Kyong Sik Lee

Expression of estrogen receptor-β in normal mammary and tumor tissues: Is it protective in breast carcinogenesis?

Using messenger RNA (mRNA) in situ hybridization, we investigated estrogen receptor-β (ERβ) mRNA levels in normal mammary, benign breast tumor (BBT), breast cancer (BC), and metastatic lymph node tissues to verify the role of ERβ in BC development and progression. ERβ expression was significantly decreased in BC and metastatic lymph node tissues compared with normal mammary and BBT tissues (p < 0.01). The intensity and extent of ERβ mRNA signals were also significantly lower in BC and metastatic lymph node tissues than in the normal mammary and BBT tissues (p < 0.01). An inverse relationship was found between ERβ mRNA level and both histologic grade (p = 0.091) and progesterone receptor expression (p = 0.052) with marginal significance, but no significant association was noted between ERβ expression in cancer tissues and the other clinico-pathologic data. The 3-year distant relapse-free survival probability was found to be independent of ERβ expression. Collectively, ERβ mRNA decreases in the process of BC development, but seems to be associated with poor differentiation.

Identification of novel deletion regions on chromosome arms 2q and 6p in breast carcinomas by amplotype analysis

DNA fingerprinting by arbitrarily primed PCR (AP‐PCR) was employed to identify molecular genetic alterations in 37 primary breast carcinomas. AP‐PCR is a PCR‐based technique that uses only one primer of arbitrary sequence that generates a molecular karyotype (amplotype) of tumors. The breast cancer amplotype generated with two arbitrary primers (MCG1 and Blue) showed a relatively high frequency (more than 20% of the tumors) of gains at chromosomes 1, 4, and 8, and of losses at chromosomes 2, 4, 6, 9, 10, 11, 13, and the X chromosome. We further analyzed the regions most commonly gained at chromosome 8 (47%) and lost at chromosomes 2 (38%) and 6 (49%) by determining the subchromosomal localization of the fingerprint bands from these chromosomes. The region of gain at chromosome 8 was mapped at 8q24.1, close to MYC. Band MCG1‐A1 was assigned to chromosome band 2q22, and band Blue‐J was assigned to 6p21. Common losses of these chromosomal regions have not been described for breast cancer. To map these deletion regions more precisely, we performed loss of heterozygosity (LOH) analysis by microallelotyping on 20 of the 37 cancers previously analyzed by AP‐PCR and another additional 52 breast carcinomas. The results suggest that the regions at 2q21–24 and 6p21–23 may harbor novel tumor suppressor genes for breast cancer. LOH at 2q21–24 (D2S2304) was more frequent in high‐grade tumors (59%) than in low‐grade tumors (29%) (P = 0.03). This suggests that this genetic alteration may be associated with tumor progression and shows the power of the amplotype approach in detecting novel genetic alterations that are useful as clinical parameters of breast cancer.

Sequential activation and production of matrix metalloproteinase-2 during breast cancer progression

The proteolytic processes are thought to be the critical point in tumor invasion and metastasis, mainly by matrix metalloproteinases (MMPs) and serine proteases. We measured the activity of MMP-2 from 28 normal, 12 benign and 126 breast cancer tissues using gelatin zymography. Inactive MMP-2 (72 kD) was expressed in 53.6% of the normal and 66.6% of the cancer tissues, respectively (P= 0.77), while active MMP-2 (62 kD) was expressed in 28.6% and 73.0%, respectively (P = 0.003). The enzymatic activity of active MMP-2 (62 kD) measured in the gel band area was 4.0 ± 7.2 mm2 in normal breasts, 7.7 ± 9.8 mm2 in benign breast diseases, 9.5 ± 8.5 mm2 in ductal carcinoma in situ (DCIS), and 12.0 ± 13.7 mm2 in invasive cancers. The MMP-2 activation ratio (62 kD/62 kD + 72 kD) was 0.12 ± 0.18 in normal tissues, 0.10 ± 0.20 in benign diseases, 0.61 ± 0.22 in DCIS, and 0.50 ± 0.28 in invasive cancers. In conclusion, MMP-2 activation was the main cause of the increased 62 kD MMP-2 activity during the early phase of breast cancer, while production of MMP-2 supplemented the increased 62 kD activity in the late phase. We suggest, therefore, that these differential expressions of MMP-2 activation and production during the different stages of breast cancer progression are potential therapeutic targets for biological or gene therapy under the concept of stage-oriented cancer treatment.[⇃]The proteolytic processes are thought to be the critical point in tumor invasion and metastasis, mainly by matrix metalloproteinases (MMPs) and serine proteases. We measured the activity of MMP-2 from 28 normal, 12 benign and 126 breast cancer tissues using gelatin zymography. Inactive MMP-2 (72 kD) was expressed in 53.6% of the normal and 66.6% of the cancer tissues, respectively (P= 0.77), while active MMP-2 (62 kD) was expressed in 28.6% and 73.0%, respectively (P = 0.003). The enzymatic activity of active MMP-2 (62 kD) measured in the gel band area was 4.0 ± 7.2 mm2 in normal breasts, 7.7 ± 9.8 mm2 in benign breast diseases, 9.5 ± 8.5 mm2 in ductal carcinoma in situ (DCIS), and 12.0 ± 13.7 mm2 in invasive cancers. The MMP-2 activation ratio (62 kD/62 kD + 72 kD) was 0.12 ± 0.18 in normal tissues, 0.10 ± 0.20 in benign diseases, 0.61 ± 0.22 in DCIS, and 0.50 ± 0.28 in invasive cancers. In conclusion, MMP-2 activation was the main cause of the increased 62 kD MMP-2 activity during the early phase of breast cancer, while production of MMP-2 supplemented the increased 62 kD activity in the late phase. We suggest, therefore, that these differential expressions of MMP-2 activation and production during the different stages of breast cancer progression are potential therapeutic targets for biological or gene therapy under the concept of stage-oriented cancer treatment.[⇃]

