Overview
This lecture covers the principles underlying cancer surgery: how a tumour is diagnosed and staged, how the patient (not just the tumour) is assessed before treatment, how a multidisciplinary meeting shapes the plan, the two possible intents of treatment (cure or palliation), how surgical margins are defined and achieved for curative surgery, and how reconstruction restores form and function after resection. It closes with a set of practical principles for practising cancer surgery.
Diagnosis and staging
Diagnosis and staging aim to answer three questions about a tumour:
- What is it? (organ of origin, cell of origin, genomics)
- Where is it?
- How is it likely to behave?
Solid tumours arise in many organs: head and neck, breast, bowel, liver, skin, bone, prostate, lung.
Staging uses the TNM system (Tumour, Nodes, Metastases). Imaging (MRI, PET/CT) is used to identify the primary tumour and nodal disease. Metastatic disease may also be identified intraoperatively, e.g. liver metastases appearing as pale/pink nodules on the liver surface.
Patient assessment
Before treatment, the patient as a whole is assessed, not just the tumour:
- Risks
- Physiological reserve / frailty
- Specific limitations
- Support
- Goals and priorities
Frailty is assessed with the Clinical Frailty Scale (Rockwood et al., CMAJ 2005), which has nine categories: Very Fit, Fit, Managing Well, Living with Very Mild Frailty, Living with Mild Frailty, Living with Moderate Frailty, Living with Severe Frailty, Living with Very Severe Frailty, Terminally Ill. Scoring frailty in people with dementia requires a separate note on the scale [slide does not elaborate].
Treatment and the multidisciplinary meeting
Cancer treatment is either local or systemic:
- Local: surgery, radiotherapy
- Systemic: chemotherapy, immunotherapy
The multidisciplinary meeting (MDM) reaches treatment recommendations by consensus. Its benefits:
- Produces the best result
- Supports knowledge and learning
- Reins in unconscious (and conscious) bias, giving a more balanced decision
- Gives clarity of intent
Intent: cure or palliation
Cancer treatment has two possible intents: cure or palliation.
Curative treatment is illustrated by examples such as endoscopic snare resection of a bowel polyp/tumour and surgical treatment of melanoma.
Margins (curative surgery)
Margin status is assessed as:
- R0: clear under the microscope
- R1: microscopic involvement
- R2: macroscopic disease left behind
An adequate margin can be achieved by:
- Extended resection
- Neo-adjuvant treatment
- Minimising morbidity and mortality
Planning a margin requires knowledge of regional anatomy, e.g. for colonic resection: the hepatic flexure, inferior mesenteric artery, left colic artery, superior haemorrhoidal artery, mesenteric blood supply, appendix and sigmoid colon.
For rectal cancer, total mesorectal excision (TME) follows a defined plane of excision through the retrorectal space, known as “the holy plane,” which lies between the mesorectum/fascia propria and the parietal fascia. Structures identified around this plane, to be preserved, include the bladder, seminal vesicles, Denonvilliers fascia (termed the rectovesical fascia in males and the rectovaginal septum in females), pelvic side wall, pelvic plexus, hypogastric nerve, pelvic parasympathetic nerves, presacral veins, superior rectal artery, sacral basivertebral veins, sacrum and the intrasacral canal venous plexus.
Reconstruction
Reconstruction restores anatomy and function after resection.
Organ reconstruction: after a resection such as a Whipple-type procedure, biliary-enteric and pancreatic-enteric anastomoses reconnect the liver (via the bile duct) and pancreas (via the pancreatic duct) with the jejunum, alongside the stomach.
Pedicled flap reconstruction: e.g. a pedicled TRAM (transverse rectus abdominis myocutaneous) flap for breast reconstruction after mastectomy. The flap, based on the superior epigastric pedicle, is de-epithelialized and configured to form the breast mound; the abdominal donor site is closed with fascial closure, leaving an abdominal scar.
Free flap reconstruction: e.g. a radial forearm free flap, where a paddle-shaped area of skin/soft tissue with its vascular pedicle is marked and harvested from the forearm and transferred (with vascular anastomosis) to the reconstruction site.
Palliation
Palliative surgery aims to improve quality of life through symptom control.
- Surgery alone is unusual; it is usually delivered as part of a wider package of palliative care.
