Oncology

Question 1

Gastric cancer staging

Answer 1

The TNM staging system for gastric cancer is used to classify the extent of cancer based on three factors: Tumor (T), Nodes (N), and Metastasis (M). Here is a summary of the TNM staging for gastric cancer:

T - Tumor (Size and extent of the primary tumor)

*	TX: Primary tumor cannot be assessed.
*	T0: No evidence of primary tumor.
*	Tis: Carcinoma in situ (confined to the innermost layer of the stomach lining).
*	T1: Tumor invades the lamina propria, muscularis mucosae, or submucosa.
*	T1a: Tumor invades lamina propria or muscularis mucosae.
*	T1b: Tumor invades submucosa.
*	T2: Tumor invades the muscularis propria.
*	T3: Tumor invades the subserosa.
*	T4: Tumor invades serosa (visceral peritoneum) or adjacent structures.
*	T4a: Tumor invades serosa.
*	T4b: Tumor invades adjacent structures (e.g., pancreas, spleen, colon).

N - Nodes (Involvement of regional lymph nodes)

*	NX: Regional lymph nodes cannot be assessed.
*	N0: No regional lymph node involvement.
*	N1: 1–2 regional lymph nodes involved.
*	N2: 3–6 regional lymph nodes involved.
*	N3: 7 or more regional lymph nodes involved.
*	N3a: 7–15 regional lymph nodes involved.
*	N3b: 16 or more regional lymph nodes involved.

M - Metastasis (Distant spread)

*	M0: No distant metastasis.
*	M1: Distant metastasis present (e.g., spread to liver, lungs, or distant lymph nodes).

Staging based on TNM

*	Stage 0: Tis, N0, M0.
*	Stage IA: T1, N0, M0.
*	Stage IB: T1, N1, M0 or T2, N0, M0.
*	Stage IIA: T1, N2, M0 or T2, N1, M0 or T3, N0, M0.
*	Stage IIB: T1, N3, M0 or T2, N2, M0 or T3, N1, M0 or T4a, N0, M0.
*	Stage IIIA: T2, N3, M0 or T3, N2, M0 or T4a, N1, M0.
*	Stage IIIB: T3, N3, M0 or T4a, N2, M0 or T4b, N0-N1, M0.
*	Stage IIIC: T4a, N3, M0 or T4b, N2-N3, M0.
*	Stage IV: Any T, Any N, M1.

This system is crucial for determining the prognosis and planning treatment options for patients with gastric cancer.

Question 2

Colon cancer staging

Answer 2

The TNM staging system for colon cancer is a method used to describe the extent of cancer spread in the body. The staging involves three main components: Tumor (T), Node (N), and Metastasis (M). Here is a summary of the TNM classification for colon cancer:
Tumor (T)
* Tis: Carcinoma in situ (cancer is in the innermost lining of the colon).
* T1: Tumor has invaded the submucosa.
* T2: Tumor has invaded the muscularis propria.
* T3: Tumor has grown through the muscularis propria into the subserosa or into tissues surrounding the colon.
* T4a: Tumor has grown through the visceral peritoneum.
* T4b: Tumor has invaded or adhered to nearby organs or structures.
Node (N)
* N0: No regional lymph node involvement.
* N1: Cancer has spread to 1-3 nearby lymph nodes.
* N1a: Involvement of 1 regional lymph node.
* N1b: Involvement of 2-3 regional lymph nodes.
* N1c: No regional lymph node metastasis, but small deposits of cancer are found in the areas around the tumor.
* N2: Cancer has spread to 4 or more nearby lymph nodes.
* N2a: Involvement of 4-6 regional lymph nodes.
* N2b: Involvement of 7 or more regional lymph nodes.
Metastasis (M)
* M0: No distant metastasis.
* M1: Distant metastasis is present.
* M1a: Cancer has spread to one distant organ or set of lymph nodes.
* M1b: Cancer has spread to more than one distant organ or set of lymph nodes.
* M1c: Cancer has spread to the peritoneum and possibly other organs.

