42 HOW TO TREAT: COLORECTAL CANCER: TREATMENT
42 HOW TO TREAT: COLORECTAL CANCER: TREATMENT
11 APRIL 2025 ausdoc. com. au need to be balanced with preservation of quality of life.
Various drugs can be used in combination or sequence, depending on the patient’ s age, comorbidities, preferences and tolerance for treatments.
There are multiple active drugs that can be used in various combinations and regimens. For example, a more aggressive induction therapy may be followed by a less intensive but more tolerable maintenance strategy or some agents are stopped before cumulative toxicities become severe. In other situations, a chemotherapy drug may be given, stopped, and then restarted at a later time, sometimes in combination with other chemotherapy drugs. Dose modifications, dose delays, and administration of supportive therapies are also employed to mitigate the impact of treatment-related side effects.
POSTOPERATIVE SURVEILLANCE
AFTER the completion of curative treatment including adjuvant treatment, patients require close follow-up to assess for recurrence. There is no standardised protocol, but it is recommended that surveillance includes a mixture of clinical history and examination, routine laboratory investigations including
1. Which TWO statements regarding preoperative staging of colorectal cancer are correct? a Colorectal cancer is staged using the TNM staging system. b Colonic and rectal cancers are treated the same way. c Colon cancers considered curable generally proceed to surgical resection, with decisions on chemotherapy determined by staging. d Intraperitoneal rectal cancers have a higher risk of local recurrence.
2. Which TWO statements regarding the preoperative workup of colorectal cancer are correct? a PET scanning is indicated in patients with an equivocal biopsy. b Staging is performed with a carcinoembryonic antigen and a CT chest, abdomen and pelvis. c A dedicated rectal MRI is used to accurately stage rectal cancer. d‘ Watch and wait’ where there has been a complete clinical response is the current Australian standard of care for rectal cancer.
3. Which THREE may be appropriate in patients with distal metastases at the time of diagnosis of colorectal cancer? a PET scan to determine the extent of the metastatic disease. b Multidisciplinary team care in a specialist colorectal centre.
Figure 8. Loop ileostomy.
CEA, and CT of the chest, abdomen and pelvis. Colonoscopy is performed within one year of the initial resection, and subsequent colonoscopy follows polyp surveillance guidelines( outlined in the How to Treat on colorectal cancer: diagnosis), with a minimum colonoscopy interval of five years. Recurrence is highest within the first two years and rare after five years. 21 A suggested surveillance protocol appears in box 4. While
How to Treat Quiz. this is often performed by the surgeon in conjunction with oncologists, involvement from GPs is often appreciated.
THE FUTURE
BOWEL cancer management continues to evolve. Future areas of promising research include the prospect of targeted therapies on the basis of specific biology, the ex vivo testing of laboratory-grown individual patient cancers to various
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c Avoiding resection of a primary tumour causing consequences in those with non-resectable distant metastases. d Systemic chemotherapy to prolong life in those where distant metastases are not resectable.
4. Which THREE statements regarding surgery for colorectal cancer are correct? a Segmental resection along vascular supply lines is the primary operation for curative intent. b Bowel preparation plus oral antibiotics is likely to significantly reduce anastomotic leak and other infective complications. c Laparoscopic surgery is an accepted standard of care for the treatment of all colorectal cancers. d Transanal excision of a rectal carcinoma has a small but significant increase in local recurrence.
5. Which THREE are challenges associated with carcinomas of the low rectum? a Preservation of the anal sphincters. b Rectal cancers can always be removed with a colorectal anastomosis. c Achieving an acceptable oncological margin. d Achieving acceptable subsequent bowel function.
6. Which THREE are key indications for a stoma? a Presence of metastatic liver disease. b Low rectal tumours requiring abdominoperineal resection and a permanent colostomy. c Diverting loop ileostomy for high-risk anastomoses. d Colostomy for high-risk anastomoses.
7. Which TWO are appropriate advice immediately following colorectal cancer surgery? a Avoiding heavy lifting for 4-6 weeks. b Consuming a high-residue diet to avoid developing constipation. c Bed rest for 4-6 weeks. d Postoperative physiotherapy and rehabilitation where indicated.
