伊藤 朝子

乳癌検診では画像診断の併用が勧められており, とくにマンモグラフィの併用について検討されているが問題点も多い。春日井市健康管理センターでマンモグラフィを併用した乳癌検診を導入して3年を経過し, その結果を検討した。当施設では30歳以上の女性を対象に視触診とマンモグラフィを併用し, 有所見者やマンモグラフィが読影困難なものには超音波検査を行っている。乳癌は16例 (0.51%) 発見され, そのうち11例が触知可能で, マンモグラフィでは14例に異常所見が, 超音波検査では15例に腫瘤所見が認められた。検診時に癌を疑ったものは12例, 病期は0～I期が11例でそのうち5例に乳房温存手術が行われた。良性腫瘤性病変の代表である線維腺腫は要精検121例中16例で, マンモグラフィで捉えられた13例中7例は非触知であった。検診時には8例が悪性疑いまたは診断困難とされ, 8例は線維腺腫と診断された。一方, 検診時に良性病変の診断であったが要精検とした41例中癌は1例 (2.4%) のみで, 後期は要精検の判定基準から良性病変を除外し, 癌発見率を低下させることなく, 要精検例中の非癌例の割合を減少させ得た。視触診とマンモグラフィを併用した検診は乳癌の早期発見に有用で, 見逃し例の減少と有所見者の性状診断のためには超音波検査が有用と考えられた。画像診断の併用は, 要精検率を増大させ, 受診者や医療側の負担を増加させる可能性があるが, 検診の精度を高くすることにより改善可能と考えられた。

乳癌検診では画像診断の併用が勧められており, とくにマンモグラフィの併用について検討されているが問題点も多い。春日井市健康管理センターでマンモグラフィを併用した乳癌検診を導入して3年を経過し, その結果を検討した。当施設では30歳以上の女性を対象に視触診とマンモグラフィを併用し, 有所見者やマンモグラフィが読影困難なものには超音波検査を行っている。乳癌は16例 (0.51%) 発見され, そのうち11例が触知可能で, マンモグラフィでは14例に異常所見が, 超音波検査では15例に腫瘤所見が認められた。検診時に癌を疑ったものは12例, 病期は0～I期が11例でそのうち5例に乳房温存手術が行われた。良性腫瘤性病変の代表である線維腺腫は要精検121例中16例で, マンモグラフィで捉えられた13例中7例は非触知であった。検診時には8例が悪性疑いまたは診断困難とされ, 8例は線維腺腫と診断された。一方, 検診時に良性病変の診断であったが要精検とした41例中癌は1例 (2.4%) のみで, 後期は要精検の判定基準から良性病変を除外し, 癌発見率を低下させることなく, 要精検例中の非癌例の割合を減少させ得た。視触診とマンモグラフィを併用した検診は乳癌の早期発見に有用で, 見逃し例の減少と有所見者の性状診断のためには超音波検査が有用と考えられた。画像診断の併用は, 要精検率を増大させ, 受診者や医療側の負担を増加させる可能性があるが, 検診の精度を高くすることにより改善可能と考えられた。

The localization of Cu/Zn-and Mn-superoxide dismutase (SOD) in breast cancer tissue (12 papillotubular carcinomas, 21 solid-tubular carcinomas, 16 scirrhous carcinomas, 1 medullary carcinoma, 1 secreting carcinoma, 1 lobular carcinoma, 1 Paget's disease) was investigated via an immunohistochemical technique using antihuman Cu/Zn-and Mn-SOD antibodies in 10% formalin fixed-paraffin embedded thin sections. Both SODs stained strongly in the normal breast gland, but not clearly in many cancer tissues. Furthermore, Cu/Zn-SOD stained more strongly in well differentiated tubular carcinomas than in poorly differentiated tubular carcinomas. It tended to stain less in tumors which recurred or had a poor outcome, and in tumors with a diploid pattern on DNA flow cytometry. Mn-SOD staining was similar to that of Cu/Zn-SOD, but no significant differences among subgroups was found, since the incidence of positively staining tumors was too small in all groups. The intensity of SOD staining seems to change in relation to cell proliferation and differentiation in breast carcinoma, and may be a prognostic indicator, since SOD decreased in poorly differentiated carcinoma and in tumors which developed distant metastasis. Thus, the localization of SOD in breast cancer tissue can provide useful information for cancer treatment.

