Trends in breast cancer treatment in Korea and impact of compliance with consensus recommendations on survival

The association between guideline adherence, age and overall survival among women with non-metastatic breast cancer: A systematic review

INTRODUCTION

Conformity with treatment guidelines should benefit patients. Studies have reported variation in adherence to breast cancer (BC) guidelines, particularly among older women. This study investigated (i) whether adherence to treatment guideline recommendations for women with non-metastatic BC improves overall survival (OS), (ii) whether that relationship varies by age.

METHODOLOGY

MEDLINE and EMBASE were systematically searched for studies on guideline adherence and OS in women with non-metastatic BC, published after January 2000, which examined recommendations on breast surgery, chemotherapy, radiotherapy or endocrine therapy. Study results were summarised using narrative synthesis.

RESULTS

Sixteen studies met the inclusion criteria. The recommendations for each treatment covered were similar, but studies differed in their definitions of adherence. 5-year OS rates among patients having compliant treatment ranged from 91.3% to 93.2%, while rates among patients having non-compliant treatment ranged from 75.9% to 83.4%. Six studies reported an adjusted hazard ratio (aHR) for non-compliant treatment compared with compliant treatment; all concluded OS was worse among patients whose overall treatment was non-compliant (aHR range: 1.52 [1.30-1.82] to 2.57 [1.96-3.37]), but adjustment for potential confounders was limited. Worse adherence among older women was reported in 12/16 studies, but they did not provide consistent evidence on whether OS was associated with treatment adherence and age.

CONCLUSIONS

Individual studies reported that better adherence to guidelines improved OS among women with non-metastatic BC, but the evidence base has weaknesses including inconsistent definitions of adherence. More precise and consistent research designs, including the evaluation of barriers to adherence across the spectrum of healthcare practice, are required to fully understand guideline compliance, as well as the relationship between compliance and OS following a BC diagnosis.

Breast cancer in China

The health burden of cancer is increasing in China, with more than 1·6 million people being diagnosed and 1·2 million people dying of the disease each year. As in most other countries, breast cancer is now the most common cancer in Chinese women; cases in China account for 12·2% of all newly diagnosed breast cancers and 9·6% of all deaths from breast cancer worldwide. China's proportional contribution to global rates is increasing rapidly because of the population's rising socioeconomic status and unique reproductive patterns. In this Review we present an overview of present control measures for breast cancer across China, and emphasise epidemiological and socioeconomic diversities and disparities in access to care for various subpopulations. We describe demographic differences between China and high-income countries, and also within geographical and socioeconomic regions of China. These disparities between China and high-income countries include younger age at onset of breast cancer; the unique one-child policy; lower rates of provision and uptake for screening for breast cancer; delays in diagnosis that result in more advanced stage of disease at presentation; inadequate resources; and a lack of awareness about breast cancer in the Chinese population. Finally, we recommend key measures that could contribute to improved health outcomes for patients with breast cancer in China.

Poor compliance with breast cancer treatment guidelines in men undergoing breast-conserving surgery

Lumpectomy is performed in a small but growing proportion of men with breast cancer. It is unknown whether men undergoing breast-conserving surgery (BCS) receive care compliant with breast cancer treatment guidelines. Patients with breast cancer in the surveillance, epidemiology, and end results (SEER) database who underwent lumpectomy between 1983 and 2009 were identified. Gender differences in the receipt of lymph node staging and adjuvant radiation therapy were assessed. Multivariate logistic regression was utilized to evaluate the independent association of gender on these outcomes. The influence of gender on breast cancer-specific survival (BCSS) was analyzed. 382,030 of 824,408 (46.3 %) women compared to 712 of 6,039 (11.8 %) men with breast cancer underwent lumpectomy. Men were older, more likely to be black, less likely to have stage I disease and more likely to have stage IV disease. Only 59.2 % of men had lymph nodes sampled at the time of surgery compared to 81.6 % of women (p < 0.0001). In addition, only 35.4 % of men received adjuvant breast radiation therapy compared to 69.8 % of women (p < 0.0001). After controlling for age, race, stage, grade, and year of diagnosis, female gender was significantly associated with receiving adjuvant radiation therapy (OR 2.9, 95 % CI 2.4-3.4) and lymph node staging (OR 1.6, 95 % CI 1.3-1.90). Five- and ten-year BCSS were 88.0 and 83.5 % for men compared to 93.2 and 88.2 % for women (p < 0.001). Men with breast cancer are less likely to receive lymph node staging or adjuvant radiation therapy following BCS compared to women.

Epidemiologic study of radiotherapy use in China in patients with breast cancer between 1999 and 2008

BACKGROUND

To investigate the use of radiotherapy (RT) in China in patients with breast cancer over a 10-year period. A hospital-based, nationwide, multicenter, retrospective epidemiologic study of women with primary breast cancer was conducted.

