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50 CPD ACTIVITY FROM PAGE 49 despite nothing to expel), rectal pain and diminished calibre of stools.8 Pharmacists should be aware of these symptoms. If patients describe the listed typical or ‘red flag’ symptoms, referral to the GP should be suggested. Box 1 Symptoms from a local colorectal cancer Typical symptoms include: • Change in bowel habits (most common symptom, 74 per cent). • Melaena. • Abdominal pain. • Unexplained iron deficiency anaemia. Less common presenting symptoms include: • Abdominal distention. • Nausea and vomiting, which may be indicators of obstruction. Treatment Surgery Following diagnosis and staging of colorectal cancer, the mainstay of treatment is surgical resection. The surgical procedure can be laparoscopic, depending on surgeon skill and hospital infrastructure. The benefits of laparoscopic procedures are associated with improved short-term outcomes, including less postoperative pain, a shortened time to return of bowel function, and a shorter hospital stay.10 Laparotomy for rectal cancer is the standard approach.11 The main immediate complication is anastomotic leakage (leakage of bowel contents at the site of the joined colon/ rectum) which is linked to high morbidity and mortality. The risk factors are associated with patient specific factors such as smoking, tumour size, advanced local disease, metastasis, operation requiring low rectal anastomosis and post- operative factors such as infection. Long term complications include incontinence and sexual disfunction. Before surgery, patients should receive counselling regarding these issues and may need support from primary healthcare providers, including pharmacists, in the long term.2 Some patients have a stoma placed either temporarily or permanently following surgery, which can impact their quality of life. The decision to form a stoma is complex. The factors at play include patient factors, the tumour, emergency resection due to obstruction or ischaemia, if the tumour is low or involves the anal sphincter complex. Reversal of the stoma can be considered after three months. Common physical complications of surgery include skin excoriation, parastomal herniation, retraction or prolapse. Other issues that most patients report include stomal leakages, odour and fear of intimacy.2 Some pharmacies carry products for stoma management. Keeping the contact details of the stoma nurse at the hospital would be ideal to assist in difficult scenarios. Chemotherapy and radiation Neoadjuvant chemoradiation Neoadjuvant radiotherapy is radiotherapy administered before bowel resection of the tumour. It is recommended for advanced rectal carcinomas in the low and mid rectum. The primary aim is to reduce the risk of local recurrence, but it may also reduce tumour size to facilitate complete excision and lead to modest improvements in long term survival.11 Radiotherapy may be delivered alongside or in combination with a fluoropyrimidines, 5-fluorouracil or capecitabine.12 Adjuvant chemotherapy Adjuvant chemotherapy is administered following bowel resection as part of a combined treatment plan. The chemotherapy is fluoropyrimidine-based and improves survival among a subset of stage II cancers (tumour has grown through the wall of the colon or rectum but has not yet spread to lymph nodes) and stage III cancers (tumour has spread through the wall of the colon or rectum and spread to local lymph nodes).3 The aim of adjuvant chemotherapy is to prevent or eradicate circulating tumour cells and micro-metastases and decrease distant recurrence.13 The length of treatment is normally six months, but may be reduced to three months for low risk patients taking capecitabine and oxaliplatin, as it was shown to be non-inferior to six months of the same therapy.14 Adjuvant chemotherapy for rectal cancers is controversial in those who received neoadjuvant chemotherapy.3 A multidisciplinary team approach is always undertaken to ensure appropriate management of patients. Neither irinotecan nor a monoclonal antibody (MAB) should be used as adjuvant therapy for patients with stage II or III colon cancer. Metastatic colorectal cancer Systemic therapy for metastatic colorectal cancer is tailored to the patient and disease specific predictive markers.3 Therapy may be curative or palliative. The decision is primarily guided by tumour burden.3 Systemic therapy includes chemotherapy backbone with a fluoropyrimidine, oxaliplatin and irinotecan regimens, either offered as two-drug or three-drug backbone with the addition of a MAB. Patients are often treated with all therapies available one after another in various sequences, depending on patient and tumour related factors.3 Biologics The MAB bevacizumab was first approved for use for colorectal cancer in Australia in 2005. Since then, it has been approved for use in other cancers.15 Bevacizumab is a recombinant humanised MAB directed against vascular endothelial growth factor (VEGF). Human VEGF mediates neo-angiogenesis (formulates new blood vessels) in normal and malignant vasculature. It’s overexpressed in most malignancies and high levels have correlated with a greater risk of metastasis and poor prognosis in many (eg, colorectal, ovarian and breast cancer). Bevacizumab RETAIL PHARMACY • JUN 2021 Figure 2. Diagram of the anatomy of the colon, rectum and anus