H. J. N. Andreyev

Kirsten ras mutations in patients with colorectal cancer: The 'RASCAL II' study

Researchers worldwide with information about the Kirsten ras (Ki-ras) tumour genotype and outcome of patients with colorectal cancer were invited to provide that data in a schematized format for inclusion in a collaborative database called RASCAL (The Kirsten ras in-colorectal-cancer collaborative group). Our results from 2721 such patients have been presented previously and for the first time in any common cancer, showed conclusively that different gene mutations have different impacts on outcome, even when the mutations occur at the same site on the genome. To explore the effect of Ki-ras mutations at different stages of colorectal cancer, more patients were recruited to the database, which was reanalysed when information on 4268 patients from 42 centres in 21 countries had been entered. After predetermined exclusion criteria were applied, data on 3439 patients were entered into a multivariate analysis. This found that of the 12 possible mutations on codons 12 and 13 of Kirsten ras, only one mutation on codon 12, glycine to valine, found in 8.6% of all patients, had a statistically significant impact on failure-free survival (P = 0.004, HR 1.3) and overall survival (P = 0.008, HR 1.29). This mutation appeared to have a greater impact on outcome in Dukes’ C cancers (failure-free survival, P = 0.008, HR 1.5; overall survival P = 0.02, HR 1.45) than in Dukes’ B tumours (failure-free survival, P = 0.46, HR 1.12; overall survival P = 0.36, HR 1.15). Ki-ras mutations may occur early in the development of pre-cancerous adenomas in the colon and rectum. However, this collaborative study suggests that not only is the presence of a codon 12 glycine to valine mutation important for cancer progression but also that it may predispose to more aggressive biological behaviour in patients with advanced colorectal cancer.

How patients manage gastrointestinal symptoms after pelvic radiotherapy.

Background : Approximately 13u2003000 patients undergo pelvic radiotherapy annually in the UK. It is not clear how frequently patients develop a permanent change in bowel habit after pelvic radiotherapy that affects their quality of life because the measures of gastrointestinal toxicity used in trials in the past have generally been inadequate. It has been suggested that patients who are symptomatic are only rarely referred to a gastroenterologist and it is not known how patients manage their symptoms.

A modified Inflammatory Bowel Disease questionnaire and the Vaizey Incontinence questionnaire are simple ways to identify patients with significant gastrointestinal symptoms after pelvic radiotherapy

After radiotherapy for pelvic cancer, chronic gastrointestinal problems may affect quality of life (QOL) in 6–78% of patients. This variation may be due to true differences in outcome in different diseases, and may also represent the inadequacy of the scales used to measure radiotherapy-induced gastrointestinal side effects. The aim of this study was to assess whether outcome measures used for nonmalignant gastrointestinal disease are useful to detect gastrointestinal morbidity after radiotherapy. Results obtained from a Vaizey Incontinence questionnaire and a modified Inflammatory Bowel Disease questionnaire (IBDQ) – both patient completed – were compared to those from a staff administered Late Effects on Normal Tissue (LENT) – Subjective, Objective, Management and Analytic (SOMA) questionnaire in patients who had completed radiotherapy for a pelvic tumour at least 3 months previously. In all, 142 consecutive patients were recruited, 72 male and 70 female, median age 66 years (range 26–90 years), a median of 27 (range 3–258) months after radiotherapy. In total, 62 had been treated for a gynaecological, 58, a urological and 22, a gastrointestinal tract tumour. Of these, 21 had undergone previous gastrointestinal surgery and seven suffered chronic gastrointestinal disorders preceding their diagnosis of cancer. The Vaizey questionnaire suggested that 27% patients were incontinent for solid stools, 35% for liquid stools and 37% could not defer defaecation for 15u2009min. The IBDQ suggested that 89% had developed a chronic change in bowel habit and this change significantly affected 49% patients: 44% had more frequent or looser bowel movements, 30% were troubled by abdominal pain, 30% were troubled by bloating, 28% complained of tenesmus, 27% were troubled by their accidental soiling and 20% had rectal bleeding. At least 34% suffered emotional distress and 22% impairment of social function because of their bowels. The small intestine/colon SOMA median score was 0.1538 (range 0–1) and the rectal SOMA median score was 0.1428 (range 0–1). Pearsons correlations for the IBDQ score and small intestine/colon SOMA score was −0.630 (P<0.001), IBDQ and rectum SOMA −0.616 (P<0.001), IBDQ and Vaizey scores −0.599 (P<0.001), Vaizey and small intestine/colon SOMA 0.452 (P<0.001) and Vaizey and rectum SOMA 0.760 (P<0.001). After radiotherapy for a tumour in the pelvis, half of all patients develop gastrointestinal morbidity, which affects their QOL. A modified IBDQ and Vaizey questionnaire are reliable in assessing new gastrointestinal symptoms as well as overall QOL and are much easier to use than LENT SOMA.