PATIENTS AND METHODS

Patients were selected randomly in 7 hospitals from 1999 to 2008. Data on overall RT, postmastectomy RT (PMRT), RT after conservative breast surgery (PBRT) and palliative RT (PRT) were recorded. RT use was analyzed, and differences were compared by using the Cochran-Armitage trend test and the χ(2) test. A total of 3732 patients were included: 1009 (27%) received RT, including 688 (18.4%) PMRT, 170 (4.6%) PBRT, 86 (2.3%) PRT, 47 (1.3%) both PMRT and PRT, and 18 (0.5%) other RT.

RESULTS

Overall use of RT increased significantly from 1999 to 2008 (2P < .001). There was a slight but significant increase in PMRT (2P = .012) and a 10-fold increase in PBRT (2P < .001); use of PRT was relatively constant (2P = .777). There was a significant difference among regions in the use of RT, PMRT, PBRT, and PRT (2P < .01). Of patients with stage III disease, 51.6% and of those with node-positive stage II disease treated by radical mastectomy, 21% had received PMRT. In patients treated by using breast conservative surgery, 83.7% received PBRT, which was not affected by stage.

CONCLUSION

In summary, in China, the overall use of RT in patients with breast cancer was quite low, but there was an increasing trend in those treated between 1999 and 2008.

Epidemiologic study of compliance to postmastectomy radiation therapy guidelines in breast cancer patients in China between 1999 and 2008

PURPOSE

To evaluate compliance with postmastectomy radiation therapy (PMRT) guidelines in breast cancer patients in China over a 10-year period.

METHODS AND MATERIALS

A hospital-based, nationwide, multicenter retrospective epidemiologic study of primary breast cancer in women was conducted. Seven first-class, upper-level hospitals from different geographic regions of China were selected. One month was randomly selected to represent each year from 1999-2008 in every hospital. All inpatient cases within the selected months were reviewed and demographic, clinical, and pathologic characteristics and treatment patterns were collected. Patients enrolled in this study had to meet the following inclusion criteria: (1) treated with mastectomy and axillary dissection; (2) information regarding whether or not they received postmastectomy radiation therapy was available; and (3) information about staging was available. Patients were divided into 3 groups based on National Comprehensive Cancer Network guidelines. Utilization of PMRT in each group was analyzed and compared between different years and different hospitals.

RESULTS

A total of 2310 patients were analyzed. There were 643 (27.8%) patients in the PMRT recommended group, 557 (24.1%) patients in the controversial group, and 1110 (48.1%) patients in the nonrecommended group. PMRT was used in 48.8% of patients in the recommended group, 15.6% in the controversial group, and 5.7% in the nonrecommended group. There was a trend toward increasing use of radiation therapy in the recommended and controversial groups from 1999-2008. The use of PMRT in the nonrecommended group remained relatively stable from 1999-2008. Fewer positive nodes and nonreceipt of chemotherapy or hormone therapy were associated with underuse of PMRT in the recommended group. In the controversial group, a higher ratio of positive nodes was associated with use of PMRT.

CONCLUSIONS

There is an apparent underuse of PMRT in the PMRT recommended group. Efforts should be made to improve the compliance to PMRT guidelines.

Evaluation of the willingness-to-pay for cancer treatment in Korean metastatic breast cancer patients: a multicenter, cross-sectional study

AIMS

To evaluate the inherent value of breast cancer therapy a willingness-to-pay (WTP) study was conducted in Korean patients with metastatic breast cancer.

METHODS

Patients were prospectively enrolled from four study centers and completed quality of life questionnaires to reflect their status pre-cancer and their current health status. Clinical and socioeconomic data were collected to characterize the population and utilize during modeling. Patients' WTP for breast cancer treatment was assessed using an open-ended question following three rounds of bidding to better hone in on their maximal WTP, starting with one of three randomly assigned start bids. Predictors of patient WTP was evaluated using linear regression models. Associations between WTP and other parameters were evaluated with correlations.

RESULTS

Korean metastatic breast cancer patients were WTP an average of KRW 8 696 329 (US$7555) per month to return to their pre-cancer health state, with those who were recently diagnosed as WTP the most (KRW 12 955 000 [$11 254]). WTP was closely associated with the patient's education level, income, personal financial difficulties, Eastern Cooperative Oncology Group performance status, and their experience of arm symptoms.

CONCLUSION

The results suggest that patients are WTP significant amounts per month for treatment. Breast cancer patients are heavily burdened physically, mentally and financially, and the present study indicated this significant financial burden by disclosing its relationship with WTP. Providing a better understanding of the inherent value of treatment will allow Koreans to better evaluate treatment in the coming era of personalized medicine.

Factors affecting survival among women with breast cancer in Hawaii

BACKGROUND

Given previous reports of ethnic differences in breast cancer survival among Hawaii's population, we investigated the role of adherence to treatment standards, treatment toxicity, preexisting chronic conditions, and obesity in the survival of 382 prospectively studied breast cancer patients representing six ethnic groups.