Sequential production and activation of matrix-metalloproteinase-9 (MMP-9) with breast cancer progression

The degradation of the basement membrane by matrix-metalloproteinase(MMP) and serine protease is a critical pointin tumor invasion and metastasis. We measured theactivity of MMP-9 from 28 normal, 12 benignand 126 breast cancer tissues using gelatin zymographywith an image analysis system. ProMMP-9 was expressedin 17.5% of the cancer patients compared to2.5% in 40 non-cancerous tissues (p=0.014).The mature form of MMP-9 (82 kD) wasexpressed only in T2–T4 stages. During the earlyphase of breast cancer (DCIS and T1 stage)progression, only production of proMMP-9 increased. However, asthe cancer grew or invaded skin (T2–T4), orwith lymphovascular permeation, both production and activation ofMMP-9 increased. In conclusion, proMMP-9 production was themain cause of increased MMP-9 activity during theearly phase, while both production and activation increasedin the late phase of breast cancer.

Clinicopathological Characteristics of Male Breast Cancer

Purpose To investigate clinicopathological characteristics and outcomes of male breast cancer (MBC). Patients and Methods We retrospectively analyzed the data of 20 MBC patients in comparison with female ductal carcinoma treated at Yonsei University Severance Hospital from July 1985 to May 2007. Clinicopathological features, treatment patterns, and survival were investigated. Results MBC consists of 0.38% of all breast cancers. The median age was 56 years. The median symptom duration was 10 months. The median tumor size was 1.7 cm, 27.8% showed node metastasis, and 71.4% were estrogen receptor positive. All 20 cancers were arisen from ductal cells. No lobular carcinoma was found. The incidence of stages 0, I, II, and III in patients were 2, 10, 4, and 3, respectively. All patients underwent mastectomy. One with invasive cancer did not receive axillary node dissection and stage was not exactly evaluated. Adjuvant treatments were determined by pathologic parameters and stage. Clinicopathological parameters and survival rates of MBC were comparable to those of female ductal carcinoma. Conclusion The onset age of MBC was 10 years older and symptom duration was longer than in female patients. No difference in outcomes between MBC and female ductal carcinoma suggests that the biology of MBC is not different from that of females. Therefore, education, an appropriate system for early detection, and adequate treatment are necessary for improving outcomes.

Overexpression of c-ErbB-2 Protein in Gastric Cancer by Immunohistochemical Stain

An immunohistochemical stain to the c-ErbB-2 protein was performed in 225 paraffin-embedded tissue blocks from patients with locally advanced gastric cancer who underwent curative resection. The overexpression of the c-ErbB-2 protein was observed in 27.4% of the patients. The c-ErbB-2 positivity showed a statistically significant correlation with nodal status and stage. The patients with an overexpression of the c-ErbB-2 protein had a tendency to a shorter survival than those without, but it was not statistically significant (p = 0.08). The 5-year survival rate after surgery was 54% in the negative staining group to the c-ErbB-2 protein and 49% in the positive staining group. This suggests that the c-ErbB-2 protein has a possible role in lymph node metastasis. Therefore overexpression of the c-ErbB-2 protein is a useful indicator of disease progression in gastric carcinoma patients who received curative surgery.

