Pre/Postoperative Care & Surgical Oncology Flashcards

In colorectal cancer staging using the TNM system, what does a T4b classification indicate?

Answer: Tumour directly invades or adheres to adjacent organs

In the TNM classification for colorectal cancer: T1 = submucosa, T2 = muscularis propria, T3 = pericolorectal tissues, T4a = visceral peritoneum, T4b = directly invades or is adherent to adjacent organs/structures (e.g., bladder, small bowel). T4b requires multivisceral resection and carries worse prognosis.

Which tumour marker is used to monitor recurrence after curative resection of colorectal cancer?

Answer: CEA (carcinoembryonic antigen)

CEA is the primary tumour marker used for monitoring post-operative recurrence in colorectal cancer. Rising CEA after curative resection (especially rising to >10 ng/mL) should trigger imaging to exclude recurrence. CEA lacks the specificity for primary diagnosis but is useful for surveillance.

What is the concept of 'surgical margins' in oncological surgery, and why does an R0 resection matter?

Answer: R0 means microscopically clear margins; R1 means microscopic residual disease; R2 means macroscopic residual disease

The R classification describes completeness of surgical resection: R0 = complete resection with microscopically clear margins (curative intent achieved); R1 = microscopic residual tumour at margins; R2 = macroscopic residual tumour. R0 resection is the primary determinant of long-term cure in solid organ malignancies.

A breast cancer patient is found to have a sentinel lymph node biopsy positive for macrometastasis. What is the implication?

Answer: Axillary lymph node dissection or axillary radiotherapy should be considered

Sentinel lymph node biopsy (SLNB) positive for macrometastasis (>2 mm) typically warrants completion axillary lymph node dissection (ALND) or axillary radiotherapy (ACOSOG Z0011, AMAROS trials have refined criteria). The decision depends on tumour characteristics, patient fitness, and planned systemic therapy.

Which principle describes the surgical approach to ensuring adequate lymph node harvest in cancer surgery?

Answer: En bloc resection with regional lymphadenectomy removes the primary tumour and its regional lymph node drainage field together

En bloc resection removes the primary tumour along with its regional lymphatic drainage field in continuity. This achieves both local disease control and accurate pathological staging. In colorectal, gastric, and oesophageal surgery, adequate lymph node harvest (e.g., D2 gastrectomy) affects staging accuracy and survival.

What is neoadjuvant therapy in the context of surgical oncology?

Answer: Treatment given before surgery to downstage the tumour and improve surgical outcome

Neoadjuvant therapy (chemotherapy, radiotherapy, or chemoradiotherapy) is given before surgery to reduce tumour size, downstage disease, improve resectability, and potentially sterilise micrometastases. Examples include FLOT chemotherapy before gastric cancer surgery and long-course chemoradiotherapy before rectal cancer surgery.