Oncology workshop 1 (colorectal cancer)

Question 1

Why is staging in cancer important?

Answer 1

• Prognosis
• Treatment

Question 2

Why does staging change over time?

Answer 2

• Due to better treatment and investigations and technology

Question 3

Explain staging in colorectal cancer (Dukes’ criteria)

Answer 3

• Dukes’ A Cancer has grown into the inner layer or muscle layer of the bowel wall Not spread to lymph nodes or other parts of the body
• Dukes’ B Cancer has grown through the muscle layer or outer layer May be growing into tissues near the bowel Not spread to the lymph nodes or other parts of the body
• Dukes’ C Cancer is any size and has spread to nearby lymph nodes Not spread to other parts of the body
• Dukes’ D Cancer is any size May or may not have spread to nearby lymph nodes Has spread to other parts of the body

Question 4

Explain TNM staging

Answer 4

American Joint Committee on Cancer

• TX – Primary tumour cannot be assessed
• T0 – No evidence of primary tumour
• Tis – Carcinoma in situ: intraepithelial or invasion of lamina propria
• T1 – Invades submucosa
• T2 – Invades muscularis propria
• T3 – Invades through muscularis propria into subserosa or into non-peritonealised pericolic or perirectal tissues
• T4 – Directly invades other organs or structures and/or perforates visceral peritoneum
• NX – Regional lymph nodes cannot be assessed
• N0 – No regional lymph node metastasis
• N1 – Metastasis in 1–3 regional lymph nodes
• N2 – Metastasis in 4 or more regional lymph nodes
• MX – Distant metastasis cannot be assessed
• M0 – No distant metastasis
• M1 – Distant metastasis

Question 5

Draw T staging

Answer 5

Question 6

Explain grading in (colorectal) cancer

Answer 6

What does it look like under the microscope?

• Grade 1 (low grade)
  
  • Cancer cells look similar to normal cells (well differentiated)
• Grade 2 (moderate grade)
  
  • Cancer cells look more abnormal (moderately differentiated)
• Grade 3 (high grade)
  
  • Cancer cells look very abnormal (poorly differentiated)

Question 7

Draw the structure anatomy of the bowel

Answer 7

Question 8

Explain the pathology in colorectal cancer

Answer 8

What is the most common pathology in colorectal cancer?

• Adenocarcinoma
• Well or moderately differentiated

Other pathologies?

• Mucinous carcinomas
• Colloid carcinomas

What else do we get in pathology report?

• Vascular or lymphatic invasion
• R0, R1, R2 (
• T N M (more than 12 nodes to accurately stage)
• Mutations (BRAF, KRAS, NRAS)
• MSI or MMR

Question 9

What is MMR and MSI?

Answer 9

• Mismatch repair proteins (MMR)
• MLH1, MSH2, MSH6 or PMS2
• They keep your microsatellite (MSI) regions of your DNA stable
• Help prevent carcinogenic mutations
• If you are MMR proficient you are MSI-stable
• If you are MMR deficient you are MSI-instable
• If you are MMR proficient you are MSI-low
• If you are MMR deficient you are MSI-high

Question 10

What is Lynch Syndrome?

Answer 10

• Hereditary non-polyposis colorectal cancer (HNPCC)
• Most common cause of hereditary colorectal cancer
• MSH2 and/or MSH6 loss suspicious for Lynch Syndrome
• Increased risk of lots of cancers
• Younger age (before 50)
  
  • Uterine (endometrial)
  • Stomach
  • Liver
  • Kidney
  • Brain
• Surveillance? (as genetic history = family history)
  
  • 2 yearly colonoscopies, annual endometrial US +-biopsy, 1-2 yearly OGDs (if +ve family history) → NOT NEED TO KNOW THIS BIT

Question 11

What factors influence surgical treatment?

Answer 11

What factors influence surgical treatment?

• Location and spread of cancer (nodes and other organs)
• Blood supply
• Lymphatic drainage
• Patient fitness
• Patient choice!

Question 12

Draw the blood supply to the bowel

Answer 12

Question 13

Draw right hemicolectomy

Answer 13

Question 14

Draw transverse colectomy

Answer 14

Question 15

Draw an extended right hemicolectomy

Answer 15

Question 16

Draw a left hemicolectomy

Answer 16

Question 17

Draw a sigmoid colectomy

Answer 17

Question 18

What to do with someone with metastatic disease (not for sugery) and presents with bowel obstruction?

Answer 18

• Colectomy
• Defunctioning stoma
• Colonic stenting

Question 19

What is the 5 year survival rates after surgical resection alone in different stages? (in CRC)

Answer 19

• 99% for stage I
• 68%-83% for stage II
• 45%-65% for stage III

Question 20

If Adjuvant Chemotherapy Stage 2 and MSI-instable/MSI-high/dMMR, treat or not?

Answer 20

NO adjuvant chemotherapy

Question 21

Treatment for adjuvant chemotherapy stage 2

Answer 21

• What is stage 2?
  
  • T3/4 N0 M0
• 6 months of oral capecitabine (twice a day)
  
  • Reduces the risk of recurrence by ~5%
• Get chemotherapy after 12 weeks (not a day over this) of curative surgery

Question 22

Treatment of adjuvant stage 3 cancer

Answer 22

• What is a stage 3?
  
  • Any T, N1/2, M0
• Adjuvant benefit to single agent 5-FU was 10%
  
  • Improved with adding oxaliplatin by 3-5%
  • Now we offer doublet chemo with a 15% benefit
  • Aim to start within 8 weeks of surgery
  • Definitely before 12 weeks