Breast Cancer Screening in Korean Women: Report of the National Cancer Screening Program in 2008

The Effect of Body Mass Index on Initial Breast Cancer Stage Among Korean Women

BACKGROUND

The relationship between obesity and breast cancer stage is not well-known in the Korean population. This study aimed to identify the effect of body mass index (BMI) on initial breast cancer stage.

PATIENTS AND METHODS

Among patients who underwent surgery for breast cancer (stages 0-III) from June 2003 to December 2018, we analyzed 4510 patients for whom there were BMI data.

RESULTS

The average BMI of our patients was 23.5 (14.2-44.9). In total, 4.6% and 24.2% of the patients had a BMI of ≥30 and 25-29.9, respectively. In the patients with obesity, the proportion of T2 to T4 was 41.4%, which was higher than that in patients with a BMI of 25 to 29 (28.4%; P = .001) or a BMI of <25 (23.3%; P < .001). There was no difference in positive rates of estrogen receptor and progesterone receptor with BMI, but obese patients were less likely to be human epidermal growth factor receptor 2 positive. Patients with higher stages were more likely to have a higher BMI. The effect of BMI on stage was stronger in patients <50 years (odds ratio, 2.439; 95% CI, 1.783-3.335). Although there was no statistical significance, tumors >2 cm were less likely to be palpable in obese patients than in patients of normal weight (nonpalpable in 33.8% and 27.0%, respectively).

CONCLUSION

Our study suggests that obesity is associated with a more advanced breast cancer stage, which represents a poor prognosis, and large tumors tend to be less palpable in women with obesity.

Retrospective observation on contribution and limitations of screening for breast cancer with mammography in Korea: detection rate of breast cancer and incidence rate of interval cancer of the breast

Background

The purpose of this study was to determine the benefits and limitations of screening for breast cancer using mammography.

Methods

Descriptive design with follow-up was used in the study. Data from breast cancer screening and health insurance claim data were used. The study population consisted of all participants in breast cancer screening from 2009 to 2014. Crude detection rate, positive predictive value and sensitivity and specificity of breast cancer screening and, incidence rate of interval cancer of the breast were calculated.

Results

The crude detection rate of breast cancer screening per 100,000 participants increased from 126.3 in 2009 to 182.1 in 2014. The positive predictive value of breast cancer screening per 100,000 positives increased from 741.2 in 2009 to 1,367.9 in 2014. The incidence rate of interval cancer of the breast per 100,000 negatives increased from 51.7 in 2009 to 76.3 in 2014. The sensitivities of screening for breast cancer were 74.6% in 2009 and 75.1% in 2014 and the specificities were 83.1% in 2009 and 85.7% in 2014.

Conclusions

To increase the detection rate of breast cancer by breast cancer screening using mammography, the participation rate should be higher and an environment where accurate mammography and reading can be performed and reinforcement of quality control are required. To reduce the incidence rate of interval cancer of the breast, it will be necessary to educate women after their 20s to perform self-examination of the breast once a month regardless of participation in screening for breast cancer.

Trends in Cancer Screening Rates among Korean Men and Women: Results of the Korean National Cancer Screening Survey, 2004-2013

Purpose

The Korean National Cancer Screening Survey (KNCSS), a nationwide cross-sectional survey, has been conducted annually since 2004. The current study was conducted to report on the trends in screening rates among Korean men and women, and to evaluate policies regarding cancer screening programs implemented to reduce the burden of cancer.

Materials and Methods

The current study used KNCSS data. The eligible study population included men aged 40-74 years and women aged 30-74 years with no cancer history. The lifetime screening rate, screening rate with recommendation, and changes in annual rates were calculated for five major cancers (i.e., stomach, liver, colorectal, breast, and cervix uteri).

Results

The screening rates with recommendation increased by 4.2% (95% confidence interval [CI], 3.7% to 4.8%) annually for stomach cancer, 1.2% (95% CI, 0.1% to 2.4%) for liver cancer, 3.0% (95% CI, 1.8% to 4.1%) for colorectal cancer, 3.7% (95% CI, 2.7% to 4.8%) for breast cancer, and 1.3% (95% CI, 0.8% to 1.8%) for cervical cancer. In 2013, the screening rates with recommendation for stomach, liver, colorectal, breast, and cervical cancers were 73.6%, 33.6%, 55.6%, 59.7%, and 67.0%, respectively.

Conclusion

Both the lifetime screening rates and screening rates with recommendation for the five above-mentioned cancers increased annually from 2004 to 2013.

