Screening of colorectal cancer (CRC) with fecal occult blood test (FOBT) improves the results of men moreso than women, and…
Screening of colorectal cancer (CRC) with fecal occult blood test (FOBT) improves the results of men moreso than women, and especially in men with left-wing tumors, Finnish researchers say. Their conclusion comes from a re-analysis of data from a large screening study.
The Finnish FOBT screening program (2004-2011) was conducted in more than 320,000 men and women between the ages of 60 and 69. Participants were randomly divided into screening and control arms. Results from this study, published in 2015, found no difference in CRC mortality between the two arms, as opposed to results from several previous randomized screening tests.
Now a research group led by Laura Koskenvuo, doctoral student, doctoral student, a gastrointestinal surgeon at Helsinki University Hospital, Finland, has examined data to assess “results beyond mortality.”
They found that two-year FOBT screening “appears to be effective in improving multiple results in men, but not in women.”
It was particularly beneficial in men with left-wing tumors. In this subgroup, FOBT screening was associated with better overall survival, lower frequencies of non-radical resection and reduced need for post-operative chemotherapy.
However, these benefits were not observed in women or in men or women with versatile tumors
The research was published online on 21
November in the British Journal of Surgery .
The team proposes that, considering that FOBT screening does not appear to be associated with improved survival in women, “screening with different methods or at different intervals or ages should be considered in women.”
The Finnish FOB study included approximately 41% of Finnish men and women who were in the target age (60-69 years) before the end of 2011.
Although there was no significant difference in CRC mortality between the screen and the control arm, the results indicate that there was a decrease in CRC-related mortality with screening in men and an increase in women. Such a finding has also been noted in other studies of biennial FOBT, the researchers comment. “Practically, no cancer screenings have been shown to affect overall mortality,” Koskenvuo said in a press release.
“However, they may still be useful in other ways. We wanted to investigate if patients could avoid more intensive treatments if they participated in screening for colorectal cancer,” she explained.
The team therefore collected data on CRC diagnoses from the Finnish Cancer Registry and examined the patient’s medical records to identify clinical and pathological TNM stages; symptoms and scope of surgery; patient’s need for acute surgery, stoma or chemotherapy and histopathological diagnoses.
From 321 311 people in the study, 743 CRC cases were detected in the screening arm and 617 were detected in the control arm.
Patients in the screening group were more likely to experience successful removal of the entire tumor, less likely to require chemotherapy, and less likely to be subjected to acute surgery.
“The control group had 50% more emergency surgery, 40% more incomplete tumor transport and 20% more chemotherapy than patients in the screening group,” explained co-author Ville Sallinen, doctoral student, doctoral student, adjunct professor at the University of Helsinki.
CRC was less common in women than in men, at a rate of 0.34% against 0.50% (risk ratio [RR] 0.82).
Women were less likely to be asymptomatic than men, at 16.7% compared with 22.0 (RR, 0.76). Female pain was the only symptom that was significantly more pronounced in women than men (RR, 1.36).
Women were significantly more likely to have right-wing tumors than men, at 32.0% versus 21.3% (RR, 1.51).
Cancers in patients in the screening arm were of lower T-category (RR, 1.25), N-category (RR, 1.14) and M-category (RR, 1.33) compared to cancer in the control arm. Men with left sides, in patients in the screening arm, were lower N category categories (RR, 1.23) and M-category (RR, 1.57) than in patients in the control arm.
Among men with left side tumors, those in the control arm were more likely to undergo non-radical sections than those in the screening arm at 26.2% versus 15.7% (RR, 1.67) and were more likely to receive post-operative chemotherapy at 61.6% versus 48.2% or (RR, 1.28).
Survival was worse in the control arm than in the screening arm of men with CRC (hazard ratio [HR] 1.31), but there was no dif Ferrerade in women [HR, 1.07].
Among men, 5 years survival rate was 68.8% in screening arm compared with 61.5% in control arm. Among women, interest rates were 70.7% and 71.5%, respectively.
With regard to tumor inhibition among men with left tumors, survival was better in the screening arm than in the control arm (HR, 1.37).  This survival was not seen in men with right-wing tumors, though (HR, 1.19). The survival rate was unaffected by tumor perception in women.
Co-author Nea Malila, PhD student, doctoral student of the Finnish Cancer Register, Helsinki, said that the large sample size is a strength in the study.
“The randomized huge number of people in public health, which meant we could objectively evaluate the benefits of screening,” she noted.
“Similar studies have not been available elsewhere,” she said.
“In the future, we need to investigate whether different screening technicians can improve the situation of female patients and facilitate the diagnosis of high-quality colorectal cancer,” the researchers conclude.
The study was supported economically by Vatsatautien Tutkimussäätiö, Research Funds of Helsinki University Hospital, Maria and Georg Ehrnrooth Foundation and Cancer Foundation Finland. The authors have not disclosed any relevant economic relations.
Br J Surg. Published online November 21, 2018. Full text
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