Emerging role of liquid biopsy in rat sarcoma virus mutated metastatic colorectal cancer: A case report

Table 1 Clinical information of the 11 patients at baseline

Case	Age	Gender	mCRC location	RAS Mutation	AA change	Histological grade	Metastasis	Presentation at baseline
Case 1	70	Female	Left colon	c.38G>A p. (Gl y13Asp) KRAS	KRAS G13D	2	Lung, peritoneal	Relapse
Case 2	62	Male	Right colon	p.Ala146Thr/Val/Pro (c.436G>C; c.436G>A; c.437C>T) KRAS	KRAS A146T/V/P	1	Liver	Relapse
Case 3	61	Male	Rectal	c.34G>T p. (Gly12Cys) KRAS	KRAS G12C	2	Lung	Relapse
Case 4	65	Female	Right colon	c.181C>A p. (Gln61Lys) NRAS	NRAS Q61K	1	Lung, peritoneal	De novo
Case 5	52	Male	Rectal	c.35G>A p. (Gly12Asp) KRAS	KRAS G12D	2	Lung, liver	Relapse
Case 6	66	Male	Rectal	c.38G>A p. (Gl y13Asp) KRAS	KRAS G13D	1	Liver	De novo
Case 7	69	Male	Rectal	c.436G>A (p.Ala146Thr) NRAS A146T	NRAS A146T	1	Lung, liver	De novo
Case 8	50	Male	Right colon	c.34G>T p. (Gly12Cys) KRAS	KRAS G12C	2	Lung, bone CNS	Relapse
Case 9	77	Male	Right colon	c.35G>A p. (Gly12Asp) KRAS	KRAS G12D	1	Liver, peritoneal, suprarenal	De novo
Case 10	67	Male	Left colon	c.35G>T p. (Gly12Val) KRAS	KRAS G12V	1	Lung	De novo
Case 11	68	Male	Left colon	c.35G>T p. (Gly12Val) KRAS	KRAS G12V	2	Liver	De novo

mCRC: Metastatic colorectal cancer; KRAS: Kirsten rat sarcoma viral oncogene homolog; RAS: Rat sarcoma virus.

Table 2 Treatment strategy

Case	1L	2L	3L	4L
Case 1	Oxaliplatin	Irinotecan	Irinotecan	NA3
	Folinic acid	Folinic acid	Folinic acid
	Fluorouracil	Fluorouracil	Fluorouracil
	Bevacizumab	Cetuximab	Bevacizumab
	(7 cycles)	(30 cycles)	(2 cycles)
Case 2	Oxaliplatin	Irinotecan	Irinotecan	Trifluridine/tipiracil
	Capecitabine	Folinic acid	Folinic acid
	Bevacizumab	Fluorouracil	Fluorouracil
	(4 cycles)	Bevacizumab	Cetuximab
		(4 cycles)	(5 cycles)
Case 3	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (8 cycles)	Oxaliplatin
	Folinic acid	Folinic acid		Folinic acid
	Fluorouracil	Fluorouracil		Fluorouracil
	(8 cycles)	Bevacizumab (30 cycles)
Case 4	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (3 cycles)	Fluorouracil
	Folinic acid	Folinic acid		Bevacizumab
	Fluorouracil	Fluorouracil
	(23 cycles)	Bevacizumab
		(12 cycles)
Case 5	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (4 cycles)	Oxaliplatin
	Folinic acid	Folinic acid		Bevacizumab
	Fluorouracil	Fluorouracil
	(12 cycles)	Bevacizumab
		(11 cycles)
Case 6	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (2 cycles)	NA
	Folinic acid	Folinic acid
	Fluorouracil	Fluorouracil
	Bevacizumab	Bevacizumab
	(7 cycles)	(21 cycles)
Case 7	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (5 cycles)	Oxaliplatin
	Folinic acid	Folinic acid		Capecitabine
	Fluorouracil	Fluorouracil		Bevacizumab
	Bevacizumab	Cetuximab
	(9 cycles)	(16 cycles)
Case 8	Oxaliplatin	Oxaliplatin	NA1	NA
	Folinic acid	Capecitabine
	Fluorouracil	Bevacizumab
	Bevacizumab	(5 cycles)
	(12 cycles)
Case 9	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (4 cycles)	Oxaliplatin
	Capecitabine	Folinic acid		Capecitabine
	Bevacizumab	Fluorouracil		Bevacizumab
	(6 cycles)	Bevacizumab
		(22 cycles)
Case 10	Oxaliplatin	Irinotecan	Trifluridine/tipiracil (12 cycles)	NA
	Folinic acid	Folinic acid
	Fluorouracil	Fluorouracil
	Bevacizumab	Bevacizumab
	(10 cycles)	(7 cycles)
Case 11	Oxaliplatin	Irinotecan	NA2	NA
	Capecitabine	Folinic acid
	Bevacizumab	Fluorouracil
	(25 cycles)	Cetuximab
		(8 cycles)

¹The patient had no conditions to change treatment.

²Stable disease.

³Death. 1L: First line; 2L: Second line; 3L: Third line; 4L: Fourth line; NA: Not applied.

Table 3 Rat sarcoma virus mutation status and survival outcomes after second line and third line treatment

Case	2L	PFS 2L (mo)	OS since 2L (mo)	3L	PFS 3L (mo)	OS since 3L (mo)
Case 1	Wild-type	35.86	46.61	Wild-type	6.21	9.96
Case 2	Mutated	3.54	33.57	Neo-RAS	3.86	29.50
Case 3	Mutated	24.39	44.82	Mutated	8.96	12.50
Case 4	Mutated	11.25	28.64	Mutated	3.79	16.39
Case 5	Mutated	9.29	34.61	Mutated	5.18	23.57
Case 6	Mutated	11.25	14.71	Mutated	2.29	2.29
Case 7	Wild-type	14.54	27.64	Wild-type	5.14	11.71
Case 8	Mutated	3.79	4.43	NA	NA	NA
Case 9	Mutated	18.96	32.39	Mutated	3.07	12.43
Case 10	Mutated	4.79	20.93	Mutated	12.93	12.93
Case 11	Wild-type	8.39	8.39	NA	NA	NA

1L: First line; 2L: Second line; 3L: Third line; NA: Not applied; PFS: Progression-free survival; OS: Overall survival; ND: Not determined as patients were kept on second line treatment due to absence of conditions to escalate treatment (Case 8) or to non-progressive disease (Case 11).

Table 4 Allele frequencies of rat sarcoma virus mutated patients

Case	Allele frequency
Case 1	ND
Case 2	ND
Case 3	36.7
Case 4	20.4
Case 5	2.6
Case 6	12.4
Case 7	ND
Case 8	45.7
Case 9	54.8
Case 10	7.6
Case 11	ND

ND: Not determined.