Barriers to cancer screening among medical aid program recipients in the Republic of Korea: a qualitative study

Few studies have examined reasons why those with low socioeconomic status do not adequately receive cancer screening. We therefore conducted a qualitative study to assess the barriers to cancer screening in people with low socioeconomic status, and to examine the reasons why Medical Aid Program (MAP) recipients do not participate in the National Cancer Screening Program (NCSP). A focus group methodology was used. Participants included MAP recipients (men aged 45-79 years, women aged 35-79 years) who had been invited to cancer screening at least twice based on the NCSP protocol, but had not been screened for any cancer from 2009-2012. We recruited participants living in the cities of Goyang and Paju. A total of 23 MAP recipients participated in four focus group discussions, including 12 men and 11 women. In this qualitative study, we identified six barriers to screening: lack of trust in the NCSP and cancer screening units; fear of being diagnosed with cancer; discomfort or pain from the screening procedure; lack of time, lack of knowledge about cancer screening or lack of awareness of the existence of the NCSP; physical disability or underlying disease; and logistic barriers. Interventions such as individualized counseling, letters and reminders, or other individually-targeted strategies, especially for those with lower socioeconomic status are required to increase participation and reduce disparities in cancer screening.

Effects of a smartphone application on breast self-examination: a feasibility study

Objectives

The aims of this study were to develop a smartphone application to encourage breast self-examination (BSE), and to evaluate the effects of this application in terms of modifying BSE behavior.

Methods

A smartphone application, based on the Android OS, was developed with functions including a BSE date alarm, a reminder to encourage mother and daughter to practice BSE together, record keeping, and educational content with video clips. Females aged 19 and over were enrolled to evaluate the effectiveness of the application. Two series of questionnaires were carried out (before and after use of the application) by e-mail, telephone, and face-to-face interviews between July and September 2012.

Results

Forty-five subjects were enrolled in the study (age 29.5-5.9 years). Of the participants, only 28 (62.2%) had ever practiced BSE and only one of these (2.2%) was carried out at the appropriate time, based on the results of the baseline survey. After using the application, the number of participants practicing BSE increased from 28 to 32 (62.2% to 71.1%, p = 0.503). In subgroup analysis (age < 30 years), the number of participants using BSE increased from 8 to 18 (36.4% to 81.8%, p = 0.002), and the number of those using it at the appropriate time rose from 1 to 15 (2.2% to 33.3%, p < 0.001).

Conclusions

The use of the developed smartphone application increased BSE in females younger than 30 years. To confirm the long-term benefits of the mobile application, additional studies must be carried out.

Trends in Cancer Screening Rates among Korean Men and Women: Results from the Korean National Cancer Screening Survey, 2004-2012

Purpose

The Korean National Cancer Screening Survey (KNCSS), a nationwide, annual cross-sectional survey, has been conducted since 2004. The current study was conducted in order to report on trends in cancer screening rates for five types of cancer (stomach, liver, colorectal, breast, and cervix uteri).

Materials and Methods

KNCSS data were collected between 2004 and 2012. The eligible study population included cancer-free men who were 40 years of age and older and women who were 30 years of age and older. The lifetime screening rate, screening rate with recommendation, and changes in annual rates were calculated.

Results

Lifetime screening rates and screening rates with recommendation for the five types of cancer rose steadily until 2010, showed a slight drop or were stable in 2011, and increased again in 2012. On average, screening rates with recommendation have shown annual increases of 4.3% (95% confidence interval [CI], 3.6 to 5.0%) for stomach cancer, 0.8% (95% CI, -0.5 to 2.1%) for liver cancer, 2.4% (95% CI, 1.3 to 3.5%) for colorectal cancer, 4.5% (95% CI, 3.9 to 5.1%) for breast cancer, and 1.3% (95% CI, 0.6 to 2.0%) for cervical cancer. Disparities in age groups and household incomes have been decreasing since 2004.

Conclusion

Cancer screening rates in Korea showed a significant increase from 2004 to 2012, and screening rates for gastric and breast cancer are now approaching 70%. The 10-Year Plan for Cancer Control target for screening rates was met or nearly met for all cancer types examined, with the exception of liver and colorectal cancer.

Development of a sampling strategy and sample size calculation to estimate the distribution of mammographic breast density in Korean women

Mammographic breast density is a known risk factor for breast cancer. To conduct a survey to estimate the distribution of mammographic breast density in Korean women, appropriate sampling strategies for representative and efficient sampling design were evaluated through simulation. Using the target population from the National Cancer Screening Programme (NCSP) for breast cancer in 2009, we verified the distribution estimate by repeating the simulation 1,000 times using stratified random sampling to investigate the distribution of breast density of 1,340,362 women. According to the simulation results, using a sampling design stratifying the nation into three groups (metropolitan, urban, and rural), with a total sample size of 4,000, we estimated the distribution of breast density in Korean women at a level of 0.01% tolerance. Based on the results of our study, a nationwide survey for estimating the distribution of mammographic breast density among Korean women can be conducted efficiently.

Trends in Cancer Screening Rates among Korean Men and Women: Results from the Korean National Cancer Screening Survey (KNCSS), 2004-2011

PURPOSE

The Korean National Cancer Screening Survey (KNCSS) is a nationwide survey conducted annually, since 2004. This study was conducted in order to report on trends in rates of cancer screening for five major cancers-stomach, liver, colorectal, breast, and cervix uteri in Korea.

MATERIALS AND METHODS

Data collected by the KNCSS between 2004 and 2011 were used in this study. The eligible study population included cancer-free men who were 40 years old and over, and women who were 30 years old and over. Lifetime screening rate, screening rate with recommendation, and changes in annual rates were calculated.

