Chronological Changes of Gastric Cancer in Community Hospital

PURPOSE: Gastric cancer remains the most common type of cancer in Korea, however, early diagnosis and surgical advancements have resulted in a better prognosis in the last few decades. The aim of this study was to investigate chronological changes of the clinicopathological features in patients with primary gastric cancer who had undergone gastric operations in Department of Surgery of Seoul Municipal Boramae Hospital. METHOD: Between November 1991 and April 2001, 634 primary gastric adenocarcinoma patients having undergone gastric operations were included in this study and divided into the two groups: 298 patients between 1991 and 1996 (early group) and 336 patients thereafter (late group). The clinicopathological characteristics, including age, gender, type of operation, gross and histologial findings, stage, and ratio of early gastric cancer, were compared between the two groups. RESULTS: The overall male-to-female ratio was 2: 1, with a mean age of 59.0 years. As the community hospital, eighty two percents of patients were resident within the same administrative district. There were no statistical differences in age, gender, type of operation, and total number of resected lymph nodes between the two groups. In contrast, cancers with a larger size, the distal one third of the location, well-differentiated adenocarcinoma, low depth of invasion, and high nodal metastasis were more prevalent in the late group (P < 0.05). Also, the proportion of earlier stages was increased in the late period (P<0.001). The ratios of early gastric cancers were 24.8, and 38.4% in the early and late groups, respectively (P<0.001) CONCLUSION: Our results suggest that the chronological changes of gastric cancer were closely related to the increased number of early gastric cancer patients, primarily due to the early detection of cancer. Therefore, to obtain the better outcomes from gastric cancer, an early diagnosis was essential from routine health check-ups and the well- organized establishment of a nation- and community-wide screening program and information on public health.

Outcome of Potentially Curative Gastrectomy in Patients with Stage IV Stomach Cancer: Based on the 5th Edition of AJCC/UICC Classification (1997)

PURPOSE: The prognosis after potentially curative resection for stage IV gastric cancer, according to the 5th edition of AJCC/UICC classification, is poorly understood. The aim of this study was to evaluate the feasibility of the curative resection in patients with stage IV gastric cancer, which were considered potentially curable cases. METHODS: From November 1991 to June 1996, 91 patients were confirmed as having stage IV gastric cancer at Seoul Boramae Municipal Hospital. Of these 91 patients, 30 who were potentially curative resected including at least D2 type lymph node dissections were reviewed retrospectively. The average numbers of totally dissected and positive lymph nodes were 43.0 (range: 26~74) and 23.1 (range: 2~47), respectively. RESULTS: The overall 1-, 2-, and 5-year survival rates of patients were 60.0%, 36.7%, 13.3%, respectively. In comparison with stage IIIb (N=20), no significant difference in survival rate was observed (P=0.1178). In univariate analysis, we found that the presence of a recurrence (P=0.0121) and a P (positive lymph nodes)/R (total dissected lymph nodes) >0.6 were correlated with poor survival rates. Long- survivors (N=12, more than 24 months postoperatively) had a tendency to be younger, less recurrent (P=0.017) and less involvement of histological perineural invasion (P=0.028). CONCLUSION: The results of the present study indicate that stage IV patients without distant metastasis may indeed be cured by potentially curative surgery.

A Porcine Model for Non-heart Beating Donor Liver Transplantation / 대한이식학회지

PURPOSE: Non-heart-beating liver transplantation has been accepted as a substitute to overcome the donor shortage problem. However, prolonged warm ischemia during liver procurement remains a obstacle to widespread use of non- heart-beating transplantation. Therefore, experimental studies to ameliorate graft injuries have been conducted, but, their clinical applications are not satisfactory yet. The aim of this study is to test our experimental model as a pertinent non- heart-beating transplantation model. METHODS: We designed porcine non-heart-beating liver transplantation model by simultaneous liver procurement of donor and recipient. Cardiac death was induced by direct cardiac injection of potassium chloride. Perfusion of normothermic hypertonic saline started after 30-min (group A, N=5), 1-hour (group B, N=4). Orthotopic liver transplantation with perfused donor liver was performed and we compared the perioperative laboratory parameter, histologic findings and survival between two groups. RESULTS: Only one (11.1%) death occurred among the nine transplant pigs. 2-day survival rates of group A and B were 60%, 50%, respectively. Group A showed a relatively acceptable posttransplant laboratory findings including liver function test and normal-looking histologic feature at the time of reperfusion and 24 hours after reperfusion. Group B showed more deranged liver function test and ischemic liver cell morphology at 24 hours after reperfusion. CONCLUSION: Our results suggest that this porcine non-heart-beating transplantation model may be the safe and suitable method. This model will be useful in further study for testing the perfusate and drugs to ameliorate the warm ischemia-induced hepatic injury.