Question 4

Most commonly diagnosed cancer (overall)

Answer 4

Lung cancer

Question 5

Most common sites for metastases of breast cancer

Answer 5

Bones
Lungs
Liver
Brain
Lymph nodes

Question 6

Li-fraumeni syndrome

Answer 6

AD

Approximately 70% of LiFraumeni kindreds have mutations in p53 gene

• breast cancers (the most common malignant neoplasm in this syndrome)
• soft tissue sarcoma, osteosarcoma, brain tumors,
  adrenocortical carcinoma, Wilms tumor, phyllodes tumor (breast), pancreatic cancer, leukemia, neuroblastoma

Chompret criteria have been identified to describe four clinical scenarios where there should be high suspicion for Li-Fraumeni syndrome and genetic counseling and testing should be offered: (1) a proband diagnosed with a Li-Fraumeni spectrum tumor prior to the age of 46 years, and at least one first or second degree relative with a Li-Fraumeni syndrome spectrum tumor; (2) proband with multiple malignancies (except two breast cancers), of which at least two are considered Li-Fraumeni syndrome associated, before 46 years of age; (3) patients with adrenocortical carcinoma, choroid plexus carcinoma or embryonal anaplastic subtype rhabdomyoscarcoma (independent of family history); and (4) breast cancer before the age of 31 years old.

Question 7

BRCA1

Answer 7

Cancers of the breast, ovary, colon, prostate

Question 8

BRCA2

Answer 8

Cancers of the breast, ovary, colon, prostate, gallbladder and biliary tree, pancreas, stomach; melanoma

Question 9

Cowden disease

Answer 9

PTEN

Cancer of the breast, endometrium, and thyroid

Question 10

FAP

Answer 10

APC

Colorectal carcinoma, duodenal and gastric neoplasms, desmoid tumors, thyroid cancer, osteomas

Question 11

Familial gastrointestinal stromal tumor

Answer 11

C-KIT, PDGFRA
GIST

Question 12

Lynch syndrome (HNPCC)

Answer 12

MLH1; MSH2

Colorectal cancer; endometrial cancer; transitional cell carcinoma of the ureter and renal pelvis; and carcinomas of the stomach, small bowel, pancreas, ovary

Question 13

Multiple endocrine neoplasia type 1

Answer 13

MEN1
parathyroid hyperplasia,

Pancreatic islet cell tumors,

pituitary adenomas

Question 14

Multiple endocrine neoplasia type 2A

Answer 14

RET

Medullary thyroid cancer, pheochromocytoma, parathyroid hyperplasia

Question 15

Peutz-Jeghers syndrome

Answer 15

Gastrointestinal carcinomas, breast cancer, testicular cancer, pancreatic cancer, benign pigmentation of the skin and mucosa

Question 16

Xeroderma pigmentosum

Answer 16

XPA

Melanoma, leukemia, skin cancer

Question 17

von Hippel–Lindau (VHL)

Answer 17

development of highly vascularized tumors in multiple organs

hhangioblastomas of the retina and central nervous system, renal cysts that develop into clear cell renal cell cancer, pheochromocytomas, endolymphatic sac tumors of the middle ear, and epididymal or round ligament cysts.

Question 18

BIRADS

Answer 18

BI-RADS Categories:

1.	BI-RADS 0: Incomplete
•	Additional imaging evaluation or comparison to previous studies is needed to make an assessment.
2.	BI-RADS 1: Negative
•	No abnormalities are found. Routine screening is recommended.
•	Risk of malignancy: 0%.
3.	BI-RADS 2: Benign finding
•	Clearly benign (non-cancerous) findings, such as cysts or fibroadenomas. Routine screening is advised.
•	Risk of malignancy: 0%.
4.	BI-RADS 3: Probably benign
•	Findings are likely benign, with a very low risk of malignancy. Short-term follow-up (e.g., in 6 months) is recommended to ensure stability.
•	Risk of malignancy: ≤ 2%.
5.	BI-RADS 4: Suspicious abnormality
•	There is a suspicious finding, and a biopsy is recommended to determine whether cancer is present.
•	Risk of malignancy: 2-95%, depending on the subcategories:
•	4A: Low suspicion for malignancy (2-10% risk).
•	4B: Moderate suspicion for malignancy (10-50% risk).
•	4C: High suspicion for malignancy (50-95% risk).
6.	BI-RADS 5: Highly suggestive of malignancy
•	The finding has a very high probability of being cancerous. Immediate biopsy and treatment are recommended.
•	Risk of malignancy: > 95%.
7.	BI-RADS 6: Known biopsy-proven malignancy
•	The patient has already been diagnosed with breast cancer, and this category is used to track known lesions and monitor treatment.

Summary:

•	BI-RADS 0: Need additional imaging.
•	BI-RADS 1 & 2: No cancer, routine follow-up.
•	BI-RADS 3: Probably benign, short-term follow-up.
•	BI-RADS 4 & 5: Suspicious or highly suggestive of cancer, biopsy needed.
•	BI-RADS 6: Confirmed cancer diagnosis.

This system is designed to assist radiologists and physicians in decision-making and to guide patient management based on the level of suspicion for breast cancer.