Role of nutritional intervention in patients treated with radiotherapy for pelvic malignancy

Up to 12u2009000 patients with gynaecological, urological and rectal cancer undergo radical pelvic radiotherapy annually in the UK. More than 70% develop acute inflammatory changes causing gastrointestinal symptoms during treatment because healthy bowel tissue is encompassed in the radiation field. In total, 50% go on to develop chronic bowel symptoms, which affect quality of life due to permanent changes in the small and large intestine. Nutritional intervention may influence acute and chronic bowel symptoms but the validity of the advice given to patients is not clear. To assess the incidence and significance of malnutrition and to examine the efficacy of therapeutic nutritional interventions used to manage gastrointestinal side effects in patients undergoing pelvic radiotherapy and those with chronic bowel side effects after treatment, a critical review of relevant original studies on human subjects was carried out using a specific set of mesh terms in MEDLINE and EMBASE databases and the Cochrane Library in September 2003. Full texts of all relevant articles were collected and reference lists were checked. Sources of grey literature including conference abstracts and web-based information were also reviewed. A total of 36 papers published in peer-reviewed journals between 1966 and 2003 were identified. In all, 14 randomised controlled trials, 12 prospective cohorts, four retrospective, two qualitative, one validation, one pilot study and two case reports were obtained. These included 2646 patients. Eight articles including three conference abstracts and web-based information were found. None of the studies was definitive because of weakness in methodology. No studies could be combined because the interventions and the end points were different. There is no evidence base for the use of nutritional interventions to prevent or manage bowel symptoms attributable to radiotherapy. Low-fat diets, probiotic supplementation and elemental diet merit further investigation.

Simple nutritional intervention in patients with advanced cancers of the gastrointestinal tract, non-small cell lung cancers or mesothelioma and weight loss receiving chemotherapy: a randomised controlled trial

BACKGROUNDnWeight loss in patients with cancer is common and associated with a poorer survival and quality of life. Benefits from nutritional interventions are unclear. The present study assessed the effect of dietary advice and/or oral nutritional supplements on survival, nutritional endpoints and quality of life in patients with weight loss receiving palliative chemotherapy for gastrointestinal and non-small cell lung cancers or mesothelioma.nnnMETHODSnParticipants were randomly assigned to receive no intervention, dietary advice, a nutritional supplement or dietary advice plus supplement before the start of chemotherapy. Patients were followed for 1 year. Survival, nutritional status and quality of life were assessed.nnnRESULTSnIn total, 256 men and 102 women (median age, 66 years; range 24-88 years) with gastrointestinal (n = 277) and lung (n = 81) cancers were recruited. Median (range) follow-up was 6 (0-49) months. One-year survival was 38.6% (95% confidence interval 33.3-43.9). No differences in survival, weight or quality of life between groups were seen. Patients surviving beyond 26 weeks experienced significant weight gain from baseline to 12 weeks, although this was independent of nutritional intervention.nnnCONCLUSIONSnSimple nutritional interventions did not improve clinical or nutritional outcomes or quality of life. Weight gain predicted a longer survival but occurred independently of nutritional intervention.

Bcl-2 expression and response to chemotherapy in colorectal adenocarcinomas.