A therapeutic Guideline of Gallbladder Polyps in Laparoscopic Era / 한국간담췌외과학회지

BACKGROUND/AIMS: The nature of gallbladder polyp is obscure before operation, and surgical indication is still controversial. The aim of this study is to suggest the therapeutic guideline for patients with the gallbladder polyps in the laparoscopic era. METHODS: Among 49 patients who received cholecystectomy because of gallbladder polyp from January 1, 1992 to December 31, 2000 in Department of Surgery, Seoul Municipal Boramae Hospital, we studied 42 histopathologically confirmed gallbladder polyp patients retrospectively. These patients were divided into two groups as true polyp(adenoma, carcinoma) and pseudopolyp(cholesterol, inflammatory, hyperplastic), and clinical characteristics were compared between the groups. RESULTS: The mean age was 48.19+/-11.09 years and male to female ratio was 17:25 in all patients. Of 42 patients, 32 pseudopolyps(76.2%) and 10 true polyps(23.8%) were confirmed by pathologic examination. Of 32 pseudopolyps, cholesterol polyps(29cases, 90.6%) were most common type. 4 carcinomas and 6 adenomas were included in 10 true polyps. Of 6 adenomas, coexistence with dysplasia was present in two cases. 1 case of carcinoma was present as arising from underlying tubular adenoma. Compared with pseudopolyp, true polyp showed significant larger size in diameter than psedopolyp(p=0.014). Despite of these statistical difference, 44% of pseudopolyps was more than 10mm in maximum diameter. 2 cases of true polyp(20%) was less than 10mm. However all of the other clinical features such as, the patients's age, sex, symptom, presence of gallstones, and number of polypoid lesion were not significantly different between the groups. All 4 carcinoma patients received laparoscopic cholecystectomy are disease free state with mean 68.5 months follow-up period. CONCLUSION: Although true polyps showed statistically significant larger than pseudopolyps in maximum diameter, there was no clear cut point dividing the two groups. All of the other clinical characteristics could not differentiated true polyps from pseudopolyps. Because of the low morbidity of laparoscopic procedure, premalignant potential of gallbladder adenoma and the adenoma-carcinoma sequence are unquestionable, an aggressive surgical intervention should be proposed in the era of laparoscopic surgery.

An experimental model of ischemia in rabbit hindlimb

This study was performed to establish an experimental model of ischemia for the investigation of new treatment modality of limb-threatening ischemia. We produced ischemia in the hindlimbs of 8 New Zealand white rabbits. Under general anesthesia, the left femoral artery was exposed, freed, and excised from distal external iliac artery to proximal popliteal and saphenous arteries. And then both hindlimbs were serially examined to assess the ischemia according to the time table until postoperative 6 weeks. We assessed clinical observation, blood pressure, radioisotopic perfusion scan, and angiography. Clinical ischemic changes of the operated feet were observed in 63%. The blood pressure of left calves was measurable on postoperative day 3 (p<0.05, vs preoperative day 2) and then gradually increased to reach a plateau in postoperative week 6. Radioisotopic arterial perfusion showed similar profiles as in blood pressure. Angiography of ischemic hindlimbs demonstrated a few collateral vessels arising from the internal iliac artery with the reconstitution of the posterior tibial artery in postoperative week 2. In postoperative week 6, collaterals remained the same in number. However, these became dilated and tortuous and showed reconstitution in distal hindleg. In conclusion, this is a reproducible, measurable, and economical animal model of hind limb ischemia.

A Guideline on the Removal Time of the Nasogastric Tube Following Gastrectomy

PURPOSE: There is no standard principle as to the nasogastric tube decompression period following gastrectomy. This prospective randomized study was done in an attempt to define the affect of the nasogastric tube decompression period on the postoperative course with a special reference to early postoperative complications, gas passing time, and the length of hospital stay after gastrectomy. METHODS: We reviewed 201 patients among 402 cases who had received gastrectomy because of gastric cancer. The patients were classified as those whose tubes were removed within 48 hours postoperatively, and those whose tubes remained for more than 48 hours (early group: n=70, late group: n=131). RESULTS: No significant differences were noted in regards to complication rate, or hospital stay. However, a significant decrease in the time to first gas passing was noted in the early removal group compared to late group (4.13+/-1.33 day vs. 4.39+/-1.50 day, P=0.040). CONCLUSION: These results indicate that the early removal of the nasogastric tube following gastrectomy is safely recommended in order to reduce patient discomfort.