S-100 protein is detectable in various human tissues, though it was first recognized as a protein specific to nervous tissues. It consists of dimers composed of α(α) and β-subunit (β). We elucidated the localization and the concentration of α and β in thyroid tissues from various thyroid disorders, using highly purified anti-human a and anti-human β antibodies.<BR>The concentration of α in thyroid tissues from Basedow's disease, papillary carcinoma and follicular carcinoma was higher, and that from medullary carcinoma was lower than that from the normal thyroid tissues. The concentration of β in malignant thyroid tumors was higher than that in either benign thyroid tumor or Basedow's thyroid. These findings were also confirmed by the immunostainings. The ratio of α to β(α/β) in Basedow's disease was higher, but the ratio in medullary carcinoma was lower than that present in the normal thyroid.<BR>In conclusion, since the concentration and localization of α and β in thyroid tissues differed in various thyroid disorders, each subunit may have different functions in the thyroid. Namely, α may be related to the cell differentiation, proliferation, and hormonal secretion from follicular cells, and β may have a close relationship to the function of parafollicular cells. These data imply that the analysis of the concentration and localization of α and β particularly in various thyroid tumors is useful in diagnosing the characteristic features of various thyroid tumors.

S-100 protein is detectable in various human tissues, though it was first recognized as a protein specific to nervous tissues. It consists of dimers composed of α(α) and β-subunit (β). We elucidated the localization and the concentration of α and β in thyroid tissues from various thyroid disorders, using highly purified anti-human a and anti-human β antibodies.<BR>The concentration of α in thyroid tissues from Basedow's disease, papillary carcinoma and follicular carcinoma was higher, and that from medullary carcinoma was lower than that from the normal thyroid tissues. The concentration of β in malignant thyroid tumors was higher than that in either benign thyroid tumor or Basedow's thyroid. These findings were also confirmed by the immunostainings. The ratio of α to β(α/β) in Basedow's disease was higher, but the ratio in medullary carcinoma was lower than that present in the normal thyroid.<BR>In conclusion, since the concentration and localization of α and β in thyroid tissues differed in various thyroid disorders, each subunit may have different functions in the thyroid. Namely, α may be related to the cell differentiation, proliferation, and hormonal secretion from follicular cells, and β may have a close relationship to the function of parafollicular cells. These data imply that the analysis of the concentration and localization of α and β particularly in various thyroid tumors is useful in diagnosing the characteristic features of various thyroid tumors.

The intracellular localization of tyrosine hydroxylase (TH), which is the rate limiting enzyme in catecholamine (CA) biosynthesis, and its activity in various adrenal and other neuroendocrine tumors was studied. TH was strongly localized in adrenal medulla, pheochromocytoma, and paraganglioma, but was scatteredly expressed in neuroblastoma. TH was not detected in adrenocortical tumors, ganglioneuroma, and other neuroendocrine tumors. Neuron specific enolase (NSE) was found in all neuroendocrine tumors, but Grimelius staining showed only the secreting granules of the tumor cells. TH activity was significantly high in pheochromocytoma and paraganglioma as compared with that in normal adrenal gland, whereas TH activity was low in a neuroblastoma and was undetectable in other tumors. These findings indicate that TH correlates well with the biosynthetic function of CA in the tumor cell and, thus, both the immunostaining of TH and the measurement of its activity in adreno-medullary and related tumors may provide some information about the process of cell differentiation in these tumors.

The intracellular localization of Cu/Zn- and Mn-superoxide dismutases (SOD), which catalyze the dismutation of superoxide radicals (O-2(-)) to O-2 and H2O2, was studied in the thyroid tissue of various thyroid disorders by an immunohistochemical technique. The concentrations of both SODs in those tissues were measured also by a sandwich enzyme immunoassay technique. Copper/zinc-SOD in thyroid tissues were identified by immunocytochemical staining in most cases of papillary carcinoma and in some cases of other thyroid disorders. In normal follicular cells this enzyme is localized in the perinuclear cytoplasm, whereas in thyroid tumor or hyperplastic follicular cells it exists homogenously in cytoplasm. Manganese-SOD stained strongly in papillary carcinoma and papillary-growing cells in the thyroid tissue of adenoma and Graves' disease. The concentrations of Cu/Zn- and Mn-SOD in thyroid tumor tissues and hyperplastic follicular disorders were significantly higher than those in normal thyroid tissue when they were compared as a function of protein or deoxyribonucleic acid contents. The ratio of Mn-SOD to Cu/Zn-SOD was significantly higher only in papillary carcinoma, except for other thyroid disorders, as compared with that in the normal thyroid. In conclusion, SOD seems to be related to cell proliferation and differentiation in the thyroid follicular cell because Cu/Zn-SOD changes its localization in tumor and hyperplastic follicular cells. and because the Mn-SOD concentration is increased in papillary carcinoma or papillary-growing cells.