METHODS

Participants were recruited from several hospitals in Honolulu. Information on tumor characteristics and treatment was abstracted from medical records. Based on the Physicians Data Query (PDQ®), we assessed compliance with recommended treatment guidelines. Vital status and cause of death data were obtained through linkage with the Hawaii Tumor Registry. Cox proportional hazard models were used to compute hazard ratios for predictors of survival.

RESULTS

After a median follow-up time of 13.2 ± 3.7 years, 115 deaths had occurred, 43 from breast cancer and 72 from other causes. After adjustment, we observed only small differences in survival by ethnicity that were not statistically significant. In addition to advanced disease stage, obesity at diagnosis was a significant independent predictor of worse and receiving PDQ-recommended treatment of better breast cancer-specific and all-cause survival. Developing high-grade toxicity was associated with worse breast cancer survival, whereas comorbidity and older age at diagnosis were associated with higher all-cause mortality. Hormone receptor status, menopausal status, and type of health insurance were not associated with survival.

CONCLUSIONS

These findings suggest that given access to healthcare, breast cancer patients experience similar survival rates. Although more information about mechanisms of action would be useful, it appears reasonable to recommend weight control to breast cancer survivors.

Cost-effectiveness analysis of 5 years of postoperative adjuvant tamoxifen therapy for Korean women with breast cancer: retrospective cohort study of the Korean breast cancer society database

OBJECTIVE

This study aimed to evaluate the cost-effectiveness of postoperative adjuvant tamoxifen therapy using data from a Korean breast cancer registry.

METHODS

In this retrospective, observational cohort study, patients were selected from the Korean Breast Cancer Society database. Women with stage I, II, or III breast cancer (diagnosed between 1981 and 2005), for whom information about tamoxifen use (20 mg/d for 5 years) and estrogen-receptor and/or progesterone-receptor status was available, were included. Cost-effectiveness was calculated from the perspective of Korean society. Using a decision analytic model based on standard clinical flow, incremental cost-effectiveness ratios (ICERs) for overall survival were calculated with stratification by disease stage and hormone-receptor status. One-way sensitivity analyses were also conducted. All results were represented as US dollars (US $1 approximately 1000 Korean won, in year-2005 values).

RESULTS

A total of 17,579 patients were included in the analysis (10,694 tamoxifen users, 6885 nonusers). Among those with stage I or II breast cancer, ICERs for estrogen-receptor positive (ER+)/progesterone-receptor positive (PR+) tamoxifen users ranged from $739 to $1939. Tamoxifen use among those with either ER+ or PR+ status (but not both) remained cost-effective: $1217 to $3107 for 1 life-year gained. However, among estrogen-receptor negative (ER-)/progesterone-receptor negative (PR-) patients, tamoxifen use was more expensive and associated with shorter survival, and most ICERs were negative values, except for those aged >or=50 years (ICERs ranged from -$462 to -$3738 for 1 life-year gained). In contrast to those with stage I or II disease, tamoxifen use among patients with stage III disease was cost-effective regardless of hormone-receptor status. However, because of the small sample size, further studies are needed.

CONCLUSIONS

In this analysis, postoperative adjuvant tamoxifen use was cost-effective for stage I or II ER+ and/or PR+ breast cancer, but not for ER-/PR- disease. Tamoxifen therapy appeared to be cost-effective for patients with stage III breast cancer regardless of hormone-receptor status. Seoul National University Hospital identifier: C-0702-019-198.

Secular trends in breast cancer mortality in five East Asian populations: Hong Kong, Japan, Korea, Singapore and Taiwan

Breast cancer risk is increasing in most Asian female populations, but little is known about the long-term mortality trend of the disease among these populations. We extracted data for Hong Kong (1979-2005), Japan (1963-2006), Korea (1985-2006), and Singapore (1963-2006) from the World Health Organization (WHO) mortality database and for Taiwan (1964-2007) from the Taiwan cancer registry. The annual age-standardized, truncated (to > or =20 years) breast cancer death rates for 11 age groups were estimated and joinpoint regression was applied to detect significant changes in breast cancer mortality. We also compared age-specific mortality rates for three calendar periods (1975-1984, 1985-1994, and 1995-2006). After 1990, breast cancer mortality tended to decrease slightly in Hong Kong and Singapore except for women aged 70+. In Taiwan and Japan, in contrast, breast cancer death rates increased throughout the entire study period. Before the 1990s, breast cancer death rates were almost the same in Taiwan and Japan; thereafter, up to 1996, they rose more steeply in Taiwan and then they began rising more rapidly in Japan than in Taiwan after 1996. The most rapid increases in breast cancer mortality, and for all age groups, were in Korea. Breast cancer mortality trends are expected to maintain the secular trend for the next decade mainly as the prevalence of risk factors changes and population ages in Japan, Korea, and Taiwan. Early detection and treatment improvement will continue to reduce the mortality rates in Hong Kong and Singapore as observed in Western countries.