Nodular hepatocellular carcinoma. Treatment with subsegmental intraarterial injection of iodine 131‐labeled iodized oil

Internal radiation therapy with subsegmental arterial injection of iodine 131(131I)‐labeled iodized oil (Lipiodol; Laboratorie, Guerbet, France) was evaluated in 24 patients with nodular hepatocellular carcinoma (HCC) ranging from 2.5 to 8.0 cm in size. 131I Lipiodol (555 to 2220 MBq in 3 to 8 ml) was injected depending on the tumor size. Tumor reduction was seen in 88.9% of tumors smaller than 4.0 cm in diameter, 65.5% of tumors between 4.1 to 6.0 cm, and 25.0% of tumors larger than 5.1 cm. The tumor size reduction corresponded to the gradual drop of serum alphafetoprotein (AFP) levels and devascularization on follow‐up angiography. Adverse reactions from treatment included fever, mild abdominal pain, nausea, and elevation of transaminases. These were mild and well tolerated by patients. This method provided long‐term local control without complications related to the thyroid, lung, gastrointestinal tract, and bone marrow.

Overexpression of cyclooxygenase-2 is associated with breast carcinoma and its poor prognostic factors

Cyclooxygenase is the rate-limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. The inducible form, cyclooxygenase-2, is known to be overexpressed in various human cancers including the colon, stomach, and urinary bladder. In this study, we evaluated the overexpression of cyclooxygenase-2 in 64 cases of breast cancer and correlated the results with clinicopathologic parameters. Immunohistochemical staining for cyclooxygenase-2 demonstrated positivity of the tumor cells in 46 of 64 cases (72%). Cyclooxygenase-2 overexpression was significantly correlated with larger tumor size and advanced clinical stage. Cyclooxygenase-2 overexpression tended to be more frequently observed in cases with presence of lymph node metastasis and in cases without expression of estrogen and progesterone; however, there was no significant correlation statistically. Nuclear and histologic grade were not well correlated with cyclooxygenase-2 overexpression. When ductal carcinoma in situ was considered separately, 32 of 42 cases (76%) were positive for cyclooxygenase-2. We conclude that cyclooxygenase-2 is up-regulated in a high proportion of breast cancers. The overexpression of cyclooxygenase-2 was associated with larger tumor size and advanced clinical stage, although lymph node status, estrogen and progesterone expression, and nuclear and histologic grade were not significantly correlated. Therefore, cyclooxygenase-2 overexpression may be a feature of the aggressive phenotype and may be useful as a prognostic indicator in breast cancer.

Gastric cancer in young patients who underwent curative resection: Comparative study with older patients

Although several studies demonstrated the poor prognosis of young patients with gastric cancer, there were few reports about the survival of young patients who underwent radical surgery. We retrospectively reviewed the hospital records of 697 patients with curatively resected locally advanced gastric cancer to compare the pathologic findings and prognosis of young patients (aged < 40 years; 91 patients) with those of older (aged > or = 40 years; 606 patients) patients. There were no significant differences in location of tumors, Borrmann types, tumor invasion, and pathologic stage between both age groups. Despite the male predominance in older patients, the male-to-female ratio was nearly equal in young patients (p = 0.022). A significantly higher percentage of young patients showed poorly differentiated histology including signet ring cell and undifferentiated carcinoma than older patients (p < 0.0001). Adjuvant chemotherapy was more frequently performed in the young patients with a variety of different regimens (85.7 vs. 72.3%; p = 0.009). The 5-year overall survival rate revealed no statistically significant differences between the young and older patients (53.1 vs. 56.6%; p = 0.820). In conclusion, the young patients with curatively resected locally advanced gastric cancer showed similar survival compared to that of older patients.

The Impact of a Focally Positive Resection Margin on the Local Control in Patients Treated with Breast-conserving Therapy

OBJECTIVE The aim of the study was to investigate the parameters affecting positive margin and the impact of positive margin on outcomes after breast-conserving therapy in patients with breast cancer. METHODS Characteristics and survival of 705 patients attempted breast-conserving therapy between January 1994 and December 2004 were retrospectively analyzed using χ(2) tests, the Kaplan-Meier methods and multivariate analyses. RESULTS Ninety-five (13.5%) showed positive margins at initial resection. Among them, 28 (4.0%) had negative margin on the initial frozen section; however, they finally turned out a focally positive margin with intraductal carcinoma on the permanent pathology. Positive margin at initial resection was significantly associated with lobular histology (P = 0.001), four or more involved lymph nodes (P = 0.015) and the presence of extensive intraductal component (P < 0.001). A focally positive margin did not influence local (P = 0.250; 95% confidence interval, 0.612-6.592) or regional failure (P = 0.756; 95% confidence interval, 0.297-5.311). Patients with a focally positive margin showed an advanced nodal stage and received a higher dose of irradiation and more systemic therapy. Nodal involvements were the most significant factor for locoregional failure. CONCLUSIONS Although the achievement of negative margins is the best way to reduce local failure, patients with a focally positive margin and favorable risk factors such as node negativity and older age could have an option of close follow-up with adequate boost irradiation and adjuvant therapy instead of conversion to total mastectomy.