Katsumi Iwase

Recently, breast cancer screening with mammography has been recommended for detection of early cancer. We have carried out mammography screening for women aged over 30 years at Kasugai City Medical Care Center over the last 3 years. Every examinee underwent physical examination by a surgeon and mammography, and those who had abnormal findings and were unsuitable for mammography underwent ultrasonography. Sixteen breast cancer patients with a detection rate of 0.51% were found by the screening. Eleven tumors were palpable, 14 were detected by mammography, and 15 were detected by ultrasonography. Eleven of the 16 cancers were found at an early stage (stage 0 or I) and 5 were treated by partial mastectomy. Fibroadenoma was found in 16 of 121 women who received further examinations. Thirteen of the fibroadenomas were detected by mammography and 7 of them were not palpable. In 8 cases, malignancy could not be completely ruled out. Forty-one patients considered to have benign lesions at the screening were further examined during the first half of the study period, and only one case of cancer was found. Therefore, we omitted the examinees with obviously benign lesions from further examination in the second half of this period. Consequently, the number of examinees who required further examination was markedly decreased without any decrease in the cancer detection rate. <BR>In conclusion, breast cancer screening with physical examination and mammography is excellent for detecting early cancer. Furthermore, the ultrasonography is useful for further observation of lesions found by screening, and in patients who are unsuitable for mammography. The use of mammography or ultrasonography for screening increases the number of patients who require further examination, increases the psychological burden on examinees and raises medical expenditure. But the keeping better quality of the screening can improve these drawbacks.

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.