OBJECTIVETo explore the application of counter-matching design in epidemiological research.

METHODSThrough elaboration of the study about gene-environment interactions in the etiology of breast cancer, methodology regarding counter-matching design and statistic methods was introduced.

RESULTSThis design improved the potential for detecting gene-environment interactions for diseases when both gene mutations and the environmental exposures of interest were rare in the general population.

CONCLUSIONCounter-matching appearsed to be more appropriate than most traditional epidemiologic methods for the study of interactions involving rare factors.

Breast Neoplasms ; epidemiology ; etiology ; genetics ; radiotherapy ; Epidemiologic Methods ; Humans ; Male

BACKGROUND/AIMS: The risk of venous thromboembolism (VTE), which encompasses deep vein thrombosis and pulmonary embolism (PE), increases in patients with cancer. Anticancer treatment is also associated with an increased risk for VTE. We conducted this study to investigate the clinical characteristics of patients with cancer and PE related to anticancer treatment in a tertiary care hospital in Korea. METHODS: We retrospectively reviewed the clinical data of patients with an underlying malignancy who were diagnosed with PE by chest computed tomography (CT) with or without lower extremity CT angiography between January 2006 and December 2007 at Seoul National University Hospital. RESULTS: Overall, 95 patients with malignancies among 168 with PE were analyzed. The median age was 64 years. The median time interval from the malignancy diagnosis to the PE diagnosis was 5.5 months. Lung cancer was the most common malignancy (23.0%), followed by pancreatobiliary cancer, stomach cancer, gynecological cancer, breast cancer, and hepatocellular carcinoma. Platinum-containing and pyrimidine analog-containing chemotherapeutic regimens were common. CONCLUSIONS: PE was diagnosed within 1 year after the cancer diagnosis in almost 70% of patients. Lung cancer was the most common underlying malignancy.
Adult ; Aged ; Aged, 80 and over ; Angiography ; Antineoplastic Agents/*therapeutic use ; Biliary Tract Neoplasms/drug therapy/epidemiology/radiotherapy ; Female ; Humans ; Lung Neoplasms/drug therapy/epidemiology/radiotherapy ; Male ; Middle Aged ; *Neoplasms/drug therapy/epidemiology/radiotherapy ; Pancreatic Neoplasms/drug therapy/epidemiology/radiotherapy ; Pulmonary Embolism/*epidemiology/radiography ; *Radiotherapy ; Retrospective Studies ; Risk Factors ; Stomach Neoplasms/drug therapy/epidemiology/radiotherapy ; Tomography, X-Ray Computed

OBJECTIVE: This study aimed to evaluate the risk factors of radiation-induced caries by using a multiple linear regression equation and to provide the basis for the effective prevention of radioactive caries. METHODS: A total of 166 patients with head and neck cancer who underwent radiotherapy were selected as subjects. The number of decayed, missing or filled surfaces were recorded. Questionnaire contents included age, sex, radiation dose, and radiotherapy techniques. Multiple stepwise regression analyses were performed to identify the risk factors of radiation-induced caries. RESULTS: Multiple stepwise regression analyses indicated that the main risk factors of radiation-induced caries were plaque index, radiotherapy techniques, time after radiotherapy, and radiotherapy dose. CONCLUSIONS The awareness of dental care and caries treatment should be improved to reduce the occurrence of radiation-induced caries in patients with head and neck cancer. In addition, intensity modulated radiation therapy should be employed to decrease the radiation exposure dose received by teeth.
Dental Caries ; epidemiology ; etiology ; Head and Neck Neoplasms ; radiotherapy ; Humans ; Radiation Injuries ; epidemiology ; Risk Factors ; Tooth

PURPOSE: The purpose of this study was to investigate the non-inferiority of omitting radiotherapy (RT) after breast-conserving surgery (BCS) for hormone receptor (HR)‒positive T1N0 breast cancer in elderly women. MATERIALS AND METHODS: From 2004 to 2014, HR-positive T1N0 breast cancer patients aged 50 years or older and receiving BCS were retrieved from the Surveillance, Epidemiology, and End RESULTS: 18 database. After propensity score matching between the no-RT and RT groups, univariate and multivariate analyses were performed. Identified prognostic factors were used to stratify the risk groups. In each risk group, 10-year cancer-specific survival (CSS) rates were compared between the no-RT and RT groups. RESULTS: After propensity score matching, the numbers of patients in the no-RT and RT groups were both 18,586. For patients who satisfied both a tumor size of 1-10 mm and a tumor grade of 1-2, omitting RT did not decrease the CSS rate at any age group, ranging from ≥ 50 to ≥ 85 years; for patients aged ≥ 50 years, the 10-year CSS rates in the no-RT and RT groups were 97.2% and 96.8%, respectively (adjusted hazard ratio, 0.862; p=0.312). However, for patients with a tumor size of 11-20 mm or tumor grade of 3-4, RT significantly increased the CSS rate irrespective of age. CONCLUSION: RT after BCS for HR-positive T1N0 breast cancer in elderly women might be omitted without causing a decrease in the CSS rate, but only in patients who satisfy both a small tumor size (≤ 10 mm) and low tumor grade (1-2).
Aged ; Breast Neoplasms* ; Breast* ; Epidemiology ; Female ; Humans ; Mastectomy, Segmental ; Multivariate Analysis ; Propensity Score* ; Radiotherapy ; Radiotherapy, Adjuvant* ; Receptors, Estrogen ; Receptors, Progesterone

