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Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 7, 2015; 21(17): 5167-5175
Published online May 7, 2015. doi: 10.3748/wjg.v21.i17.5167
Sex- and gender-specific disparities in colorectal cancer risk
Sung-Eun Kim, Hee Young Paik, Hyuk Yoon, Jung Eun Lee, Nayoung Kim, Mi-Kyung Sung
Sung-Eun Kim, Jung Eun Lee, Mi-Kyung Sung, Department of Food and Nutrition, Sookmyung Women’s University, Seoul 140-742, South Korea
Hee Young Paik, Department of Food and Nutrition, Seoul National University, Seoul 151-742, South Korea
Hyuk Yoon, Nayoung Kim, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam 463-707, South Korea
Author contributions: Kim SE summarized the data and wrote the manuscript; Paik HY contributed to the study concept and revision of the manuscript; Yoon H and Kim N provided the data and revised the manuscript; Lee JE drafted and revised the manuscript; Sung MK formulated the idea and contributed to the revision and approval of the final version of the manuscript.
Supported by Mid-Career Research Program, No. 2012R1A2A2A01046228 of the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science, and Technology as well as the Gendered Innovations in Science and Engineering; No. 350-20130047 of the Center for Women in Science, Engineering and Technology (WISET) of Korea funded by the Seoul National University Research and Development Business Foundation.
Conflict-of-interest: The authors have no conflict-of-interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Mi-Kyung Sung, Professor, Department of Food and Nutrition, Sookmyung Women’s University, Cheongpa-ro 47-gil 100, Yongsan-gu, Seoul 140-742, South Korea. mksung@sm.ac.kr
Telephone: +82-2-7109395 Fax: +82-2-7109453
Received: January 5, 2015
Peer-review started: January 6, 2015
First decision: February 10, 2015
Revised: February 26, 2015
Accepted: March 31, 2015
Article in press: March 31, 2015
Published online: May 7, 2015
Processing time: 127 Days and 15.4 Hours
Abstract

Colorectal cancer is one of the most common causes of cancer morbidity both in men and in women. However, females over 65 years old show higher mortality and lower 5-year survival rate of colorectal cancer compared to their age-matched male counterparts. The objective of this review is to suggest gender-based innovations to improve colorectal cancer outcomes in females. Women have a higher risk of developing right-sided (proximal) colon cancer than men, which is associated with more aggressive form of neoplasia compared to left-sided (distal) colon cancer. Despite differences in tumor location between women and men, most of scientific researchers do not consider sex specificity for study design and interpretation. Also, colorectal cancer screening guidelines do not distinguish females from male, which may explain the higher frequency of more advanced neoplasia when tumors are first detected and false negative results in colonoscopy in females. Moreover, socio-cultural barriers within females are present to delay screening and diagnosis. Few studies, among studies that included both men and women, have reported sex-specific estimates of dietary risk factors which are crucial to establish cancer prevention guidelines despite sex- and gender-associated differences in nutrient metabolism and dietary practices. Furthermore, anti-cancer drug use for colorectal cancer treatment can cause toxicity to the reproductive system, and gender-specific recurrence and survival rates are reported. Therefore, by understanding sex- and gender-related biological and socio-cultural differences in colorectal cancer risk, gender-specific strategies for screening, treatment and prevention protocols can be established to reduce the mortality and improve the quality of life.

Keywords: Colorectal cancer; Sex; Gender; Screening; Treatment; Prevention

Core tip: The objective of this review is to suggest gendered innovations to improve colorectal cancer outcomes. Women are more prone to right-sided colon cancer than men, which is associated with more aggressive form of neoplasia compared to left-sided colon cancer. Genetic and epigenetic factors as well as dietary habits play roles in sex-specific differences in colorectal cancer risk. We also suggest that socio-cultural environments partly explain gender-specific differences in colorectal cancer risk. Therefore, sex- and gender-specific strategies for research methods as well as protocols for screening, treatment, and prevention should be established to reduce the morbidity and mortality of colorectal cancer in women.