Telomerase Activity in Human Breast Tumors

BACKGROUND: Telomerase is a ribonucleoprotein enzyme that synthesizes telomeric DNA onto the ends of chromosomes, thereby preventing the replication-dependent shortening of those ends. Telomerase activity is detected in a wide range of cancers of various tissues, and its expression may be a critical step in tumor progression. Our objective was to determine if detection of telomerase activity may be an indicator for diagnosis of breast cancer and if any association exists between telomerase activity and prognostic factors of breast cancer. METHODS: Using a polymerase chain reaction-based telomerase activity assay, we examined telomerase activity in 30 breast cancer specimens (2 ductal carcinoma in situ, 28 invasive ductal carcinoma), 25 benign lesions (14 fibroadenomas, 11 fibrocystic diseases), and 24 normal breast tissues (13 adjacent to malignancy, 11 adjacent to benign lesion). RESULTS: Among surgically resected samples, telomerase activity was detected in 23 (77%) of 30 breast cancers. While telomerase activity was not detected in any of the 11 specimens of fibrocystic disease and the 11 normal tissues adjacent to benign lesion, surprisingly low levels of telomerase activity were detected in 5 (36%) of the 14 fibroadenomas and 1 (7%) of the 13 normal tissues adjacent to malignancy. There was no significant difference in expression of telomerase among prognostic factors of breast cancer. CONCLUSIONS: In summary, telomerase activity may be useful in the diagnosis of breast cancer. We found no correlation between telomerase activity and stage, tumor size, or LN status. Mechanisms of telomerase expression are still under investigation; therefore, the significance of telomerase expression in malignant tumors and their progression remains to be determined.

Telomerase Activity in Human Breast Tumors / 한국유방암학회지

Telomerase is a ribonucleoprotein enzyme that synthesizes telomeric DNA onto the ends of chromosomes. thereby preventing the replication-dependent shortening of these ends. Telomerase activity is detected in a wide range of cancers of various tissues, and its expression may be a critical step in tumor progression. Our objective was to determine if detection of telomerase activity may be an indicator for diagnosis of breast cancer and any association between telomerase activity and prognostic factors of breast cancer. Using a polymerase chain reaction-based telomerase activity assay, we examined telomerase activity in 30 breast cancer specimens (2 ductal carcinoma in situ, 28 invasive ductal carcinoma), 25 benign lesions (14 fibroadenomas, 11 fibrocystic diseases) and 24 normal breast tissues (13 adjacent to malignancy, 11 adjacent to benign lesion). Among surgically resected samples, telomerase activity was detected in 23 (77%) of 30 breast cancers. While telomerase activity was not detected in any of 11 specimens of fibrocystic disease and 11 adjacent normal tissues to benign lesion, surprisingly low levels of telomerase activity were detected in 5 (36%) of 14 fiboadenomas and 1 (7%) of 13 adjacent normal tissues to malignancy. There was no significant difference in expression of telomerase among prognostic factors of breast cancer. In summary, telomerase activity in breast cancer may be useful in diagnosis of breast cancer. We found no correlation between telomerase activity and stage, tumor size or LN status. Mechanisms of telomerase expression are still under investigation; therefore, the significance of telomerase expression in malignant tumors and their progression remains to be determined.

Needle Localization Biopsy of 546 Nonpalpable Breast Lesions

A retrospective review of 546 consecutive female patients who had undergone mammographically controlled needle localizations was performed to assess the effectiveness of the technique and to analyze the number and the characteristics of the criteria malignancies found in this group. Localization biopsy was recommended if one or more of the following criteria were present: evidence of a mass, microcalcifications, parenchymal distortion, and/or spiculation. Of those 546 patients who had undergone specimen mammography after needle localization biopsy, a lesion was detected on 544 cases and missed in 2 cases(0.3%). Fifty-five cancers were detected(10.1%) Histologically, the cancers included 23 invasive and 32 in-situ tumors. The predominant histologic cell type was ductal in origin with only three having lobular characteristics. Postoperative pathologic findings of the lymph nodes showed 3 of the 55 were positive for metastases. In summary, the technique of preoperative needle localization in this series had a 99.7% success rate. The cancer detection rates for a 'mass with a microcalcification', a 'microcalcification', and a 'mass' were 17.0, 14.0, and 5.1% respectively. As a conclusion, needle localization biopsy is a safe and effective method for definitely diagnosing nonpalpable breast lesions.

Needle Localization Biopsy of 546 Nonpalpable Breast Lesions

A retrospective review of 546 consecutive female patients who had undergone mammographically controlled needle localizations was performed to assess the effectiveness of the technique and to analyze the number and the characteristics of the criteria malignancies found in this group. Localization biopsy was recommended if one or more of the following criteria were present: evidence of a mass, microcalcifications, parenchymal distortion, and/or spiculation. Of those 546 patients who had undergone specimen mammography after needle localization biopsy, a lesion was detected on 544 cases and missed in 2 cases(0.3%). Fifty-five cancers were detected(10.1%) Histologically, the cancers included 23 invasive and 32 in-situ tumors. The predominant histologic cell type was ductal in origin with only three having lobular characteristics. Postoperative pathologic findings of the lymph nodes showed 3 of the 55 were positive for metastases. In summary, the technique of preoperative needle localization in this series had a 99.7% success rate. The cancer detection rates for a 'mass with a microcalcification', a 'microcalcification', and a 'mass' were 17.0, 14.0, and 5.1% respectively. As a conclusion, needle localization biopsy is a safe and effective method for definitely diagnosing nonpalpable breast lesions.