In the last year, a number of studies have reported the expression of bcl-2 in colorectal adenocarcinomas. However, the influence of bcl-2 expression on response to chemotherapy and outcome in patients with advanced colorectal adenocarcinoma has not been reported. We analysed bcl-2 expression in 231 colorectal tumours from patients that were treated by surgery alone or with 5-fluorouracil-based chemotherapy. Of 231 tumours, 149 (64.5%) overexpressed bcl-2. Bcl-2 expression was associated with low plasma CEA levels (P=0.013) and inversely associated with poor differentiation (P=0.049). However, bcl-2 expression did not significantly influence failure-free or overall survival in surgically treated patients. In the group of patients receiving 5-fluorouracil-based chemotherapy bcl-2 expression did not influence response to chemotherapy; nor did it effect failure-free or overall survival.

K-ras mutations in patients with early colorectal cancers

Background—Published data are contradictory about the importance of K-ras mutations in advanced tumours and are not available for early cancers. Aims—To establish whether specific K-ras mutations are prognostic markers in early stage colorectal adenocarcinoma. Methods—The presence of K-ras exon 1 mutations were correlated with tumour recurrence in two groups of patients: group 1 was a consecutive series of patients with resected colorectal adenocarcinoma at low risk of recurrence; group 2 were patients referred for chemotherapy after relapse of previously resected early stage tumours. K-ras mutations were detected by direct sequencing of whole tissue samples in all patients and in some, the leading edge and centre of the tumour were also microdissected out individually and sequenced. Results—Mutations were present in 26 (26.5%) of 98 patients in group 1; 14 patients developed a recurrence, four (28.5%) of whom had a K-ras mutation. Seventy nine patients have not developed tumour recurrence, 22 (28%) of whom had a mutation (p=0.84). K-ras mutations were present in five of 14 patients in group 2. Microdissection did not increase the number of mutations detected. Conclusions—Individual K-ras genotypes are distributed homogeneously throughout early stage colorectal adenocarcinomas, but detection of a mutation has no apparent prognostic value.

Can biological markers act as non-invasive, sensitive indicators of radiation-induced effects in the gastrointestinal mucosa?

Backgroundu2002 Reliable, non‐invasive biological markers of the severity of radiotherapy‐induced damage to the gastrointestinal tract are not available. Clinicians continue to use symptom scores as surrogate indicators of toxicity.

Antisense treatment directed against mutated Ki-ras in human colorectal adenocarcinoma.

BACKGROUND Kirsten ras (Ki-ras) mutations are common in gastrointestinal cancer and one codon 12 mutation, glycine to valine, is particularly aggressive in colorectal cancer. AIMS To investigate if this valine point mutation could be targeted with antisense oligonucleotides and to determine the efficacy of any antisense/mRNA interaction. METHODS Twenty nine antisense oligonucleotides were screened against target and control Ki-ras RNA in a cell free system and against target and control cell lines in culture. RESULTS The activity and specificity of the oligonucleotides varied. Results for the individual oligonucleotides were consistent in a cell free model and in cell culture using two different uptake promoters. Only one oligonucleotide was specific in its cleavage of target Ki-ras mRNA in the cell free system and appeared specific in cell culture, although changes in Ki-ras mRNA and protein expression following a single treatment could not be detected. Experiments in the cell free system showed that the point mutation is relatively inaccessible to oligonucleotides. Other sites on the Ki-ras RNA molecule, away from the point mutation, can be targeted more effectively. CONCLUSIONS Successful targeting of the clinically relevant Ki-ras point mutation with antisense oligonucleotides is difficult because of RNA structure at the mutated site and is inefficient compared with other sites on the Ki-ras mRNA.

Clinical trial: normal diet vs. partial replacement with oral E028 formula for the prevention of gastrointestinal toxicity in cancer patients undergoing pelvic radiotherapy

Backgroundu2002 Acute gastrointestinal symptoms affect 90% of patients during pelvic radiotherapy. Elemental diet is protective in animal models. A nonrandomized study suggested benefit from a partial elemental diet. A pilot study suggested that radiotherapy patients only tolerate oral elemental diet comprising one‐third of total calories for 3u2003weeks.