair-wise comparisons and data decomposition into singular value decomposition (SVD) modes. The method selected for the functional analysis used the Kolmogorov-Smirnov test. Expressional profiles obtained in 105 samples of whole tissue sections were used to establish oncogenic signaling alterations in progression of CRC, while those representing 40 microdissected specimens were used to select differences in KEGG pathways between epithelium and mucosa. Based on a consensus of the results obtained by two normalization algorithms, and two probe set sorting criteria, we identified 14 and 17 KEGG signaling and metabolic pathways that are significantly altered between normal and tumor samples and between benign and malignant tumors, respectively. Several of them were also selected from the raw microarray data of 2 recently published studies (GSE4183 and GSE8671). CONCLUSION/SIGNIFICANCE: Although the proposed strategy is computationally complex and labor-intensive, it may reduce the number of false results.

Preoperative radiotherapy and local excision of rectal cancer with immediate radical re-operation for poor responders.

BACKGROUND AND PURPOSE: To report an early analysis of prospective study exploring preoperative radiotherapy and local excision in rectal cancer. MATERIALS AND METHODS: Mucosa at tumour edges was tattooed. Patients with cT1-3N0 tumour <3-4 cm were treated with either 5x5Gy+4Gy boost (N=31) or chemoradiation (50.4Gy+5.4Gy boost, 1.8Gy per fraction+5-fluorouracyl and leucovorin; N=13). Thirteen patients from the short-course group were unfit for chemotherapy. The interval from radiation to full-thickness local excision was 6 weeks. The protocol called for conversion to a transabdominal surgery in case of ypT2-3 disease or positive margin. RESULTS: The postoperative complications requiring hospitalization were recorded in 9% of patients. The rate of pathological complete response was 41%. The rate of patients requiring conversion was 34%; however, 18% actually underwent conversion and the remaining 16% refused or were unfit. During the 14 months of median follow-up, local recurrence was detected in 7% of patients and all underwent salvage surgery. Of 19 patients in whom initially anterior resection was likely, 16% had abdominoperineal resection performed for a conversion or as a rescue procedure. CONCLUSION: Our study suggests that the short-course radiation prior to local excision is a treatment option for high-risk patients.

An integrated LC-ESI-MS platform for quantitation of serum peptide ladders. Application for colon carcinoma study.

Mounting evidence indicates that MS analysis of the human blood peptidome allows to distinguish between cancer and non-cancer samples, giving promise for a new MS-based diagnostic tool. However, several aspects of already published work have been criticized and demand for more methodical approach has been formulated. Motivated by this we undertook a systematic study of the plasma and serum peptidome using an integrated ESI-LC-MS-based platform, equipped with new data analysis tools for relative and absolute peptide quantitation. We used a high resolution LC-ESI-MS to analyze well-separated MS signals corresponding to peptides, and measured the variability of >1000 peptide signal amplitudes across a set of plasma and serum samples from healthy individuals. By spiking serum samples with known amounts of isotopically labeled versions of a selected set of peptides we measured the variability of their absolute concentration in this sample set and demonstrated a strong influence of clotting time on the concentration of these peptides in serum. Finally, we used this new LC-ESI-MS analytical platform for the differential analysis of healthy versus colon cancer serum samples and found that it was possible to distinguish the two groups with 89.8% sensitivity and 94.6% specificity.

Quality of life, anorectal and sexual functions after preoperative radiotherapy for rectal cancer: report of a randomised trial.

BACKGROUND AND PURPOSE: Patients (N=316) with resectable cT3-4 low-lying and mid-rectal cancer were randomised to receive either preoperative 5x5Gy irradiation with subsequent surgery performed within 7 days or chemoradiation (50.4, 1.8Gy per fraction plus boluses of 5-fluorouracil and leucovorin) followed by surgery after 4-6 weeks. No differences were found in sphincter preservation, survival, local control and late complications. Early complications were less frequent in the short-course group. The aim of this report is to find out whether large doses per fraction of short-course schedule result in more severe anorectal and sexual dysfunction and quality of life (QoL) impairment. MATERIALS AND METHOD: Patients who were free of disease were asked to answer the QLQ-C30 and those without stoma were, additionally, asked to fill in a questionnaire of anorectal (19 items) and sexual function (1 item). RESULTS: Two hundred and twenty-two patients (86% response rate) completed the QLQ-C30 and 118 (86% response rate) the anorectal-sexual function questionnaire. The median time from surgery to filling in the QLQ-C30 questionnaire was 12 months, and to filling in the anorectal-sexual function questionnaire - 13 months. We did not find significant differences between the randomised groups regarding QoL and the anorectal and sexual functions. Approximately two-thirds of patients had anorectal function impairment. Approximately 20% of patients stated that this considerably influenced their QoL. CONCLUSIONS: QoL and the anorectal and sexual functioning did not differ in patients receiving short-course radiotherapy, as compared to those receiving chemoradiation.