PURPOSE: Traditionally, three-dimensional conformal radiation therapy (3D-CRT) is used for neoadjuvant chemoradiation in locally advanced rectal cancer. Intensity-modulated radiation therapy (IMRT) was later developed for more conformal dose distribution, with the potential for reduced toxicity across many disease sites. We sought to use the National Cancer Database (NCDB) to examine trends and predictors for IMRT use in rectal cancer. MATERIALS AND METHODS: We queried the NCDB from 2004 to 2015 for patients with rectal adenocarcinoma treated with neoadjuvant concurrent chemoradiation to standard doses followed by surgical resection. Odds ratios were used to determine predictors of IMRT use. Univariable and multivariable Cox regressions were used to determine potential predictors of overall survival (OS). Propensity matching was used to account for any indication bias. RESULTS: Among 21,490 eligible patients, 3,131 were treated with IMRT. IMRT use increased from 1% in 2004 to 22% in 2014. Predictors for IMRT use included increased N stage, higher comorbidity score, more recent year, treatment at an academic facility, increased income, and higher educational level. On propensity-adjusted, multivariable analysis, male gender, increased distance to facility, higher comorbidity score, IMRT technique, government insurance, African-American race, and non-metro location were predictive of worse OS. Of note, the complete response rate at time of surgery was 28% with non-IMRT and 21% with IMRT. CONCLUSION: IMRT use has steadily increased in the treatment of rectal cancer, but still remains only a fraction of overall treatment technique, more often reserved for higher disease burden.
Adenocarcinoma ; Bias (Epidemiology) ; Comorbidity ; Continental Population Groups ; Humans ; Insurance ; Male ; Odds Ratio ; Radiotherapy ; Radiotherapy, Intensity-Modulated ; Rectal Neoplasms

OBJECTIVE: To explore the relation between diabetes mellitus and clinicopathological factors and the incidence of radiation pneumonitis in patients with non-small cell lung cancer. METHODS: The data of 332 patients with non-small cell lung cancer, who were admitted to the Department of Oncology of Third Xiangya Hospital of Central South University between January 2007 and August 2009, were collected retrospectively. The patients were divided into a diabetes mellitus (DM) group (n=45) and a non-diabetes mellitus (NDM) group (n=287). The clinicopathological factors were compared between the two groups. The patients who received radiotherapy were further divided into a diabetes mellitus (DMR) group (n=33) and a non-diabetes mellitus group (NDMR) group(n=287), and the incidence of radiation pneumonitis was compared. RESULTS: A total of 45 patients (13.55%)developed diabetes mellitus. There was significant difference in the body-weight, age and hypertension (P<0.05), while no significant difference in the pathologic factors, such as tumor pathological type, degree of differentiation, and classification of malignant tumors (TNM) stage between the two groups(P>0.05). No significant difference in the irradiation area was found between the DM group and the NDM group(P>0.05). The incidence of radiation pneumonitis in the DMR group was 42.42%(14 out of 33), while 21.31%(39 out of 183) in the NDMR group, with significant difference in the incidence of radiation pneumonitis between the DMR group and the NDMR group(P<0.05). The risk value in the DMR group was 2.721 folds (95%CI, 1.253-5.910) that in the NDMR group in patients with non-small cell lung cancer companied with diabetes mellitus. CONCLUSION Diabetes mellitus is the risk factor of radiation pneumonitis for patients with nonsmall cell lung cancer who receive radiotherapy.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Non-Small-Cell Lung ; complications ; pathology ; radiotherapy ; China ; epidemiology ; Diabetes Mellitus, Type 2 ; complications ; radiotherapy ; Female ; Humans ; Lung Neoplasms ; complications ; pathology ; radiotherapy ; Male ; Middle Aged ; Radiation Pneumonitis ; complications ; epidemiology

Adult ; Age Factors ; Aged ; Aged, 80 and over ; Antineoplastic Agents ; therapeutic use ; Carcinoma ; epidemiology ; pathology ; radiotherapy ; Disease-Free Survival ; Female ; Humans ; Hypopharyngeal Neoplasms ; epidemiology ; pathology ; radiotherapy ; Hypopharynx ; surgery ; Kaplan-Meier Estimate ; Male ; Middle Aged ; Neoplasm Staging ; Prognosis ; Proportional Hazards Models ; Radiotherapy, Adjuvant ; Radiotherapy, Intensity-Modulated ; Retrospective Studies ; Sex Factors ; Smoking ; epidemiology ; Tumor Burden

