Flexible sigmoidoscopy in the randomized prostate, lung, colorectal, and ovarian (PLCO) cancer screening trial: added yield from a second screening examination.
BACKGROUND
Among randomized trials evaluating flexible sigmoidoscopy (FSG) for its effect on colorectal cancer mortality, only the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial screened its participants more than one time. We report outcomes from the PLCO screening FSG program and evaluate the increased yield produced by a second FSG.


METHODS
Participants were screened by 60-cm FSG in 10 regional screening centers at study entry and 3 or 5 years later, depending on the time of random assignment. Results from subsequent diagnostic intervention were tracked and recorded in a standardized fashion, and outcomes were compared according to sex and age. The protocol discouraged repeat FSG in persons with colorectal cancer or adenoma diagnosed after the initial FSG.


RESULTS
Of 77 447 enrollees, 67 073 (86.6%) had at least one FSG and 39 443 (50.9%) had two FSGs. Diagnostic intervention occurred in 74.9% after a positive first FSG and in 78.7% after a positive repeat FSG. The second FSG increased the screening yield by 32%: Colorectal cancer or advanced adenoma was detected in 37.8 per 1000 persons after first screening and in 49.8 per 1000 persons after all screenings. The second FSG increased the yield of cancer or advanced adenoma by 26% in women and by 34% in men. Of 223 subjects who received a diagnosis of colorectal carcinoma within 1 year of a positive FSG, 64.6% had stage I and 17.5% had stage II disease.


CONCLUSIONS
Repeat FSG increased the detection of colorectal cancer or advanced adenoma in women by one-fourth and in men by one-third. Screen-detected carcinomas were early stage (stage I or II) in greater than 80% of screened persons. Colorectal cancer mortality data from the PLCO, as the definitive endpoint, will follow in later publications.
UPMC Cancer Pavilion (POB II), Pittsburgh, PA 15232, USA. jwepid@pitt.edu
Joel L
JL
Weissfeld
Robert E
RE
Schoen
Paul F
PF
Pinsky
Robert S
RS
Bresalier
V Paul
VP
Doria-Rose
Adeyinka O
AO
Laiyemo
Timothy
T
Church
Lance A
LA
Yokochi
Susan
S
Yurgalevitch
Joshua
J
Rathmell
Gerald L
GL
Andriole
Saundra
S
Buys
E David
ED
Crawford
Mona
M
Fouad
Claudine
C
Isaacs
Lois
L
Lamerato
Douglas
D
Reding
Philip C
PC
Prorok
Christine D
CD
Berg
D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000175:diagnosis; D011471:Prostatic Neoplasms / Q000175:diagnosis; D016032:Randomized Controlled Trials as Topic; D017678:Sex Distribution; D012737:Sex Factors; D012812:Sigmoidoscopy / Q000295:instrumentation