Evaluation of Mass Screening for Thyroid Cancer

Mass screening for detecting both thyroid and breast cancer in adult women was carried out in Samsung Cheil Hospital between March 31, 1996, and March 31, 1997. The total number of subjects during those 13 months was 3869. At first, the screening was by inspection and palpation using experienced surgeons. Thyroid abnormalities were found in 183 subjects through physical examination but thyroid nodules were identified by thyroid sonography in only 170 patients who were required to undergo a cytologic examination (FNAB). The total number of thyroid cancer cases detected was 23. The detection rate was 0.59%. In contrast, 8 cases of breast cancer were discovered during the same screening, with a detection rate of 0.21%. The size of the thyroid tumor was 2 cm or less in 20 patients (87%). The thyroid cancers detected by mass screening were discovered at an earlier stage and will show a better survival rate. As thyroid cancer can be found at an earlier stage by mass screening, the program is useful for the early detection and early treatment of thyroid cancer.

Breast-Conserving Surgery With or Without Radiation Therapy for Early Breast Cancer

Breast conserving surgery (BCS) with radiation therapy (RT) has been considered an alternative to a radical mastectomy in the surgical treatment of early breast cancer. Breast-conserving therapy (BCT) can achieve a more favorable cosmetic outcome than a mastectomy in patients with early breast cancer. However, it is widely recognized that RT following BCS is an impediment to improve the cosmetic outcome of a BCT-treated breast. If the local recurrence (LR) rate is acceptable and LR can be controlled with salvage surgery, an appropriate conservative surgical procedure without RT will be a reasonable option for some patients with early breast cancer. Between 1990 and 1996, 60 patients were enrolled in a retrospective study to examine whether or not RT could be avoided following conservative surgery in patients with early breast cancer. There was no significant difference in local recurrence rate between the RT and the non-RT groups (6.3% vs 10.7%). The characteristics of suitable BCS without RT would be negative axillary lymph-node metastasis, low nuclear grade, a 1 cm negative resection margin and no lymphatic vessel involvement. In conclusion, breast-conserving surgery without RT is a reasonable option for some patients with early breast cancer.

Bilateral Breast Cancer

Bilateral breast cancer is not a common clinical problem, and its occurance is not suprising in this paired organ. Bilateral breast cancer is categorized as synchronous or metachronous. We propose to evaluate clinical and biological characteristics in bilateral breast cancer. Previous cancer in one breast is the strongest known risk factor for cancer to develop in the second breast, and a young age at dignosis of a breast cancer and lobular type of tumor are additional risk factors related to bilaterality. Seventeen cases of bilateral breast cancer have been admitted to the department of General surgery, Samsung Cheil general Hospital from 1980 till 1995. We report the analysis of these cases with the references. The incidence of bilateral breast cancer among all case of total breast cancer was 2.1%(17/827). Synchronous breast cancer was 3 cases(0.4%) and metachronous breast cancer was 14cases (1.7%). The median age was 41 years. The mean age at diagnosis of the primary tumor in the metachronous group was 40 years. Among metachronous cases, the mean interval between the treatment of the primary cancer and the detection of secondary cancer was 37months. The clinical stage was 0-I in 12%, II in 50%, III in 32%, and IV in 6% of tumors. The majority of patients (88%) were clinically node positive. Out of a total of 34 tumors, the clinical tumor size Tis-T1 in 8 tumors, T2 in 21 tumors, and T3 in 5 tumors. Histopathologic type of the pimary tumor was the same with the second in 70%(12/17). The location of secondary breast cancer was in the upper outer quadrant in 9 cases, and in the upper medial quadrant of breast in 2 cases. The premenopausal primary cancer was in 50% of the patients, and postmenopausal primary cancer was in 50% of patients for whom this information was available. Median survival period was 57 months, and 5 year survival rate was 80%. Bilateral breast cancers have similar biological features to unilateral breast cancer more freqently than would be predicted by chance alone. The similarity in clinical aspects of unilateral and bilateral breast cancers should be considered in clinical management of patients with breast cancer. Further investigation is required to know these similaritics and differences between unilateral and bilateral breast cancer.

Breast Cancer Screening of 13,791 Women by Physical Examination and Mammography

This study is to clarify the efficacy of breast cancer screening by physical examination and mammography and to compare the diagnostic outcome of breast cancers detected by screeening with that of breast cancers found at out-patient clinic. Between March 1995 and July 1996, A total of 13,791 women were screeened for breast cancer annually by physical examination and mammography at Samsung Cheil Hospital Breast Center and 20 breast cancers were detected. In the same period, another 166 breast cancers were found at out-patient clinic. These two groups of breast cancers were analyzed and compared. Of those 13,791 screened women, the recall rate for further examination was 9.8%(n=1,350) and the biopsy rate was 1.06%(n=146) respectively. Twenty breast cancers were detected so that the breast cancer detection rate was 0.15%. T-stages of screened group were T0;25%, T1;55%, T2;15% and T3;5%, while those of out-patient clinic cases were T0;4.8%, T1;43.4%, T2;44.6%, T3;7.2%.(p<0.05). Axillary lymph node metastasis was negative in 80% of screened group but in 59% of out-patient clinic cases.(p<0.05). Pathological stages of screened group were; stage0;25%, stageI;40%, stageII;35% and those of out-patient clinic cases were stage0;4.8%, stageI;24%, stageII;56%, stageIII;14.4%, stageIV;1.2%(p<0.05). Early breast cancers were significantly more frequent in the patients detected by screening at breast center than those of out-patient cilinic cases. The breast conservation surgery was done in 40% of screened group but only in 12.7% of out-patient clinic cases(P=0.00029).This study indicated that the efficacy of breast cancer screening by physical examination and mammography was significant for the early detection of breast cancers.