Abstract, Academic Surgical Congress 2014: See also: Introductions Disparities between men and women are omnipresent in many malignancies. In colon cancer, women usually fare slightly better. However, women also often tend to be underrepresented at screening initiatives. We hypothesized that the introduction of nationwide screening for colorectal cancer could have led to shifts in the status quo. We therefore assessed whether differences existed in terms of screening presentation at our center and whether this influenced staging and outcomes in our colon cancer population. Methods We included all patients over 50 without a previous history of colorectal cancer that have been treated surgically for colon cancer at our center from 2004 through 2011. Screening events included screening colonoscopies, as well as fecal occult blood tests. Chi-square statistics and relative risk (RR) computations assessed for the significance and magnitude of differences in screening rates between genders; as well as differences in several pathologic characteristics and death rates between women not diagnosed through screening and the remainder of the population. Results We included 919 patients, of whom 451 (49.1%) were female. Women were less likely to be diagnosed through screening (26.2% vs. 32.7%; RR: 0.8, 95%CI 0.66-0.98; P=0.037). Compared to the remainder of the population, women not diagnosed through screening were at significantly higher risk (all P<0.001) for having high-grade tumors (RR=1.61), lymph node metastasis (RR=1.37) and distant metastasis (RR= 1.65). This is reflected quite clearly in relative risk of death directly and uniquely attributable to colon cancer (RR: 1.65). Conclusions Female patients were less likely to be diagnosed with colon cancer through screening methods and subsequently were at risk for presenting with advanced disease and thus having higher mortality. This demonstrates the beneficial effect of diagnosis through screening, and shows that disparities in screening rates lead to disparities in outcomes.

1. Women Are Diagnosed With Colon
Cancer Less Often Through Screening,
Worsening Staging and Prognosis
Ramzi Amri,1,2
Liliana G Bordeianou,1,2
Patricia Sylla,1,2
David L Berger 1,2
1
Massachusetts General Hospital, Division of General and Gastrointestinal Surgery.
2
Harvard Medical School, Department of Surgery.
02/05/15
9th
Annual Academic Surgical Congress, February 4-6 2014
Integrated Oral Presentations I: Clinical Trials/Outcomes 2: Colorectal
(22.9)

2. Introduction
• Colon cancer affects men, women equally
• Screening is independent of gender
• Women historically fare slightly better 1
• Screening changes the affected
population
• Reports show underscreening in women2-5
➤Is this true for our center?
➤What are the implications?1 Murphy G, et al. Int J Cancer. 2011;128(7):1668–1675.
2 Meissner HI, et al. . Cancer Epidemiol Biomarkers Prev. 2006;15(2):389–394.
3 Shapiro JA, et al. Cancer Epidemiol Biomarkers Prev. 2012;21(6):895–904.
4 Stock C, et al. Gastrointest Endosc. 2010;71(2):366–381.e2.
5 Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep 2008;57(10):253–258.

3. Methods
• Included:
• Surgical colon cancer patients at MGH 2004-2011
• >50, no prior CRC: n=919
• Comparison:
• Men vs. women
• Non-screened women vs. other patients
• Statistical analysis
• Ordinal: χ2
, continuous: Mann Whitney U
• Multivariate: Cox & binary logistic regression

4. Results: baseline
Women presented with:
•Higher median age
•Lower CRC-associated
comorbidity
•Better lifestyle
But
•Lower screening rates
Male Female P-value
N (%) 468 (50.9%) 451 (49.1%) -
Age (median, IQR) 68 (17) 71 (20) 0.012
Comorbidities
Charlson (mean, ±SD) 3.16 (1.6) 3.26 (1.9) 0.56
DM2 22.2% 17.1% 0.05
IBD 3.8% 1.8% 0.058
Lifestyle
Current smoking 14.3% 10.2% 0.057
Ever smoking 65.0% 46.4% <0.001
BMI (mean, ±SD) 28.2 (5.8) 27.0 (6.8) 0.004
Presentation
Symptomatic 59.2% 64.5% 0.096
Emergency admission 9.4% 10.6% 0.53
Screening diagnosis 32.7% 26.4% 0.036
Endoscopy – Low risk 25.0% 19.7% 0.056
Endoscopy – Hx polyps 5.8% 4.7% 0.47
FOBT* 3.6% 3.3% 0.92
Palliative cases 1.7% 1.8% 0.94
Preop. chemotherapy 3.4% 1.8% 0.12
History of polyps 13.5% 13.1% 0.87

5. Results
Non-
screening
Women
(n=332)
Others
(n=587)
RR (95% CI) P-value
Surgery
Surgery duration (M, mn) 118 (108) 127 (95) - 0.053
Multivisceral resection (%) 20.2% 9.0% 2.26 (1.62-3.17) <0.001
Pathology
Nodal metastasis (%N+) 47.6% 34.8% 1.36 (1.16-1.59) <0.001
Distant metastasis (%M1) 12.3% 5.5% 2.27 (1.45-3.53) <0.001
High-grade tumor (%) 26.1% 16.1% 1.62 (1.23-2.13) <0.001
EMVI (%) 34.5% 25.9% 1.34 (1.09-1.63) 0.005
Admission
Duration of stay (M, days) 5 (4) 4 (4) - 0.035
Perioperative metastasis 17.8% 11.1% 1.60 (1.15-2.22) 0.004
Mortality (%) 2.4% 1.0% 2.35 (0.83-6.74) 0.11

6. Results
Univariate Multivariate
Binary outcomes
(logistic regression)
OR (95% CI) P-value Covariates OR (95% CI) P-value
Metastatic disease 1.59 (1.17-2.17) 0.003
FU 1.52 (1.12-2.08) 0.008
FU, AJCC 0.95 (0.65-1.39) 0.80
Metastasis in follow-up 1.27 (0.84-1.94) 0.26
FU 1.28 (0.84-1.95) 0.25
FU, AJCC 1.05 (0.68-1.62) 0.83
Death – all causes 1.84 (1.39-2.44) <0.001
Age, CC 1.43 (1.04-1.96) 0.027
Age, CC, AJCC 1.14 (0.82-1.59) 0.43
Death – colon cancer 1.95 (1.38-2.75) <0.001
Age, CC 1.73 (1.19-2.51) 0.004
Age, CC, AJCC 1.30 (0.87-1.96) 0.20
Duration outcomes
(Cox regression)
HR (95% CI) P-value Covariates HR (95% CI) P-value
Survival duration 1.66 (1.32-2.08) <0.001
Age, CC 1.44 (0.96-1.53) 0.002
Age, CC, AJCC 1.02 (0.80-1.28) 0.90
Disease-free survival 1.52 (1.17-1.98) 0.002
Met. Presentation 1.10 (0.84-1.44) 0.48
AJCC 1.00 (0.77-1.31) 0.98
FU: Follow-up; CC: Colon cancer-adjusted Charlson comorbidity score; AJCC: Staging
OR: odds ratio HR: hazard ratio –calculated for non-screening women vs. other patients

7. Conclusions
• Women were less likely to be diagnosed through
screening means.
• Unscreened women: 73% added risk of mortality
• Multivariate models: link with staging
• Screening∨Advanced disease∧Mortality∧
• Disparities in screening = disparities in
outcomes
• Limitation: single-center.
• Further research: Why

8. Questions?
Disclosures: None.
Contact:
E: ramzi_amri@harvard.edu
W: hsph.me/ramri