RESULTS

Both lifetime screening rates and screening rates with recommendation have increased since 2004. On average, screening rates with recommendation have shown an annual increase of 4.2% (95% CI, 3.3 to 5.2%) for stomach cancer, 1.1% (95% CI, -0.5 to 2.7%) for liver cancer, 2.2% (95% CI, 0.8 to 3.6%) for colorectal cancer, 4.0% (95% CI, 3.0 to 4.9%) for breast cancer, and 0.2% (95% CI, -0.9 to 1.3%) for cervical cancer. Increases in rates of cancer screening, with the exception of liver and cervical cancers, were significant, and screening rates for stomach and breast cancer in particular showed a marked increase.

CONCLUSION

Cancer screening rates among Koreans showed a consistent increase from 2004 to 2011 and rates of screening for gastric, breast, and cervical cancer are approaching 70%.

Comparison between screen-detected and symptomatic breast cancers according to molecular subtypes

Breast cancer screening programs make it possible to detect early cancer, thus reducing breast cancer mortality. We studied the clinicopathologic characteristics and prognosis of screen-detected invasive breast cancer compared with symptomatic breast cancer. And we compared the result according to molecular subtypes (luminal A, luminal B, Her2, and triple negative), with the goal of identifying the role of screening in each subtypes. From January 2002 to June 2008, 3,141 patients who underwent surgery for the treatment of invasive ductal carcinoma at Samsung Medical Center were included. Among them, 1,025 patients were screen-detected, and 2,116 patients who were screened over 2 years or never were symptomatic. We retrospectively reviewed the clinical and pathologic data. Screen-detected breast cancer was associated with older age, smaller tumor size, more hormone-receptor positive, less lymph node involvement, earlier stage, and reduced mortality compared with symptomatic breast cancer (P < 0.001). According to the molecular subtype, luminal A was most common (63.6%) and showed the most obvious survival benefit in screen-detected tumors in comparison with symptomatic tumors (5-year OS: 99.7 vs. 96.5%, 5-year DFS: 96.4 vs. 90.7%). Screen detection was independently associated with improved overall and disease-free survival outcomes after adjustment for covariates (HR 0.32, P = 0.035; HR 0.58, P = 0.020, respectively) only in the luminal A subtype. Differences in pathological features such as tumor size, nodal status, grade, and age at diagnosis with different molecular subtype distributions may explain the survival advantage of patients with screen-detected breast cancer. Screening programs seem to have a different efficacy depending on the molecular subtype of the breast cancer, especially in the luminal A subtype, for which screen detection acts as an independent prognostic factor itself.

Trends in Cancer Screening Rates among Korean Men and Women: Results from the Korean National Cancer Screening Survey (KNCSS), 2004-2010

Purpose

The Korean National Cancer Screening Survey (KNCSS) is a continuous nationwide survey implemented by the National Cancer Center in Korea since 2004. The purpose of the present study was to report trends in cancer screening rates for the five major cancers (stomach, liver, colorectal, breast, and cervix uteri) in Korean men and women.

Materials and Methods

The study used KNCSS data collected between 2004 and 2010. The survey was conducted on Korean men aged 40-74 years and Korean women aged 30-74 years with no history of cancer diagnosis. The annual percentage change and corresponding 95% confidence intervals were used to examine changes in annual screening rates.

Results

Screening rates with recommendation increased by 4.4% annually for stomach cancer, 1.5% for liver cancer, 2.8% per year for colorectal cancer, 4.5% for breast cancer, and 1.2% for cervix uteri cancer. The increasing trend in cancer screening rates, with the exception of liver cancer, was significant.

Conclusion

Cancer screening rates have increased consistently from 2004 to 2010 among Korean men and women. Stomach and breast cancer screening rates in particular have increased markedly.

Risk factors and control strategies for the rapidly rising rate of breast cancer in Korea

Due to the aging population and tremendous changes in life style over the past decades, cancer has been the leading cause of death in Korea. The incidence rate of breast cancer is the second highest in Korea, and it has shown an annual increase of 6.8% for the past 6 years. The major risk factors of breast cancer in Korean women are as follows: Early menarche, late menopause, late full-term pregnancy (FTP), and low numbers of FTP. Height and body mass index increased the risk of breast cancer in postmenopausal women only. There are ethnic variations in breast cancer due to the differences in genetic susceptibility or exposure to etiologic agent. With the epidemiological evidences on the possibility of further increase of breast cancer in Korea, the Korean Government began implementing the National Cancer Screening Program against breast cancer in 2002. Five-year survival rates for female breast cancer have improved significantly from 78.0% in early 1993-1995 to 90.0% in 2004-2008. This data indicate that improvement of the survival rate may be partially due to the early diagnosis of breast cancer as well as the increased public awareness about the significance of early detection and organized cancer screening program. The current primary prevention programs are geared towards strengthening national prevention campaigns. In accordance with the improvement in 5-year survival rate, the overall cancer mortality has started to decrease. However, breast cancer death rate and incidence rates are still increasing, which need further organized effort by the Korean Government.