Prediction of mesorectal nodal metastases after chemoradiation for rectal cancer: results of a randomised trial: implication for subsequent local excision.

BACKGROUND AND PURPOSE: For patients with rectal cancer treated with full thickness local excision the risk of mesorectal nodal metastases has to be very low. The aim was to assess this risk after preoperative radiotherapy in relation to pathological T-category. PATIENTS AND METHODS: Three hundred sixteen patients with resectable cT3-4 low rectal carcinoma were randomised to receive either pre-operative 5 x 5 Gy irradiation with subsequent surgery performed within 7 days or chemoradiation (50.4, 1.8 Gy per fraction plus bolus 5-fluorouracil and leucovorin) followed by surgery after 4-6 weeks. The pathological reports of patients who fulfilled entry criteria and had preoperative irradiation followed by transabdominal surgery were analysed. RESULTS: Significant downstaging of primary tumour (P<0.001) and of nodal disease (P=0.007) was observed after chemoradiation in comparison with short-course irradiation. In chemoradiation group, for patients with complete pathological response and for ypT1 category, the rate of nodal metastases was low - 5% (95% confidence interval [CI] 0-14%) and 8% (95% CI 0-24%), respectively. The rate of ypN-positive disease in chemoradiation group was similar to that recorded in short-course irradiation group for ypT2 category 26% (95% CI 14-38%) vs. 28% (95% CI 16-40%), P=0.83 and for ypT3-4 category 55% (95% CI 41-69%) vs. 64% (95% CI 54-74%), respectively, P=0.37. For ypT2 category after chemoradiation, the rate of nodal disease remained high even in subgroup with low residual cancer cells density (20%, 95% CI 4-36%). CONCLUSIONS: For patients with tumours downstaged by chemoradiation to ypT0 and ypT1 full thickness local excision may be considered as an acceptable approach, because the risk of mesorectal lymph nodes metastases is low. The selection criteria for preoperative radio(chemo)therapy and local excision are discussed.

Prospective, randomized trial examining the role of gentamycin-containing collagen sponge in the reduction of postoperative morbidity in rectal cancer patients: early results and surprising outcome at 3-year follow-up.

OBJECTIVE: The study was carried out to evaluate the efficacy of the gentamycin collagen sponge placed in the pelvic cavity after excision of rectal cancer in view of postoperative complications and the risk of cancer recurrence. METHODS: A total of 229 patients were recruited into the study and randomized into two groups: GRM(+), in which a gentamycin collagen sponge was used, and GRM(-), without the sponge. Tumors were resected using a TME technique. In the GRM(+) group, the sponge was placed into the tumor bed. RESULTS: Analysis covered 218 patients for whom all follow-up data were available. There were fewer early postoperative complications in the GRM(+) group: 20.7 vs. 37.5%; p=0.044. This effect was found mainly in patients with surgery lasting longer than 3 h. After 36 months' follow-up, the overall survival after R0 resection for the GRM(+) and GRM(-) groups was: 88.66 vs. 73.96%. There was significant reduction in the distant metastasis rate in favor of the GRM(+) group. CONCLUSION: The use of the gentamycin collagen sponge after excision of rectal cancer is safe and reduces the rate of early postoperative complications. The reasons for the lower rate of distant metastasis in the GRM(+) group are not clear, but the patients enjoy significant survival benefits.

Total cystectomies in the surgical treatment of rectal cancer with prior chemoradiation: analysis of postoperative morbidity and survival.

BACKGROUND AND AIMS: Curative surgery for rectal cancer seldom requires urinary tract resections. The study investigated morbidity and survival following resection of rectum with total cystectomy following chemoradiation for primary rectal cancer. PATIENTS AND METHODS: 19 consecutive patients with primary nonresectable rectal cancer undergoing preoperative chemoradiation and operated on by a multidisciplinary team of surgeons. RESULTS: Morbidity was moderately low, and only five cases required surgical reintervention. No postoperative deaths were observed. Long-term survival in this group of patients compares well with the survival of patients with primarily nonresectable rectal cancer without the involvement of urinary bladder. CONCLUSION: Extended pelvic exenteration due to rectal cancer is relatively safe and in selected patients offers long-term survival and a chance of a cure. Involvement of the urinary bladder does not adversely affect outcome of rectal cancer treatment.