The Diagnostic Accuracies of Fine Needle Aspiration Biopsy, Mammography and Ultrasonography in Palpable Breast Mass

BACKGROUND: Although an increasing number of breast abnormalities are detected by screening mammography, most breast cancers are presented as a palpable mass. Cytologic specimens are frequently diagnostic and may be easier to obtain. This study was done to compare the diagnostic accuracies of clinical breast exam, fine needle aspiration biopsy (FNAB), mammography and ultrasonography, and to establish the algorithm to manage the patients based on the results of FNAB. METHODS: From Jan. 1992 to Dec. 1997, one hundred and twenty-seven women out of 470 patients with a clinically palpable mass underwent concurrent FNAB, mammography, and ultrasonography. All patients ultimately had histologic confirmation by surgical biopsy. RESULTS: The sensitivity and the specificity of the tests were as follows: 79.2% and 74.4%, respectively, for clinical breast exam; 62.2% and 98.6%, for mammography; 55.8% and 93.3% for ultrasonography; and 66.7% and 100% for FNAB. Of note, the accuracy of the FNAB was significantly higher for lesions 2 cm or larger than for lesions smaller than 2 cm (p=0.034). All patients who were positive for malignancy on FNAB (n=20) presented with breast cancer. Among the 16 patients with suspicious results on FNAB and breast cancer on surgical biopsy, 3 had normal findings on mammography and ultrasonography. In the cases of negative findings for malignancy in three tests (n=55), no breast cancer was found on the final surgical specimen. CONCLUSION: It is recommended that FNAB must be performed on all palpable masses and that when the FNAB is postive for cancer, definitive surgery be performed with intraoperative frozen biopsy. Patients in whom mammography, ultrasonography and FNAB were negative for malignancy can be observed without the need for an open biopsy. Additionally, (1) when the results of FNAB are suspicious or (2) when the mammagraphy and ultrasonography results are suspicious even though the FNAB results are negative for malignancy, an open biopsy is required to exclude the possibility of the breast cancer.

The Result of Surgical Treatment of Complicated Peptic Ulcers: Analysis of Factors Affecting the Morbidity Rate

BACKGROUNDS: The aim of this retrospective study was to compare patients treated for complicated peptic ulcers with special reference to the morbidity and the mortality rates and its determining factors according to the type of surgery. METHODS: From Jan. 1988 to May 1996, a total of 168 patients with complicated peptic ulcers underwent surgical treatment. Among them, 39 patients were lost during the follow up period and 10 cases were operated on due to pyloric obstruction, so we analyzed 119 cases according to the type of surgery (definitive or minimal). Definitive surgery means acid-decreasing procedures such as a gastrectomy or a truncal vagotomy with drainage procedure. Minimal surgery means life-saving procedures such as primary closure or bleeding vessel ligation. The type of operation was determined according to the preference of the individual consultant surgeons at our institute. RESULTS: There were 70 definitive and 49 minimal operations (6:4). The mean follow-up period was 20.6 months (range: 11-73 months). The risk factors affecting the morbidity and the mortality were comparable for both groups. In spite of little statistical significance, the results of definitive surgery were superior to those of minimal surgery in morbidity (15.7%:20.4%), mortality (0%:6.1%), recurrence (5.5%:12.2%), and Visick grading scale 1 & 2 (92.8%:81.6%). The determining factor affecting morbidity was the presence of combined disease (p=0.001) only; other factors such as age, anemia, leukocytosis, presence of preoperative shock, transfusion amount, and type of operation did not affect the morbidity rate. CONCLUSION: Considering that there were no differences in postoperative morbidity and mortality between definitive and minimal surgery, it is better to perform definitive surgery on patients who have no serious combined disease.