8. Which THREE statements regarding adjuvant therapy in colorectal cancer are correct? a Adjuvant therapy is used to improve the cure rate in early-stage disease or prolong disease control in advanced disease.
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COLORECTAL CANCER: TREATMENT
chemotherapy and immunotherapy agents and the identification of patients where chemoradiotherapy and immunotherapy may remove the need for surgery.
However, the greatest potential gain is from increased uptake of bowel cancer screening. With uptake still below 50 %, there is enormous potential to improve bowel cancer outcomes through screening. Expansion of the screening program to those aged 45 will only be beneficial
b There are limited chemotherapy / immunotherapy agents active in colorectal cancer. c Patients with stage I and favourable stage II disease are generally not offered adjuvant chemotherapy. d Postoperatively, the use of adjuvant chemotherapy is tailored to the individual needs of the patient with extraperitoneal rectal cancers.
9. Which THREE statements regarding metastatic or recurrent colorectal cancer are correct? a Efforts to prolong survival need to be balanced with preservation of quality of life. b Systemic therapies have extended the average survival. c Immunotherapy has revolutionised the treatment of colorectal cancer. d Targeted therapies have further improved results.
10. Which THREE are part of postoperative surveillance following colorectal cancer? a PET chest, abdomen and pelvis annually for the first three years. b Shorter intervals between colonoscopies because of surveillance for polyps or a possible genetic predisposition. c Three-monthly carcinoembryonic antigen and routine laboratory testing for the first two years. d Colonoscopy within one year of the initial resection and at minimum five-yearly intervals.
Box 4. Suggested surveillance protocol for colorectal cancer
• Three- to six-monthly clinic visits for five years.
• Three-monthly carcinoembryonic antigen( CEA) and routine testing( FBC, EUC, LFT and iron studies) for the first two years.
• Six-monthly CEA and routine testing( FBC, EUC, LFT and iron studies) for three years.
• CT chest, abdomen and pelvis annually for the first three years.
• Colonoscopy within one year of the initial resection and at minimum five-yearly intervals.
• Shorter intervals may be required because of surveillance for polyps or a possible genetic predisposition.
if clinicians, health bodies and governments can improve the overall uptake across Australia.
CASE STUDY
DAVID, a 60-year-old man, presents to his GP with tenesmus and dark red PR bleeding. He has obesity( BMI of 30kg / m 2) and a history of ischaemic heart disease and a cardiac stent. He is on clopidogrel.
A digital rectal examination reveals a hard mass just palpable by the tip of the finger. He is referred for colonoscopy which reveals a distal third rectal cancer, clear of the sphincter. CT scan shows a single metastasis in the left lobe of the liver. MRI rectum reveals possible positive lymph nodes in the mesorectum and T3 invasion into the mesorectal fat.
David has stage IV disease; however, it appears to be surgically resectable. After his case is discussed at a multidisciplinary meeting, he undergoes a combination of chemoradiation( oral chemotherapy to sensitise the tumour to the radiotherapy) and total neoadjuvant chemotherapy( giving all of the chemotherapy up-front).
Restaging reveals no new metastatic disease and downstaging of the initial rectal cancer. A PET scan is performed to confirm the absence of other metastatic disease.
During this time, he undergoes a weight-loss regimen, including the use of semaglutide, and loses 15kg. A stress echocardiogram is normal.
David then undergoes a synchronous left hemi-hepatectomy with an ultra-low anterior resection and diverting loop ileostomy. Although the subsequent histopathology shows involvement of one out of 17 lymph nodes, it is decided that further chemotherapy is not required because it was given preoperatively. Three months after the surgery, and after confirming the anastomosis is intact, his loop ileostomy is reversed.
David will undergo close surveillance for the next five years.
CONCLUSION
GPs are a very important part of the patient’ s clinical team. Knowledge of the treatments involved in managing colorectal cancer can help guide patients through this very complex and often overwhelming time.
References Available on request from howtotreat @ adg. com. au