To understand trends in the clinical characteristics of radiation oncology over the last 10 yr in Korea, annual survey questionnaires were sent to all of Korean radiation oncology facilities since 1990. Questionnaires addressed basic radiation therapy facilities and the clinical information. Responses were obtained from all facilities, and data collected from 1997 to 2006 was analyzed. The numbers of new patients that have undergone radiation therapy and the numbers of hospitals with a department of radiation oncology have steadily increased over the past 10 yr, and totaled 37,215 patients and 60 hospitals, respectively, in 2006. However, the proportion of patients irradiated among total cancer patients has remained below 30% over the last 10 yr. The numbers of prostate cancer, breast cancer, and hepatoma have increased by more than 3 fold over the past 10 yr. Moreover, the percentage of irradiated patients treated by brachytherapy was 10.3% in 1997, but this gradually fell to only 4.2% in 2006. The information collected described the role played by radiation oncology in Korea. Continuous surveys are required to enable trends to be detected.
Brachytherapy/utilization ; Female ; Health Care Surveys/statistics & numerical data ; Humans ; Korea/epidemiology ; Male ; *Neoplasms/epidemiology/radiotherapy ; Questionnaires ; *Radiation Oncology/methods/statistics & numerical data/trends ; Registries

PURPOSE: To elucidate risk potentiality of frontline radiotherapy associated cataracts in primary ocular adnexal mucosa-associated lymphoid tissue lymphoma (OAML). METHODS: Data from eight consecutive patients of 41 total OAML patients who had undergone cataract surgery after frontline radiotherapy were analyzed. RESULTS: The median patient age was 46 years (range, 36 to 69 years). The median total radiation dose was 3,780 cGy (range, 3,060 to 4,500 cGy), and the mean duration from radiation irradiation to cataract surgery was 36.60 +/- 8.93 months. Preoperative lens opacification was primarily at the posterior lens subcapsule, and best-corrected visual acuity (BCVA) was 0.43 +/- 0.21. Patients underwent the phacoemulsification surgical procedure with posterior chamber intraocular lens insertion. The average BCVA improved to 0.90 +/- 0.14 after cataract surgery. Two patients underwent posterior continuous curvilinear capsulorhexis, and one had posterior capsule rupture. For posterior capsule opacification (PCO), three patients received Nd:YAG laser posterior capsulotomy after the initial surgery, and one patient is currently under consideration for laser posterior capsulotomy. CONCLUSIONS: Radiotherapy increased posterior subcapsule opacification at a relatively young age in primary OAML. Phacoemulsification was a manageable procedure without severe complications, and final visual outcomes were good. However, because after-cataracts progressed earlier than did senile cataracts, close follow-up should be considered for PCO management.
Adult ; Aged ; Cataract/*epidemiology/etiology ; Eye Neoplasms/*radiotherapy ; Female ; Follow-Up Studies ; Humans ; Lymphoma, B-Cell, Marginal Zone/*radiotherapy ; Male ; Middle Aged ; *Phacoemulsification ; Radiation Dosage ; Radiotherapy/*adverse effects ; Retrospective Studies ; Risk Factors

OBJECTIVEThe purpose of this study was to investigate whether the associated diabetes mellitus exerts a certain effect on the development of radiation pneumonitis in patients with non-small cell lung cancer.

METHODS156 patients with non small cell lung cancer were treated with three-dimensional conformal radiation therapy in this study, including 52 associated with diabetes and 104 non-diabetic patients as a control group. All the patients were followed up for one year and the development of radiation pneumonitis was observed. Radiation pneumonitis was diagnosed according to the criteria of radiation therapy oncology group. The morbidities of radiation pneumonitis in the two groups were compared. The relationships between the morbidity of radiation pneumonitis and blood sugar level as well as diabetic history were analyzed by chi-square test.

RESULTSTwenty-one (40.4%) of 52 patients with diabetes had radiation pneumonitis (grade 2 or greater), while in the control group only 22 of 104 patients (21.2%) suffered from radiation pneumonitis. There was a statistically significant difference between the two groups in the morbidity of the radiation pneumonitis (P < 0.05), with a relative risk value of 2.05 (95% CI, 1.17, 3.58). The rate of the radiation pneumonitis in the patients with a lower blood sugar level (< 7 mmol/L) was significantly lower than that in those with a higher blood sugar level (30.6% vs. 62.5%, P < 0.05). However, the rate of radiation pneumonitis in the patients with a longer diabetic history was not significantly different from that in those with a shorter diabetic history (P > 0.05).

CONCLUSIONNon-small cell lung cancer patients with diabetes mellitus are more vulnerable than those without to radiation pneumonitis. Therefore, diabetes mellitus is a newly discovered risk factor to radiation pneumonitis, and the blood sugar level is positively correlated with the morbidity of radiation pneumonitis.

Adult ; Aged ; Blood Glucose ; analysis ; Carcinoma, Non-Small-Cell Lung ; blood ; complications ; radiotherapy ; Diabetes Mellitus ; blood ; Female ; Humans ; Lung Neoplasms ; blood ; complications ; radiotherapy ; Male ; Middle Aged ; Morbidity ; Radiation Pneumonitis ; epidemiology ; etiology ; Radiotherapy, Conformal ; adverse effects ; Risk Factors