Diagnosis

Diagnosis

Colorectal cancer diagnosis relies on clinical, endoscopic, radiological and pathological findings. Clinical diagnosis may be possible by per rectal examination for low rectal tumours but the majority of diagnoses rely on endoscopic and radiological methods. Both of these complex modalities are available in strength on the St. Vincent’s campus.

Colonoscopy will identify most cases and enable biopsies to be taken for pathological confirmation. Colonoscopies are performed every day in the endoscopy units and allow rapid diagnosis. Therapeutic colonoscopy for the removal of small tumours (polypectomy) is also a frequent occurrence. Obstructing cancers can be relieved by endoscopic stenting either obviating the need for surgery in advanced cases or allowing stabilisation prior to potentially curative surgery (see therapy).

Computerised tomography assesses the presence of spread (metastases) outside the bowel. The arrival of CT colography (virtual colonoscopy), available on the campus, greatly assists cases where colonoscopy is either unsuccessful or inappropriate. As with endoscopy, radiology can also be therapeutic with the development on site of radiofrequency ablation. Chemoembolisation of large cancers is also available through the expertise of our diagnostic imaging colleagues. The modern treatment of the common rectal cancer is absolutely dependent on the availability of both pelvic magnetic resonance imaging and endoanal ultrasound . These modalities assess the size and depth of rectal cancers and help decide whether patients would best be served by pre-operative neoadjuvant chemoradiotherapy. (see publications).

Endoscopy

The endoscopy unit in the new hospital wing is a state of the art facility with provision for radiological screening in addition to a full complement of conventional diagnostic and therapeutic endoscopic techniques. Routine colonoscopic procedures include ileoscopy, snare and endoloop polypectomy, saline assisted polypectomy, endomucosal tumour resection, argon laser therapy, benign and malignant stricture dilatation and both emergency and elective trans-endoscopic metal stent placement.

Surgery

The Surgical Unit functions as an integral part of the multidisciplinary team. Surgical resections are performed in elective, urgent and emergency settings for all stages of colorectal cancer where appropriate. The unit has a depth of expertise in operative management in both standard and laparoscopic resection. Laparoscopic resection was reintroduced in September 2002 following the early favourable results of International trials and such resections now comprise 25% of all colorectal cancer resections. Apart from curative resection, laparoscopic surgery is also performed selectively for palliation. There is no other unit in Ireland with such an extensive experience in this field.

The Centre for Colorectal Disease also has a specialist interest and expertise in rectal cancer. In this context, we have a large cohort of patients in the past 5 years who have received neoadjuvant chemoradiation for locally advanced following preoperative evaluation.

Pathology

The Pathology Department provides a comprehensive diagnostic service to patients with colorectal cancer. This includes a full array of services including Clinical Biochemistry, Haematology, Microbiology, Histopathology and Molecular Pathology. The Clinical Biochemistry Department including Nuclear Medicine provides a state-of-the-art tumour marker service for GI malignancy.

The Histopathology Department has developed a unique working relationship within the umbrella of the Centre for Colorectal Disease. Funding from the Cancer Strategy and Heath Research Board has enabled developments in many areas. The current service provides on-call collection of fresh specimens which allows optimal triage for diagnostic and research purposes. A specialised Colorectal Medical Scientist who is responsible for digitally archiving all specimens has been appointed. This person also triages tissue for specialised molecular studies and has developed a standard testing service for prognostic and predictive markers. Standardised dissection and reporting of all colorectal cancer specimens have been developed to an international level. A Consultant Pathologist specialised in Gastrointestinal Pathology oversees all aspects of the service. The diagnosis of familial-associated colorectal cancer has been greatly assisted by the development of immunohistochemistry for mismatch repair proteins and the development of PCR for microsatellite instability. Translational research is continuing to bring newer tests into the diagnostic arena. The presence of all relevant Pathology staff at multidisciplinary meetings including service audit and research enhances the delivery of care to the individual patient. Hospital and Laboratory accreditation have also greatly enhanced the service.