A Case-Control Study of the Association between Glutathione S-transferase (GST) M1 and T1 Genetic Polymorphism and Breast Cancer in Korean Women: Preliminary report / 대한암학회지

PURPOSE: A hospital-based case-control study was conducted to evaluate the role of glutathione-S-transferase (GST) Ml and Tl genetic polymorphism for developing breast cancer in Korea. MATERIALS AND METHODS: Histologically confirmed incident cases of breast cancer (n=176) were selected from inpatients at the Department of General Surgery, Seoul National University Hospital (SNUH), Borame hospital, and Asan Medical Center from 1994 to 1998. Women with no self-reporting past history of any malignancies who were selected from the inpatients at the same department at three hospitals during the same period served as controls (n 118). Information on the life-styles including reproductive factors were obtained by interview using questionnaire. Age and education adjusted odds ratio and 95% confidence interval were estimated by unconditional linear logistic regression. RESULTS: These subjects had similar risk factors for developing breast cancer to general Korean population based on other epidetniologic studies previously performed in Korea. GSTI1 null type showed a borderline significance relation in the breast cancer risk (adjusted OR=1.6, 95% CI=0.96-2.62), however, GSTM1 null type was not significant (adjusted OR=1.1, 95% CI=0.67-1.80). Particularly noteworthy was an borderline increasing tendency (p<0.1) of the breast cancer risk with the risk null genotypes assessed by multivariate logistic regression model after adjusting age and education: the putative low-risk genotype with both GSTM1 & GSTT1 wild type, OR=1.0; one putative high risk genotype with GSTM1 null or GSTMl null type, OR=1.9 (95% CI=0.92-3.74); all two putative high risk genotype with both GSTM1 & GSTT1 null type, OR=2.0 (95% CI=0.89-4.68). CONCLUSIONS: These findings suggest that both GSTMl and GSTT1 null type might be the risk factor of developing breast cancer in Korean women. Further investigation with larger sample size should be needed to provide more concrete information on the role of GST genetic polymorphism in breast cancer.

Complications of Dual Lumen Catheter for Hemodialysis Patients

INTRODUCTION: Central venous catheterization by dual lumen catheter (DLC, Perm Cath ) is used for temporary or permanent vascular access. Although it has many advantages such as rapid insertion, emergent usage or long-term maintenance, there are still clinically important complications associated with insertion procedure and maintaining period. PURPOSE: To define and manage the various kinds of complications is important to avoid repetition of them and to guide for selection of vascular access in long-term hemodialysis patients. MATERIALS AND METHODS: Between May 1993 and April 1996, we experienced 95 cases of DLC in 88 uremic patients for the following reasons: 12 cases in 12 patients for ARF and 83 cases in 76 patients for ESRD. We used external or internal jugular veins and the method of insertion was percutaneous venipuncture in internal jugular vein (88 cases, Rt.=84, Lt.=4) and venotomy in external jugular vein (7 cases Rt=7). The complications and their therapeutic options were analyzed retrospectively. RESULTS: Group I complication is associated with insertion procedure, including cardiac arrhythmia (n=65, 68.4%), minor air embolism (n=3, 3.2%), hematoma on puncture site (n=15, 15.8%) and difficult catheterization on multipunctured patients (n=3, 3.2%). Group II complication is associated with long term maintanence use of catheters(mean period=8.3 mos) and includes catheter thrombosis (n=15, 15.8%), inadvertent cuff exposure (n=10, 10.5%) and bacteremia (n=16, 16.6%). The management of complications were as followings. Cardiac arrhythmia occurred during guidewire insertion was completely resolved with wire retraction and clinically detected minor air embolism was recovered spontaneously in all cases. Hematoma on puncture site was controlled by compression in 13 cases and 2 cases were resolved after catheter removal. All of the difficult catheterization was solved with fluoroscopic guide insertion. Most of catheter thrombosis were controlled with urokinase infusion (n=13), but in 2 cases, catheter removal was required. All cases of inadvertent cuff exposure led to ascending infection, among them 6 cases were controlled with catheter removal and the rest of them was controlled with aseptic dressing and antibiotics. Five out of 16 cases (5.3%) with bacteremia were not controlled with antibiotics and resulted in catheter removal. CONCLUSION: To avoid unfavorable complications such as uncontrolled hematoma or bacteremia, fluoroscopic guide insertion and aseptic handling of exit site is important. And it should be remembered that location of cuff should be far from the exit site (> 2 cm) to avoid inadvertent traction.