- The risk/benefit calculation differs from curative surgery.
Conclusion: principles of practice
Key take-home principles
- Gather information and have a plan.
- Work in a team; be kind to your teammates.
- Be humble; ask for help and advice in difficult cases.
- Know how you are doing, both short and long term.
- Don’t be a hero; it is not about the surgeon.
- The patient is in charge and at the centre.
- You cannot always cure cancer, but you can put patients in a positive space.
- Always be there for the patient when things do not go well.
Each type of cancer has typical behaviours but still varies widely between people, who also vary widely in age, co-morbidities, goals and priorities, so treatment must be tailored to both the disease and the person.
Self-test
- What three questions do diagnosis and staging aim to answer about a tumour?
- What does the TNM staging system stand for, and how is nodal/metastatic disease identified?
- List the five domains covered in pre-treatment patient assessment.
- Name the nine categories of the Clinical Frailty Scale, from least to most frail.
- Distinguish local from systemic cancer treatment, giving an example of each.
- What is a multidisciplinary meeting (MDM), and what are its stated benefits?
- Distinguish the two intents of cancer treatment.
- Define R0, R1 and R2 margin status.
- Describe the strategies available to achieve an adequate surgical margin.
- Describe the plane of excision used in total mesorectal excision, and name three structures it aims to preserve.
- Distinguish pedicled flap reconstruction from free flap reconstruction, giving an example of each.
- What characterises palliative cancer surgery, and how does its risk/benefit calculation differ from curative surgery?
- List four of the practical principles given in the lecture’s conclusion for practising cancer surgery.
- A patient is being planned for curative rectal cancer resection. Explain how staging, the MDM, and margin assessment (R status) each contribute to that treatment plan.
Answers
Reveal answers
- What is it (organ, cell of origin, genomics), where is it, and how is it likely to behave.
- TNM = Tumour, Nodes, Metastases; nodal and metastatic disease are identified with imaging (MRI, PET/CT) and can also be seen intraoperatively (e.g. liver surface nodules).
- Risks, physiological reserve/frailty, specific limitations, support, and goals and priorities.
- Very Fit, Fit, Managing Well, Living with Very Mild Frailty, Living with Mild Frailty, Living with Moderate Frailty, Living with Severe Frailty, Living with Very Severe Frailty, Terminally Ill.
- Local treatment acts directly on the tumour site (surgery, radiotherapy); systemic treatment acts throughout the body (chemotherapy, immunotherapy).
- A meeting where treatment recommendations are reached by consensus; it produces the best result, supports knowledge and learning, reins in bias for a more balanced decision, and gives clarity of intent.
- Cure (aiming to eliminate disease) versus palliation (aiming to control symptoms and improve quality of life without eliminating disease).
- R0: margin clear under the microscope. R1: microscopic tumour involvement of the margin. R2: macroscopic disease left behind.
- Extended resection, neo-adjuvant treatment, and minimising morbidity and mortality.
- The plane follows the retrorectal space (“the holy plane”), between the mesorectum/fascia propria and the parietal fascia; it aims to preserve structures such as the bladder, seminal vesicles, Denonvilliers fascia, pelvic plexus, hypogastric nerve and pelvic parasympathetic nerves (any three).
- A pedicled flap keeps its original blood supply attached and is moved into place still connected to it (e.g. TRAM flap for breast reconstruction); a free flap is fully detached with its vascular pedicle and reattached by microvascular anastomosis at the recipient site (e.g. radial forearm free flap).
- It aims to improve quality of life via symptom control, is usually delivered alongside a wider package of palliative care rather than alone, and involves a different (more conservative) risk/benefit calculation than curative surgery.
- Any four of: gather information and have a plan; work as a team and be kind to teammates; be humble and ask for help; know your short and long term results; don’t be a hero; keep the patient in charge and at the centre; support patients positively even when cure isn’t possible; be present for patients when things go wrong.
- Staging (TNM, imaging) defines the extent of disease and guides feasibility of a curative approach; the MDM brings different specialties together to reach a balanced, consensus treatment recommendation and clarify curative intent; margin assessment (aiming for R0, using extended resection or neo-adjuvant treatment if needed) is then used intraoperatively and pathologically to confirm whether the curative goal was achieved.