Do the benefits outweigh the side effects of colorectal cancer surveillance? A systematic review

Table 1 Benefits and side effects of colorectal cancer surveillance

Benefits	Harms
Reassurance of surveillance	Impact of false positive tests
For the CRC survivor	Over diagnoses
For spouses and family	Complications related to the screening tests
Improved survival	Labeled as sick or at high risk
Control of treatment effects	False assurance of disease free status
Is the societal harm-to benefit ratio acceptable?

CRC: Colorectal cancer.

Table 2 Comparison of randomized trials assessing follow-up after colorectal cancer curative surgery n (%)

Trial	Cancer stage included	Enrolled (n)	Recurrences	Time to cancer detection (mo)	Metastases surgeries (n)	Overall 5-yr survival	Disease free 5-yr survival	Survival after met surgery
Ohlsson 1995
Total	Dukes A, B, C	107	35 (33)
Intensive		53	17 (32)	20 (median)	5	75	78	29% 5 yr
Control		54	18 (33)	24 (median)	3	67	71	22% 5 yr
Makela 1995
Total	Dukes A, B, C	106	43 (41)		8	58		Overall 3 pts mean 26 mo survival
Intensive		52	22 (42)	10 (mean)	5	59
Control		54	21 (39)	15 (mean)	3	54
Pietra 1998
Total	Dukes B, C	207	82 (39)					Overall 8 pts mean 29 mo survival
Intensive		104	41 (39)	10.3 (mean)	21	73	68
Control		103	41 (40)	20.2 (mean)	6	58	53
Rodriegez-Moranta 2006
Total	TNM II and III	259	69 (26)					NA
Intensive		127	35 (27)	39 (mean)	18	75	NA
Control		132	34 (26)	38 (mean)	10	73
Secco 2001
Risk adapted intensive	Low risk vs high risk	108	74 (68)	Total	31	48	NA	NA
Risk adapted low intensive		84	27 (32)	13.5 (mean)		82
Minimal follow-up: High risk		84	58 (69)		13	35
Minimal follow-up: Low risk		61	25 (40)			60

NA: Not available.

Table 3 Probability of false positive test results (1-specificity) for commonly used colorectal cancer follow-up tests

Test	False positive rate (1-specificity)	Ref.
Serum CEA	10%	[54]
CT-hepatic metastases	5%-28%1	[55-58]
CT-other abdominal metastases	2%	[58]
Contrast enhanced ultrasound-liver	4%-33%2	[56,57,59]
Ultrasound-liver	50%	[59]
CT-lungs	4%	[58]
Colonoscopy	0%	[32]

¹Based on specificity estimates from individual studies of 89%[55] (n = 24), 95%[58] (n = 115), 72%[56] (n = 87), and 91%[57] (n = 100);

²Based on specificity estimates from individual studies of 96%[60] (n = 68), 96%[57] (n = 99), and 67%[59] (n = 56) subjects. The last was the only to employ intraoperative confirmation of hepatic metastases. The annual probability of at least one false positive test for a patient with no actual recurrence would be 41% in each of year one and two, and 28% in each of year three, four, and five. Over the entire five-year period, the probability of at least one false positive would be 87%. CT: Computed tomography; CEA: Carcinoembryonic antigen.