Cigarette Smoking, Alcohol Consumption, and Breast Cancer in Korea / 한국역학회지

A hospital-based case-control study was conducted to assess the relationship between cigarette smoking, alcohol consumption, and the risk of bgreast cancer in Korea. Histologically confirmed incident cases of breast cancer(n=146) were selected from the inpatients at the Department of Surgery, Seoul National University Hospital and Borame Hospital during 1994 to 1997. Women ithout self-reported past history of any malignandies were regarded as controls and selected at the same hospitals during the same period(n-153). Information on life-styles including cigarette smoking, alcohol drinking, and reproductive history were obtained by direct interview using standardixed questionnaire. Each case was matched with one control by 5-year age category(n=146). Adjusted odds ratios and 90% confidence intervals were estimated by unconditional linear logistic regression model. For smokers, age at first smoking was significantly associated with the breat cancer risk(adjusted OR=14.1, 90% CI=1.24-364.2). Particularly noteworthy was an increasing tendency of the breast cancer risk with the duration of alcohol consumtion in years aong alcohol drinkers(ptrend<0.1). These findings suggest that cigarette smoking at an earlier age and alcohol intake might contribute to the risk factor of breast cancer in Korean women. Further investigation on the association between genetic polymorphism of xenobiotic metabolism enxymes of environmental carcinogens and breast cancer should be needed.

High Risk Group for Female Breast Cancer in Korea / 대한암학회지

PURPOSE: A hospital-based case-control study was conducted to find out risk factors for developing breast cancer in Korea. MATERIALS AND METHODS: Histologically confirmed incident cases of breast cancer(n=280) were selected from inpatients at the Department of General Surgery, Seoul National University Hospital during 1994 to 1997. Women with free of self-reporting past history of any malignancies were regarded as controls who were selected from the inpatients at the Department of Obstetrics and Gynecology of the same hospital during 1992 to 1994(n=930). Information on life-styles including reproductive factors were obtained by direct interview using questionnaire. Age- and education-adjusted odds ratio and 95% confidence interval were estimated by unconditional linear logistic regression. RESULTS: Based on the risk factors identified by both this study and other epidemiologic studies previously performed in Korea, high risk group for female breast cancer in Korea was established as follows. (1) women with age over 50, (2) women who have a family history of breast cancer, (3) women with age at menarche before 14-year old, (4) women with age at menopause after 50-year old, (5) women who were not experienced a full term pregnancy, (5) nulliparous women (6) women with age at her first fullterm pregnancy after 35-year old (7) women who were not experienced breast feeding, (8) women with body mass index more than 25 kg/m2 or with body weight more than 64 kg. CONCLUSION: Life-time risk of breast cancer, as an indicator of absolute risk, according to the risk factors should be pursued in further prospective studies with community population.

A Clinical Analysis of Stage IV Gastric Cancer

From 1988 to 1994, 62 of 262 patients admitted to the Boramae City Hospital with gastric cancer were diagnosed as stage IV. Among them, 5 patients were lost during follow-up, so we analyzed 57 patients retrospectively. This study elucidates whether a palliative resection offered any survival advantage compared to non-resectional treatment. Of the 57 patients, 7 (12%) received a non-curative resection, 36 (63%) a bypass procedure, and 14 (25%) an exploratory laparotomy. There were no operative mortalities and morbidity. Univariate survival analysis demonstrated that the median survival and the 1- and the 2-year survival rates were significantly higher in the resected patients. The median survival and the 1- and the 2-year survival rates were 15 months, 71%, and 57% with a non-curative resection, 7.3 months, 25%, and 8% with bypass procedure, and 6.3 months 33%, and 17% with an exploratory laparotomy. To perform the analysis within relatively homogeneous groups, patients with different operations were further stratified into two groups according to the spread of disease: local (T4) and distant (M1) spread. The median survival of the T4 group was 11.4 months whereas that of the M1 group was 6 months. Although there was no statistical significance in this study, it is noteworthy that, compared to a bypass procedure and a exploratory laparotomy, a non-curative resection seems to have a survival benefit in the M1 group (median survival: 528 days vs 131 days and 182 days, p=0.0926). In conclusion, although this study has the limitations of a retrospective study and a univariate analysis performed without consideration of basic patient characteristics (age, weight loss, nutritional status, etc.), palliative resection seems to be justified in patients with stage IV gastric cancer if it is performed with acceptably low mortality and morbidity.

Clinical Significance of Several Hepatic Function Tests in Hepatectomized Patients / 한국간담췌외과학회지

BACKGROUND/AIMS: To reduce the rate of recurrence and to prevent postoperative liver failure, it is necessary to determine the extent of hepatic resection preoperatively in primary liver cancer patients. The aim of this study was to examine the clinical significance and correlation among several preoperative liver function tests. METHODS: Twenty-nine patients who underwent hepatic resection for hepatocellular carcinoma from November 1994 to March 1995 at the Department of Surgery, Seoul National University Hospital were analyzed. Fifteen patients had gross cirrhosis. Major resections were performed in two patients, segmentectomy in 6 patients, subsegmentectomy and limited resection in 21 patients. Maximal removal rate of indocyanine green (ICG Rmax), ICG retention rate at 15 min(ICG R15), oral glucose tolerance test(oral GTT), arterial ketone body ratio(AKBR) and computed tomographic volumetry, as well as conventional liver function test and prothrombin time were done preoperatively. RESULTS: There were significant correlations among Child's class, prothrombin time and ICG R15. AKBR, oral GTT, ICG Rmax, liver volume had no correlations with any other tests. Liver failure occurred in 2 patients(6.9%). No tests, except ICG R15, could predict the patients with liver failure. ICG R15 value of these two patients were 27% and 29%, respectively while those of the remaining 27 patients ranged from 1 to 22% (mean 11.9%). CONCLUSION: Neither standard liver function tests nor hepatic function studies such as AKBR, oral GTT, CT volumetry were useful as preoperative prognostic indicators in hepatic resection. ICG R15 test is a simple test and good predictor of liver failure after hepatic resection.

Menstrual and reproductive factors related to the risk of breast cancer in Korea: Ovarian hormone effect on breast cancer

To support the ovarian hormone hypothesis in the etiology of breast cancer, a hospital-based case-control study with community controls was conducted to evaluate the relationship of intervals among menstrual and reproductive events to the risk of breast cancer in Korea. The cases were 190 breast cancer patients, who had been histologically diagnosed at Seoul National University Hospital from Jan. 1, 1993 to Jun. 30, 1994. Included were cancer-free women, who had undertaken the Gynecological examination at the same hospital (n=190). Women recruited for a survey of diabetes prevalence in Yonchon County, adjacent to Seoul City, were taken as a community control group (n=190). Information on menstrual and reproductive factors with other life-styles was collected through a direct interview by the well-trained interviewers. The adjusted odds ratios and the 95% confidence intervals were based on the unconditional logistic regression model. Likelihood ratio test for trend was applied for the ordinal variables. Early age at menarche, late age at natural menopause, late age at first full term pregnancy, and fewer number of full term pregnancies are independently associated with the high risk of breast cancer in Korea. Moreover, the interval between the age at menarche and the age at natural menopause of community controls (29.9+/-6.15 years) was significantly shortened compared to breast cancer cases (34.9+/-4.42 years). Particularly noteworthy was that intervals between the age at menarche and the age at first full term pregnancy of both control groups (9.0+/-3.72 years for hospital controls; 7.2+/-4.04 years for community controls) were significantly shortened compared to breast cancer cases (11.0+/-4.51 years). These findings support the hypothesis that the longer exposure to ovarian hormones during the reproductive years, the higher the risk of breast cancer.

Menstrual and reproductive factors related to the risk of breast cancer in Korea: Ovarian hormone effect on breast cancer

To support the ovarian hormone hypothesis in the etiology of breast cancer, a hospital-based case-control study with community controls was conducted to evaluate the relationship of intervals among menstrual and reproductive events to the risk of breast cancer in Korea. The cases were 190 breast cancer patients, who had been histologically diagnosed at Seoul National University Hospital from Jan. 1, 1993 to Jun. 30, 1994. Included were cancer-free women, who had undertaken the Gynecological examination at the same hospital (n=190). Women recruited for a survey of diabetes prevalence in Yonchon County, adjacent to Seoul City, were taken as a community control group (n=190). Information on menstrual and reproductive factors with other life-styles was collected through a direct interview by the well-trained interviewers. The adjusted odds ratios and the 95% confidence intervals were based on the unconditional logistic regression model. Likelihood ratio test for trend was applied for the ordinal variables. Early age at menarche, late age at natural menopause, late age at first full term pregnancy, and fewer number of full term pregnancies are independently associated with the high risk of breast cancer in Korea. Moreover, the interval between the age at menarche and the age at natural menopause of community controls (29.9+/-6.15 years) was significantly shortened compared to breast cancer cases (34.9+/-4.42 years). Particularly noteworthy was that intervals between the age at menarche and the age at first full term pregnancy of both control groups (9.0+/-3.72 years for hospital controls; 7.2+/-4.04 years for community controls) were significantly shortened compared to breast cancer cases (11.0+/-4.51 years). These findings support the hypothesis that the longer exposure to ovarian hormones during the reproductive years, the higher the risk of breast cancer.